Mulsanne's Corner

Petit Le Mans 2011

All news content copyright Michael J. Fuller, unless otherwise noted
Oak Racing Pescarolo LMP1, Sebring 201110.8.11

>>We chatted briefly with Oak Racing's Technical Director, Christophe Chapelain, at Petit Le Mans about Oak Racing's impressions of Road Atlanta and what the organizations future holds.

But first it seemed apropos to seek clarification of the relationship between Oak Racing and Pescarolo.  Chapelain explains:  Oak Racing's involvement with Pescarolo began back in 2008 when the team (then as Saulnier Racing) purchased and raced Pescarolo chassis during the 2008 season, continuing into 2009.  But with Pescarolo's collapse in mid 2010, the relationship change significantly;  Oak Racing's President Jacques Nicolet stepped in and purchased all of the intellectual property of Pescarolo.  At that moment in time Pescarolo effectively ceased to exist.  But Nicolet reformed Pescarolo Sport, employing many of Pescarolo's old employees.  A joint design department was also established.  In the mean time, Pescarolo Team was born and Henri Pescarolo was able to return to racing.  Subsequently Oak Racing has taken over the manufacturing and design aspects of the Pescarolo LMPs, and moving into 2012 we will see the “Oak Racing Pescarolo” moniker transition into simply “Oak Racing.”
Oak Racing Pescarolo LMP2 splitter, Petit 2011Road Atlanta's propensity of right hand corners vs. not so many left hands making setting up the car an interesting proposition compared to other tracks and tire choice becomes a decision of between medium and hard compounds.  The setup conundrum is further complicated by the new 25 mm skid, which ultimately imparts less downforce but increased drag.  Road Atlanta requires a high downforce setup in order to extract the maximum performance for one lap.  And interestingly enough,  the #24 Oak Racing's LMP1 was the fastest gas powered LMP through Turn 1 [timing Sector 2] in qualifying.  The Oak car was as fast as the Peugeots and only .1 second behind the Audis through Sector 2, thought about 10 mph down in top speed through the speed trap.  Says Chapelain, “But for the race, the setup requirement is for slightly less drag, if only to allow the drivers the opportunity to overtake slower traffic on the straights.”  The switch to the low downforce setup was also to the benefit of engine cooling. 

Oak Racing's LMP2 is carrying similar levels of downforce, if slightly less, than their P1.  The P2 car's front splitter has been trimmed to reduce drag and overall downforce.  This is evident by the reduced length outer sections and the long center portion.  The splitter reduction is rebalanced with changes made to the rear wing.

With the relatively minor regulation changes for 2012, specifically the mandated louvers for the rear fenders and the implementation of the rear fin for all chassis (new and grandfathered), Chapelain tells us that Oak Racing will embark on a winter development program in order to mitigate the aero impact of these mandatory changes as well as redress the car's aero balance.  Oak will utilize the RUAG scale model wind tunnel in Switzerland.

But plans are more ambitious looking towards 2014.  With the ACO indicating that the 2014 LMP regulations will be available before the end of the year, Oak Racing will begin development of the 2014 car throughout 2012 with the idea of fielding the car in 2013.  If the regulations are produced before the end of the year, this time table will be possible but it is in the ACO's court.

For 2014 Oak Racing is expecting to develop a new closed top monocoque as the proposed 2014 regulations will apparently mandate a closed monocoque. It also seems likely the implementation of a Kinetic Energy Recovery system will be required, if not explicitly mandated, given the push towards a fuel efficiency formula. And while it seems ambitious to assume a new car with KERs could be on the track in 2014, the new chassis will designed from the outset to accept. Willing KERs partners could be found in Williams Hybrid or Magnetti Marelli, just to name two, as there is a burgeoning KERs market for privateers to tap into.

Delta Wing show car, Petit Le Mans 20119.30.11

>>Today started off with the unveiling of the Delta Wing show car to the Petit Le Mans audience and the announcement that Michelin will be the tire partner for the project.  This is a huge announcement as the project would have been hard pressed to turn laps, once the car is completed, without a tire partner to develop the bespoke 4" wide fronts.  

With the tire partner announcement out of the way, the only major 'i' to dot is who will supply he powerplant.  Speaking with Ben Bowlby, this isn't as problematic as it seems if you consider that the engine in the DW will be non-stressed:  the rest of the car can be designed around until that deciscion is made.  Regardless, we suspect an engine partner will be announced shortly given the December track test debut.

When asked directly about the Aston Martin AMR-One origins of the monocoque (9.13.11 entry), Bowlby offered an initial hesitation followed by, "There's been some speculation...and it is accurate."  The use of the AMR-One tub is pretty straight forward; vastly reduced lead times.  Not to mention reduced hassle as the AMR-One tub has already undergone all the necessary crash testing and meets the latest ACO crash regulations.

We spoke at length with Delta Wing designer Ben Bowlby and will be putting that interview together, along with a more detailed analysis on the Delta Wing project, at a later date.
Peugeot 908, Petit Le Mans 2011The trailinge edge engine cover gurney on the Peugeot 908.  

