RetroRims VW Alloy & Steel Wheel Blog

Twin Engined VW Mk2 Golf

Posted on 28/02/2013 by retro7

That same year, 1983, Kalle Grundel took the Group A Golf GTI rally car to victory in the German Rally Championship and, behind the scenes, VW .Motorsport were starting work on its replacement as the new Golf was phased in. L p to that point, Group 1 and Group lb GTIs had 148 or 150bhp for the track and the rally cars, in Group A, anything from 170bhp to 200bhp depending on spec. The Bimotor Scirocco was originally devised as a Group B rally weapon, but it w as not until 1985 that the green light was given to incorporate the lessons learnt from this car into an official rally machine. The Twin Golf was not going to enter the fray of international rally ing though; its objective was an attempt at the Pikes Peak hill climb record with successful GTI driver Jochi Kleint at the wheel.

Pikes Peak in the Rocky Mountains in Colorado is over 13,000ft high. The view from the startline, over 8,500ft up, is breathtaking and of course the altitude extracts a heavy toll on naturally aspirated engines. The winding, loosesurface road up the mountain is 9.4 miles long and has 156 turns.

VW’s challenge to nature had a pair of l,807cc Oettinger engines of 195bhp apiece to power it and, running an 11.0:1 compression ratio, they supplemented the combined 390bhp at 7,500rpm with 3381b/ft of torque at 5,800rpm. Performance was not dissimilar to the Bimotor Sciroccos with a 0-60mph time of 4.3 seconds and a top speed of 162mph depending on final drive. It was quickly established that the altitude was doing the car’s engines no favours and for a really serious assault on the Peak in 1986, a change of tactics w as called for. To keep the car in its engine capacity class, and use turbocharging, VW had to resort to the use of much smaller engines. Their choice was the l,300cc Polo engine, and these small power units were modified to take a KKK turbocharger each, with intercooling. Bosch K-Jetronic fuel injection was grafted onto the engines and boost pressure was variable between 1.4 and 2.0 bar. At peak boost, these 8.5:1 compression engines kicked out 250bhp each giving a sum total of 500bhp at 7,000rpm and 3841b/ft of torque at 6,000rpm. Weighing just 2,3101b, 1001b less than a Corrado and about 2501b heavier than a Golf GTI, the 1986 Twin Golf was good for a 3.4 second burst to 60mph and a top speed of 193mph!

That car was still essentially a Golf beneath the sheetmetal work, though, and for the 1987 attempt on the Peak, VW fielded what amounted to a silhouette racer. The centre section of the car was a monocoque cell constructed largely from aluminium in the best racing-car tradition. From this were hung the front and rear tubular space frames to w hich the engines and suspension components were attached. Although, to onlookers, the front and rear detachable engine covers were perfect replicas of a production Golfs, even with standard looking wheelarches, these were just glassfibre components held in place by quick release fixtures. The car weighed just 2,2441b and had 652bhp to propel it. That is a power-toweight ratio of 3.431b bhp! Unlike all the previous cars, this one had the engines mounted in-line. Those engines were a pair of 1.8-litre 16-valve Golf engines prepared by Kaimann Racing to full competition spec. An intercooled KKK turbocharger boosted each one to 1.3 bar at full throttle and, with the 8.5:1 compression ratio, output was 652bhp at 6,800rpm and 4281b/ft at 6,400rpm. Two huge fans extracted air through the rearmounted radiators giving the rear of the car the appearance of a James Bond movie car that looked equally capable of aquatic duties. 0-60mph took 4.1 seconds and the car was geared for just 114mph through Formula 2 Hewland gearboxes and running on 225/50VR16 tyres.

The three Pikes Peak Golfs never won their events but they finished in the top ten in the three years they competed. They provided valuable experience with regard to the synchronization of two engines in one chassis and what could be achieved with four-w heel drive. These full-house competition Twin Golfs were also the ultimate expression of an idea that was born over a fewdrinks in a bar seven years earlier.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Golf G60 Limited

Posted on 24/02/2013 by retro7

In automobile production, economies of scale are all-important. The main Volkswagen plant is geared to produce cars like the Golf in runs extending ultimately to eight-figure numbers.

The few hundred thousand Scirocco, Golf Cabriolet and Corrado models are farmed out to the coachbuilders Karmann. Even smaller runs like the 5,000 Rallye Golfs produced for motorsport homologation are made in the Brussels plant. One-offs or very small runs of really special cars are the speciality of VW Motorsport. For VW Motorsport is more than just the factory’s competition department. Like BMW, VW sees its Motorsport division as playing a rather wider role. In their new premises in Hannover, VW Motorsport personnel are competition, development, limited edition production and customer special wishes rolled into one. They even have a restoration department which can turn rusting hulks into pristine exhibits for the VW AutoMuseum in Wolfsburg – or for customers.

In the squeaky-clean main workshops, a visitor would see the mechanics working on existing Rallye Golfs, or knocking new bodyshells into shape for their competition debut, while other specialists may even be building the 130bhp VW LT Van support vehicles that follow the rally cars to events. Turn the corner and you are confronted w ith the area w here the ‘specials’ are built. A oneoff heavily modified G60 Passat was being built for VW Motorsport head, Klaus-Peter Rosorius, during my visit, and in a bay next to it, a customer’s standard looking Polo hatchback was in for servicing and tuning. It had a supercharged G40 engine under the bonnet; GTI performance in a shopping car! Directly opposite this a fivedoor Golf syncro with slightly flared arches and big w heels lay at rest. A turbocharged 200bhp 16valve engine had been installed in this car. The rest of the facility was given over to production of just 70 Limited Edition Golfs.

Built largely by hand, these cars were based on a fivedoor syncro with its viscous-coupled four-wheeldrive system. To this was added ABS, power steering, electric windows, central locking, steel sunroof, heated front seats, a full leather interior and an on-board computer. Tuners in Germany have already begun to exploit the latent potential of the G60 engine, offering conversions ranging from 180bhp to 200bhp for the Corrado and Rallye Golf. VW Motorsport go one better right from the start by applying the G60 supercharger to the 16-valve rather than the eight-valve engine. The result is 21 Obhp (DIN) at 6,500rpm and 1861b/ft of torque at 5,000rpm with an 8.8:1 compression ratio and the supercharger providing 23psi of boost. More than that, this power is developed from an engine  86  with full compliance to US emission regulations via a pair of three-w ay catalytic convenors, a clean engine that runs on super unleaded fuel! Digifant electronic injection is important in achieving such controlled efficiency.  The Limited mav look like a standard five-door Golf with 6V2J x 15in BBS alloy w heels and 195 50YR15 Pirellis, but this wolf in sheep’s clothing has the drivetrain from the Rallye Golf including its complete front-end beneath the standard front wings. This means that the inner arches are larger to take wide tyres without fouling the suspension and the new gearbox and large capacity radiator are also grafted in. ‘Thus, various bits of the car are sent from Brussels and Wolfsburg to come together in I lannover. 21 Obhp in a car the size of a Golf is a lot, but the Limited is not a strippedout racer; it is a compact, all-weather luxury express. It tips the scales at 2,8051b at the kerb which makes it some 7001b heavier than a GTI 16Y. ‘That weight eats into the performance, but even so 7.2-second 0-60mph time and a 142mph top speed is not to be scoffed at. ‘The Golf G60 I limited is the fastest production road car to have left any VW plant destined for a private customer. Like most of the projects that emanate from VW Motorsport, it was the brainchild of Klaus-Peter Rosorius. it took a long time to realise this project,’ he explained, ‘but we were fortunate to have the help of many engineers in the design and development department at Wolfsburg. ‘The idea w as to have a nice, elegantlooking production Golf without external modifications but lots of fascination under the bonnet.’ That aim has been achieved by the 70 Limited cars which are restrained in outward appearance even to the point of having simple, single headlamps. One customer who owns No 031 has fitted a four-lamp grille and wider 7J Borbet alloy wheels but all the other Limited cars have left the factor} in their metallic anthracite paintwork with just the blue grille surround and subtle VW Motorsport badges to distinguish them as instant classics. As for the future, Limited Editions of the Corrado and Passat have not been ruled out and when the VW V6 engine is released, who know s what w e might see from VW Motorsport.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW and the Karmann Connection

Posted on 15/07/2011 by retro7

No Volkswagen story would be complete without reference to the Osnabruck coachbuilders, Wilhelm Karmann GmbH. Over half a century older than VW itself, Karmann was founded in 1874 and taken over by Wilhelm Karmann on August 1, 1901. The company manufactured its first car bodies, for Diirkopp, Opel and Benz, the following year. The association with Volkswagen began in 1949 with production of the Cabriolet version of the Beetle, Type 15A. Eventually, Karmann made 330,000 of these cars and one of the very first now resides in the VW Auto Museum in Wolfsburg. Karmann continued to produce specialized low-volume cars based on Beetle running gear for many years, introducing the famous VW Karmann Ghia coupe in 1955. That same year, Beetle production passed the magic 1,000,000 figure, an achievement never before recorded in German car-manufacturing history.

The entry of Volkswagen into the Brazilian market with a factory’ producing the Beetle and variants of it prompted Karmann to expand its own facilities and, in 1959, Karmann Ghia do Brazil was set up to meet VW’s needs in that potentially huge market. The links between VW and Porsche helped Karmann gain business from the latter and they began to make some of the bodies for the 356B in 1961, beginning with the short-lived hardtop coupe version and then continuing with the standard coupe shape until the end of the 356 series. The 901 prototype was presented by Porsche at the Frankfurt Show in 1963, and when it went into production as the 911 and 912, Karmann were again able to provide Porsche with much-needed additional capacity, assembling and trimming bodies in parallel with Porsche’s own Stuttgart plant. For the mid-engined 914, the joint VW-Porsche project launched in 1969, the bodyshells were all made by Karmann. In 1974, Karmann employees assembled the first of the new-generation VWs, the Scirocco.

A striking design study shown by Giugiaro at the Frankfurt Show in 1973 was a clean-cut coupe called Asso di Picche (Ace of Spades), interesting because it was based on the Audi 80 which shared its floorpan with the first Passat and provided the engine from which the GTI power unit was derived. Had this car been productionized, it would have been ahead of its time – and right in the Scirocco class. The Ace of Spades was built for Giugiaro by Karmann and now rests in the latter’s museum.

Giugiaro and Karmann co-operated again, on officially VW-sanctioned Scirocco Mk2 prototypes in 1977. A wooden study was made first, with no interior, followed by a realistic metal mock-up. Both, had the same overall shape, differing only in details like bumpers and lights. The wheelarch shapes, bumpers, and the crease in the flanks of the car echoed the Maserati Quattroporte prototype that Giugiaro showed at the Turin Motor Show the year before, under-lining how designers tend to use certain aesthetic motifs on more than one prototype before moving on. The wraparound bumpers and front indicator lights from the Scirocco II Study were adopted by VW on the production Mk1 for the 1978 model year showing how a completely different design proposal may influence a current model.

