I made some recordings of my car under full throttle first through 3rd gears, I attached a microphone placed in the engine compartment to my laptop, and used sound recorder - it sounds pretty cool.

http://studentweb.walshcollege.edu/j...turbosound.wav
http://studentweb.walshcollege.edu/jniemi/wheelspin.wav
http://studentweb.walshcollege.edu/jniemi/hirev.wav