Despite weight, power and rim-width restrictions being tightened during the 1988 Sports Car Club of America (SCCA) TransAm series, Audi and its driver Hurley Haywood emerged as dual Champions. Relying on the American services of former Jaguar and British sports-car specialists Group 44, Audi won eight of the thirteen races.
The driving squad also included Hans Joachim Stuck and 1980/1982 World Rally Champion Walter Rohrl, fielding two of three Audi-built quattro circuit saloons at each event.
Although Audi and its ancestors at Auto Union have strong racing parentage, the technical impetus behind the Audi marque’s Eighties revival was first displayed in World Championship rallying. The Quattro line became synonymous with images of flame-spitting coupes that progressed from 200 standard horsepower to more than 550. These rapid test-beds helped to prove the Torsen differential long before it entered its now routine place in Audi production quattros.
In Europe the last works Quattro coupe was on the 1985 Rallye Sanremo. The factory also managed World Championship Group A honours on the 1987 Safari with 200 turbo quattro saloons, Hannu Mikkola defeating Walter Rohrl in an unexpected 1-2 result.
Whilst the Audi Sport department on the fringes of the main Ingolstadt factory zone was finding the transition from Group B supercars to Group A even tougher than its innate pessimism had predicted, the enormous American export market turned sour tor Audi.
“Unintended acceleration”, became the nightmare phrase to Audi executives watching a plunging sales graph. Some good news was needed as the company fought for its reputation every time another lawsuit surfaced. Sport was chosen to offset the bad publicity that was bleaching Audi’s North American status from quality German import to risky buying proposition.
Audi had already supported an annual foray to the Pikes Peak Hill-climb for the works quattro coupes of increasing bestiality, Michele Mouton, Al Unser and Walter Rohrl all scoring their anticipated victories, Rohrl’s against the fiercest opposition from Peugeot. But this annual jamboree was too infrequent; clearly a more regular presence was required.
There were precedents for selecting the 200 quattro saloon as a racer, such as the five-valves-per-cylinder record-breaker, and winning performances in French national saloon car racing. Yet the overriding commercial consideration was that this was the shape Audi needed to support with USA racing prestige.
I say “was” because the 1989 season will see Audi switch to IMSA’s GTO category, with a more radical machine based on the silhouette of its 90 quattro, now considered in need of racing exposure in the United States. Recent opportunities to talk to key Audi personnel about the racing revival have supplied a fascinating picture of the way this determinedly individualistic arm of VW operates.
Again I choose the phrase with care, for “individualistic” truly applies to a company which preserves elements of its road-going technique wherever it competes, including the inline, front-mounted five cylinders, and permanent 4WD. These elements, and some technological tips from the Supercar rally era, shaped Audi’s challenger for the 1988 SCCA campaign. To its credit, Audi, in association with roll-cage specialists at Matter, chose to build its own machine based on a gutted and strengthened 200 steel chassis rather than simply become customers for a tubular spaceframe racer.
Audi engineers did not have long to complete the job, for they also had to redevelop the comparatively primitive 10-valve five that had preceded the 20V Sport SI alloy unit in World Championship Rallying. From its early negotiations and contact with the Bob Tullius Group 44 team, Audi knew that any attempt to field four-valve-per-cylinder engines would result in further restrictions from the organisers.
Thus the 10-valve fives were brought out of rallying retirement (when they had yielded a quoted 360 bhp at 7000 rpm and 331 lb ft of torque at 4000 revs, all from 2.1 litres) and examined for new world potential.
The Audi Board of Directors approved the American racing programme in October 1987. By April 15, 1988, the day before the opening TransAm round at Long Beach, Audi Sport had delivered three cars!
The specification on key points varied during the season because the SCCA added 200 lb in ballast, a 54mm turbo air inlet restrictor and reduced rim widths an inch beneath those Goodyear covers. Nevertheless Audi R & D at Ingolstadt, now headed by Jurgen Stockmar, rose to the challenge. According to Herr Stockmar, power actually increased during the season, even allowing for the SCCA turbo strangulation. In early 1988 the 2110cc (79.5 x 85mm) unit provided 510 bhp at 7500 rpm, plus 362 lb ft of torque at 4500 revs. Stockmar reported an increase to 570 bhp by the end of the season, whilst other official sources quoted 540. That is primarily because boost is adjustable, so long as it is not cockpit-controlled.
