Tuning topics
Race modifying Jaguar’s XJ-S for European endurance events
WHEN I heard that Jaguar was to go racing in European Touring Car Championship events again my first reaction was, “Oh no! We’ve seen all this before. Why should it work now, when it Was such a disaster in 1977?” Then I started getting phone calls from Germany. At eight o’clock in the morning it’s difficult to argue with an irate trans-European caller who wants to know, “if Jaguar can race that XJ-S as a touring car, why cannot Porsche bring the 911S, or BMW the M1?” There were questions about the numbers produced and the size of the rear scats, all good touring car stuff in which the “other guy” is always trying to runs rampant cheater, while the injured entrant speaking to you has never run even a gram underweight or with an engine so much as a c.c. oversize. Up to this point, where the calls from Europe grew more persistent and the stories in the weeklies ever more specific, I had hoped nobody would be interested in the Jaguar until it had proved itself.
Then, just a few months after the project was first seriously voiced by Tom Walkinshaw Racing (TWR) to sponsors Motul, the French oil concern, the car appeared at Monza for the March opening round of the 1982 European Touring Car Championship. It was immediately obvious that Tom Walkinshaw, who was sharing the driving with “Chuck” Nicholson, had tackled the problems of racing a jaguar with a professional acumen that was totally absent in the original over-complex Broadspeed XJ Coupé project. Instead of a mass of engines strewn over the paddock after a year long gestation period, this young TWR / Motul project — which has blessing and co-operation from Jaguar Cars, but is reportedly not a direct factory-financed project — was surviving hours of Monza practice with honour. It had troubles of course, but it was fastest for much of qualifying time and was not tempted into a pole position battle when a BMW 528i tipped it to quickest time by 2/10ths for a four-hour race. Listening to the accounts of fellow journalists and rivals — one of whom described the car as, “simply gorgeous-looking, but no way a touring car!” — I felt compelled to go down to Kidlington and see the black beast for myself. Especially as it had comfortably led the opposition (9 sec. lead after 18 laps) until a chicane scuffle, not an initial mechanical failure, subsequently led to retirement. A gearbox oil cooler line was so badly damaged that retirement followed after 45 laps, roughly one hour of racing time.
Kidlington, just a few miles outside the Oxford ring road, has been home for TWR and the increasing web of other activities that have seen Walkinshaw move from full time racer to preparation specialist, retailer and racer. To gauge the worth of the cliché “Canny Scott,” you need look no further than Tom. Amiable until contradicted or crossed, Tom is a muscular Scottish gendeman who realised that formula car racing might be for those of less intelligence when the variety of machinery he drove in Formulae Atlantic and 5000 broke beneath him. One memorable outing literally leaving him with just the steering wheel to brandish at Brands Hatch, questioners asking “what happened?”
Ford, BMW, Mazda were the manufacturers who employed his talents as a driver. Ford got a rapid RS2000 and Capri pilot but were not keen enough to stay Tom’s preference for European long distance events. BMW were the obvious home and he drove all manner of cars for Munich / Alpina, ironically defeating Jaguar on their last 1977 UK appearance at Silverstone, when the green Alpina BMW CSL held off Andy Rouse in the Jaguar until a crash decided the matter minutes from the end. So Tom certainly saw how Alpina BMW did things in endurance racing: from air jacks to careful attention that ensured, “not a nut and bolt goes on the car that isri working, and working hard for a living”.
For Mazda, Walkinshaw beciune not only driver capable of winning one of touring ca racing’s most valued prizes — the 24 hours a Spa-Francorchamps (1981) with journalist Piero Dieudonne — but also of bringing back twi British touring car Championships via the RX-7 and the talents of Win Percy.
Walkinshaw is still involved with Mazda as th, wealth of fascinating artistic impressions arm= the office testify, but now it is “more on thi rallying side and development for that sport” There is a Walkinshaw-owned Mazda dealershij at nearby Dorchester and the man also ha financial ownership of DART, the Silverstone-based sole distributors of Dunlot racing tyres, also an Alpina-BMW franchise fo the UK and the responsibility of running thi factory Rover 3500 team in Britain. It was this lot: link that led to the jaguar project and continents confusion, because everyone automaticall, assumed that TWR would run the Rover is Europe this season and opposition was readied or that basis.
