I did a search and didn't come up with too much. 3 questions...TIA

a.) Let's say I want to raise it by .5 or 1 point, how much whp will I gain?

b.) Will the gains matter if I have a stock R or an NA setup? What I mean by that is, if I raise the compression by 1 point on a stock R and an R with Toda Spec B's, will I see similar gains?

c.) What's the highest Compression Ratio can i go up to on an ITR using 93 octane without having any worries?

 

im not sure how much power you get out of higher CR's. So i wont give you a number. The CR will matter if youve got more aggressive cams than stock. IMO to be safe, the highest CR should be about 11:1. Im pretty sure others have much more informative things to say...but OH WELL

 

Every point you go up you can expect about 2-4% gain. With bigger cams a higher CR is what you need to get the most of them.
Some people would say 11.0-11.5 would be easily streetable, but some people have been able to get away with 12.0-12.3:1 CR without any major problems. Meaning that they had to fatten the mixture and/or retard the timming a little bit to prevent detonation, or have there ECU tunned to handle a 12:1 CR.

 

On pump gas I wouldn't go much higher than 11-11.5:1. Remember when it gets hot you car will be prone to detonatin some. Running 12:1 compression CAN be done but damn you have to monitor your engine closely.

I would recommend beefier injectors and J&S safeguard, VAFC, etx

Too much money I believe unless your car is a race car.

I run close to 11:1 compression and I pulled almost 200 to the wheel. That compression is more than adequate and safe for pump gas.

 

I always that the most you can go 93 oct was 11.0, until I saw the Celica GTS @ 11.5. Damnn, how do they get away with that.

 

For every point in compression (increase) works out to a 4% power increase.