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"Doki" wrote in news:f1umuv$si3$ snipped-for-privacy@registered.motzarella.org:

Google it. :-)

Try rec.auto.sports.f1 - there are a couple of aerodynamicists on there. You might even find the equations have been posted before if you Google the group.

P is power, F is force, V is speed, S is area, rho is density:

P = FV, (1)

and force is equal to drag:

F = Cd 0.5 rho V^2. (2)

So, insert (2) in (1):

P = Cd 0.5 rho V^3, (3)

and

V = (2P/Cd/rho)^(1/3).

Strangely enough, one of the pedal-power groups appears to have come up trumps:

All SI units? Where's frontal area in that lot?

Paging TOG

Bugger. It should read:

P is power, F is force, V is speed, S is area, rho is density:

P = FV, (1)

and force is equal to drag:

F = S Cd 0.5 rho V^2. (2)

So, insert (2) in (1):

P = S Cd 0.5 rho V^3, (3)

and

V = (2P/S/Cd/rho)^(1/3).

S = CG ^ ---------------- STEEP HILL

Ta for that. I'm using a 15% fudge factor for transmission losses & rolling resistance (looking at various versions of the Golf) and I get rather high top speed figures for MK2s and 3s and 4s, but pretty much bang on for the later MK5s. I suspect this could be down to gearing mind, as the MK2s are geared to get to the red line pretty sharpish in fifth rather than to reach all out top speed, and it's also perfectly possible that VW didn't want the MK2 G60 to do 155mph given that it's probably generating considerable lift at that speed.

In article , Doki writes

It is the same as what you should all ready know for fluid dynamics except the fluid isn't quite as much of a fluid but is still very dynamic. Easy really.

messagenews: snipped-for-privacy@bath.ac.uk...

Don't forget that if the drag is higher than the power output lower in the rev range the car may never get to the top of it's powerband in top gear.

You can cheat with:

It has the 1991 16v in there already and there is nothing to stop you adding any more you like if you have the right information.