BACK Mulsanne's Corner NEWS
September/October 2009
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All news content copyright Michael J. Fuller, unless otherwise noted

>>Aston Martin's George Howard-Chappell is doing what he does best, whinging.  An article on quotes Howard-Chappell as signaling the death knell for coupes at Le Mans with the elimination of the increased inlet air restrictor diameter alloted to the closed top cars.  "There will be no incentive to do a closed car, and you need that because a coupe is more work."  That said, Howard-Chappell seems to impishly add, "There is a small aerodynamic advantage in running a closed car," only to hammer in,"but there are so many negatives."  Woe is me.  Let's say the "small" aerodynamic advantage is on the order of 5% increased L/D, this would equate to about a 50 lb. drag reduction, or conversely, a 200 lb. increase in downforce.  Just in looking at the drag figures, you're looking at a 3 mph advantage in straight line.  So with that said, I'm sure the "disadvantages" of engineering doors, a windscreen wiper and defogging system, as well as the additional weight higher up (so many disadvantages after all) is well worth the aerodynamic advantage for just showing up with a roof on the car.

>>Wirth Research has commissioned a development program to design a new LMP for 2011, this according to Nick Wirth.  Not wanting to wait around for Acura's decision (which is due, "before the end of 2009"), and with the 2011 rules in hand, Wirth Research has already begun preliminary design work.  Says Wirth, "...we have a few ideas."  At this early stage, not knowing what engine will be used isn't as big a detriment as it might seem, "That's not a major/early issue with 2011 power plants and our car architecture."  Therefore there isn't necessarily an "Acura" badge on this LMP.  But given that the privateer chassis market is rather tight, Wirth Research doesn't have any interest in pursuing a LMP on their own.  That being said, it does appear a manufacturer would need to be involved as Wirth admits, "[there's] no funding required to move forward at the moment, but funding [would be] required to complete the project."  

Petit Le Mans news:

Acura ARX-02a, Petit Le Mans 2009>>Speaking to Nick Wirth on Friday in the paddock, he was excited with the prospects of a wet race and he got his wish.  Unfortunately it still didn't play into the ARX-02a's hands.  There are those on the teams that feel the wide front tire concept simply hasn't worked.

We also spoke briefly about the Scott Sharp incident.  Wirth mentioned that everything was destroyed in the accident, "...even things like the battery box were destroyed."  The replacement tub was the 3rd chassis, and more notably, the only replacement chassis.  There are no others.

After their rebuild, Highcroft "cribbed" their chassis setup from De Ferran.  Apparently that's been the nature of the relationship all season, no competitive barriers between the organizations.

Which leads us to what we're hearing about the future of the Acura program.  It is growing less likely that we'll see Acura return (Gordon Kirby has already said Acura is done).  We understand HPD staff has been let go and we also understand that since about mid-season the HPD effort has had it's budget cut such that there are no spares on the shelves, everything is made to order from Wirth Research with a 6 week delivery time.  Has Acura already made a decision?  It's looking likely and it won't be the one we'd like to see.

>>Audi Motorsports head Wolfgang Ullrich was heard over the race track PA system talking with Radio Le Mans about the future of the Audi R15, and it was interesting to hear him mention the hold up with the ACO over the future regulations might cause pause for Audi to continue forward.  At very least it was, in his words, "...frustrating".  Completely understandable considering, as mentioned on these pages, the ACO draft regulations for 2010 face us with regulation changes for next year in the face of major changes for 2011 which doesn't make an ounce of sense.  But at the same time we understand that in all actuality Audi is well into the design of the R15's successor ("successor" as a 2010 update of the R15 or a true 2011 car we're unsure--but we can imagine both are underway) such that Audi Motorsports was operating with a skeleton crew at Petit; most of their engineers were back in Germany working away on the new car.  

>>A Michelin engineer was overheard confirming that Audi's issue at Le Mans this year were tire and downforce related.  Apparently the R15 generates significant downforce and a factor fold more than the Peugeot 908 which could nearly triple stint its tires at Le Mans.

