well im in the process of rebuilding a gsr motor for boost. just pistons, rods, blockguard, valvejob. but i was wondering if i could swap in the motor with 9:1 compression pistons and still run the stock ecu with no tune because i cant get all the things needed to turbo for a while. so is it kewl to run n/a w/ low comp pistons and no tune??

thanks

 

Boosted-Hybrid said the motor he tuned that went from 10:1 to 9:1 compression took 6-7 degrees more timing at peak to reach MBT, so be prepared for a fairly significant power loss if you can't bump up the timing.

 

o ok thanks

 

Bump cuz I wanna know too! I plan on building the bottom end of my LS with forged pistons and rods, and I wanna break in the motor before I boost on it. I'm thinking that it will be okay with stock ecu and injectors, correct me if I'm wrong. My compression ratio is not that big of a jump though. Going from 9.2:1 to 9:1.

 

i am currently breaking in my gsr motor too, i have just had it fully built with pistons. rods, blockguard, valves etc, i am running a stock p30 ecu and injectors that come with a b16a2 motor, i have basically swapped my b16a2 motor for a gsr motor, do i need to adjust timing etc?
by the way i have dropped the c/r from stock to 9:1.

info given on this post would be of great help

 

a car will run fine with a lower compression ratio & stock ecu/injectors.

reduced mine from 9.3:1 to 8.5:1 and I can't tell the difference when running stock.

 

sweet this really helped

 

Car will run fine but you should not beat on it. It's pretty hard to blow up an NA engine but you still can hurt them. I've seen so many of these fake mugen chips being installed and 40k later the engine comes to me with burned valves...

-Michael

 

well im planning on dropping the comp from 10 to 9 with probably some je's, and soon after that im piecing together a turbo kit and tuning with crome. so no mugne chip here!