ACO 2009 regs

[zac510]

I can't seem to find any discussion about the regs so I've decided to start a new thread dedicated to the topic.

Direct ACO link to summary of changes here:
http://www.lemans.org/24heuresdumans..._regl09_gb.pdf

Mulsanne Mike's summary:
http://www.mulsannescorner.com/newssept08.html

Personally I'm surprised there aren't more aerodynamic changes to the LMP cars considering how uppity they were getting about the flying cars in June. No changes to the front end downforce either but I suppose they will expect the teams to decrease front downforce to maintain the aerodynamic balance.

A quick calculation shows that the increased gurney area is only 2000mm2, up by 6.6%. The gurney area is cancelled out by the skinnier wing. Coupled with the decrease wing width and chord, how much drag will this really add? I have ignored the '4 seconds' of decreased lap time as they have only quoted this in relation to the 2010/11 rules, not the 2009 rules.

Can someone give input into the less chord and taller gurney - might this force the teams to run a higher AoA, closer to stall, to recover downforce?

Allow me to get a bit vain here, but I've always enjoyed the sheer size of the rear wings on the LMP cars, it's very much part of the 'look'. Hopefully they don't cut them down significantly. The BTCC rear wings are thoroughly disappointing, little more than tokens.

In the Audi 2009 thread I proposed that Audi might ask for more of a concession to open cars, perhaps in engine power, but that seems to have been squashed by the 0.3mm increase to air conditioned cars (effectively all closed protos). They might be happy with the equalisation between closed and open cars and perhaps the smaller rear wing will have less of a negative influence on open cars.

And then there's the expected drop in restrictor sizes for both production homologated LMP1 engines and diesel LMP1 engines. Might they be able to do another lap with this less horsepower?

Would anybody else care to cover the GT categories for us?

[deggis]

It has been talked about here...

http://tentenths.com/forum/showthrea...107659&page=13

New thread not needed, imho. Just ends up in a way that same things are discussed twice.

[zac510]

Ah, sorry. That thread is more about 2011 though. A mdo may want to merge my post in though.