ok so i need to pick some pistons. im looking for streetable pistons that i dont necessarily have to run 93 octane with, but im also looking to make decent power.

so what compression ratio should i be looking to run (plan is a b16 head so no extra compression from the head).

im thinking that the CTR piston compression of 12.4:1 might be a little high? thinking more along the lines of PR3 or P30 pistons for 11.5-11.7ish compression? but im not sure where to find the PR3's or p30's...

any input?

 

CTR's will be too high for a stock ECU and 93. You'd need something tunable (crome, uberdata, hondata). 11.5 should be ok, I might pull out a little timing if I were you though.

 

The P30 pistons would be the best choice. You may still want to get something that will allow you to alter fuel and ignition maps.

And since the compression ratio is increased, you will always HAVE to run premium fuel. A low octane fuel will cause detonation that could blow the motor.

 

yeah im definetly gonna have a tune...not dumb enough to trust a stock ecu.

big question tho...

jdm p30 or usdm p30? jdm gives slightly more compression ut how much?

 

oh and is there really any advantage to boring out .25 and running over sized pistons?

 

The P30 piston only exists in the JDM B16A. The USDM B16A uses a PR3 piston. The PCT piston is found on the B16B and will raise your compression to above 12:1. I would say to run the P30 pistons.

Not really. You will gain a little displacement, but not enough to make a difference. Oversized pistons are meant for cylinders that had to be bored out because of large scratches that honing would not get rid of or an out of round cylinder.

 

good..looks like ill go with p30's and not touch the block unless the walls are rusted or anything...since i take it honing can e doe without having to change piston size?

im getting an ls block, crank, oil pan for 75 bucks

 

Yeah, honing must be done anytime the piston rings are replaced...and you will want to replace them with a fresh build. Use a honing attachment with a 400 grit or finer stone.

 

awesome...thanks!