ive noticed that my 1-2 shifts are very slow when high up in the rpms. Such as racing. I can't force it or it grinds. I have to wait til rpms drop and it falls in 2nd then let go of the clutch.
I'm not saying I have to wait a whole second or even half a second for it to fall in but definitely won't shift nearly as fast I'd like.
its a stage 4 ACT clutch and my previous stage 5 clutch was the same way. It's the same in my y7 trans and my y8 trans

my question is is the only way to really power shift is with a twin disc? Would a clutch master cylinder solve this?

96 civic d16y7 sc31 turbo on about 40psi around 500hp