>>We're told the ECO Radical tipped the scales into the 4-digits, i.e., well past the 900 kgs minimum.  They were a non-starter due to over-heating concerns.  Ironic considering the ambients on race day were a good 15 degrees below what had been seen throughout the week.

Check out Race Car Engineering's Acura ARX-02a and Audi R15 articles
>>We've received the draft text of the 2010 ACO regulations, these are the relevant bodywork changes:

Art 3.4.1, b/

The complete rear wheels must not be visible above the horizontal plane passing through the axle centreline. They must be hidden by means of rigid bodywork elements (wire mesh forbidden).

These elements must:

  • Have a constant thickness,
  • Be designed in such a way that air passing through them is directed toward the ground at the exit.
  • Be strongly attached to the bodywork throughout the event. Should one part or the whole elements are missing; the car will be stopped in the pit.


All bodywork behind the rear wheel centerline and more than 200mm above the reference plane must form a smooth, continuous, unbroken surface without cuts, and be visible from above the car with the rear wing removed. Vertical surfaces or surfaces with convex shapes are allowed so long as their entire top edge is visible from above.

For 2010 only, for the cars homologated for 2009, the rear fenders of which are not entirely in compliance with the above rule, waivers could be granted by the ACO at the express and justified request of the manufacturer provided:

  • The waivers so granted follow the spirit of the rule above (no excrescence on the bodywork),
  • the request is made to the ACO before October 30th, 2009,
  • a detailed description of the rear fender is given to the ACO

If these waivers are granted, they will be sent to the other competitors and no modification of the rear fenders will be permitted in 2010

Art 3.5.4 - Front part


In the area situated :

Backward of the front contour of the car,

Forward of the front axle centreline,

Over the overall width of the car,

At 300 mm maximum from the reference surface,

All visible parts of bodywork from the underside must form a continuous surface, without openings, slots or cut-outs. The only openings permitted are the minimum gaps necessary for wheel and suspension part movements (suspension travel and steering) and sensors for measuring the ground clearance (LMP1 only).

The rear edges of the elements that form this surface (trailing edges) included those in front of the front wheels must:

Be forward of the front axle centreline,

Have a minimum thickness equal to 3% of the maximum length of this surface (vertical projection), and no less than 10 mm.

With the exception of the front edge of these elements (leading edge), the distance between the lower surface in contact with the air streams and the upper surface in contact with the air streams must be greater than the thickness of the trailing edges over the entire area of the element.

 For 2010 only, the surface visible from the underside between the front of the car and the front axle centreline can be made of 2 separate elements provided:

  • They are in front of the front wheel axle centreline
  • They have a symmetrical profile
  • The trailing edge has a minimum thickness equal to 3% of the maximum length of the profile and no less than 10 mm.
  • the trailing edge is perpendicular to the profile center line
  • They are no profile extension beyond the trailing edge.

For 2010 only, the surface visible from the underside between the front of the car and the front axle centreline can extend rearward of the front wheel axle centreline, and it is permitted to limit the rear trailing edge thickness to no less than 30 mm.

Art 3.5.6- Skid block

At the end of the practices and at the beginning of the race, a maximum wear will be permitted of :

  • 5 mm on the flat sections situated in the front and at the rear of the skid block.
  • 3 mm on the rounded section in the middle of the skid block.

Art 3.6- Aerodynamic devices

These profiles must not have a profile extension beyond the trailing edge and the trailing edge must:

  • Have a minimum thickness equal to 3% of the maximum length of the profile but no less than 10 mm.
  • be perpendicular to the profile center line
  • Have a trailing edge of 30 mm minimum. With the exception of the leading edge, the thickness of the profile must be greater than the thickness of the trailing edge over the entire area of the element.