The most significant Volkswagen on the company’s stand at the 1979 Geneva Motor Show was the Golf Convertible. Just as the GTI started a new trend towards hot hatchback cars, the Golf Convertible was the first in a line of drop-top versions of modern front-wheel-drive cars. It was an entirely new species; cars like the Fiat 124 Sport Spyder or the Alfa Romeo Spider no doubt had the same mechanicals as their saloon and coupe brethren and, in the case of the Fiat, the same floorpan and suspension as well, but they were sporting two-seaters with little or no rear-seat accommodation. The Golf featured a modified hatchback bodyshell and thus retained the full four-seat capability of the original car. The prototype was produced by Karmann in 1976. The company was so well entrenched in producing Cabriolet Beetles and Karmann Ghias that it was a natural progression for them to build the first Golf Cabriolet for presentation to VW’s Board, and undertake the subsequent production.

A variation on the same theme rolled out of the Osnabruck prototype shop a year after the Golf Cabriolet production line started rolling. The Jetta Cabriolet in some ways actually looked better proportioned than the Golf which had a high, stubby tail in production form. The Jetta never made it to production; the yellow prototype now sits in the Karmann Museum just sixty feet from the Golf Cabriolet study.

Karmann are coachbuilders rather than manufacturers. They may build prototypes of complete cars for manufacturers and indeed undertake the difficult transition from prototype to production for that manufacturer, but they still rely on their client for all mechanical assemblies. Thus the engine, gearbox, suspension and some interior components come from Volkswagen to be built into the Golf Cabriolets, Sciroccos and Corrados that roll out of the Karmann factories. Small-volume production is their speciality, and to give some idea of why Volkswagen sub-contracts the building of these models to Karmann, a comparison of Golf and Scirocco production figures is interesting. In 1988, VW in Wolfsburg announced that they had produced the 10 millionth Golf, 13 years after the launch of the first car. Between “1974 and 1981, Karmann produced 504,100 Scirocco Mk1s, and up to September 1989, they had made 272,000 Mk2 cars. From 1979 to September 1989, 267,000 Golf Convertibles were built. The first year of Corrado production totalled approximately 17,000 cars.

Coachbuilders like Karmann, however, do not always wait around to take their cue from major manufacturers like VW, Ford or BMW. With major resources at their disposal, it is today possible for them to build one-off prototypes or even just present their ow n interpretations of how they see a particular model evolving. The latter case is more the norm and at major international motor shows, Karmann usually takes a stand not far from Volkswagen. Over the years, they have exhibited show cars with different spoilers, special paintwork, non-standard alloy wheels and invariably custom interiors in leather and fabric. A prime example is the red Scirocco 2 with colour-coded bumpers, Ronal alloy wheels and special half-leather interior that did the 1987 show circuit. The 1988 theme was a two-tone Scirocco and Golf Cabriolet pair, painted silver with metallic anthracite grey applied from bumper level down, extending to the wheelarches. 6J x 14in eight-spoke flat-faced alloy wheels from RII were used. The Scirocco 16V show car also had a colour-coded rear spoiler and wing mirrors, and had its rubber side protection strip removed. A different front grille with just three large horizontal slats was used. Inside, black leather with grey fabric inserts gave the cars a classy but still sporty feel.

The Frankfurt Show in 1989 was the first showing of a Karmann interpretation of the new Corrado, and the silver car that took pride of place on the revolving platform was tastefully and luxuriously appointed. The exterior was standard save for a set of attractive 7J x 15in Centra five-spoke alloy wheels which helped to fill out the arches and give the car a better stance. But the interior was upholstered in light tan and brown hide which complemented each other beautifully both in colour co-ordination and the way the two leathers were used to highlight facets of the car’s interior sculpting. This is the sort of work that a coachbuilder like Karmann excels at and it would be a shame if VW missed the opportunity to commission limited runs of such cars.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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Dream maker: Treser Walter

Posted on 15/07/2011 by retro7

Treser is a leading supplier of aftermarket equipment for the Golf and Scirocco family. But he also deserves a special place of his own in this anthology of the GTI because, apart from Formula 3 racing cars, the Treser Sportscar is the only purpose-built special vehicle so far to use the Golf GTi powerplant. It was perhaps an obvious choice for someone who had worked at VW Audi before going independent. Along with Jorg Benzinger, Walter Treser shared joint parent-hood of the Audi quattro concept. It was these two men who realised the potential of marrying the 4WD parts of the military VW litis to an Audi 80 saloon floorpan, and managed to convince the product strategy committee to approve the car for further development.

It had seemed that Walter Treser, the son of a hotelier, was destined to enter the world of gastronomy. As a boy, however, it was technology and cars in particular that became his fixation. He taught himself to drive at eight, built himself a motorcycle at 14 and by 18 had proved he could drive his car on two wheels. In 1962, aged 22, Treser passed his exams in automotive and aeronautical engineering and went to work for Daimler-Benz and then Veith Pirelli where he was put in charge of the experimental tyre department, developing low profile tyres like the P7. Treser moved to Audi in 1977 where he worked closely with Ferdinand Piech, head of the experimental department. It was not long before his obvious talent earned him the post of Head of the Preliminary Experimental Department and he became the youngest member of the Committee for Technological Strategy. With the development of the quattro under his belt, Treser under-took the organisation of Audi’s rally sport involvement. From March 1980 to August 1981, he was head of the Audi Competition Department. On January 1, 1982, Treser founded his own company, Walter Treser Automobiltechnik und Design in Ingolstadt to develop and manufacture high-quality aftermarket components for Audi cars as well as exclusive specialized models based on Audis. On August26,1985, he founded Walter Treser Automobilbau GmbH in Berlin to develop the sports car that had been his childhood dream.

An extremely high standard of design and manufacture enabled Treser to gain independent car manufacturer’s status from the West German Federal Department of Transport soon after he started his business. Professionalism is something that he pursues relentlessly in his projects. Originality was another of his assets. Treser can never be accused of taking styling cues from other designers. He introduced blacked-out tail-lights on his quattros first. The factory’ subsequently adopted the style. His radical sculptured body-styling for Audi and VW cars has not been mimicked by anyone else.

There has been some debate as to whether the style of the Sportscar is the culmination of the design details that Treser had been working with in various Audi and VW styling kits up to that point or if indeed he was trying ideas for the Sportscar all along. The truth is probably a bit of both, but there is a clear lineage of development in his products, symbolized by a coloured drawing done for him by an employee and framed on his office wall. It shows an open door with the stylised ‘ 1′ that is the Treser logo, in the distance. That ’1′ used to be an Audi corporate logo and Treser uses it now with their authority, which shows the high regard they have for him.

Three prototypes and a few partly finished cars and several patents are lying around in the hands of the receiver, for sadly the Sportscar is no more, killed off by politics and short-sighted bankers who jointly and severally failed to see the up-and-coming international boom in the market for reasonably priced small sportscars. Those who refused to finance Treser in 1987 must now be kicking themselves in the wake of the success of cars like the Mazda MX5 Miata and Lotus Elan, the latter very similar in concept to Treser’s ill-fated Sportscar.

In 1985, Treser’s first company was doing a brisk trade. He had a staff of 65 and an annual turnover of £10 million. The time seemed right to embark on the Sportscar project. A well sorted sty ling and tuning programme, originally based around Audi cars, had been expanded to include the ubiquitous Golf GTI , beginning with alloy wheels, black tail-lights, gearknob and steering wheel. A new front grille and then a dramatic full body kit were added, followed by engine conversions. The Sportscar required a compact and powerful engine that could be augmented by tuning parts already in the Treser programme. The logical choice was the VW GTI 16-valve unit, and the mid-engined two-seater was designed around this powerplant.

Designing, developing and manufacturing a whole new car is a very time-consuming and expensive business that must be measured in millions of Pounds, Dollars or indeed Deutsch-marks. But Treser was initially lucky. I le was given the first push away from the shore by the City of Berlin which was looking for dynamic young entrepreneurs. They delivered a factor) site, a £500,000 research grant and various tax benefits to get the company going. But a larger Malaysian investor had pulled out of the project even before this, and raising the 15 million DM capital ultimately required was a hard uphill slog.

In the meantime, the Sportscar slowly took shape. The first concept drawings existed as far back as autumn 1983. By May 1984 a wooden model had been made and wind-tunnel testing was underway. The first full-size model appeared in October 1985 and, in March the following year, the Treser stand at the Geneva Show had a full-scale half of the model mounted in a mirror wall to reflect the image of a complete car. A year later, the chassis prototypes were running, and the complete prototype was unveiled at the 1987 Frankfurt Show.

The little Sportscar was the centre of attraction on Treser’s stand and the press information given away revealed that there was far more to the car than just a thoughtfully sculptured body based on VW Golf GTI 16Y mechanicals. In his capacity as a recognized vehicle manufacturer, Treser was not content simply to sell a small number of cars to European countries. One of the serious export markets that Treser had found for his Audi con-versions was the USA. The safety and emissions regulations there are complex and very trying for even large manufacturers, and require substantial financial investment for the testing and development of components that comply. Treser was thus fortunate in being able to use the VW engine which was already certified for the USA should he decide to sell the car in that market. While motive power was not a problem, the body structure and chassis had to be designed from the outset to comply with American DO T as well as European crash and safety regulations. Clumsy impact bumpers are a thing of the past thanks to new plastics technology used by manufacturers like Porsche, and to this end the Treser Sportscar was designed with a defined crash area filled with a foam material to absorb impact energy . The foam was embedded between the covering laminate shells of the deformable zone. Elastic front and rear bumpers were integrated and were designed to absorb parking bumps without damage.

Aerodynamically, a cigar-shaped vehicle is the theoretical ideal. In the real world this is impractical and so a kamm tail is the next best thing. Although the two-seater Treser Sportscar is not a fastback in the true sense even when the top is raised, its profile resembles a wedged semicircle and gives smooth airflow over its contours, which have been sculptured in places as necessary to admit or extract air. The bodywork construction is novel. The body itself is glassfibre and Treser hold the patent for AVUS, a lightweight but very rigid aluminium composite structure which is used for the floor of the car. The material is corrosion resistant and easy to adapt to aero-dynamic requirements. One of the aluminium chassis profiles is used as a service conduit and all the ducts and pipes required for cooling, brakes, clutch, gear selection and heat run through this. The front and rear suspensions are located on their own subframes. MacPherson struts are used at both ends with progressive minibloc springs, lower wishbones and anti-roll bars. Ventilated disc brakes are used at each corner.

Convertible cars are practical only when the sun is shining. The rest of the time the disadvantages – waterproofing, noise and security – are prominent. A detachable hardtop is a good solution but you cannot take it with you wherever you go. The Treser Sportscar neatly sidesteps this problem with the design that Treser pioneered in 1983 on his quattro Roadster. An ingenious hinged hardtop with counterbalance weights disappears backwards below the rear deck when it is not needed and this solves the problem without impinging on cabin or boot space.

