what is the affect of this..?

[Birel99]

I am not certain but I believe that Audi (open cockpit) are allowed a larger tyre in width compared to the puegeot (spelling?) 908 HDI.
I am not %100 sure on this....

[bettonracing]

There is an ongoing aerodynamics article in RaceCar Engineering about LeMans Prototypes that would shed some light on this topic. (Editions posted below)

Here's some relevant information from previous discussions I've had/read:

• Closed cockpit cars are generally considered to be a stiffer chassis. (This obviously doesn't say that open cockpits are inadequate, just that closed is stiffer)

• Closed cockpits have the potential to provide lower drag bodies. It is debated that this advantage is negated by the complexities involved (both aerodynamically as well as in design and manufacturing).

• Open cockpits are easier to design & manufacture (esp when u factor in things like the lack of a driver cooling system & doors, and the inherent problems with using a cockpit like glare and complex chassis FEA).

• Food for thought: Audi has built/ been involved in at least 2 closed cockpit cars (R8C in '99 & Bentley LMGTP in '00 and '01) and are currently running open cockpit. Rumor has it that their decision was based on the reduced development time of the open cockpit. Whatever their reasoning, their choice does have some merit considering their success.


There is (was?) a rule in LMP that dictates that the car must have a rectangular profile from top view. This still allows for some curvature of the body (use 'wings' to create the relevant edges) but there may be other deciding factors (as mentioned earlier in this thread).

Regards,

Kurt.

EDIT
Racecar Engineering Vol 17 No 11 & No 12 (Nov & Dec) have the LMP aero articles.

[Ogami musashi]

i find that quiet unbelievable as f1 cars these day still creates a good deal of downforce from the diffuser area from the bottom of the car about 30%
and the thing is that the coke bottle shap design has no influence on the amount of downforce created by the diffuser it merely speed up the airflow and hence decrease the amount of drag and increase the overall efficiency of the car downforce/drag wise

Yeah and i think since 2006(?) the sidepods coke bottle shape extended to 3D (it was obvious on the R26) to decrease the pressure drag from the Inlet-sidepods section.

Actually the side pods were made symmetrical IIRC to negate the lift created at the stake.

But anyway diminishing pressure drag on a lifting/downforce body always increase lift/downforce.

By decreasing the pressure drag on that part of the body the up side and bottom side net pressure forces are increased.

Somehow this was possible due to the V8 area.

For LMP car i think the reason is in the rules as i recall many group C 3.5 liters cars having coke bottle shape everywhere it was possible.

In contrary to the FIA, ACO is aiming at more Drag.

Shall we escape that sad fate for as long as possible.

[bettonracing]

I find that quiet unbelievable as f1 cars these day still creates a good deal of downforce from the diffuser area from the bottom of the car about 30% and the thing is that the coke bottle shap design has no influence on the amount of downforce created by the diffuser it merely speed up the airflow and hence decrease the amount of drag and increase the overall efficiency of the car downforce/drag wise

Not trying to be an antagonist, but...

http://philsci-archive.pitt.edu/archive ... 1/aero.pdf
Page 17. 3rd paragraph.

The Coanda effect is also utilised on a modern Formula 1 car with the purpose, not of generating downforce directly...

(Don't forget to take Your grain of salt with this paper... eg. The Brabham BT46B was not banned from competition. It was withdrawn by The team owner [Bernie] due to conflicting interests... That being said it does seem a bit more scientific [valid] than the "I think" approach...)

Regards,

Kurt