i currently have the JDM ITR pistons to put in my build (gsr block, gsr head), which will give about 11.5:1 compression. now i was thinking of getting some CTR pistons instead. only thing is they are considerably heavier. but then again they will give me about 13:1 compression and .006 piston to deck height. and dont suggest aftermarket pistons, the car is being built to HC specs for HC so only Honda OE pistons are allowed.

so heres the low down:

JDM ITR pistons:
11.5:1 compression
not too heavy
no need to get new injectors
no need to clay motor

CTR pistons:
13:1 compression
a little heavier
need to get new injectors (not a big deal since ill sell the old ones)
will need to clay motor to check valve clearances

some other things to keep in mind:
GSR head
skunk2 stage2 cams

obviously the ctrs will yeild more power, but will it be worth it? give me your input.
anyone ever have a similar setup?

 

your gonna have to do a little bowl work to get the gsr head and the ctr piston to clear

 

I would go with the ITR pistons.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NATURAL &raquo;</TD></TR><TR><TD CLASS="quote">your gonna have to do a little bowl work to get the gsr head and the ctr piston to clear
</TD></TR></TABLE>

if that's true, i'd say do it! i think the cr will more than make up for the weight of the ctr pistons... i still regret not putting them in mine

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NATURAL &raquo;</TD></TR><TR><TD CLASS="quote">your gonna have to do a little bowl work to get the gsr head and the ctr piston to clear</TD></TR></TABLE>
explain what you mean and why you say that. theres tons of people on here who have (or claim to have) CTR pistons in GSR engines that are seemingly stock (minus tuning and bolt ons)

 

https://honda-tech.com/zerothread?id=1206288

this thread for example, rocket from RM, and another guy both claim to have the setups and neiher of them say anything about bowl work

 

bump

 

i would say itr pistons

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NA.GEORGE &raquo;</TD></TR><TR><TD CLASS="quote">i would say itr pistons</TD></TR></TABLE>
why. please give your reasoning.

bump

 

have you ever considered some p30's?

 

yes, but they arent an ideal fit. plus R pistons have longer skirts and the low friction coating. longer skirts = more stability in the cylinder. besides the JDM ITR pistons give almost the same compression as the p30's anyway ITR's being a tad more, since the ITR pistons have a higher compression height.

looking at 11.59 with JDM ITR and 11.50 with p30's

 

ITR pistons

flat top piston=more power


Compression isnt everything

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VtecKiDD &raquo;</TD></TR><TR><TD CLASS="quote">ITR pistons

flat top piston=more power


Compression isnt everything</TD></TR></TABLE>

explain this please, ive never heard of this. or point me somewhere where it is explained.

 

IMO

flat top pistons makes more power, more even flame front, less turbulence, more efficient motor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VtecKiDD &raquo;</TD></TR><TR><TD CLASS="quote">IMO

flat top pistons makes more power, more even flame front, less turbulence, more efficient motor

</TD></TR></TABLE>

Exactly. If you want more compression, mill the head.

 

wich headgasket are u using? how much clearance do you have w/ ITR psitons and gsr head?...would a thinner headgasket will replace the CR that the CTR pistons provide?