Piston Size Difference

[Wr3sTl3b0y]

hey i got a 89mm 11 to 1 compression i think it is would i be better off going with a 12 to 5 to 1 what would that do?

[killer400ex]

you would mean a 12.5:1 and yes it would make a big difference, anytime you raise the compression you make big power gains, but you also run a higher risk of detonation and blown head gaskets or broken head studs from the increase in pressure. i have a 11:1 and it gets the job done just fine, if you were to use a 12.5:1 you would constantly have to run race fule, like 105 octane and up, with 11:1 you can run regular pump gas, but it has to be 93 octane and up

[TRXRacer1]

Originally posted by killer400ex
like 105 octane and up 105 is more then enough for a 12.5:1, you wouldn't need any more.

[killer400ex]

it all depends on what you can buy, i wasnt telling him to go out and buy more than 105 but i was telling him that 105 is as low as he should go, and i run 110 when i race

[Wr3sTl3b0y]

hey where do you guys get 105 octane any where around here i can only get 93 the most i would definatly go with 105 if i could find it

[katch26]

I used to get mine at the pumps by the drag strips.....cam2.