200psi....what octane

[tecatecrazy]

well I decided to finally put my high comp head back on my t3. hasnt been on since last detonation about 2 years ago...and Ive never had it on a kx cylinder ,should make real good power. pretty sure prior detonation was due to wrong octane (have always run 91) and dont want to go through that again so I'm wondering what fuel I need to run. not looking for guesses, need some real experience here.

thanks,
Joe

[SWIGIN]

i raced a 89 q-racer 250 with 220psi and i ran 93....i tried mixing race gas a few times with that motor and it ran the same as pump gas

[Unclediezel]

200psi??????

91 definitely wont cut it, Most pump gas may not be enough, You are stompin VERY close to Race gas or av- fuel. Octane boost works better on lower grade fuels , so that may eliminate the option. There is a math formula , but not sure how it goes. It will probably put you somewhere near 96- 97

[KASEY]

i tried mixing race gas a few times with that motor and it ran the same as pump gas

this is a very correct statement,,,, it shouldn't run better just a little slower burn to help out with the POSSIBILITY of detonation on a hard pull,,,, so if your not really pulling the guts out of it ,,, it won't make a difference,,,

[hrc85250r]

a general rule for race gas 50/50 is above 210 or so.... i run premium in my
R that has 220 psi, no problems....

[SWIGIN]

iv run as high as 240psi on pump gas...but the base gasket didnt like it much...lol

[SWIGIN]

this is a very correct statement,,,, it shouldn't run better just a little slower burn to help out with the POSSIBILITY of detonation on a hard pull,,,, so if your not really pulling the guts out of it ,,, it won't make a difference,,,

i didnt mean i was exspecting a proformance gain...what i was checking by running race gas was to see if i had a detonation problem that i wasnt able to feel or hear.