When the first prototype was completed on March 29, 1987, optimism in the company was high and, despite mounting financial problems, Treser announced plans for a one-make race series using a slightly modified version of the car. The plan was that 30 cars, or about a week’s production, would be committed to the series. The main championship sponsor was Hydro Aluminium, supplier of the alloy and plastic sandwich material used for the floor of the car, with co-sponsors Bilstein, Pirelli and Recaro. Just over a year later the Treser TR1 was able to give an impressive demonstration of its dynamic abilities in the first event of the planned series, held at the Avus track in Berlin. The race attracted 19 Treser owners from four countries, including Walter Treser himself. He started last on the grid and by the end of the race had worked his way up through the field to sixth position. It was a great tribute to Treser that all the cars finished the race, proving an important point about the thorough development and production-worthiness of the design. But fate took an unkind turn and a few weeks later the company was in serious trouble, with a possible last-ditch rescue attempt being negotiated with Oettinger. This fell through and on August 16 the receivers were called in. If there is a lesson to be learnt from Walter Treser’s misfortune, it is that trying to design and build a car and raise finance at the same time is not humanly possible. Compared to what it would cost a major manufacturer to design, develop and tool up for a sportscar, the £5 million that Treser needed was peanuts; Mazda and Lotus have spent much more than that on the Miata and Elan. Once again, short-sighted financial institutions have totally misjudged the fast-moving motor industry and missed being able to back a company that would have been at the leading edge of the new wave of sportscar fever that has now gripped countries across the globe.

The originality of design and high-quality standards of manufacture that characterized the Sportscar are evident too in the products of the continuing Treser Audi and VW styling and tuning operation. Treser modifications for the GTI started off in 1984 simply as an extension of the bolt-on parts available for Audis. These first parts were the distinctive alloy wheels for the Golf and Jetta Mk2 cars made only in a metric size as Treser had an agreement with Michelin. This size is known as 165TR365 and is approximated 6.5J x 14.4in. The tyre size is 200/55R365 TRX 86H – which makes our Imperial system seem simple by comparison! Also available were a Treser steering wheel and gearknob.

The next product was once again an extension of the work Treser had done on Audi cars. His black tail-light design had been picked up by Audi for the upgraded quattro and Treser released a kit for the GTI which consisted of blacked tail-light covers and a black centre piece that attached to the tailgate. Visually, this helped to break up the bulk of the rear panel and proved very popular amongst GTI owners despite the high cost. The full body styling kit which followed in 1986 was very dramatic and completely changed the appearance of the Golf. It had to be laminated to the bodywork and was no weekend DIY job. Accompanying it was an optional new tailgate with a wraparound glass design. The special glass was very expensive to manufacture, and this was reflected in the price. Wider wheels and tyres became available with this kit and were once again the Treser/Michelin design but with 180TD390 (7.1 J x 15.4in) rims and 220/45VR390 TRX tyres. Koni dampers and special springs were offered as a package to lower and stiffen the car.

By this time also, an engine modification package had been developed for the 16V and this involved re-boring and fitting new pistons to bring the capacity out to 1.87 litres. The cylinder head was polished, ported and gas flowed and a new camshaft fitted which improved torque and economy. The result of these changes was 163bhp at 6,600rpm, up from 139bhp at 6,100rpm, but more significant was an improvement in torque throughout the range, taking out the dips in the standard car’s curve, and peaking 121b/ft higher at 5,000rpm.

Latterly, a simplified styling kit has also been offered which has a slightly different front grille, and you can buy the various parts individually. With the release of the Treser Corrado styling kit at the Frankfurt Show in 1989, Treser showed a new three-spoke alloy wheel design. This answered the criticisms of owners who did not wish to be restricted to the Michelin system. The wheel is available in 7J x 15 in and 7J x 16 in sizes for 205/5OVR15 and 225/45VR16 rubber. Engine modifications that apply to the Corrado and Golf include a 240bhp turbocharged 16V engine or, for those with the G60, a useful power increase to 210bhp is achieved by modifications to the engine, supercharger and electronic fuel/ignition management.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Tuning for Power and Style

Posted on 13/07/2011 by retro7

Amongst European languages, English and German share many root words. The old adage that there may be something lost in the translation also holds true, though, and one of the common words that has evolved a slightly different meaning in the two vocabularies is ‘tuning’. On the British side of the Channel, ‘tuning’ means setting up correctly, as in the calibration of ignition and fuel settings to manufacturers’ specifications. It can also refer to engine modifications for power. In German parlance however, ‘tuning’ takes on a broader meaning which covers other areas of vehicle modification. Thus, we have ‘spoiler tuning’, ‘suspension tuning’ , and ‘motor tuning’. Needless to say, people everywhere have been tuning cars for years to improve engine and chassis performance, but the commercial road-car tuner outside of the motorsport field is largely a phenomenon of the last three decades. The oldest of the ‘VW tuners goes back further, though. Oettinger started off in 1946 with the Okrasa Beetle by fitting hydraulic brakes and then went on to extracting more performance from the flat-four engines.

Seven years later, Karl Meier, one of the first engineers with VW, designed the first spoiler for a road car. Enthusiasts quickly recognised the contribution this made to the stability- of the Beetle at speed and his company, Kamei, grew from there.

Both BBS and Zender started around the same time, in 1970, the former making superlative light alloy wheels and the latter, spoilers. BBS was founded by Heinrich Baumgartner and Klaus Brand. The company name comes from their surname initials and that of Schiltach, the town the company is based in. They started off with the intention of making accessories for racing cars but before long this developed into the aftermarket for road cars too. The company was floated on the German stock exchange in 1987. Hans-Albert Zender started off as a one-man show and today employs over 300 skilled people in four linked companies that cover activities from design, marketing, original equipment manufacture and restoration to new car retail.

Another contemporary firm, D&W, also started in 1970. Detlef Sokowicz and Werner Bauer, an insurance salesman and a car accessories sales-man respectively, were chatting in a pub in Dortmund about a business venture that would in time change the face of the aftermarket industry in Germany forever. They realized that the days of plastic roses and furry’ steering wheels were over and that quality and function were soon to be the industry watchwords. They withdrew their savings and opened a car accessories shop in Dortmund, carrying quality accessories from companies like BBS, Kamei and Zender. Their reputation soon spread far beyond the Ruhr and they were able to move to big new premises in nearby Bochum. The attraction for customers was a radical open-plan showroom where goods were imaginatively displayed. In the centre was a coffee bar with a selection of catalogues and motoring magazines for customers to browse through at their leisure while piped music provided a relaxed atmosphere. D&W has expanded dramatically with six of their own specialist stores in Germany and agents all over the world; nearly half a million of their specialist catalogues are sold every year and they have their own range of styling kits and accessories as well as continuing to sell the products of other manufacturers.

These big four German accessory manufacturers have been astute enough to spread their influence far and wide across the globe to America, Australia and Japan as well as most of the countries in between. But they would not have had the opportunity to do so were it not for the sudden craze for styling kits and wheels created by the phenomenal success of the Golf GTI . Before the Golf came along, only cars like the BMW 2002 and Opel Manta provided any sort of market for personalization. Mercedes-Benz made superb but rather staid cars which did not appeal to the younger buyers. The Golf on the other hand had the perfect image to scoop up buyers from all age groups and all walks of life.

Kamei, BBS and Zender all responded to the new \~W with front and rear spoilers and then complete body kits. Before long, many other smaller companies jumped on the bandwagon and were creating their own designs to offer customers even more variety. Most of these kits started off being made from glassfibre, but, as production numbers increased, the bigger firms started to use more exotic materials like polyurethane and PL -RRIM which are injection moulded and less easily damaged in daily use. But the tooling for such mouldings is very expensive, so the smaller companies still use hand-laid glassfibre today.

The early designs were very functional; they were meant to enhance the shape of the car by offering a more integrated look, enhance aerodynamics by incorporating a front spoiler with brake cooling ducts and enhance the stance and roadholding by offering the chance to cover wider wheels and tyres. As time went by, more radical changes were made by designers like Michael Neumann of Style Auto, who created a very sculptural styling kit for the Golf. The more brutal lines of the Zastrow kit appealed to others, while in Italy, Orciari sought to change the frontal appearance of the car dramatically. Engine cooling was not one of this kit’s strong points! Further down the line, W alter Treser was the first to undertake a serious styling change to the Golf 2 that looked integrated rather than stuck on, but the prohibitive cost of his kit precluded a flood of sales.

In the meantime, Vittorio Strosek had created the sensational wide-bodied Ferraris and Mercedes for Koenig, and this style, introduced at great expense to the top end of the market, began to filter its way down to the GTI enthusiasts. Thus, the late 1980s found a rash of wide-body kits on sale for the Golf and Scirocco. Notable ones come from Rieger Tuning who has the widest range of kits with small and intermediate body size alternatives on a similar theme. While the small BBS and Zender style kits can be painted and fitted by a skilful DIY enthusiast, the wide-bodied kits require the full facilities of a body shop and take as long as three weeks to fit properly. They need the cutting away of the original wheelarches, bonding, laminating and foam filling. The need then to virtually respray the whole car has given many people the excuse to make the colour change they always fancied.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Wheels and Tyres

Posted on 12/07/2011 by retro7

Both in visual terms and for the sake of handling and roadholding, the first move you should make when tuning your car is in the wheels and tyres department. A nice set of alloy wheels with low-profile tyres really sets a car off even before you get involved in uprated suspension and body styling. The difference is instantly visible when you compare the car to a standard one of the same type, and the low-profile rubber gives you better handling, grip and braking, making your car safer as well as more satisfying to drive.

The larger the wheel, the lower the profile the tyre needs to be to maintain the same gearing and rolling radius (important for speedometer calibration). A larger wheel looks better and helps to fill out the wheelarches visually. It also exposes the brakes to better airflow and thereby aids brake cooling when the car is being driven hard. For early cars which came on 5.5J x 13in wheels, the natural upgrade was the so-called Plus One conversion. Using 185/60HR14 tyres on 6J x 14in wheels, this provided the same rolling radius as the 175/70HR13 standard rubber but put more rubber on the ground. The Plus Two system was 195/50VR15 rubber on 6J x 15in alloys. This was the largest size that could be accommodated under standard arches. The use of this tyre size with 7J x 15in alloys is possible, but on some cars the wheelarches have to be radiused or contact will be experienced over big bumps or when the car is loaded.

