i did a search but i couldn't find it, anyways, about how much hp or tq is gained per octane,i figured like .3 or something, but does any one know the exact answer

 

Octane does not help in the performance, other than if you use too low for your engine, you will get knocking and other programming will take over in the LS1's. Check out http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm A little information on octane.
Tony

 

Check out this other thread that's sort of about the same question (or related to).

Basically, higher octane gas will not give you more horsepower/torque, but using lower than required will cause a lack of potential HP/TQ.

 

Higher octane is not used to gain more power. It is used to resist detonation.

Only use as much octane as you need for your engine to run properly and knock free. Any more and it will actually lose power. A higher octane unleaded fuel contains no more energy than lower octane, it just resists detonation that much more to run more timing or most boost. Higher octane fuels are also harder to burn, so in your normal street engine your car should actually be slower if you run too much octane.

There was a thread in the Advanced Tech section with a very detailed explanation by rskause but it seems to have disappeared...?