As before, Audi power-units use Motronic ignition and fuel-management in association with KKK intercooled turbocharging and dry sump lubrication. Yet the unit retains injection, exhaust and turbocharger on the “hot” side of the slanted engine installation and only a single overhead camshaft is used, whereas the 20V unit is of crossflow design and naturally had dohc. American competition faced a powerplant which was far from Audi’s best, but the transmission and chassis have made up for this. As with its later rallying quattros, Audi specified a six-speed gearbox, unusual in competition as it has the full synchromesh that is absent on the Prodrive BMW or Peugeot six-speeders. Change quality is reputedly remarkable, but the 4WD element is even more important in the opinion of Walter Rohrl.
“Sorting out the car with Dieter Basche from Audi Sport was a big thrill for me. Particularly when, right from the start, Hans Stuck said it was the best-mannered car he had driven,” says Rohrl.
“That was something special, and so is the four-wheel drive on a racing circuit, especially the street kind in Dallas and Niagara Falls. There it is bumpy and you need precision, but with 4WD you always have a wheel on the ground to transmit power and help you forward.”
Another 4WD option is to vary the amount of power delivered front-to-rear rather than simply side-to-side on a single axle. The Audi was set up with a basic philosophy of making it handle like a refined rear-drive racer, with a 25% front and 75% rear mechanical bias. As in rallying a number of limited-slip devices were employed during the season. In the centre Audi used either viscous couplings with planetary gear-sets, or the Torsen self-locking unit. The front remained true to a viscous coupling whilst in the rear all three popular types of locking device were assessed during the season; ZF multi-plate, Torsen and viscous coupling.
By comparison the suspension was pretty straightforward, but here I quote only the year-end figures for the American racing quattro and it must be remembered there were alterations during the season. The Bogedamped and strut-suspended 200q ran 12in wide by 16in diameter BBS wheels, but the season saw them use anything from 12 to 13.5in width Goodyears. Behind those wheels lurked enormous ventilated disc brakes with adjustable balance: the fronts measured 13in diameter x 1.25in thick.
Quoted weight at the end of the season was 1115kg (2453 lb). That is heavier than Audi would have liked, but still flyweight cornpared to the standard machine’s 3102 lb. In 1989 organisers have suggested that Audi should race at 110% of the weight shown in German catalogues: some 1220kg/2684 lb in the case of the 90 saloon.
Dimensionally the 200q in racing trim looked anything like the road car from the front, but it was built on a wheelbase within 0.5mm of the standard 105in. Length increased modestly — from 189.25in to 192.8in — but width was well up at some 80in in place of 71.4in, a reflection of the radical changes in the lightweight plastics used to clothe that steel underbody.
The track was not increased quite so much as you would suspect, competing at nearly 64in versus a production figure of nearly 58in. Those who have seen the quattro in a race report that it towers over contemporary Chevrolet Corvettes. In fact, it wore a roofline height of 52.7in compared to the standard 56in.
Jurgen Stockmar emphasised that high power from a comparatively small engine and all-wheel drive “has not made it easy for us as some European journalists made it seem. Chevrolet and Ford (through Mercury division) were our biggest rivals and we have seen how much they have improved their lap times over the previous years.”
The TransAm rulemakers were not about to grant a licence for the German company to come over and thrash the American teams again in 1989 without some very tough negotiations over weights, rim widths and power-unit specifications, which is why Audi eventually opted for the freer regulations of IMSA racing. Having prepared a winter testing example of its 90 racer to conform to these rules, it finally committed itself in mid-January to the GTO category.
Herr Stockmar concluded with a rueful grin: “OK, it is nice to see that our rivals acknowledge the success of the quattro system in racing, but it would have been an even harder technical task to win in TransAm again next season. We were having to test every alternative, because we always had to be prepared for any kind of change in the regulations.” JW