The very latest trend is to 16in diameter wheels as with the Nothelle package for the Golf Rallye, but only a car with as much wheelarch clearance as the Rallye can use these wheels without arch modification. The tyre size in 205/45VR16. When going to such wheel sizes, always bear in mind that the larger the wheel and the lower profile the tyre, the greater the chance of wheel damage on rough roads. Large potholes have been known to bend expensive alloy wheels, so if you live in an area with badly made roads, both ride comfort and your wallet may dictate no more than a Plus One wheel and tyre package. Also, when you are considering putting more rubber on the road, remember the law of diminishing returns. A 20% increase in tyre width gives you a 10% increase in grip – but only up to a certain point. Complications like over-sensitivity to changes in road surface such as patches and white lines, and a sharp deterioration in grip and steering feel under difficult conditions – when there is standing water on the road, for example -can set in if you pursue the wide tyre philosophy too far.

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VW Suspension Tuning

Posted on 10/07/2011 by retro7

Following wheels and tyres, the next priorities in modifying your car to make it perform better are suspension and brakes, again before you touch the engine. You will find that with more cornering power at your disposal, your point-to-point times will be quicker anyway, as cornering speeds will begin to be limited only by visibility, by the need to retain the vital ability to stop safely within the distance you can see to be clear.

You will also find that a car with better suspension control is more comfortable to ride in as it does not roll so much in corners or give that uncomfortable wallowing sensation when driving on bumpy roads. Again, you can go too far. A car that is made too stiff in its suspension settings can be most uncomfortable. It is jiggly, you can leave the seat over big bumps and you will have less traction in bumpy corners as the car takes off over undulations. And it is skittish in the wet.

Ride and handling are thus a compromise, and VW in fact set a very high standard with the stock fuel-injected cars. The Mk1 cars are slightly under-damped and prone to rock-roll slightly in fast bumpy bends but the Mk2 car is superb straight out of the box. That is not to say that the Mk2 GTI cannot be improved. Far from it. To understand fully how the various suspension tweaks improve a car’s handling, let us look at the forces acting on a car when it is driven on the road or track.

Roll: a by-product of cornering, roll takes place along the longitudinal axis and in a softly sprung vehicle tries to lean the car excessively to the detriment of comfort and cornering ability. The more a car rolls, the greater the slip angles of the tyres and the less of the useful tread area is doing work. The primary component that will reduce this condition is the anti-roll bar, or swaybar as it is called in America.

Pitch: occurs on the transverse rotational axis and causes a car to dive under braking or squat under acceleration. In the absence of anti-dive, anti-squat geometry being designed into the suspension by angling the lower arm locating points, the springs and dampers play the major role in reducing the amount of pitch. Good progressive suspension prevents harsh oscillations.

Yaw: a force that provokes body motion around the vertical axis, yaw affects all the suspension components. In an ideal situation, a vehicle’s suspension should provide completely neutral handling, but most cars are designed to provide mild understeer which allows the front of the car to go wide in corners. This is a safe characteristic to keep the average driver from getting into trouble especially when braking or suddenly decelerating in a bend where a neutral vehicle could then move into oversteer and perhaps spin. If you stiffen just one end of the car at a time, you can induce severe yaw conditions; stiffening the rear induces oversteer while stiffening the front only creates understeer. Suspension development is very much a question of balance.

Modifications: to save customers a lot of time and trouble, aftermarket suspension manufacturers have developed kits for various cars providing just uprated springs, or dampers, or matching springs and dampers (which is better), as well as upgraded anti-roll bar kits to be used with the stock suspension or in conjunction with the spring and damper kits. The European manufacturers, like Bilstein, Koni, Sachs, Spax and others, favour the spring and damper kit approach while the Americans, with a more conversion-orientated custom-car background, tend to go the whole hog with upgraded anti-roll bar kits and better quality locating bushes as well.

Bushes locate suspension components to prevent metal-to-metal contact and provide isolation from road shock and noise. They are used in all moving components in the suspension and steering in modern cars and if a manufacturer is over-generous with these rubber bushes, the car can feel rubbery in its handling and ride. Too much lateral movement in suspension bushes does not help accurate suspension location and makes a car feel woolly in corners. Conversely, the metal or metal and nylon rose joints used in racing suspension are too hard and direct for road use and would destroy themselves in short order. Upgraded high-quality road-car bushes made of polyurethane, like the AutoTech ones, will keep the suspension components in check while maintaining adequate comfort. Polyurethane steering bushes will sharpen up the GTI’s steering, which has a slightly dead feel about the straight-ahead position.

AutoTech in California are US distributors for Hor Technologie parts. Hor are an original-equipment manufacturer who supply suspension, exhaust and other components to German car makers like BMW and VAG but who do their own range of aftermarket parts too. AutoTech are also agents for the excellent Japanese-made Tokico adjustable shock absorbers which match up well with Hor springs. The UK agents are Steiner Engineering.

Amongst the European suspension manufacturers, you will find that each of the kits you can buy has different characteristics and so will please customers looking for different kinds of performance. The Koni suspension has adjust-ability of damper settings as its strength. You can raise and lower the rear spring pans to adjust ride height and the dampers can be tailored from soft to fairly hard settings if you want to commute in the week and then do club events at the weekend. Koni now have another damper design with a semi-active electronically controlled system – the normal kit is user-adjustable from the shock towers.

The Bilstein Sportpak was the first kit on the market for the original GTI and gives a firm ride but brilliant handling. It may be too firm for those who live near less-than-smooth roads, and the gas filled dampers are not adjustable. The kit for the Mk2 is more supple and was the last of the three Europeans to appear.

While Sachs were last on the scene with the Mk1 GTI kit, they were at the head of the queue with the Mk2. Their Mk1 kit strikes a good comfort/handling balance for most people but may still be too soft for really press-on drivers. The Sachs Mk2 kit, on the other hand, is well-nigh perfect, with very little comfort lost over the standard suspension, and it also gives very progressive handling on the limit. All these kits lower the ride height by about an inch which helps stability.

It is not unusual for road testers in different countries to form slightly different opinions of a given car, especially in ride and handling terms. There are several reasons for this, not least of which is that suspension settings are in fact often tailored to the country of destination. The Americans like a softer-riding car despite the good quality of their roads and enthusiasts then complain that the car does not handle properly. Grip and tyre noise are affected by the content of the road surface and this varies from country to country. Thus, a Pirelli P6 manufactured in the UK for local use may turn out to be different from one made at Pirelli’s German factory or indeed one made in the home market of Italy. Suspension, wheel and tyre tuning must thus be done for local conditions and, on that score, companies like Automotive Performance Systems (APS) in California specify different damper settings for their Bilstein kits from those that you would find in Europe. By the same token, a German-bought set might prove a touch hard for use in the LK. Caveat emptor…

Anti-roll bars: the suspension design of the Golf and Golf-derived cars allows the inside rear wheel to pick up under hard cornering. While this is safe in practice, it is indicative of a very severe roll attitude. The solution is to increase the roll stiffness of the chassis without affecting suspension travel and thus ride comfort adversely. The AutoTech front anti-roll bar is a direct replacement for the factory original and comes with all the fitting hardware. The rear factory bar is part of the torsion beam assembly and thus upgrading it means adding an additional external bar. Such an external bar will have different pivot points from the torsion beam and, once the beam is deflected, this would cause the anti-roll bar to push or pull the end of the beam out of alignment. AutoTech’s rear bars use a clever sliding end design to allow the beam to move properly and yet be usefully acted on by the anti-roll bar.

Stressbars: when a car is cornered hard, the forces produced by the act of the tyres gripping the road transmit high loadings back through the suspension to the monocoque bodyshell. Even though the mounting points are reinforced, the shell still deflects. A hatchback car with its large rear aperture is less rigid than a saloon, a convertible potentially even worse. When the shell deflects, it affects the suspension geometry, the accuracy of which is vital for good handling and grip. The Golf Mk1 shell is much less rigid than the Mk2 and the Cabriolet even weaker despite substantial bracing to compensate for the loss of the roof. The Cabriolet also has a higher centre of gravity and so benefits even more from suspension bracing and uprating.

The weakest point of the Mk1 chassis is the lower front and the car benefits tremendously from a lower brace to stabilize the lower wishbone mountings. This has been done in more than one way by various manufacturers. The normal after-market European brace is a single bar which attaches to the front joints of both lower wishbones via the retaining bolts and then has two further bolts which attach it to the floorpan. Realising the weakness of the chassis, the factory developed a similar brace for the Scirocco 16Y and this used a wholly tubular design with four mounting points which did the same job. Techtonics market a brace for the Mk1 cars which they admit is a direct copy of this.

The most comprehensive lower strut brace is the triangulated, fully adjustable one from AutoTech which is really a subframe. This connects the front and rear mounting points of the lower wishbones for maximum bracing and is then triangulated between front and rear bars. It is fully adjustable to take in the production tolerances of individual cars.

A lower brace is more effective than an upper one on all Mk1 floorpan cars, i.e. Golf 1, Scirocco 1 and 2 and Jetta, but an upper shock tower brace is icing on the cake. The improvement in turn-in and cornering stability is instantly felt with the lower brace and steering becomes more positive. In the long term, the continuous loadings on the suspension strut towers weaken a car’s structure. The upper stressbar helps to prevent this fatigue and staves off squeaks and rattles in higher-mileage cars. The Mk2 has a rigid front subframe from the factory- and only needs a top stressbar.

As the rear torsion beam twists, so the loadings are transmitted to the bodyshell. A simple adjustable bar can be used to join the tops of the towers and this is easily removed when you need to use the car’s full luggage earning capacity. For more serious high-speed work, a multi-link triangulated set up is available from APS (Neuspeed) which has permanent fixtures in the bodywork via aircraft type Nutserts. The crossbrace, however, can still be removed.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Brakes

Posted on 08/07/2011 by retro7

For owners of right-hand-drive Golf, Jetta and Scirocco cars with the Mk1 floorpan, brakes are rather a sore point. Because RHD was something of an afterthought, RHD cars retained their brake servo on the left-hand side of the bulkhead and the pedal action was transmitted via a bell crank linkage system with no less than eleven pivot points! This was somewhat less effective than the system used by Ford with their Escort or by BMW in their contemporary cars, and left VW owners with a rather dead-feeling pedal and brakes that seemed inadequate for the car’s performance. Although you could take up the slack in the linkage, it soon loosened again and you would end up adjusting it every three months or so. Various solutions to the problem were tried. GTI Engineering would tighten up the linkage and fit Mintex M171 racing pads in the early days. This offered some improvement but the linkage would loosen with time and the racing pads, while they worked well when cold, unlike the Ferodo DS11s , would glaze-up easily in slow driving, made dreadful graunching noises when used hard and inevitably wore out the standard discs more quickly. At one point, GTI Engineering even tried grafting Ford Granada discs onto the Golf and these worked quite well but could only be used if you had 14in or larger diameter wheels fitted. It was also an expensive solution.

In 1985, the Italian brake manufacturer Tarox came on the scene with a replacement ventilated disc that was also slotted for better cooling and wear characteristics. With their own matching pads, this brake set worked very well and gave good stopping power, better pedal feel and superior fade characteristics. Tarox also make a set for the Mk2 Golf and, with the already satisfactory four disc Mk2 set-up, this gives a GTI exceptional braking ability.

