ok i have a couple questions that i need answered pretty quick. I have a gsr motor and im going to be running skunk2 stage 2 cams. heres what i need to know. i either want to use CTR pistons or a local guy has a set of JDM ITR pistons and rods and a mugen head gasket for sale. the ITR pistons and rods only have about 9k on them and the HG is new. i calculated the ctr pistons on http://www.c-speedracing.com/h...c.php and it came out to 12.0 comp. rating, thats where i want to be. now if i used the ITR pistons and Mugen headgasket they would be 11.6 (if its a 2 layer) or 12.0 (if its a 1layer). the only reason i am considering the ITR's is because i can get the pistons, rods and HG for cheaper than the CTR pistons and rings. so am i going to have any clearance issues with either set up? which would you go with?

 

Well, I was in the same position as you....I was going to go with CTRs but decided on the JDM ITRs just to keep the CR down a bit for fuel reasons. I am running a stock 3 layer headgasket however, i am running the RS camshafts which have 12mm lift on the intake and 11.5mm on the exhaust....so I didnt really want to risk any clearance issues to gain minimal compression by using a thinner headgasket. If you want more compression, go with CTRs and an OEM head gasket, wont have any clearance issues as long as the head isnt milled. Good Luck!

 

thanks, anybody have other opinions?

 

As far as clearance goes ive never had any personal experiance with S2 st2 and ITR pistons and a thin hg. A good way to do this is clay it while its all apart (but im sure you have heard that alot already). As far as using thinner headgaskets/milling your head, i personally wouldnt go that route unless you buy some cam gears and spend some time with a timing light. Because when you shorten the distance between the distance between the middle of the crank gear, and the middle of the cam gear (using a thinner headgasket) you effectively "lengthen" the timing belt by a half a tooth or so. causing the cam timing to be off as well as the ignition timing. I am personally a big CTR fan, as i have them in my motor with a stock 3 layer. But again, this is just my prefrence, it just seems like less hassle for me to not have to worry about timing my car to get it correct, i can just have the cam gears at zero and install the Timing belt.

-sander

 

thanks for the info. i do have cam gears so thats not a problem but i think ill just go with the CTR's. i was trying to save some cash but hey its only $150 differance.

 

cool let us know how it goes

-sander

 

will do, i should have dyno #s up in 2 weeks