From 0-24 in six months . . .
Le Mans may be a test of endurance but, as XJ220C designer Richard Owen explains, getting ready for the event has been more like a sprint
Cross Channel ferry users wary of Union Jack-beshorted racegoers take note: Jaguar is back at the Sarthe. Irrespective of the marque’s presence, the Le Mans 24 Hours has always held especial appeal to British racing fans, but Jaguar’s appearance on the entry list has traditionally boosted takings at the P&O booking office.
There is a difference this year, however. Jaguar’s Class of ’93 will not be operating on the same performance plane as the recent series of XJR racers that pulled off outright victories in 1988 and 1990. Victory, if it comes, will be at the expense of GT opposition from Porsche, Lotus, Venturi and others. All the same, as you will read from Win Percy’s accompanying track impressions of the XJ220C, he feels that it is feasible to expect a decent overall result.
Fifth? Sixth? Seventh? Who knows? The point is that there is already a sense of confidence about the XJ220C’s prospects, even though, at the time of writing, its racing potential has only been tested in a glorified club racing event, a 15-lap National GT race at Silverstone that substituted for the first round of the proposed International GT series for which, it is alleged, only three entries were forthcoming.
Competing against a diverse mixture of modified Porsche 911s (a hangover from a discontinued club racing series), a couple of Escort Cosworths and a Morgan Plus-8, it’s hardly surprising that the fledgling Le Mans racer should have scored a dominant victory. Even so, Richard Owen, chief engineer on the XJ220 road car that débuted at the 1990 Birmingham Motor Show and now chief designer on the racing team, felt that the experience was beneficial.
“It was very valuable for us, especially as we’d only got the definitive version of the car out, with the latest suspension and so on, on the previous Wednesday. We were encouraged by how fast, and reliably, it ran.”
Owen’s drawing board is no stranger to turning out winning racing cars. He revolutionised Sports 2000 in 1983, with the all-enveloping Aquila. Soon rechristened the Shrike, the basic design had taken five S2000 titles by the time Owen transferred to JaguarSport in 1990.
Not a man given to wild ostentation or foolish predictions, he assesses his brainchild’s immediate prospects in calm, measured tones.
“At Silverstone we were still in the early stages of fine-tuning the car and optimising its settings. Everything we did, in testing on Wednesday and Thursday and during qualifying on the Saturday, produced an improvement in the right direction. If a car’s responsive to changes, that’s usually a good sign. In that respect, it exceeded our expectations.”
A sum total of 15 racing laps might seem like slender preparation for a round-the-clock slog such as Le Mans. A full endurance run will take place between now and June 19/20, of course (apparently. an earlier attempted simulation at Bruntingthorpe had to be aborted when the brakes went awry).
It was always going to be something of a steep learning curve, the race programme having only been sanctioned in November last year. Owen draws strength from the road car programme, however, even though the XJ220 was not specifically conceived for competition.
“It was not my brief to design a car that would be raced, though I suppose that always lingered as a possibility. I believe I was hired as a racing car designer to do a road car because the XJ220 was more like a racer than a road car.
“We started the race programme from the happy position of having done an immense amount of durability testing with the road car. Some of the fundamental aspects of the road version have been subjected to perhaps even more extreme durability tests than the racing car will be faced with, so I’d say already we’ve gone a long way towards analysing the engine, chassis and gearbox.”
Consequently. Owen is sure that the XJ220C is close to full race effectiveness and, more importantly, that it will have sufficient armoury to win its class.
“The biggest difficulty will be actually getting to the finish. At the moment, to be honest, I don’t have a very good idea of what our opposition will be in terms of performance, or just how quickly they’ll go. I believe that we’ll have a substantial performance advantage. We’re more worried, as people always are, about reliability than outright speed. I haven’t had time to study the entry list in detail, but I would think that some of the Porsches will provide strong opposition. The works car of Röhrl and Stuck was fast and reliable at Sebring. In motor racing, one of the things you don’t do is to underrate the opposition, particularly someone like Porsche, with its history of producing quick, durable endurance cars. (Owen’s words proved to be startlingly accurate: at the Le Mans test, two days after this interview, the works Porsche lapped some 12s faster than the quickest of two XJ220Cs present. .
“I’m sure that will change as the GT category flourishes. As that happens, it’ll become more competitive, and we’ll be trying to increase the pace while maintaining reliability.”
