They are very fast!! There are plenty of mods that you can do it to realy make it scream. I have on mine is reeds, port & polish DG exhaust modded air box, dial-a-jet and some other things i can't remember right now. Here is a good article on the tri-z for some awsome mods!!
http://www.quadpit.com/mags/1985/3-4w-acti...eport-tri-z.htm