Originally Posted by JB-370z

I did say "Higher hp numbers" should have been more specific I apologize. There can be fuel challenges with both high and low compression when trying to gain “High hp numbers” or levels. Finding the sweet spot would be ideal for any setup.
It goes both ways. You dont want to go too low or high in my book. This is because the lower you go the more boost you need to throw at it. More boost means higher temps and higher temps means greater chance of detonation. Same thing with high compression. Higher compression naturally runs hotter than lower compression. As you turn up the boost on higher compression you will be adding more heat as well which means higher chance of detonation. High boost low compression or Low boost High compression is fine but fuel issues are known to come up with wanting to gain high hp levels. What I am trying to say is. 10:1 seems like a better choice than 9:1 just cause you need less boost to make the same power and turbo's will spool quicker with the 10:1 application vs 9:1. I dont know how this would work with superchargers though. The whole point of lowering the compression would be to create less heat which makes a less chance for detonation which makes it easer to tune and give a little forgiveness when tuning if the tune is a tad off. Which means safer to most people.

Also, it seems like 10:1 works out perfect for the GT-R.