Grafting the rear discs from a Mk2 onto an earlier car is not a straightforward task. The hubs are different for a start. If you can find a crashed Scirocco 16V, it is easier just to swop the rear axles and, of course, the brake proportioning valves have to be changed too.

While the initial idea was to get better pedal-feel and retardation by fitting larger discs to RHD cars, if LHD cars had satisfactory anchors with the same equipment, did it not make more sense to attack the problem at source? Autocavan certainly thought so and this British VW tuner sensibly brought out a stiffer, braced brake bar that fitted to the bulkhead and reduced the linkage pivot points to just two.

BR Motorsport’s Brian Ricketts came up with a large servo conversion kit that raised brake line pressure considerably and gave a vastly better pedal feel. He also developed a bigger disc conversion. With both these modifications in place, he effectively put paid to the old joke, ‘Why is a GTI like an Exocet? Because nothing will bloomin’ well stop it!’.

This did not mean that LHD markets were entirely happy with their brakes. When they uprated their engines, the American tuners sensibly looked for better stopping. AutoTech and APS offer big disc conversions for early and late GTI-based cars. Their latest kit uses the front discs from the G60 Corrado to stop the 170bhp turbocharged, supercharged or 2.0-litre cars they sell to clients. Buying a kit like this from these firms is very cost effective because not only do you get all the parts you need, and even Aeroquip braided hoses if you specify them, but, because of the quantities they buy from original equipment manufacturers, these tuners are able to offer the kits for about two-thirds the price you would pay if you assembled all the parts yourself from your local VW dealer.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Engine Tuning

Posted on 23/06/2011 by retro7

The basic VW water-cooled single-overhead-camshaft engine has proven very amenable to tuning for more power and torque. It is a simple and strong engine, coupled to a very robust gearbox that is able to take the output of forced aspiration engines, unlike some competitors’ products which are more obviously built down to a price. The fact that the basic design started off as a 1.5-litre carburettor-equipped engine and has now ended up being taken to over 2 litres (albeit based on an evolution block) speaks volumes for the Tightness of the basic design. From a l,471cc 70bhp engine, over 200bhp has been extracted in road-going, naturally aspirated form and nearly 300bhp with nitrous oxide injection. Road-going forced aspiration engines give anything from 160bhp to 250bhp, with massive torque.

If anything, the VW engine starts off with one basic disadvantage; it does not have a crossflow head design on its eight-valve version. A crossflow head, where the intake and exhaust tracts are on opposite sides, is logical for optimum gas flow, but the eight-valve engine lacks this refinement. For all that, it gives no ground to its obvious competitors, and in smoothness, power and torque delivery, it was the class standard for many years. The increased efficiency of the Oettinger and VW factory 16-valve crossflow heads reaped immediate rewards in power and torque and it is this newer version of the same basic engine that will take the GTI-based cars into the 1990s.

Brian Ricketts of BR Motorsport was the former Engineering Director of GTI Engineering, and the first British engineer to do serious modi-fication work on the GTI back in 1977. According to Brian, the 1.6-litre engine was over-engineered for the task it had to perform. Not having done such a car before, VW erred on the side of strength. Brian remembers building a 182bhp car,

back in 1979, that revved to 8,500rpm. The internals had no special toughening or crank hardening. All that was done was a blueprint and balance. This car was a Group 2 European Saloon Car Championship runner. There are no particular major problems with the engine, says Brian, apart from the fact that, as they get older, some heads tend to crack between the valve seats. Sometimes blocks crack at the ends between the oil drain holes and head studs, but we are talking of massive mileages, between 80,000 and 100,000 miles. Of all the engines, the 110bhp 1.6 is potentially the most reliable because it is the simplest of the lot with the least moving parts.

The early 1.8-litre engines had head gasket problems but this was cured by changing the head bolt torque-down sequence. Valve guides on these engines could also give way at around 30,000 miles or less. The material was sub-sequently changed, and longer guides used to prevent the valves ‘walking about’ on the seats. Usually though, problems with GTI engines arc not failings of the engine but of ancillaries, especially those with electronic control systems. The 16-valve car is a favourite here as it can suffer from idle-stabilization circuit problems. Some-times these are erratic and hard to trace. In 1984 cars, the wiring for the idle-stabilization circuit was too short and, with engine movement under acceleration and braking, it tended to chafe where it went through the bulkhead.

The 1.6-litre GTI engine is identified by the EG code stamped on the block. The Mkl 1.8-litre engine is a DX, the Mk2 an EV and the Digifant injection cars are denoted by the PB mark. The 16-valve is the KR series.

When you open up the 1.6 and 1.8-litre engines, the chief difference you will notice is in the combustion chamber design. The 1.6 has a flat head with the combustion chambers wholly in the piston tops. This design is akin to the racing VW engines and is preferred by tuners. The 1.8-litre engine’s combustion chambers are shared by the head and the piston tops. The early Mk2 1.8-litre engines and then the 1984-onward DX engines in the Scirocco used air-shrouded injectors to clean up the idle mixture for smoother running, cleaner emissions and better fuel economy. These air-shrouded injectors gave better atomization and had idle air coming down the air rail when the throttle was closed. The air travelled through a bypass into the head which shut off as soon as the throttle was opened.

Another change around this time was the move from a direct oil-to-air oil cooler to a water-to-air one. The water-to-air oil cooler aids the initial heating of the engine oil with resultant shorter engine w arm up. This also meant that the engine could come off its cold-start cycle faster with a resultant reduction in emissions and fuel consumption.

In late 1985, eight-valve cars went over to hydraulic tappets which were in fact the same as those used on the Mercedes-Benz 190E 2.3-16 and later the Cosworth Sierra. With the valve spring platform sunk further into the head, these engines had shorter valves. In service, they work very well with an extremely low failure rate.

On the induction side of things, the change from DX to EV 1.8-litre engines was marked by a re-arrangement of the air-flow meter box to the other side of the engine. A larger air-filter (same size as the Ford Capri 2.8 injection) was used and the compound throttle body was changed from a 38/45mm unit to the Audi-type 38/52mm unit. The longer inlet tract gave it better torque characteristics to pull the now larger car, rather than going for greater horsepower.

When the 16-valve engine first came out, there were complaints that cars did not meet their performance claims. Early cars had 44mm diameter intake runners and the factor}” enlarged these to 50mm which improved matters somewhat. US-spec cars with their emission-controlled engines and 123bhp come with this smaller diameter manifold, so a quick power boost can be achieved by using the 50mm Euro manifold. It is not cheap however, and on the Corrado, the 44mm manifold is used again.

On the exhaust side, the factory cast iron manifold on 1.6 and early 1.8-litre engines is not badly restrictive. Careful machining can produce good flow improvements and a swop to a four-branch extractor may not be as significant as with some other manufacturers’ engines. One gaff the factory made with the early 16V engines was the horrible conical exhaust downpipe that was internally split in the middle 60mm down. For the 1986 model year, they reverted to the tw in down-pipe. The conical downpipes also suffered badly from cracking.

The cylinder head of the Digifant-equipped car is unchanged apart from the holes for the injectors which are smaller. In South Africa, a 2-litre version of the 16-valve engine has gone into production to make up for the power loss experienced at the high altitude on the reef. This 2-litre block was first put in the heavier Passat in Europe, with a catalytic convenor. In this form, it produces 136bhp at 5,800rpm and 1341b/ft of torque at 4,400rpm. Because there are not the same strict emission laws in South Africa as in Europe, the factory there has been able to tune the 2-litre engine for over 150bhp: in any case they cannot use the catalyst equipped G60 engine as there is no lead-free fuel available. As far as Europe is concerned, for the time being, such an engine would be too close in power output to the G60 cars, but this does not mean we might not see the 136bhp high-torque version of the 2-litre in the Golf GTI in the future.

In pure engineering terms, the 2-litre block is an improvement. It is a development of the KR 16V block with its front machined to fit the breather box. There is 5mm more clearance inside the block with the bore centres being spaced out slightly more. The intermediate gear Internally, the chief difference between the 1.6 and 1.8-litre engines was in the combust-ion chambers. The 1.6 had a flat head with the chambers in the piston tops, while the 1.8 had chambers partly in the head and partly in the pistons. shaft is smaller and the oil pump drive is bigger to give more crankshaft clearance. The oil feed system is superior, with oil jets from the main gallery squirting oil onto the undersides of the pistons. In previous modified 1.8 engines taken out to 2 litres, the bottoms of the pistons would foul the oil jets ifyou installed the system. Now, all 2-litre conversions use the Passat block as a starting point.

Engine modifications for increased power fall into four main categories: minor tweaks; bolt-on components; internal work; and, assuming you don’t already ow n a G60, adding forced induction. Nowadays, emission-control legislation is increasingly complex and restrictive in many countries, though as yet less so in the UK than in many other places. While power tuning an engine, if well done, can keep it as ‘clean’ as the standard specification, this is not always achieved. I f you live in a country or state where the limits are tight, it is important to check that any modifications you plan to make to your car are not going to bring you into conflict with the law.

Minor tweaks: whether you own a new or used GTI , it is amazing just how much improvement you can often gain simply by having the engine tuned to the optimum manufacturers’ standard specification. The engines are very sensitive to correct fuel/air ratios, and it is almost impossible for a dealer without a rolling-road facility to set up an injected car with 100% accuracy. The static CO setting can be corrected at idle with an exhaust-gas analyser, but w hat the car does under load may be entirely different.

It is not uncommon for a car referred to a dealer with a complaint of lack of pow er to be found to have a perfect CO reading at idle. On a rolling road, however, it turns out to be running lean at the top end. This can be very bad for the engine, causing pinking or detonation; in extreme cases the mixture can be weak enough to cause a holed piston if the car were to be driven fiat out for a short period. Production tolerances in the injection system, and perhaps too the effects of wear, mean that some cars remain correctly tuned while others cannot be set rich enough under full load. The difference can mean one car giving its full 112bhp while another produces perhaps onlv 95bhp.

Bolt-on components: basically, the car needs more fuel under load and one way to achieve this is to fit a modified warm-up regulator with a vacuum take-off in the intake plenum. Under full manifold depression, this squirts extra fuel into the system to restore power. The alternative is a rising-rate fuel pressure regulator which increases fuel pressure upon demand. Both these methods work well because they supply extra fuel only under load, w hereas if you simply raise the fuel pressure or modify the air metering flap, you alter the whole fuel-delivery curve and make the engine run over-rich at low speeds.

Getting more air in will give a useful power increase. For that reason, the large throttle body is a good upgrade for Mkl cars. Also, a free-flow air filter from a reputable manufacturer like K&N or Pipercross will help the engine breathe better while keeping damaging dirt particles out. You can even drill holes in the bottom of the air box to increase flow, but if you do, make sure you change the filter more frequently. You will also have to suffer more induction noise.