Tom takes up the story of how the racing Jaguar project began. “Racing saloon cars areas important part of our business, so when a new se, of regulations were issued we automatics”, evaluated them, just as we look at everything it this field.” Those new regulations were those fo, the international Group A, basically catering his touring cars produced in numbers of over 5,001 per annum. Tom continued, “we knew there wan a good chance of the Belgians adopting Group A. besides the recommendation that it form the basit of the European Touring Car series instead ol Group 2.”
Of course the regulations kept changing, not so dramatically as those for Group C endurance racing, or the sudden lurches in policy that seem to afflict Grand Prix, but enough to keep TWR revising their estimations of potential winners. Eventually they decided to simplify their search for a competitive Group A project, “early in September last year we drew up a spec of what we wanted in an ideal Group A car,” recalled Walkinshaw with a deprecatory grin.
“The priorities were that the suspension be of the wishbone type, to accommodate every inch of rubber allowed by the regulations (a MacPherson strut hogs that vital space of course — Secondly we wanted a car with fairly large diameter wheels, because you are allowed logs) OP on diameter 2″, or down for that matter. If wc went up r on a car with 14” wheels that would obviously allow a lot of extra space for brakes, which would be free in Group A any way. Looking at the engine regulations we could see that they allowed a fair his of internal modification but, and this is a bit puzzling to me, the induction and exhaust were pretty restricted. So we needed a car with fuel injection because at least with injection we could force the fuel in and not have to rely on the pulsing action of an efficient exhaust manifold to take it all out again quickly, which is very much the case with a carburated engine.
“We then looked at what the opposition was likely to be for our ‘ideal’ car; in fact what cars could be used whether by ourselves or the opposition. By this stage our investigation had purpose because BL Motorsport had asked to see what the prospects were of running the Rover in Europe during 1982.
“We thought the possibilities include:, Mercedes, who haves 5-litre VS, the well-proy „BMW.; ..TurobboviouFsoiyrdnvMRustwanegre mond, iCrit eerce, rso( ei; in winning outright, no the tendency was to look at the bigger capacity cars. This tendency to favour cubic capacity, plus a factory preference now apparently leaning toward rallying, ruled Mazda out of the reckoning.
Examining the Rover in detail and with experience that has seen the BL hatchback five-door end Ford’s reign with the Capri in British events, Walkinshaw reluctantly concluded that it wasn’t the right car for the job. It had MacPherson struts: “we could cram in 10. overall width without modifying the body, but it really would be a tight fit,” felt Walkinshaw, the present Rover V8s are only carburated and, though Tom did not mention it tons, it may have been that the lack of disc-braked back axle was a factor too. Certainly Tom was not keen on the Rover’s cast iron exhaust manifolds for, “these are very important on a V8 and I knew that it would be very hard to get the fuel consumption we wanted, which is roughly the same as BMW. This is vital, so as not to incur the extra pit stops, which need a 2-3s lap speed advantage to offset the extra fuel stop.” There is a definite equation here between speed and consumption, and the listener ends up thinking that a lightly modified big engine giving over 51/2 m.p.g. and roughly 400 b.h.p. is the right way to go.
As soon as the equation between speed over four hours (and one 24 hour race, for Spa has always been important to TWR) and m.p.g. materialised, the Rover with 31/2-litres working hard began to look as though, “it would sort out the early season European races. Then, when the big cars began to get their act together we would be in trouble. So why not have a big car in the first place?” Tom asked himself. When the Jaguar name was mentioned, the tendency was to instantly disMss it, remembering what had gone on is Europe in 1977.
That the XJ-S was homologated at all was owing to the Australians, who wanted loran it in their Bathurst endurance race. BL had homologated the XJ-S in Group 1 and there it had lain, neglected by Europeans but a force to be reckoned with in modified American form (courtesy Bob Tulius) for Trans Am. When the FIA decided to implement Group A in 1982 they automatically transferred a lot of cars from Group 1 into the new Group A. The XJ-S was amongst them. Now Tom sat down with long standing friends at Jaguar. Informal meetings and social gatherings formed the backcloth against which the Jaguar return to saloon car racing went from passing jest to a deadly serious project. TWR had one of the 1977 Broadspeed coupes out of the Syon House collection. It was painfully obvious that the big coupe, originally a brilliant conception, had become “a committee car, a four-wheeled equivalent of a racing Camel,” in one observer’s words. The old coupe was really heavy (nearly 1,700 kg.) despite an amazing specification that is even now not freely commented upon. The weight limit for the biggcst capacity class in 1982 Group A would be 1,400 kg. Two vital principles were now established: this racing XJ-S would weigh in at the limit and it would not be a complicated car. All its systems were surveyed and the lessons of the past painfully absorbed: no more fans cooling extra radiators, or pumps lubricating pumps. This Jaguar would outwardly be a steel shell XJ-S benefiting from modifications rather than re-engineering. As Tom says, “if Jaguar do things the way they do, and it’s been a very successful way for the XJ-S is acknowledged to be one of the best cars in the World, then who am I to tell them they’re wrong, designing my own Jag racer?”
