>>Lee Stohr has been busy winning the DSR National Title.  Mark Jaremko took the Stohr WF1 to the National Title at the SCCA Run-offs and in the mean time destroyed the Mid-Ohio qualifying time by 2 seconds even lapping faster than all the CSRs!  The WF1's aerodynamics are the responsibility of Wayne Felch (above left--Lee Stohr Middle, Mark Jaremko right).  Development consisted of full scale pressure mapping and the work centered on developing a new front splitter, rear tunnels, and rear wing.  Bodywork patterns and molds were then made in-house and  Composites Unlimited was contracted to manufacture the bodywork from pre-preg composites.

>>A couple of house keeping items here.  I've received two requests for helps for various items/information over the weekend, read these and see if you can lend a hand.  Thanks!

I'm wondering if you can put out the word and help me find a wide-span main rear sportscar element that I can buy for a few hundred dollars?  Old/obsolete is fine (something within the past 10-15 years, preferably); I need bags of rear downforce for very little $--this is a personal project, not a pro effort... I'm hoping you know of a sportscar person with an element (or two) collecting dust somewhere...

This is for a sedan that I've built to World Challenge GT specs, and will be competing in the NASA 25 hrs of Thunderhill near Sacramento.  As the race is both 25hrs long, filled with 80 cars (all likely slower), and it often rains for most of the race, an overabundance of downforce will actually be a blessing when dealing with rain and traffic.  I've incorporated both a very deep splitter, Reynard CART upper FWing elements, and long flat bottom floor up front, and need to balance it with similar high levels of rear downforce.

I've called in a bunch of friends that have volunteered to drive--Memo Gidley, Scott Bradley, Chip Herr, and the Editor of Car & Driver--the faster and more striking the car looks and performs, the better. If you know of anyone that'd take pity on me and ship out a stout rear element (and/or matching 2nd element if possible) to use, I'd greatly appreciate your help asking around.  Again, I have a few hundred bucks I can offer, but that's about it.  I'm hoping our Mulsanne's community can help with a homegrown project here!

NOTE: the car tests on Nov. 7th for the first time, and the day will be used for both a shakedown and a wealth of setup work; I need the rear wing in place for the test, so having something in my hands in CA by the first few days of November is necessary.  Because I don't know what I'll be getting, or what fab work I'll need to do (end plates, mount plates...), the earlier, the better.

Respectfully,

Marshall Pruett
Marshall Pruett Motorsports Engineering
www.racedataengineering.com
mpme_rdaATmsn.com

david.sims947ATntlworld.com

>>File this under spurious rumor for now (though note where you heard it!).  But it is with enough detail and from a reliable source that I felt justified in publishing it as there is a large information void regarding the subject of the new Audi LMP car.  Word is that the car will be diesel V12 powered.  It is no secret that Audi is coming back with a new car that will be diesel powered.  But up until now all talk had centered around a V10 turbo diesel.  My source, who knows better than I, indicates that a move to a V12, "reveals that they are after the maximum allowed volume and/or the highest possible revs in the diesel."  Simplified, diesels generate power by increasing boost pressure or throwing more fuel into the cylinder.  Both of these methods increase the likelihood that the head will separate from the block and aren't necessarily conducive to endurance racing reliability.  A V12 will allow for more revs which, while not eliminating reliability issues, moves the stress on the engine from the head bolts to elsewhere (the cylinder heads will be under enough stress as it is!). 

And while we're at it, why diesels anyway?  Again, simplified, with the regulations pegging engine power to around 650 via the engine inlet restrictor, few gains (if any can) be found in trying to increase absolute horsepower; the inlet restrictor is very effective and works by simply limiting the amount of air that can be brought into the engine and therefore the absolute power.  So engine performance gains are found by improving engine drivability, fuel efficiency, and torque, all the areas low in the rev. range where the inlet restrictor can't effect.  This is one of the reasons Audi introduced the FSI engine (direct injection) as it showed gains in drivability and fuel efficiency.  While a racing diesel engine does have its challenges and compromises (weight and a premium on intercooling efficiency which potentially effects aerodynamics), the benefits are massive amounts of torque (750+ lb-ft vs. 500) and increased fuel economy.  It is predicted that with a similar fuel tank size (to a gasoline powered LMP1 engine), a diesel will be able to run 2-4 laps longer at Le Mans.  So the performance gains are worth any engineering headaches.

>>The Petit Le Mans updates will be along shortly.  In the mean time, Dave Lynn sends us this image of the completed Mazda RX-792P (seems he finally got around to liverying the car on Friday night...sheesh).  The car (chassis no. GTP001) has been in Jim Downing's shop for the past few months undergoing a full restoration in anticipation of the Seven Stock Mazda meet.  The car was dropped off at Jim's at the same time Dennis Spencer took delivery of his two RX-792Ps (chassis GTP003 and a showcar [mid-page here]).  Bob Chapman and I were able to photograph GTP001 in detail, courtesy of Jim Downing, the Tuesday evening before Petit.