There are discussions that the ACO plans fewer bodywork changes for 2011 than previously expected.  One wonders then the status of regulations aimed at further reducing the chance of yaw induced flips as that appeared to have been one of the ACO's focus in regards to bodywork changes for 2011.
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>>It was another rainy day at Road Atlanta.  Drizzle persisted off and on though fortunately there wasn't the downpours associated with yesterday.  All of the prototypes present (Acura, Audi, Autocon, Drayson Lola, Oreca-Courage), barring Peugeot, made it out on track today.   
Audi R15, Petit Le Mans 2009>>This week the Audi is running the revised specification that the car raced in at Le Mans this year.  Here we see the revised engine cover.  The revisions to the rear engine cover  were apparently as a direct result of a request from the ACO.
Audi R15, Petit Le Mans 2009>>Here's the engine cover as Audi raced at Sebring this year.
Audi R15, Petit Le Mans 2009>>The nose vent exit is reduced, again, as raced at Le Mans this year.

Interestingly, one of Audi's issue at Le Mans this year was a result of the downforce load the car was carrying and the Michelin tire's inability to cope with those loads.  This was a known issue ahead of the race and much time and effort was put into finding a solution.  Ultimately, given the short time frames (8 weeks before the race), this led to a compromise in the car's setup.  In order to reduce front load the chassis was raked nose up.  This led to the third spring element to be fully packed out with bump rubbers, effectively compromising grip and traction in the critical areas of the track (Porsche curves, Ford chicane).  

In addition to the tire issue, it is our understanding that the R15 was also simply carrying too much drag for Le Mans.  Apparently the ducts that channel air through the rear of the car were generating too much drag for downforce gained.  The suspension shrouds were an attempt to mitigate this but their effects were negligible and the shrouds were effectively invisible from a drag reduction standpoint, hence they were on (Sebring, one car ran them the other didn't) and then off the car (Le Mans and now Petit).

At the moment the R15 is being revised for 2010 and the Petit Le Mans is being considered a post-Le Mans test session with the revised 2010 car in mind.
Oreca Courage, Petit Le Mans 2009>>This is our first close up look at the Oreca 01 AIM.  This is a shot of the rear diffuser strake, notice the cut outs.
Oreca Courage, Petit Le Mans 2009>>Full louvers but for one for the Oreca at Road Atlanta.
>>Ok, so I was a little overly critical of the Eco Radical effort yesterday.  In fairness the car seems much better turned out than the last time I saw the car at Sebring in 2008.  Recall then ( 3.19.08 entry) that the rear wheels weren't even centered in the wheel wells; clearly that car never was going to race anywhere.  Well much to their credit, the diesel Radical was out turning laps today (and yesterday), even in the wet.

>>Today's running at Road Atlanta in preparation for the Petit Le Mans this coming weekend was effectively washed out and culminated in a gully washer just after noon time.  IMSA canceled running as clay was washing onto the track, the paddock, pit lane, etc., etc.
>>Teams used the time to set up and simply catch up on car maintenance.  Drayson had their new Lola to bits.    
Audi R15, Petit Le Mans 2009>>Audi were working away.  It's good to see them back.  The R15 is in Le Mans specification but Road Atlanta trim (downforce levels).  So essentially that means all the non-circuit specific modifications we saw on the Audi (turbo intake, revised rear wing endplate mounts, air vent behind front wheel trailing edge, etc.) are on the car this week.
>>The Eco Radical SR10 has arrived.  Ian Dawson was seen looking over the details.  We understand they are slated to run through the scrutineering line on Wednesday at 11:40am.  Is it being cynical in pointing out they will be one of the last teams to run through the tech line?
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>>Within days of winning the Le Man Series manufacturer's title, Aston Martin Racing (Charouz Racing specifically) has put up for sale one of their chassis from this season.  According to, Lola Aston Martin LMP1, chassis #  B0860 HU 02, can be yours for about $1,765,000.  What then for Aston Martin racing after this year if they are selling off cars? has an article that addresses that.  In a nut shell, Aston Martin, via Prodrive, will be designing their own bespoke LMP1 aimed at the 2011 regulations.  What happens next year, though, is less clear.  It appears there is a good chance that Aston Martin will simply skip next season to focus on 2011, this indirectly as a result of the lack of published regulations for 2010, but also to more heavily invest into Aston Martin Racing's future.