Also note, gone is the low-in-the-middle engine cover trailing edge we saw at Sebring, though apparently it was tested in at least one of the practice sessions:

Peugeot 908, Sebring 2011
Peugeot 908, Petit Le Mans 2011At one point during the morning practice Peugeot tried a shorter gurney on the sister car.
Audi R18, Petit Le Mans 2011Compare the Peugeot's engine cover gurney to Audi's.  Audi's is maybe 5 mm tall.  Though also note the diffuser trailing edge gurney below the engine cover trailing edge.
Peugeot 908, Petit Le Mans 2011Peugeot is still utilizing the trimmed-short and notched trailing edge diffuser strake.  This was first noted way back in 2008 on the 908 HDi FAP.  What's also interesting is the emulation seen elsewhere on pitlane...
Rebellion Lola Toyota B10/60, Petit Le Mans 2011Lola has utilized the shortened and notched diffuser strake since at least 2009.  The Rebellion Lola B10/60 Toyota here.
Oak Racing Pescarolo LMP1, Petit Le Mans 2011Oak Racing's LMP1 also utilizes the Peugeot-trim diffuser strakes, though Oak extends them to the trailing edge of the diffuser.
Audi R18, Petit Le Mans 2011The R18 is utilizing vortex generators in the front diffuser.  We understand this is part of a conscious effort to prematurely separate the trailing edge flow to the (presumably) detriment of aero performance, but in order to better control trailing edge airflow and to prevent particulate ingestion into the downstream radiator inlets.  This has been a consistent design detail on recent Audi prototypes (R10, R15+, R15+). is an online shop for performance parts & accessories, including headlights and tail lights

Lola Aston Martin B09/60, Petit Le Mans 20119.29.11

>>Looking into the front access hole of the Aston Martin Racing Lola Aston Martin B09/60, we can see the evaporator core (that item that looks like a radiator that can be seen in the right hand access hole) for the car's air conditioning system.  
Oak Racing Pescarolo, Petit Le Mans 2011Oak Racing experimented with a "lower" downforce package during the middle of the morning session, changing the entire rear wing assembly and complementing the package with new louvers (below).
Oak Racing Pescarolo, Petit Le Mans 2011Oak Racing's less aggressive front louvers.
Oak Racing Pescarolo, Petit Le Mans 2011The "full" louvers.  These are on the LMP2 Oak Racing Pescarolo (car #35).
Oak Racing Pescarolo, Petit Le Mans 2011The #24 Oak Racing Pescarolo  had a coming together with the #11 Porsche GTC in morning practice with resulting heavy damage.  
Oak Racing Pescarolo, Petit Le Mans 2011By the start of the night session the car was nearly repaired and the #24 made it out about half way through practice.
Rebellion Lola Toyota, Petit Le Mans 20119.28.11

>>There's a rumor that the American Le Mans Series could be the beneficiary of the Le Mans Series' decision to eliminate the LMP1 category next year with talk that ALMS fields could be bolstered by European LMP1 runners.  While this would be good, file this under, "believe it when we see it."  Talk is cheap after all...

Rebellion is running double dive planes and full louvers for now.
Rebellion Lola Toyota, Petit Le Mans 2011The Rebellion car is also sporting gurneys on the outboard rear fender trailing edge.  Over the years we've seen these on the Audi and Peugeot and can only speculate that the area is somewhat productive.
Audi R18, Petit Le Mans 2011Very little has been said about Audi's rear composite subframe/gearbox carrier since we last discussed it during the Le Mans weekend (6.5.11 entry) other than the expected "no comment."  Our speculation back in June was that Audi had designed the rear composite subframe to carry the gearbox and to take all suspension loading as a work around of the regulations that disallowed quick change gearboxes.  This weekend we have effectively confirmed that is indeed what Audi's design intention was with the R18's gearbox.  But we still can't determine 100% the "why."  Because in the same breath it's been mentioned that the gearbox has been designed robust enough as to be bullet proof (or nearly so).  So why go to the effort to create a quick change gearbox system rules-workaround?
Audi R18, Petit Le Mans 2011We note that the Audi R18's rear brake duct inlet does not attach directly to the  rear brake duct, allowing air to spill past the brake duct proper and to exit the rear of the car.  We also note the location (arrow) of a vertical splitter and suspect it might be guiding that residual brake inlet air (and any other air tumbling through the engine bay in the general vicinity) to exit out across the outer edge of the diffuser trailing edge.  Naturally, in general terms, the idea would be to simply improve diffuser performance, and blowing reorganized air across the trailing edge of the diffuser might be a way to achieve this.  

The 5 mm wire mesh is for rules compliance; "blocking" mechanical items from view above the rear wheel centerline.  Shows you just how low the Audi's rear bodywork gets.
Oreca 03 Nissan LMP2, Petit Le Mans 2011The Oreca 03 Nissan LMP2 has these interesting triangular cut outs in the diffuser strake.  We first saw these on the Oreca 01 LMP1 back in 2009.   Of course the Oreca 03 is a derivative of the Oreca 01 and bears more than just a passing resemblance...Also note the variable height, "optimized," trailing edge gurney.
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ęCopyright 2011, Michael J. Fuller