More air needs more fuel if you are to keep the mixture correct. If your system is borderline, as explained already, it will now definitely need modification. Assuming the correct mixture balance, a good air filter is worth an extra one or two bhp.

Restricted air flow into the engine is one limiting factor on its performance; exhaust back-pressure on the way out is another. A good extractor manifold helps gases get away quickly and is worth a few bhp. It works best if used with a complete free-flow system like those made by Super Sprint, Jetex, Leistritz, Gillet, Ansa Sebring or Hor Technologie. A good-quality system may cost more to start with but if it gives more power and lasts longer it is an investment. The basic requirement for a good manifold is that the four pipes should merge gently; the real subtlety comes in achieving this without abrupt changes in cross-sectional area. This allows the gases an easy path and creates less adverse turbulence. Internal work: porting and polishing cylinder heads and manifolds is looked upon as a black art by some. It is really a common-sense operation, but one in which the skill ofthe operator is still at a premium so that certain gifted technicians do 165 better than others. Even after optimum port and chamber design using a Superflow flow bench, I have seen the work of two different machinists produce different power outputs from visually identical heads!

It is more important to port-match manifolds to the head than to polish them. The sparkling smooth inlet manifolds you see at shows are not in practice the best thing for power production, because polished tracts tend to ‘wet out’ with fuel droplets, especially where the atomization path is fairly long. This happens more with carburettors than fuel injection. So it is best to have a slightly matt surface. Port matching is important so that mixture flow and then exhaust gas flow is as smooth and unimpeded as possible. Smooth and shaped combustion chambers that induce enough turbulence to achieve more efficient mixture burn are a great help, while reprofiling of the valves and valve seats to get mixture velocity up and spent gases out should be aimed for.

As with most engines, useful power is to be found in the heads. The 16-valve head can be cleaned up and flowed to give an improvement in inlet and exhaust flow rates of as much as 24% and 44% respectively. With reshaped valves, this work is worth nearly 20bhp. There is an engineer-ing formula that states the ideal relationship between inlet and exhaust valve sizes, and by taking the inlet valves from 32 to 34mm and the exhaust valves from 28 to 28.5mm significant increases in power and low-speed torque are achieved. Note how small in real terms the enlargements are. While valves that are too small strangle the flow in the head, you have to be very careful with valve sizes because you can reach a situation where over-large valves give you a worse result through reduction in gas flow velocity.

As far as the use of lead-free petrol is concerned, all GTI-type engines can use lead-free as they have hardened valve seats. What has kept VW from allowing owners to use lead-free on 16V cars in the UK up to now was the non-availability of high-octane (97 RON) lead-free. It was a matter of octane rather than lead content. The fuel catalyst Carbonflo, however, has been tested and proven to allow the use of normal 95 octane lead-free in 16-valve GTI engines with no loss of power or chance of damage. There is thus nothing to stop GTI drivers from being environ-mentally conscious.

It is quite common for enthusiasts to have gas flowing, porting and polishing done and then a free-flow exhaust fitted. The step beyond this, though, takes the owner into a realm where serious money has to be spent. The old adage ‘there is no substitute for cubic inches’ still holds true today, and when it comes to making effortless power, there is no other recourse but to enlarge engine capacity for torque – unless you are willing to resort to supercharging or turbocharging.

Engine response is directly linked to compres-sion ratio which is why race cars run compression ratios far beyond the 10:1 that is the normal maximum for road cars given the quality of today’s pump petrol. Note, though, that really wild cam-shaft profiles with a lot of overlap reduce the effective compression ratio whatever the simple volumetric figure may be, so that the compression figures you see for out-and-out racing engines are not always directly comparable with road-car power units. US specification cars run 8.5:1 com-pression ratios compared to 10:1 on Euro GTIs. A good upgrade with an engine capacity increase is thus high-compression pistons. There are a lot of myths around about pistons. Yes, all the racing boys used forged pistons, but they are not necessarily the best thing for road use. Because they expand more when heated, they are looser in the bores and thus make more noise when the engine is cold, wearing the bores and allowing oil to blow past. For road use, cast pistons are just fine. All GTI s have forged steel crankshafts, so they are as strong as they need to be for any road application.

One of the favourite early conversions takes the l,588cc engine to l,847cc by boring it to 82.5mm and using a long-stroke 86.4mm crankshaft. When you consider that a complete engine rebuild involves a certain amount of labour, doing such a conversion on a high-mileage engine is a worthwhile alternative to straightforw ard recon-ditioning. The capacity increase is worth 15bhp and, combined with head work, change of camshaft and valve work, BR Motorsport claim 140bhp at the flywheel for such an engine.

For cars that start off with the l,781cc block, an l,870cc conversion using the standard stroke of 86.4mm and 83.0mm oversize pistons gives a more oversquare and freer-rewing engine. With modified head, cam and balancing, this gives 142bhp and a lot more low-speed torque. A similar conversion on a 16-valve unit is worth 170bhp and is as powerful an engine as most people will ever need.

For ultimate power, the 2-litre Passat block is used and, with a l,984cc capacity from a bore and stroke of 82.5mm x 92.8mm, 190bhp is possible with head work, a camshaft change and other minor modifications. The largest commercially available conversion for a 1.8-litre GTI engine is the AutoTech 2.1-litre kit which has an 84.0mm bore and 92.8mm stroke for 2,057cc. In eight-valve form, this gives 150bhp and with a 16-valve head, 170bhp, when used with an AutoTech cvlinder head and exhaust. The kit uses the 2-litre Passat crankshaft, AutoTech/Mahle oversized cast pistons, new bearings and a special head gasket. For the 16-valve engine you also get a set of reduced-height oil squirters, necessary because of the size of the crankshaft. (This would not be necessary if you started with a 2-litre Passat block, but the gains from an extra 70cc are not worth the cost of a new block.) ABT Tuning in Germany do a similar engine for which they claim 180bhp. Master of the big-engine conversions in the USA is the Riverside-based company Techtonics, run by long-time VW tuner and GTI guru Darrell Vittone.

So far, the most powerful naturally aspirated road-going GTI around was done by BR Motor-sport and Weber distributor Auto Technique of Luton for Glyn Jones. The Weber Alpha engine management system was added to a BR Motor-sport 2-litre engine and this has endowed the car with 205bhp at 6,500rpm at the flywheel, 181bhp at the front wheels, and a whopping 1631b/ft of torque at 5,250rpm. The important thing is how well the Weber system has filled out the troughs in the power and torque curves compared to the already well tuned BRM 180 car. With ever-tightening emission laws, this kind of fully programmable engine management looks like becoming the tuners’ accessory of the near future.

Camshafts: most of the larger tuners are now producing tuned cars with catalytic convenors, giving increased power w ithout affecting emission levels. Valve timing is a critical factor in the power vs emissions balance. Camshafts with too much overlap let through a lot of unburnt fuel and are therefore ‘dirty’. The famous German camshaft manufacturer Schrick does a range of camshafts for catalyst-equipped cars.

A larger-capacity engine can take a cam with a longer duration. Thus while a 260-degree duration cam may be very wild for a 1.6-litre car, it is mild when used on a 2-litre version of the same engine. Experience has shown that, for normal road driving, that 260-degree cam in a 2-litre car has such a nice civilized feel, near-stock idle – and yet so much pulling power. Anything wilder produces a car with a frustrating lack of bottom-end torque.

Many people rely too much on 0-60mph and top speed figures as a guide to a car’s performance. A slightly slower car in these terms which has more torque and is faster from, say, 30-50mph and 50-70mph will be quicker and less tiring to drive in give-and-take traffic and fast country-road conditions. Remember, bhp gives you top speed but torque gives you acceleration. Your exit speed from a corner defines your speed down the straight. Therefore, a car with good handling and grip and plenty of torque will alw ays score over the screamer w hose power is all at the top end. A torquev car that does not have to work so hard will also rew ard you at the petrol pump.

Forced induction: the robust Golf engine responds well to turbocharging, and with a good installation, as done by Callaway in the US and Turbo Technics in Britain, you will find a turbo GTI just like the standard car in terms of drivability, only much more powerful. The fact that the intake and exhaust are on the same side on the eight-valve engine means that the heat reflective shielding has to be carefully done to prevent fuel vaporization taking place. Apart from that, careful routing of intercooler pipes and casting of a high-quality exhaust manifold to take the turbo are the main design problems a turbo installer will encounter. The excellent chassis of the GTI-type cars require less uprating to take the power of a turbo than some other hot hatch-backs and, on the whole, power increases to between 150bhp and 190bhp are reasonable for road use.

If you have four-wheel drive, you can afford to turn the wick up higher, as Abt Tuning did with their turbocharged 220bhp 16-valve engined syncro. This is the sort of power that would not go very well in a car with just front-wheel drive. Really pushing the limits of a front-driven Corrado chassis is the Oettinger five-valve-per-cylinder engine. Shown at the 1989 Frankfurt IAA Show, the new head has three inlet and two exhaust valves on a l,760cc (81.0mm x 86.4mm) engine block. Turbocharged, this engine gives 250bhp at 6,200rpm and torque is a phenomenal 2141b/ft at 2,500rpm. It is likely that wheelspin limits the Corrado’s 0-60mph time to 6.1 171 seconds. Top speed is 162mph! With the normal four-valve head on his engine, Treser claims 240bhp and a 15Kmph top speed for his Corrado. 0-60mph is similar to the Oettinger car.

Supercharging, popular for aviation piston-engines in the last war and for cars in the 1920s and 1930s, is making a comeback. VW is the first major manufacturer to produce a supercharged car in the second half of the 20th century, but even before the debut of their G60 models, several aftermarket tuners had had a go. Nothelle tried a 150bhp car back in 1984/5, as did Brian Ricketts when he was with GTI Engineering. In Britain also, Steiner Engineering built a 160bhp super-charged car using American parts from Auto-Tech, with limited success. Supercharging scores for its instant response and superb low-end lugging power. The cars are not dramatically quick off the line, but it is in mid-range acceleration, as when overtaking, that you reap the benefits. As with turbocharging, you need to lower the compression ratio and control the whole fuelling and ignition set-up, electronically if possible, for optimum performance and knock resistance. It would be interesting indeed if the Weber Alpha system could be applied to a super-charged version of the GTI engine.

Nitrous Oxide, chemical symbol N0 2 , is 32% oxygen by weight and is compressed and”stored in a gas bottle at -178 degrees C. When it is injected into an engine, it vaporizes and takes the heat from the incoming atmospheric air. The extra oxygen present combines with extra fuel in the combustion chambers and gives a great increase in power. A ‘fogger nozzle’, which mixes the N0 2 and fuel, is placed next to the throttle body on the inlet plenum at a calculated distance to provide optimum atomization. In stage one on a 180bhp l,802cc Golf, the power increase is around 40bhp.

