Porsche's Le Mans recharge
With extra electro-power and a three-car entry, Stuttgart aims high for the 919’s second 24 Hours – even if it’s downplaying its targets
Writer Gary Watkins
is this the year that Porsche adds to its record tally of 16 victories in the Le Mans 24 Hours? And perhaps launches a bid for a first world title since 1987 off the back of success in the middle weekend in June?
The German manufacturer is playing down its chances in public as it maintains the respectful rhetoric with which it joined the World Endurance Championship last season. But the reality is that Porsche, as a newcomer to the series still, has more to gain than its rivals. Which is why it could, or perhaps even should, be ahead of Toyota and Audi when it arrives at the Circuit de la Sarthe in June.
The LMP1 prototype that Porsche is racing this year retains the 919 Hybrid moniker of last year’s WEC challenger, but in fact it is an all-new machine. The concept of the car and its hybrid powertrain haven’t changed, but it has undergone a complete redesign right down to its carbon-composite monocoque. The decision to build a new car wasn’t a reaction to the failings of the original 919, rather an admission, explains Porsche LMP1 technical director Alex Hitzinger, that a new group couldn’t be expected to optimise “its first design shot” in year one. A new car for season two was in the plan as long ago as 2011.
Porsche believes it has hit its performance step-up targets, but there are three crucial areas in which the 2015-spec 919 is an improvement: it is kinder on its Michelin tyres; it is on the weight limit; and it has more hybrid punch.
For the 919’s maiden victory in last November’s WEC finale at Interlagos, a new high-grip track surface (laid for the Brazilian GP earlier in the month) masked the car’s appetite for its tyres, levelled the playing field with Toyota and allowed Neel Jani, Romain Dumas and Marc Lieb to claim Porsche’s first world championship endurance victory since 1989. Porsche was able to turn the one-lap pace that it had shown from the beginning of the season into the required speed over a stint, and then double-stint a set of Michelins when it mattered at the end.
Hitzinger explains that this has been addressed by “changing the suspension and optimising the structure of the whole car”, which included increasing the overall stiffness. Porsche’s drivers immediately reported that the new 919 was more balanced through a corner and that the underlying trait of mid-corner understeer had disappeared. Nevertheless the design boss suggests that there is “still work to do over a long run”.
Porsche’s hard work on its hybrid systems has paid off. It hasn’t changed the concept of front-axle kinetic and exhaust-driven retrieval and battery storage, but it has moved up from the sub-class that allows for six megajoules of retrieved energy to be deployed to the highest division that permits eight. That has taken it clear of reigning champions Toyota, which has opted to remain in the 6MJ class with its updated TS040 HYBRID, and maintained the megajoule gap to Audi, which has gone from two to 4MJ with its heavily-revised R18 e-tron quattro.
Hitzinger says the advantage of running in the higher class is likely to be maximised at Le Mans, where Porsche is confident that it will be able to regenerate the full amount of energy over the long 8.47-mile lap. It is less sure that it will hit the maximum on other circuits. The boosting level at the seven other tracks on the WEC schedule is determined by dividing the track length by that of Le Mans and multiplying the result by a factor of 1.55. That means the recuperation required per mile is significantly higher than at Le Mans.
“I am confident about the 8MJ at Le Mans, but less so for the other tracks,” says Hitzinger. “But there is obviously a break-even point and I’m confident that we will be above that in terms of the performance gain at the other tracks.”
The real triumph of Porsche’s design team for 2015 is achieving the jump in hybrid power while keeping the new 919 under the 870kg weight limit. “The perfect scenario,” is how Hitzinger sees it. “More performance for less weight.” This represents gains that its rivals will, says Hitzinger, “have to find somewhere else”.
The second-generation 919 is 30kg lighter than its predecessor, which ran at about 900kg throughout last season.
“We were overweight last year so by stepping down that is performance in the pocket,” he says. “And 30kg is quite a lot of lap time. The same goes for the move up in recuperation – it’s time in your pocket because that is how the regulations are written.”
The redesign of the 919 aerodynamic concept includes a visibly revised profile to the nose, but Hitzinger says that the significant tweaks are “the ones that no one sees”. And by that he means the revisions under the bodywork.
The engine has a new turbocharger to reduce lag and improve response and a new lighter crank. While Porsche was at it, a few extra cc were added to its V4 petrol-powered engine. The direct-injection powerplant should still be regarded as a 2-litre, but a lengthening of the stroke has taken it from just below to just above that mark.
Porsche is also upping its game for Le Mans by running three cars in the 24 Hours, and as preparation in the Spa WEC round in May. It was a big decision, because it didn’t want to compromise the two regular series entries (Jani, Dumas and Lieb and Mark Webber, Timo Bernhard and Brendon Hartley), or simply turn up with a third car that was some kind of afterthought.
Porsche admitted early last season that it was considering an additional car but the final decision, taken at board level, didn’t arrive until the end of November.
“We always said that if we went to Le Mans with a third car it would have to be a strong car,” says Porsche LMP1 team principal Andreas Seidl of the entry to be driven by Force India Formula 1 driver Nico Hülkenberg and two graduates from Porsche’s GT squad in Briton, Nick Tandy and New Zealander Earl Bamber. “We want them all on an equal level, which is why we have been rotating the three crews for each car through testing.”
Even with a new, improved car and an expanded programme, Porsche is remaining humble in its expectations both for the season and Le Mans.
The first version of the 919 led Le Mans and was on course for second position early in the penultimate hour, but you won’t find anyone within the race team to go on record in suggesting that win number 17 — and a first since 1998 — might be possible in 2015.
Porsche talks about winning more podiums – Webber uses the term “grabbing some low-hanging fruit” – than the six pieces of silverware it collected in 2014 as well as being, says Seidl, “in a position at least to challenge for victories” in the regular six-hour races. Its stated targets for Le Mans are slightly more modest and don’t stretch beyond a podium.
“Getting at least two cars to the finish would be a major achievement,” continues Seidl. “It would be naive to say that we could win Le Mans in year two.”
It would be wrong for Porsche, with its rich Le Mans heritage, to start talking up its chances ahead of the 24 Hours. But to suggest that it has built an all-new car to go to France with the aspiration only of making it onto the podium can’t be right. Porsche’s preparations for 2015 mean it has to be considered a contender – whether it admits it or not.