I am going to be rebuilding my gsr in a month or two with JDM ITR pistons(the spoon ones) and a spoon 2 layer headgasket. Im guessing that will raise my compression to around 11.6:1....Besides runnning on 93 octane, what else should I do? Ignition timing at 16? Or do I need it lower? Should I get colder spark plugs? I am trying to avoid detonation....I have a VAFC too if you guys have any fuel tuning advice....thanks a lot.

 

Thats LOW compression. you will be fine.

 

LOL, I guess it's all relative

 

i think he's refering to low compression engines you are suppose to turn back the timing.

 

Naw, if I know SgT (and I don't) he's saying that 11.6:1 is low. I guess when you run in the 12s (for both CR and ET) it is low.

BTW, no need to dial down the ignition timing in a low CR engine.

 

You are correct sir. WIth 12.2:1 CR I run 18 degrees timing and 92 octane with -0- ill effects.

 

What are you using to manage your fuel? Because I have been thinking about running CTR pistons (12.2:1) on 92 octane. But will I need to adjust my fuel or just my timing to have no signs of detonation?

 

Stock ECU with 10000rpm limiter.
if you are worried about detonation, then get a J&S ver.0

 

How much do those run and how exactly does it work? Does it just retard timing if the motor starts to detonate?

 

I think the ver 0 runs under 500.
it retards timing if it hears any detonation.

 

But you're running higher fuel pressure and bigger (much bigger) injectors right??

 

yes, but who would do all this work and run stock fuel injectors?
Thats like running 9s in the 1/4 and not having a parachute.

 

My point is that your reply implied in a way that 12.x compression is ok on 92 octane <u>without</u> mods to the fuel system - which is what the guy was asking about. Just trying to prevent misconceptions that's all.

 

where did I imply that 12:1 with stock parts was good?
We were discussing 11-11.5:1 with stock parts which would be fine.

 

I guess it's how you read the posts - my bad.

 

There's at least two or three cars locally that run 12:1 or higher daily driven on stock injectors. Just a mapped ECU and fuel pressure are the only fuel/ignition mods. All of these motors are hitting well over 185/130 at the wheels.

It's just a matter of tuning it right. No rookie tuner will be able to run 12.5:1 on his first motor build experience without ill effects. Just takes a little experience is all.

But to answer your question man, if it'll make you feel safer running step colder plugs then go for it. If I were you I would let it eat. Run 19-20 degrees timing and add fuel from there. I highly doubt you will detonate at 11.5:1

 

thanks a lot for all your help guys....I'll let y'all know how it turns out for me and my all motor quest..lol

 

I got 2 B20 VTEC running 12.8:1 on 92 octane with 0 side effects 18 timing.

haha. Its true....Ran a 11.8 this weekend in a 92-95 hatch...NO FIBERGLASS doors...only hood.

Jeff