Originally Posted by JDMPONY00
i want to boost my car around 15-20psi max since thats all my greddy kit will be able to give me, but heres my real question should i buy forged lower compression pistons or keep the same compression even thought i know its better to go lower compression it will decrease the power and since im not gonna be boosting enough to compensate for the hp loss im thinking about buying forged 10.1cr pistons instead of 9.1 any thoughts.
I get knock on pump gas above 19 PSI. My pistons are 9:1. I have a front-mount intercooler. Forget that it's a Mitsubishi for a second and realize that pump gas has it's limitations. You make power by flowing air, not by pressurizing it. All that does is make the intake charge hotter. Raising the compression will add power, sure... but it's more likely to pre-ignite with pump gas unless the whole front of your car is an intercooler or you're running water injection.
If you're not building that rotating assembly like a brick shithouse, don't raise the compression. Forged pistons will give you a little more durability when you get knock from pre-ignition, but that won't save your rods or crank.