Pyro, I don't think there will be a need to do the CFS thing with how the game uses sound files. I have solved the problem by mixing two wavs into one. One wav is the sound of the engine lower rpms and the other is at high rpms. When the throttle is low, the gurgle of the low rpms comes through and at high throttle the high whine comes through fantastic!
As soon as I'm initally done with the set, I hope I can send it your way to be posted on the downloads section of AH website. I don't think anyone will be dissapointed with them. I'm having a load of fun myself, and now even more that I have figured a way to get best sound at all rpms!
fscott