Only in one important area would the basic principles of the road car be abandoned: the inboard rear brakes would have to go. On the TWR racer you will find 13″ vented units by AP on all four comers, using four piston calipers. The ensemble is the result of the British company’s response to the increasing speeds offered by turbocharged Grand Prix cars.
By late October 1981 Walkinshaw had convinced himself that a racing Jaguar could be a serious challenger under the new Group A rules. Now he had to convince others. “I knew from the start that Jaguar were out,” Tom commented quietly, “they were just filled up with new model work and it had always been plain to me that there would be no finance in the direct sense.”
Part of that plain speaking included a session for Walkinshaw with Jaguar Cars Chairman John Egan. To his eternal credit, Egan was not frightened by the company’s previous ex,rience and the promise of technical cooperation in the form of the fashionable “Think Tank” process was agreed. In plain English that means that if TWR have a problem they can go and ask Jaguar how they recommend solving it, rather than trying to fabricate a pure racing solution without consultation.
To illustrate such a process I would cite the case of cooling ducts, fans, and auxiliary radiators. TWR were able to talk directly with the aerodynamicists who developed the car originally and come away knowing where the high and low pressure areas were once the car was in motion. Utilising such knowledge virtually all cooling requirements could be met by some of the cleverest and best integrated touring car ducting I have ever seen, rather than using fans re create an airstream. Ford boast about air management on their Escort, but when you look at how TWR make moving air all but stand on its head to reach the neatly nicked away oil coolers for engine and transmission, the term takes on a whole new meaning. I did ask what the drag factor (C.d) was, but I didn’t seriously expect an answer apart from “very good”, which one would expect from a professional team. Preferable to a grip lie anyway . . .
There are a number of subsidiary trade sponsors upon the Jaguar’s black flanks, but the name of Motul is the result of an October 1981 approach by TWR. No figures were relayed rout of course — “a lot,” and a wistful grin from Walkinshaw was the reply — but the French suppliers of the Synthetic 300 V race oil agreed to let Tom have four months before deciding whether the Jaguar project could be fielded M Europe. It would only be raced, as agreed with Jaguar and Motul, if it proved competitive in testing. Perhaps the surprise of the project, and another lesson learned from the past, has been Tom’s basic approach of racing rather than testing to progress the car. He reasons, “while you can control the pace at which you are running there will be things that don’t break, but that will break as soon as you have to run at the pace of others on a race track.” Also integral to the decision logo ahead were Dunlop, for Tom needed the technical support from Birmingham.
Turning the Jaguar into prototype metal TWR worked to a brief which included:—
1, The car must be en the weight IMM.
2, It must be easy to service.
3. Nothing outside the essentials to be included, applies particularly to cooling and lubrication systems.
4, No buy British Policy. What’s best for the lob goes on (e.g. BBS Mahle wheels; Bilsteins, Recaro seat etc.).
5, Car robe maintained on a “lifing” aeroPlar. basis. Access to parts that need to ba routinely serviced, replaced (choice of three differential ratios for example) or reForrer., under racing or between eaccA, must be good.
6, A minimum of 6 m.p.g.
7, Engine to be developed for m.p.g. and endurance rather than power, but no less than 380 b.h.p.
There are only some 20 people at TWA Kidlington no this would be no massive manpower effort. From theory into metal racing XJ-S would occupy November 1981 to early February 1982. Three men were assigned 1. maintain and assemble the car under chief mechanic Kevin Lee and team manager Fall Davies. The chassis would be the responsibilitY long time TWR employee Eddie Hinckley Tom completed all the test driving. Perhaps the most important role was that of New Zealander Alan thou, for he had the responsibility of making Jaguar’s magnificent VI2 into a reliable and comparatively abstemious performer. Based on what had happened in 1977 one would have disrrUssed his chances of achieving much.
