I tried to top out my '08 ZX6R one night coming home from S.C. on I20 I ended up only getting to 178 there was a long sloping hill going down and the bike floated for about 2 second. I had the thought of a rock or debris in the road throwing and killing me so I stopped. In a car it's only been 150~155 my 91 mr2 turbo, 88 supra and my IS300 all seemed to be geared for that speed. I haven't seen what the top end is with my new transmission.