In stage two, four fogger nozzles are used, one next to each inlet tract. It is vital to ensure that each cylinder gets the same amount. On a test vehicle, stage two was worth an extra 70bhp. When this is in use, the ignition timing has to be retarded. N0 2 can only be used for acceleration runs both because of the limited size of the gas bottle and because it should only be used on full throttle if you are not to damage the engine. It is a cheap way to get dramatic power increases, but you must ensure the system is installed properly and that the engine is healthy enough to take the strain of the dramatic increase in output.

Carburettors: last but not least, and perhaps an unlikely end to the engine tuning section of a book on a fuel-injected car, it is worth noting how effective carburettors are on a GTI. When VW first started experimenting with the Sport Golf, they tried the lOObhp carburettor engine from the Audi 80GT and pronounced it not powerful enough. From there on, the K-Jetronic injection system was adopted. Hut for ultimate power, there is no substitute for a single choke per cylinder, which is why the Weber Alpha injection system using bespoke single throttle bodies mounted on Weber DCOE carburettor manifolds is so effective. If you are not concerned with drivability, consumption or emissions, then sticking a pair of DCOE Weber carbs on a 2-litre 16-valve GTI engine is an interesting way to find 140-150bhp with the noise to match. If the head, cams and exhaust are done too, this motor should be good for 180-190bhp with plenty of torque in the narrow band when it is on cam.

The ultimate innocent-looking Q-car was produced for a customer by London-based Steiner Engineering, who built a 16-valve carburettor-fed engine into a five-door Golf 1.3 GL bodyshell. Standard on the outside apart from wider wheels and tyres, this 150bhp monster has the full AutoTech/I lor/Tokico suspension, strut brace and anti-roll bar set-up installed as well as heavy duty brakes. BMW 325is and Porsche 944s do not know what hit them!

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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Lasting Impressions

Posted on 18/05/2011 by retro7

As modern cars have become more and more competent and refined, they have tended also to become more and more devoid of character. While this may not bother most of the people who buy them – salesmen, executives, housewives, to whom a car is primarily a way of getting from A to B – it is a vital loss to anyone who considers himself or herself an enthusiastic driver. How refreshing, then, to find a thoroughly modern and well engineered car which feels as though it is meant to be enjoyed, not just used. In this respect, the high-performance VWs excel. Their engines and drivetrains positively encourage hard driving and, at the end of the day, they will come back for more when rivals are wilting under the strain. The build quality and durability of VW products is such that they can withstand hard driving – short of actual abuse – for very high mileages. Members of the press are not kind to cars when it comes to taking performance figures and’assessing hand-ling and grip at test tracks and it is notable that a VW that has covered the customary 12-15,000 miles before it is removed from the press fleet is still as taut and rattle-free as the day it left the factory. We have noticed various vehicles from rival manufacturers feeling distinctly loose and worn after 15,000 miles of such treatment.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Golf GTI

Posted on 18/05/2011 by retro7

The first time I drove a Golf GTI in the late 1970s, I knew I had found the car I was looking for. Up to that point, I had had various Italian sporting coupes that were fun to drive but had horrendous build quality, poor reliability and rust problems. The smoothness, tractability and will-ingness to rev of the GTI’ s 1.6-litre engine were almost unbelievable after the hiccups of car-burettored Italian machinery, and the doors closed with a bank-vault quality that promised a lasting relationship.

What was immediately apparent was that this little nugget of a car was exactly as big as it had to be and had the handling and grip to match its performance. It was the perfect size to negotiate London traffic and nip into parking spaces that were denied to small BMWs and, at the same time, its hatchback with folding rear seats made it an extremely useful car for carrying ‘tools of the trade’ or simply for an extended tour of the Continent. No wonder then, that the GTI, especially in black, soon became the pet of the Chelsea and Kensington set in London and ultimately the supreme ‘yuppie’ car across the globe. That type-casting was most unfortunate though, for the GTI, tame enough as it was to perform mundane urban duties, really came into its own on the open road where its sharp handling, small size and superb power-to-weight ratio made it an agile cross-country runner. It was equally at home on motorways and could run nearly flat-out for hours on end thanks to a strong engine and an oil cooler. It was unfortunate that the body structure and drivetrain conspired to create a boom in the rear of the cabin which was irritating to rear seat passengers. This happened at about 70mph, the British speed-limit on motorways, and meant that more serene progress was made above or below this speed.

The engine of the GTI 1600 felt almost unburstable. It would start first turn of the key even if the car had been lying idle for weeks and, once warmed through, would pull to the red-linelike a turbine, accompanied by a lovely rorty exhaust note. The gearchange quality was also excellent. The short stubby lever in the later five-speed cars was like a big flick-switch. With comparatively short movements across and up and down the box, it was a joy to blast this car along twisty A and B roads. The gear speeds were perfectly chosen: the five close ratios took up perfectly one after the other, producing one long blast of sustained acceleration if you did a standing-start to top speed run. Miss a gear, say if you went from third to fifth in normal driving to save on fuel, and you knew that the engine had dropped off the cam. In the more powerful l,800cc version, you could do this with impunity as the extra torque covered the ‘hole’ in the gear-box that resulted from skipping a gear.

The GTI had two obvious dynamic failings, one minor and the other only manifest in right-hand-drive cars. The minor flaw in its dynamic makeup was that the rack-and-pinion steering was slightly vague about the straight ahead. Once through this ‘loose’ area though, it was nicely weighted and communicative. Right-hand-drive GTIs had to have a cross-linkage to couple the brake pedal to the servo on the left-hand side of the bulkhead. This had rather too many pivot points, and the whole arrangement introduced so much flexing and lost motion that the pedal feel on RI ID cars gave great concern to fast drivers. Many aftermarket tuners attempted various combinations of discs and pads, but it was not until the problem was tackled at source, by improving the linkage and then fitting a bigger servo and discs, that a solution was found.

All cars based on the Mkl floorpan also tend to hit their bumpstops on hard bumps taken at speed. This seems to be a characteristic of the wheel travel and suspension design on the Mkl and is not cured even by fitting the progressively sprung Bilstein, Koni or Sachs spring and damper sport suspension.

If the opposition was getting as fast or faster in terms of raw power, as 1982 drew to a close, VWreplied with the l,781cc engine, offering just 2bhp more but with more torque in the low and mid engine-speed ranges. The bigger engine was not quite as sweet as the 1600, but it delivered the goods in a more relaxed manner and made for an easier car to drive swiftly. That extra torque was very telling when exiting corners. I remember testing a Toyota MR2 at Castle Combe circuit, w here my times were just 1.5sec a lap slower than Chris Hodgetts, the Toyota saloon car racing champion in a Corolla GTi : the little Toyota w as as fast as the GTI to 60mph and had a higher top speed but, coming out ofthe bends, a colleague in a Mkl 1800 GTI was pulling away quite notice-ably, showing just how much torque counts in fast driving.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Golf GTI Mk2

Posted on 18/05/2011 by retro7

The first Mk2 GTI I drove was a left-hand-drive car that had been personally imported to the UK. Coming out of a Mk 1, you were instantly struck by the more solid and substantial feel of the newer car. It was much quieter and more comfortable on the road, showing how standards changed during the nine-year lifespan of the first Golf. Although the early Mk2 GTI s had a similar engine to the late Mk l cars, small revisions to improve low-speed torque even further had left it a slightly lower-rewing unit. Extra size and weight also made the car feel less nimble.

On the race track, though, the new car showed its edge. With a longer wheelbase, it was less prone to oversteer on throttle lift-off even though it would still lift its inside rear wheel off the ground in very hard cornering. The car felt more stable and was very forgiving even if its driver was not quite up to scratch. I remember one incident at a GTI Drivers’ Club meet at Goodw ood w here one ham-fisted pilot got it totally wrong and went into a corner too fast (for him) and on the wrong line. Following behind, I saw him dangle a rear wheel in the air, lock up the other rear wheel in a puff of tyre smoke as he attempted to lose speed, and more or less manage to collect himself as the car barely deviated from its line. In many other cars, the driver would have left the corner backwards, but the GTI had enough in reserve to save its hapless driver from that ignominy.

Despite sporting spring and damper settings, the GTI Mkl had a comfortable ride and the occasional bottoming out at the front was more heard than felt. The ride quality ofthe Mk2 was even better. The longer wheelbase made its contribution to stability and ride, and longer wheel travel in the suspension, with re-rated springs and dampers, resulted in a chassis that took all road surfaces in its stride. The most important thing for British owners, though, was that the RHD version had been designed-in right from the start. ‘This meant that RI ID cars had a 182 different bulkhead with the brake servo moved accordingly, as well as a proper RHD wiper mounting too. With ventilated discs in front, and solid discs at the rear in place of the drums on the Mkl , the new GTI dramatically extended the braking confidence window for its drivers.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Mk2 Golf G60

Posted on 18/05/2011 by retro7

It may surprise many people to learn that the G60 GTI is actually slower than the 16V to 60mph although it has a higher top speed. Unlike the aftermarket turbocharged cars, the factory-super-charged GTI does not greet your depressed right foot with an intoxicating rush of power; it is a far more progressive beast than that. For those who have revelled in the characteristics of a powerful turbocharged car, the rather laid-back G60 may well come as a disappointment. It is smooth and progressive and totally unobtrusive, although if you wind down the window you can share the odd-sounding whine with onlookers, for the G60-powered VWs sound like no other cars. Where the supercharger scores is in intermediate-gear acceleration and tractability.

With its lowered suspension and big wheels and tyres, the G60 has a higher level of grip on a smooth road than the 16-valve, and the latest power-steering set-up is a far cry from the over-light arrangement offered on the very early 16V cars. The smooth surge of power from the G60 engine is very satisfying as you blast from corner to corner on a twisty road, and there is the feel, as with all GTIs , that the basic chassis is capable of handling even more power.

An interesting technical innovation VW launched with the Golf G60 was their Electronic Differential Lock (EDL) which uses the ABS sensors to detect variations in wheel speed. Unlike the BMW and Mercedes-Benz ASD systems which reduce engine power to compensate for lack of traction, the VW system works by slow ing the wheels down. If you should encounter a puddle of water or loose gravel mid-bend, you will not get the dramatic loss of composure you might in a standard car. The system only works if there is a difference in speed between the driven wheels. So it is still possible to spin the wheels if both are on a surface of equal frictional coefficient. If you were to launch the car on a loose surface, you would thus spin the wheels, but the moment one wheel reached a grippv surface, the antics would be called to a halt.

