I'm sorry to go back to the other conversation, but I have two F1 sounds CD, from two different producers.
I think it's impossible to reproduce the sound of an engine without having an engine on your car or dynamo.
I took the CD's to a Home Theather expo and noone equipament were campable to sound like a real F1 car. F1 sound is such a amazing experience that you cannot have it without beeig in an F1 race or test session (or on a F1 team garage... :P)
I quite like GP4 original sounds...
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Rocker