Love this clip.
 

This is one mean GT-40. There's nothing like the sound of a race tuned motor.http://www.youtube.com/watch?v=iN-J4Jydnkc I can't believe that I can't seem to find any clips of race prepped Z's racing. I saw two of them at a Corvette show years ago. They had #'s and race sponsors all over the cars. They had full roll cages in them and of course were not street legal anymore. Race only. I wish I would have got more info on them but at the time I didn't have mine yet so it didn't really matter much to me.