The tendency toward oil surge, inevitable in such a large wet sump unit, has been reduced by an internal sump baffling system that Walkinshaw wryly describes as, “capable of coping with a Torrey Canyon disaster!” Total capacity of the system is around 18 pints and very high flow rates are maintained to provide a steady 70 psi. reading. The system is far less complex than one might have imagined, using a smaller sump pick up point than might have been expected, looking successfully toward minimising recovery in pressure should surge become beyond control. An extra breather was added to the system after the initial test run of February 6/7. It had been found that the high oil level being run within was allowing a very slow return feed during the longer comers of British Leyland’s Gaydon proving ground.
From an extra power viewpoint TWR were almost overcome by the largesse of Jaguar engineering in standard form. The single overhead camshaft per bank motor is rated at 299 b.h.p. in standard 90 x 70 mm. (5,343 c.c.) trim, comfortably in excess of the 240 b.h.p. BMW expected to extract from their competition Group A version of the Munich 2,788 c.c. six. Thus it is not surprising to hear, especially bearing in mind the spirit of the regulations (which are biased in favour of modification rather than replacement engineering in 1982-Group A) that a very high percentage of standard parts are retained. The valve gear camshaft profiles took some tirne to establish in conjunction with the hybrid production Lucas-Bosch electronic infection sVstem. Mechanical injection from Lucas was avoided as the company have now abandoned the Production of such systems (the Cosworth DFV’s future requirements have been carefully established and catered for by a “once-and-for-all Production” leaving the team little alternative).
The production pistons are replaced but the May principles are retained in as much as the compression is a highish 12:1. The bottom end of the production vehicle was described to me as, “very strong and certainly man enough to cope with the power and r.p.m. we anticipated”. At Monza in March the VI2 required only 6,500 r.p.m. to build a convincing 12s lead in the oPening laps, but the r.p.m. limit will normally be 7,000. “It’s safe to 8,000/8,500 revs”, says Tow candidly, “but then you wind up walking the 500 b.h.p. and 3 m.p.g. path, and we had already established that was not what we wanted win European events”. We did not voice the thought, but for 20 lappers in Britain next year, Insr such exciting b.h.p. figures might be entirely suitable. At Monza consumption averaged 5.5 to 5.9 m.p.g. Further work with Lucas on part ottle economy and absent progressive metering should realise 6.5 m.p.g.
Tom banded over a power and torque set of readings for the first engine they constructed. At Peak vsdues the torque was up from a production rating of 316 lb. ft. at 4,000 r.p.m. to 387 lb. ft. 6,500 r.p.m. Between 5,000 and 7,000 r.p.m. ever 300 b.h.p. was available, culminating in .3 I?-h.P. as the best reading.
From its February testing debut in the primacy of Gaydon, to the March c g ‘ of attention’ dine,th„eeaaa Paddock, the teamhave binned potent on practical engineering rather than theory. That first weekend at Gaydon saw a 100 mile shakedown and was continued the following weekend at the same venue. There were three days at Goodwood — “when we found out it’s cold in February and did a little bit of tyre sorting as well as getting some friendly police to chase off a certain press photographer!” By March 2nd they had progressed to Silverstone briefly before meeting a March 4th obligation to test at Zolder, Belgium, with Bilstein gas dampers. Ferodo made sure their pads were coping manfully with the extraordinary demands of a large touring car in full flight. They say Jaguar enthusiasts in the surrounding Belgian flatlands are still humming a 12 cylinder rhapsody at the memory of that private test day. All testing was conducted on Weber downdraught carburetters while the injection system was adopted for the first race, dispensing with the prototype’s cutaway bonnet.
March 21st was the racing debut, but Tom estimates they fitted in something like 6 hours of practice on the preceding two days of that Monza meeting. “We had to ensure we were ready for a 4 hour race, checking out pit stops with the air jacks and centre-nut wheels. We reckon 30 secs, or so for 115-litres (25.33 Imperial gallons) of fuel and changing all four wheels and tyres. So far as the tyres go, I’d just say they are round and black, wet or dry. We do expect to change them at our pitstops and we do have some qualifying rubber ready for use, but hope that it will never be required.” Winning races appeals more than split second pole positions at present.
“We’ll take the flak”, is how Tom secs the first half of the season with a car that is only months old in a race development for a new series of regulations. A second car will only be completed when they are happy with the specification and performance of the first. When that second car arrives, the drivers are presently predicted as Porsche dealer Peter Lovett and Pierre Dieudonné.
