I can't answer your question, but I wanted mention that there's an in-development game called Stunt Derby which is doing simulation-based engine noises; the developer (Alex Austin) might have some experience/knowledge to share if you ask him:
 

I'm working on a system in OpenAL that manages multiple audio sources, each with its own unique level of reverb. I want to reuse the same reverb effect preset per scene (for example, inside a cave, I would use the same reverb effect with the EFX_REVERB_PRESET_CAVE preset), but I want to update the …