im doing a simple rebuild on my gsr. i was planning on using us itr pistons which would give me about 10.8 compression and running a jdm gsr ecu because that is made for 10.6 compression so i think that would be fine to run with the stock gsr cams. but i was thinking that i will eventually be putting in cams and would benefit from the jdm itr pistons but that puts me at 11.3. the problem is i am planning on just running the straight jdm gsr ecu and gsr cams for a while until i have money for cams and a tune with other suporting mods. so my question is will a jdm gsr ecu be safe to run a basically stock gsr with jdm itr pistons on 92-93 octane. thanks.

 

You may get away w/ it by retarding your timing and running colder plugs. Get some more opinions though from other reputable tuners and builders.

 

yeah, im nervous because i know that the gsr cams will not bleed of much compression as if i were running say a pro 1 so im worried about detonation. i guess i may be better off with the us itr but ill see what other people say. thanks

 

Just for reference, I ran a USDM ITR ecu on my GSR w/ USDM ITR 82mm pistons skunk2 IM, bolt ons and stock cams until I got a tune about a month later. CR was about 11.3:1 and I set timing to 18 degrees and ran ITR plugs. No damaged to the motor, but still it was a risk.

 

In my GSR I ran USDM ITR pistons on the stock ECU for about 1 year. I also ran ITR plugs and adjusted the timing. It did not run perfectly but very close, on very hot days I would get a check engine light from the O2 sensor.

Then I got a Hondata S300 and tuning.


Modified by OH_1fstgsr at 7:48 AM 2/27/2008

 

thanks for the opinions, i dont think i will have a problem with the us itr's because it should only be about .2 compression higher than a jdm gsr. 10.8 vs. 10.6. im going to be running stock valves and a 3 layer gasket and only a surface to the head to clean it up so nothing else should bump up my compression. im guessing you had other mods done to get 11.3 out of us itr's. that would be the compression i am looking for after a cam install and tune and thats why i am trying to see if i could use the jdm itr's.

 

I have 82mm USDM ITR pistons, flat faced valves and milled head. Estimated about 11.25-11.35:1 CR.

 

You're worrying for no reason. You'll be fine with your JDM GSR ecu with your setup as you plan. They're wont be any issues.

What issues or concerns were you thinking you would have?

 

i was worried that if i run the jdm itr's and have about 11.3-11.4 compression that i might detonate without having a tune. im sure when running that kind of compression on pump gas that some timing gets pulled to prevent detonation. thats why i was nervous about running the straight jdm p72 ecu.