Octane vs compression

[HouserCRF450]

I'm lookin at different compession pistons for my crf 450, what octane gas for what comp piston? I can get 99 octane from the pump over here but don't wanna have to run race fuel again as it costs a fortune over here. Lookin at 13:1 > compression :ermm: any help would be appreciated, also anyone know what comp a sparks piston is:confused:

[CHEVYZ]

I think that you would be safe with a 13:1 running 99. I run 93 in my 06 450r and it has a 12:1 without a problem. I would imagine running 99 would be fine for 13:1.

[stocktires]

What cam are you running? How fast are you?

[400eXr1d3rZ]

93 octane is ok for 13:1 compression piston.

[HouserCRF450]

Originally posted by stocktires
What cam are you running? How fast are you?

standard crf cam, A level rider

[stocktires]

Definatley dont go higher that 13:1 then (on 93 pump, on 99 it would be fine), I might would even consider a 12.5:1 if your gonna stick with a stock cam. A better rider on a stock cam can give a high compression motor more abuse than the average joe.

[HouserCRF450]

Cheers :D