Ah, yes. The GT category. Just as international sportscar racing appears set for the great assembly area in the sky, along comes a GT class to offer hope of salvation. Optimists dream of grids peppered with Bugattis and McLarens, realists think in mildly less esoteric terms: Porsche, Ferrari, Lotus and Jaguar. At Le Mans, the GT class is varied, containing works cars from Porsche, Jaguar and Lotus, alongside myriad private Venturis, Chevrolet Corvettes, BMW M5s, Ferrari 348s and, predictably, lots of 911 derivatives.
“Response has been disappointingly lethargic, I think. I don’t want to harp on about the governing body, but somebody needs to put a stake in the ground, don’t they? Somebody has to say: ‘These are going to be the rules’. Normally what happens is that a designer is presented with a set of rules and you evolve the best racing car you can around them. This is a different situation, in that the cars pre-exist the rules. Therefore manufacturers such as Porsche and ourselves, who have different products, different sizes, weights, shapes and all sorts of configurations, are naturally trying to lobby to push the rules in a direction that benefits them. I presume that’s why the rules keep changing. He with the loudest voice keeps pushing them around. I’m not pointing a finger at anybody, nor am I saying that people shouldn’t lobby. What I am saying is that the governing body, or whoever is going to set the rules, should be strong enough to say ‘We will decide. We’ll listen to everything you have to say, but at the end of the day we’re going to set down the rules.’ If it favours some more than others, that’s just how it’s going to be. We’ll have to make the best of it.”
Thus far, procrastination over producing a definitive set of GT regulations has been of far greater nuisance value to Owen than any of the “usual teething problems” which have beset the formative stages of the XJ220C’s transformation from road-going supercar to Le Mans racer.
“When it comes down to it, the design parameters for any track racing vehicle are pretty much the same. I’d say the priority of those parameters changes somewhat, according to what you’re doing with the vehicle. In other words, this is an endurance car so you wouldn’t be quite as paranoid about weight as you would for an out-and-out single-seater such as a Formula One car. That doesn’t mean we aren’t interested in weight. Of course we are. I’m just saying that the priorities vary slightly. Although I’ve never done a Group A touring car, I’d imagine the GT preparation process is quite similar, in that you take the standard road car and throw away the parts that you’re obviously not going to need, the trim, the seats, the air conditioning and the stuff like that, and you make small modifications to the parts you are going to keep. On to that you graft the purpose-built and designed parts to enable you to go racing. The biggest problem so far for us designers has been moving goalposts. It seems like every week we get a different set of rule proposals landing on my desk. In fact the latest set, which is due to be ratified on June 8/9, is a long way off the sort of car we’ve spent a great deal of time and money developing.
Whatever, Owen is confident that what TWR and JaguarSport now have is approaching the realms of a state-of-the-art GT contender, with impressive power and torque characteristics: 500 bhp, from around 4500 of 6800 available rpm, and 550 lb ft. Both power and torque curves are said to be flat . . . once the V6’s twin turbos have chimed in.
“With any car of so much power, there’s always potential for improvement, because if you can harness it you will yield better results. With the (mandatory) air restrictors as they are though, there’s not much chance of getting more power. We’ve made real progress in getting the car comfortable for the drivers. A lot of that is down to how you get the chassis to handle the sudden surge of torque that comes in when the turbo comes on boost.I think the drivers are quite excited by that! By the end of the Silverstone weekend, Win (Percy) thought we had a very sane, driveable motor car. That’s a big factor at Le Mans. You can’t have the drivers’ eyes standing out on stalks for 24 hours.”
With peak power available a long way from maximum attainable revs, the XJ220C should, in theory, be able to run at high speeds without putting too high a strain on engine or transmission.
“That,” says Owen, “depends what you compare it with. In road terms, the engine and transmission will be very highly stressed. They’ve been designed for the purpose, however. We certainly won’t have to rev the engine highly. That comes about because of the air restrictor.”
For all the heartening progress the team has made with the XJ220C, Owen confesses, with typical reserve, that he is “worried” about every aspect of the Le Mans programme, and that he will continue to be so until the race is over.
“We’re not going to change the fundamental design of the car in any way. The only thing that remains for us to do is to optimise chassis settings, ride height, springs, bars and all those things that make it as quick as it can be and to make it as comfortable as possible for the drivers, so that they can maintain it somewhere near its peak performance.”
And the biggest challenge of a project such as this?
“Same as usual, probably. Doing a great deal of work in a very short space of time. ” S A