Judging by the gleam in Walldnshaw’s far-sighted grey eyes he is looking for that happy state of affairs to arrive around June when the Championship emerges from comparatively slow circuits that are hardest on a big car onto the spaces of Brno’s magnificent public road layout. Late June for Austria’s Österreichring; Nürburgring on July 4 and the reduced, but still challenging Spa-Francorchamps track from July 31st to August 1st. All except Spa are 4 hour races. Those with a taste for the Nürburgring might care to note that Jaguar’s previous best result of the 1976-77 XJ Coupe schedule was at the ‘Ring, when a hastily repaired machine managed second, driven by Derek Bell/Andy Rousé.
Looking beyond this largely experimental opening season in Europe there is an obvious future for the XJ in the British Touring Car Championship of 1983. Then the rules are expected to be as for the European series (Group A) whereas the present rules are an untidy hybrid of Group 1 and have a 31/2-litre restriction. The latter capacity regulation should disappear too.
Perhaps we all expected too much from Broadspeed and Jaguar last time, an expectation eagerly fanned by the initial BL PR support. This time, at Tom’s request (and that of Jaguar Cars, I suspect), there’s not a PR man to be seen, just a small team of extremely tough racers putting together a car capable of bringing back the European Touring Car Championship to a Jaguar driver for the first time since German sportsman Peter NOcker took the title in a 3.8 saloon. That was in 1963, the first year that the European series was held.
Since then only Mini Cooper S derivatives (1964: Warwick Banks and 1968, when John Handley and John Rhodes won a division apiece) and a 1965 tide win for John Whitmore’s factory Lotus Cortina have brought Britain European victories. Companies like Alfa Romeo (1970) Ford Cologne (Weslake V6 Capris, 1971/72) and Audi (1980) are more typical European winners. The big winners? BMW. After their class struggles of the sixties, developing a turbo 2002 to beat the Porsche 911 before that was outlawed as a touring car, BMW emerged with the winged CSL in 1973 and won every tide until 1980, when Audi interrupted by winning the Makes ride. Last year the 635 CSi brought BMW back a European Championship tide, but with a production requirement of 5,000 p.a. BMW are temporarily forced to rely on the 528i, which could obviously do with a 535i cousin if it is to even start in the same overall horsepower / speed class as the Jaguar. — J.W.
Technical notes
I was not able to detail the racing XJ-S fully at the time of writing but the following appeared salient when walking around the dissembled car in late March, following its Monza debut.
Engine: as per text, aluminium wet sump V12 of 5.3-litres with electronic ignition (CDI system), racing Serck front radiator, oil cooler, electric fan for water radiator. Currently rated at 400 b.h.p. with 7,000 r.p.m. limit. Time to change engine, approximately 1 to 1 1/2 hours.
Transmission: Manual 4-speed Jaguar gearbox with one net of homologated racing ratios available. Racing single plate clutch, limited slip differential. Oil cooling for gearbox and differential. Time to change gearbox, 1 hour. Time to change differential (choice of three ratios) half hour. Geared for 155 m.p.h. at Monza.
Body: Steel two door with internal alloy roll cage and light tubular engine bay stays. Weight reduced from 1981 Geneva Show catalogue figure of 1,750 kg. to 1,400 kg. Built-in air jacks. Quick release systems for fluid lines, electrical connections and front wings. Premier 120-litre petrol tank.
Cockpit: Untrimmed bare steel with single Recaro race seat. Fabricated centre console with switchgear for: ingnition and fuel (4); differential and oil cooler; lights; fan booster for demist. Willans harness, racing steering wheel (4-Spoke).
Instrumentation: 0-150 p.s.i. oil; 50-151rC oil; Jones 0-9,000 r.p.m. tachometer; 40-120`C water; 0-30-70 p.s.i. fuel pressure.
Steering: Power-assisted, std. rack, extra castor and camber geometry.
Suspension: Alternative lightweight titanium coil springs available; Bilstein adjustable ride height gas dampers; hybrid production and race fabrication of double front wishbones and rear double coil spring per side / lower wishbone system around Jaguar principles.
Brakes: AP vented competition discs, 13 x 1 5/8″ thick; four piston calipers.
UK appearances: Donington, May 2nd; Silverstone, September 12th.