real clutch kit resultes?

I have been reading all the post for clutch kit installs and how guys feel by the seat of their pants a difference. I’m not looking to hear who has the best kit out there just real before and after results they can tell me. Like if they raced a buddy with the same machine before and after and how much difference did it make. Anybody do an 1/8 mile before and after? I have been all over youtube looking also.