93egSLEEPER

hey guys,
getting ready to do a small NA build to get my car back up on its feet til i get my other motor built since i just popped my boosted gsr, yes its going to be 600+whp boosted, but i had a quick question.

I have a gsr block, crank and rods. I want to do a high compression build using oem pistons. i know the best choice would be either p30 (JDM B16) or p73 (JDM ITR) for upping the compression. i know the CR of the p30 would be somewhere like 11.5-11.6 and the p73 would be in the 11.3 range. should i just stick w/ the ITR stuff since it matches rods?

thanks for the input.

Romo Pyro

Well, the p30's have a higher dome cc but a shorter compression height, where as the p73 has a smaller dome but higher compression height, personally I went with the jdm itr pistons for a reduced risk of the piston dome slapping anything, but that's with an 89mm crank and ls rods. Use zealautowerks.com 's compression calculator to do your research, but one quick note, I believe (not sure) that their headgasket thickness is a little off for oem hg's. .26" vs .29"(I think this is oem but someone correct me if not)

*Edit*
I just used the compression calculator on the website I posted above:
JDM P30 in a GSR: 11.44:1 Static CR w/ .29" HG
JDM P72 in a GSR: 11.49:1 Static CR w/ .29" HG
(CR's at 190' above sea level cuz I live in the east bay, Cali)
Hope this helps.

mikesrex

I'm running the JDM ITR pistons in my setup and have no problems at all with them. I make 209WHP and run 12.3@107.9 with 1.74 60' in a 2105lb car with a GSR stroke, built GSR head, GSXR1000 ITB's and a cast iron ITR header.

from what I see the compression is about the same, but the P30 is a tad bit more. I would go with whatever I could get for a cheaper price. I got the JDM ITR rods and pistons from a friend as a gift.

Romo Pyro

Those are impressive numbers, mind pm-ing me your setup? I'm trying to break 200whp with OS p73's. Just wanted to see where my build will stand when it's done

HONDRETTI

i've always used the c-speed racing honda compression calculator...
http://www.c-speedracing.com/howto/c...c/compcalc.php

JDM P30 in GSR: 11.599:1 cr
JDM P72 in GSR: 10.600:1 cr
JDM P73 in GSR: 11.362:1 cr

btw the headgasket thickness yields .029 in. opposed to .29 in.

95 Integra gsr

hey thought you saID IN THE OTHER THREAD THAT TURBO IS BETTER, SO WHY THE ALLMOTOR BUILD?

RagingAngel

Those figures aren't accurate since it doesn't take into account the compression height of the piston.

In terms of actual compression from highest to lowest:

CTR > JDM ITR > P30 > PR3 > US ITR