[serialk11r]

You could be right, perhaps the typical race cam anecdotes apply to cars which run too much overlap or have other issues affecting combustion quality. As far as charge motion goes, I think it's still an important topic, although it's particularly important with direct injection because of the small amount of time the fuel has to mix. Increasing lift will affect tumble flow, from what I've read.

But yea, max mpg, you want a long duration cam (to squeeze the maximum amount of power out of the engine too), sacrificing low end VE, very high compression ratio, assuming you don't change low end combustion stability, which is likely a big if.

I saw some talk of the gearbox, and I'm not familiar with the speeds encountered on the track but I imagine you want 4-5 close ratio gears for track use, and a ridiculously long 6th for cruising. With such a powerful engine it's probably better to have more like 7 but 7 speeds are a new thing. With that much displacement and the 944s gearbox, your mpg prospects aren't looking so good, and the ratios have quite wide spacing which isn't ideal for racing, of course. With say a 968 gearbox (which has nice close ratios) and longer final drive (since your engine is relatively low rev, high torque), you could end up with a pretty healthy cruising rpm. That was just a random example, I have no idea what transmissions bolt up easily and whatever.