Compression ratio/ knock question

[94talontd]

I will be installing a turbo on my na 4g63 soon. I will be running 9.0 to 1 compression. I see a lot of guys running 8.3 to one CR on here for boost/knock reasons. When I go to push some decent boost am I gonna have a lot of problems with detonation? How much worse will 9 to 1 be compared to 8.3 to 1? Am I gonna be able to push a reasonably high boost?( say about 15 to 20 p.s.i probably on a 16g or 50 trim).

 

[Talon2139]

I wouldn't say it is worse it is just going to detonate much more quickly than the 8.3 to 1 pistons. On that note you could get some bigger injectors and an wideband o2, and as long as you keep your a/f at a safe level you should be fine.

 

[donniekak]

It's not the afr's that will be causing problems. It's the timing maps on a 1g turbo ecu. They were designed with 7.8:1 compression. A chip, ostrich, or link will really help get the most out of the 9:1 pistons.

 

[floader]

The compression may limit your max boost but it will really make the car more responsive. You will make more torque faster than a low compression motor, a good thing on a street car.