im in the middle of starting an ls/vtec build my question what pistons to get if i want to have a compression ratio somewhere in the 12's i know type r's will give me 11:5 but i dont think that will be enough to get me 180+whp of course with camshafts upgraded fuel system and what oh yea i have a gsr head

 

well u got to remember u will need to be careful with clearance issues

but if u like to get up there use JDM P30 pistons even higher then PCT's

 

i would like to have around a 12:1 cr i dont think it would tap im asking now though because i'd really hate to find out the hard way of course im gonna clay it first but i really wouldnt want to order new pistons

 

p30's aren't higher than PCT's just so you know.

 

i would like to see this

 

according to c-speedracing the pct's will give me a 12.2 cr and the p30's will give me a 11.8 cr. The valves wouldnt/shouldnt tap at 12.2 cr would they?

 

oh and would i be ok running 93 octane on this kind of compression?

 

pct's give more like 13+ compression. c-speed doesn't take into account that they sit higher. do a search in the all motor forum. Its been covered in depth. And i think you could run then on pump gas....friend of mine did it in his lsvtec.