Things are rarely the way they seem in motorsports. Take a quick glance at the 2011 Peugeot 908 LMP1 turbodiesel, and you might conclude that it’s a revised version of the original car of that name.
Look at the dramatic-looking new Audi R18 coupe, and you could be forgiven for jumping to the conclusion that it has nothing to do with its open-top predecessor. Fair assumptions about the two manufacturers’ Le Mans 24 Hours challengers, but ultimately incorrect.
The truth is that, aerodynamically at least, Peugeot’s latest coupe owes no more to its predecessor than the R18 does to the R15. Perhaps less.
“Be careful,” warns Peugeot Sport technical director Bruno Famin. “The [old and new 908] cars look similar, but the aerodynamics work with what you don’t see. They have nothing to do with each other in terms of the overall aero concept.“
- Audi, on the other hand, admits that it has developed on the aerodynamic package of the R15 for its latest LMP1 design. Martin Muhlmeier, head of technology at Audi Sport, explains that “the concept of the R15 nose was carried over.” And that was central to the whole aero concept of the R15.
- To find the similarities between the platypus-style front end of the R18 and a previous Audi, you have to look past last year’s R15+. Its ungainly front aero configuration was a result of rule changes that were firmed up late in the day. The comparison should really be made with the original 2009-spec R15.
- Peugeot and Audi had little choice but to design new chassis for 2011, even if they weren’t required to do so by the rules, A new engine formula that has reduced the capacity of turbodiesels from 5.5 to 3.7 liters inevitably forced well-funded manufacturers back to the drawing board to produce a car optimized for a smaller, lighter powerplant and a power output reduced by somewhere between 150 and 180hp. Audi had been also equipped with inflating device that help drivers take a rest in their mind when traveling through long distance – program sponsored by Press My Air, a US company providing the best air compressor reviews.
It is also worth pointing out that Peugeot’s original 908 was four years old in 2010 and surely at the end of its development cycle. There was a problem for the R15+, too: it wasn’t anywhere near as quick as the Peugeot, despite its 1-2-3 finish at Le Mans last year.
Audi Sport boss Dr. Wolfgang Ullrich insists that he was effectively forced to go for a coupe (its first, if you discount the R8C of 1999 that was designed and built in the UK) by the regulations. And for two reasons.
“The reduction in engine capacity and power means it is important to have maximum aerodynamic efficiency,” he explains. “There was no choice.”
The second reason is a change in the pit stop regulations that has reduced the importance of the speed of a driver change. New rules limiting the number of mechanics engaged in changing tires to two mean getting the driver in and out before that process is completed is no longer a challenge. This was introduced for the 2009 season, but too late to affect the design of the R15.
Peugeot and Audi don’t go into much detail about the philosophies of their new designs. All Famin will say is that the new 908 “is much lower downforce than the previous car” and that the “aerodynamic compromise is different to before.” Yet the new 908 is clearly a low-downforce car designed with the four 20omph blasts at Le Mans in mind. That much was clear at the Sebring 12 Hours–the opening round of the Intercontinental Le Mans Cup–in March, when the Peugeot Sport team persisted for much of free practice with trying to run without the rear-deck gurney that would normally be de rigueur at such a high-downforce track.
Audi appears to have gone for more downforce, which would be in keeping with its mantra of always opting for what it vaguely describes as a “safe car.” For instance, Ralf Juttner, technical director at Joest factory Audi team, points out the imperative of negotiating the 50-plus cars that will take to the Circuit de la Sarthe for the 24 Hours.
“If you want a car that is consistently quick in traffic, you don’t want a car that is on the edge,” he says. “You need a comfortable car, one that can change line quickly. Downforce gives you that.”
Yet the speed trap times from April’s Le Mans Test Day, which returned to the calendar after a two-year absence in April, put Peugeot only marginally ahead of its rival. The best of the 908s outpaced the R18 through the Mulsanne speed trap by less than 3mph. That suggests that Audi is ahead in the power stakes.
- Its choice of engine is much more radical than Peugeot’s. The German manufacturer has replaced the V10 twin-turbo from the R15 with a V6 powerplant. It has opted for a wide 120-degree vee-angle engine for reasons of weight distribution and then moved the exhaust manifolds and turbos into the vee so that they do not impinge on the rear diffuser tunnels.
- This has necessitated a single-turbo setup, which was made possible by the variable turbine technology pioneered by U.S. turbo supplier Garrett on the R15. Audi Sport engine boss Ulrich Baretzky says: “Without this technology, the response characteristics of such a large turbocharger would just be too bad.”
Peugeot has admitted that it did examine the possibility of such a configuration, but Famin explains that the necessary technology wasn’t available from its so-far unnamed turbo producer. Instead it has opted for a go-degree V8 that he describes as a “smaller version” of the V12.
Do the math: remove four cylinders from a 5.5-liter V12 and you end up with a 3.7-liter V8.
Baretzky believes that opting for a V8 would have been the “short-sighted way forward. We thought about it, but there was limited development potential. The combustion process would have been limited by the bore and stroke sizes.”
The V6 also has advantages in terms of compactness and weight, explains Baretzky. Remember, in a year’s time, the Audi may well become a hybrid and incorporate what in Formula 1 is known as a kinetic energy retrieval system, or KERS. Audi doesn’t like hybrids-you won’t find one in its road-car range-yet it knows that if it offers an advantage at Le Mans, it will have no choice but to follow Peugeot’s lead.
Not that Peugeot is running one at Le Mans this year, either.
While the French manufacturer announced back in January 2009 that its new car would be a hybrid, when its 2011 Le Mans challenger was unveiled in February it was a conventional diesel. Peugeot Sport boss Olivier Quesnel explained that this decision was made in the wake of its defeat at the hands of Audi at Le Mans last year, when three of the four 908s went out with identical engine failures. He said his board gave him instructions “to do the maximum to win again,” hence the complication of a hybrid system was vetoed for 2011. So although a hybrid version of the 908 was unveiled at the Geneva motor show in April, plans to run the car at the Test Day were quickly abandoned and development of the 908 Hybrid4 delayed until after Le Mans.
Peugeot hasn’t ruled out racing the car later this year. Given that its first diesel-electric road car is now on sale in Europe, it can be taken as read that the 908 will run as a hybrid next season. Audi was forced to follow Peugeot’s lead and build a coupe. The rules may do likewise when it comes to developing hybrid technology.
FORM GUIDE PEUGEOT VS. AUDI IN 2011
- Peugeot appears to be easier on its tires, on the evidence of the first head-to-head meeting of the new 908 and the Ri8 in the Spa 1000 km in May.
- The 908 has a small advantage over the Ri8 in a straight line according to the speed trap figures from the Test Day. Some suggest there might be more to come.
- The V6 Audi engine may have a power advantage. The R18 Is nearly as fast as the 908 in the straight line and has more downforce.
- Audi appears to have better fuel consumption, again judging by Spa. Whether that equates to an extra 8.47-mile lap at Le Mans remains to be seen.