The chassis of the GTI G60 is firm, make no mistake. This is not a soft-riding motorcar, and yet it never really jars your sensibilities. On a rough surface, you are left in no doubt that the car is firm, and the power steering provides plenty of feedback of information. The car’s handling and grip are simply phenomenal. Helped by the EDL, it puts every one of the 160bhp down convincingly. If anything, grip with EDL has changed the handling of the standard car from understeer and lift-off tuck-in to understeer and then neutral. Those used to deliberately using the lift-off tuck-in of the normal GTI as a driving technique will get a fright the first time they try to induce that effect on an EDL-equipped G60. The only way to bring the tail round is to take a stab at the brakes to alter the weight transfer more dramatically.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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Motorsport VW Mk2 Golf Limited

Posted on 18/05/2011 by retro7

If the Golf G60 feels as though its chassis could handle more power, the Limited provides that power in the form of 210bhp from a supercharged 16V engine. Wisely, VW elected to pair it with their syncro 4WD system. While the standard G60 unit merely enhances the tractability of the eight-valve engine, the 16-valve version releases the full potential of the supercharger system. Acceleration is vivid, with 60mph coming up in 7.0 seconds. But what is impressive is that the power never seems to tail off until you hit the rev limiter just past 7,000rpm. Get to 100mph…smooth onward urge. 186lb/ft of torque at 5,000rpm is 3-litre pulling power and, with the drive going to all four wheels, once the fronts begin to slip under the strain of the torque, the handling balance of this car is beyond the capabilities of a normal front-wheel-drive GTI. Power-on in a tight corner and the Limited adopts a more neutral stance and full throttle can be applied early once the car is settled. In wet corners, power sliding out on opposite lock is possible, another fun element denied to the FWD Golf enthusiast. For all that, the Limited is a refined and mature vehicle that cossets its 120mph…and it is still pulling hard. Very low down, the engine still does not have the razor-edge response of a good naturally aspirated unit. Frustratingly – because it is so good past 2,500rpm – it does take a fraction of a second to ‘come to the boil’ and really get going. This is probably a function ofthe lower compression ratio (compared to a stock 16V) and/or insufficient gas speed at low rpm, a problem with many multi-valve engines.

Once it starts to build up, though, it is intoxicat-ing and you find yourself using the gears for the sheer exhilaration of feeling the strong and occupants in its leather upholstery and pampers them with luxuries like electric windows, central locking and a sunroof.

Only 70 Motorsport Golf Limited cars were made, lovingly constructed by VW Motorsport personnel during 1990, but this wolf in sheep’s clothing, looking just like any metallic black five-door Golf with a set of BBS wheels, is the ultimate hot-hatchback of its day just as surely as the original Golf GTI was. Advances in technology and in market conditions have created in this car a level of sophistication as telling today as that of the first GTI in 1975. Ironically, this Q-car shares one flaw with that original GTI: in its attempt to remain discreet in appearance, with just two headlamps, its night-driving capabilities are severely hampered.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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Golf GTI Cabriolet

Posted on 18/05/2011 by retro7

Just as the Golf GTI spawned many imitators such as the Escort XR3i and the Peugeot 205 GTi , so the success of the Golf Cabriolet pushed rival manufacturers to make open versions of their hot hatches. While the Mk2 Golf has pursued refinement in its chassis and overall deportment, the Carbriolet retains the more raunchy and vibrant feel of the original GTI . Because of this, it remains a better open-air fun car than its direct rivals. The engine of the Cabriolet is smooth, sweet and torquey and, when you have the hood down, the powerful rasp of the exhaust note under hard acceleration adds to the sensation of open-air motoring.

With more weight in the rear, the Cabriolet has a different handling balance from the GTI . Its tuck-in is more pronounced if you lift off the throttle at high cornering speeds and the way to avoid an oversteering situation is to flick the steering wheel straight as you lift off. For an open car converted from a saloon, the VW Cabriolet has good structural rigidity. Scuttle shake is detectable but it is not worrying. Acceleration and top speed are down on the GTI because of the extra weight and the blunter shape, but open-air motoring is not about flat-out driving: it is about enjoying the sights and sounds around you in a car that is tactile, responsive and civilized. The Golf Cabriolet has these attributes in full measure.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Jetta

Posted on 13/05/2011 by retro7

The extra weight at the rear and thus the differently placed centre of gravity of the Jetta in both Mk1 and Mk2 forms creates a car with slightly different handling characteristics from the Golf. If you lift off on the limit in a Jetta, the oversteer tendency is greater, especially if the boot is loaded. Driving an empty Jetta GTi 16V back-to-back with a Golf GTI 16V at Donington circuit one morning, it quickly became apparent that the different balance of the Jetta in fact helped to cut understeer and made the car turn-in better. From a driver’s point of view, this can be quite desirable. In terms of grip, the tw o cars are pretty evenly matched but I suspect that in steady-state cornering on a skidpan, the Golf would ultimately produce a higher lateral g figure as it would not move into oversteer so quickly.

Driving both cars around Oulton Park, a hilly circuit with several fast dips and crests, I was impressed with how well the Golf and Jetta handled with four people on board. Both cars could comfortably be driven on the limit in this load configuration with extremely safe and stable track manners. Many good road cars lose their composure rapidly when subjected to the rigours of on-the-limit driving around a racing circuit. The Golf and Jetta and of course their Scirocco and Corrado stablemates are rare cars that offer equally exemplar} behaviour on both road and track, one-up or fully loaded.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Scirocco

Posted on 13/05/2011 by retro7

I have fond memories of the fuel-injected Scirocco Mk1 and Mk2 cars, having owned both after a brief flirtation with a Golf GTI 1600. When you drive a Scirocco, you sit in a fairly reclined position compared with the upright Golf, and, combined with the car’s lower height and centre of gravity, this gives the impression of greater cornering stability. In real world terms, the skid-pan numbers of the two cars are not significantly different, but I have always felt a little braver cornering a Scirocco hard on a race circuit. The slight pitching motion induced by fast bumpy corners and caused by fairly soft rear dampers on all the Mkl Golf and Scirocco 1 and 2 cars was felt least of all on Scirocco 1. Sitting higher up in the Golf, you felt if more.

With more weight and overhang, the Mk2 Scirocco was less nimble than the first car. Even compared with the Golf Mk2, though, it is a quiet and refined car that is a pleasure to drive, especially in 112bhp form. It was not until I stepped back into a Scirocco Storm Mkl that I realised how much more agile the original was. The older car was also much noisier, so if you do a lot of long distance work, the progress in refinement is a welcome thing.

The 16-valve Scirocco was only made in LHD form and sold in the UK to special order. I was lucky enough to have sampled the car in Germany in 1985 at the original press launch. With its lower strut brace and uprated springs and dampers, the car was a lot tauter than a Scirocco GTI and stopped better too, thanks to rear discs. When driven back-to-back with the Golf GTI 16V, though, it quickly became apparent that even these modifications could not begin to close the gap with the new-generation chassis. But for all that, the Scirocco 16V looks set to become a classic. Although the Scirocco is still in production, the 16V was the definitive factory car and the used-car market in Germany has already begun to underline that thinking.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

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VW Corrado

Posted on 12/05/2011 by retro7

While in essence the Corrado has the fioorpan and chassis from the Golf GTI Mk2, its rear axle design benefits from further technical progress made between the launch of Golf 2 in 1983 and the new Passat in 1987. The most significant feature is the passive rear-steer effect given by the special bushes that locate the trailing arms. The dynamic effect of rear wheel steering is better turn-in, better crossvvind stability and more stable cornering. The Golf 2 is already very good when driven on the limit. It is initially hard to believe that the Corrado is significantly better, but those flexible bushings work very well and help to reduce understeer in fast corners. The reduced slip angles enhance cornering power and the Corrado’s poise through corners sets new standards for front-wheel-drive hatchback cars.

The Corrado 16V is about 400lb heavier than the equivalent Golf GTI 16V. Thus you have to use the gears more to get up to speed, but superior aerodynamics mean that the car is quick once you have overcome inertia. The Euro-spec G60 offers performance more in line with the looks and chassis behaviour of the car, but with a penalty at the petrol pump as with any car that uses forced aspiration. The stiffer chassis creates even higher levels of handling and roadholding than the 16V, but the ride is firmer too. On smooth German roads this is fine, but on some broken British A-roads, the ride can become a little jittery.

In terms of build quality and refinement, the Corrado is superb. The car feels hewn from the solid. The driving position will be familiar to those who have owned Sciroccos or even a Porsche 924/944! The difference is that you can get two adults into the back seats of the Corrado and its ability to cruise happily at three-figure speeds makes it a real Grand Touring coupe.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

Posted in VW Corrado

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Enthusiasts All

Posted on 12/05/2011 by retro7

For many years, VWs have been enthusiasts’ vehicles, witness the huge number of Beetle owners world-wide who make the effort to join VW Clubs and take part in organized events. But even the Beetle craze has been overtaken by the fanatical following of GTI owners. In Germany, almost every large town has a GTI Club and in both Holland and Germany there are Scirocco Clubs to cater for the VW coupe as well. Germany also has a few Golf Cabriolet Clubs for open air fans, and we will probably see Corrado Clubs starting up before long.

The Americans tend to integrate GTI enthusiasm into their normal VW Clubs but in Britain there is the GTI Drivers’ Club and Club GTI while the hard-core South Africans have the very active GTi Club of SA. Club gatherings in all countries range from a monthly regional get-together for drinks and car talk to full-blown events at racing circuits. But the most spectacular GTI events occur at an international level. These tend to involve the VW importer and main dealers in the host country and are professionally organized, with technical lectures, exhibitions, film shows, sprints and slaloms.

The most famous of these giant GTI gatherings is the annual GTI Treffen (Convention) at Maria Worth on the edge of the Worthersee, a lake in Southern Austria. The first of these events in 1982 started off quite innocently as a small gathering of GTI enthusiasts. The meeting was a success and Volkswagen fuelled the fires by circulating details of the 1983 event to VW owners in Germany and Austria. Nearly 800 cars turned up for the second event. The scale of the event took it beyond club-level organization, and so Volkswagen took over the logistics in association with the local tourist board. The numbers of cars and people attending has been growing every year, and in 1985, the cars attending produced a six mile long GTI traffic jam. Last year, with a record number of 1,160 cars at Maria Worth including a contingent from the British Club GTI, a monument to the GTI was carved out of stone by a group of craftsmen.

Another growing event is GTI International which is organised by Volkswagen Audi Car magazine in the UK. In its second year in 1989, GTI International moved to the Transportation and Road Research Laboratory in Crowthorne, Berkshire, and under brilliant May sunshine, was a stunning success with 1,000 cars turning up over the weekend. The test establishment has a huge car park with room for slaloms and handling tests and there is a timed quarter-mile sprint, concours d’elegance, technical seminars, exhibitions and displays. In 1990 there will also be a sound-off competition for cars with customized audio systems. In 1989, several participants came over from Germany and as the fame of this event spreads, it could well equal the GTI Treffen in attendance in the years to come.

©Ian Kuah. This article was published with explicit permission from author Ian Kuah

Posted in VW Mk1 Golf, VW Mk1 Golf GTI, VW Mk1 Jetta, VW Mk2 Golf

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VW Mk2 Golf Country

Posted on 10/03/2011 by retro7

Posted in VW Mk2 Golf

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