>>A few weeks ago the ACO released this document which defined chassis regulations changes expected for 2010.  The document laid out the areas of the car and commented on what was in the pipeline for the rear of the car but stated that while changes to the front were forthcoming, they were not yet determined:

At the front:

Confirmation within 15 days of the aerodynamic definition of the front of the cars. It is currently under study and consultation with the manufacturers taking into account the technical feasibility and cost issues.

We are now told that the ACO has finalized the regulations for the front end of the car.  

The new front end regulations define trailing edge thickness of wing (chord) sections with the primary rule stating that the trailing edge thickness is to be 3% of the chord length with a minimum of 30 mm for chord lengths over 1000 mm, and a minimum of 10 mm for chord lengths under 333 mm.  It's interesting to note that these chord lengths are for either symmetrical or non-symmetrical wings, therefore there's no benefit to running symmetrical wing sections any longer.  Recall that symmetrical wing sections had some design freedom in that their placement was free (true downforce producing, non-symmetrical wing sections were limited to the rear of the car, i.e. the rear wing) and you were allowed a "pointy" trailing edge; there was an unwritten regulation that stated that non-symmetrical wings sections had to have a minimum trailing edge thickness of 30 mm.  So in essence there's no longer any reason to utilize symmetrical wing sections given the trailing edge thickness rules don't make any distinctions between the two.

At the rear, the changes were stated:

Closing of the part behind the rear wheels. The use of grills or fairings to cover the rear wheel above the axis of the axle will no longer be allowed. The bodywork must be closed in this area and must carry the rear lights, rear stop lights and indicators.   

So in essence, any opening above the rear wheel centerline needs to be covered by bodywork.  We understand that the ACO has further stipulated that any air allowed to pass through this bodywork can't be directed upwards.  So if you were going to put a louver panel in this area you have to point it downwards.  They also state that this part must be rigidly attached to the car and that if it becomes dislodged during the event it needs to be replaced.  The ACO are adding drag to the cars with these changes.  

The ACO also added this definition regarding the bodywork at the very rear of the car:

On the sides:

Bodywork located at the rear of the axis of the rear wheels and above the reference plate must form a smooth, continuous, unbroken surface of convex form only, without cuts. It must not be set back more than 100mm in relation to the width of the bodywork at the axis of the rear axle (measured horizontally).

Therefore bodywork can't be offset inboard more than 100 mm (from the maximum width of the car).  The statement, "[bodywork]
must form a smooth, continuous, unbroken surface of convex form only," seems to be a difficult one to pin down.  If I understand this wording, it would very much appear that every car on the grid is illegal and will need a redesign inasmuch as the trailing edge of the rear bodywork is typically joined by concave shapes.

All of the modifications are aimed at slowing the cars down or redefining previously controversial or ambiguous areas.

Looking over all of the changes that need to be made, it seems evident that every single car on the grid is non-compliant and will need to be modified in some manner.  But at the same time the ACO is adamant that these are changes that need to be made for 2010 only; the ACO still has not defined the 2011 chassis rules.  And while it's reasonable to think that the 2010 modifications will carry through to 2011, we're fully expecting there to be a rash of additional modifications further aimed at reducing aerodynamic induced incidents with the implementation of the 2011 chassis rules set.  Thus it would appear big changes would be expected for the 2011 rules that would require yet another trip back to the drawing board.

As far as I see it, the ACO needs to adopt the 2011 chassis rules now in order to avoid the hassle and expense of modifying existing cars to these new 2010-only rules now and then to have to do it again for 2011.   Now I assume that the ACO is studying the aerodynamic safety concerns and the main crux of whatever happens to the 2011 chassis rules will hang onto those expected changes.  But the ACO have had more than 12 months to define the new aerodynamics safety rules, they should simply implement them for 2010 or simply put all of this off until 2011.  

While the economy is showing signs of recovery, the fact of the matter is that racing is a luxury and very much dependent on discretionary
spending.  But back to back regulation changes, 2010 and 2011, simply doesn't make an ounce of sense even in a good economy.  Is this further proof that the ACO's regulations are designed for one event only and the entire organization doesn't get racing series management?  I think so...
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ęCopyright 2009, Michael J. Fuller