PDA

View Full Version : compression question


shanes14
09-03-2008, 04:32 PM
i am working on a ka-t project and I'm not sure what pistons to go with.

i have some cp pistons in my possession, but is low compression the way to go?

i cant decide on if i should use them or not


opinions please?

HalveBlue
09-03-2008, 04:47 PM
Yes.

Turbo charging = lower compression.

What's the comp on the pistons.

shanes14
09-03-2008, 06:18 PM
9.0:1 i believe

drftthatshit
09-04-2008, 03:36 PM
if you wana push boost in the future because trust me you will get tired of 7psi really quick. I would go to at least 7:0:1 that way your choise of boost range is much more larger...... the only reason i say 7psi is thats all your gonna be able to push with the pistons you have in your possetion hop this helps man

HalveBlue
09-04-2008, 07:36 PM
Uh...no.

How much boost you run depends on more than just comp ratio. A lot more.

9:1 is perfectly fine.

The SR20DET has an 8.5:1 comp ration from the factory and can run significantly more than 7 psi of boost safely.

Generally speaking lower comp ratios are better for FI engines. If you want to find the optimal comp ration you'll have to do some research and calculations.

FWIW, I'd have no problems throwing those CP's in my engine.

In the end it all comes down to exactly what you want out of the engine.

shanes14
09-04-2008, 11:12 PM
i decided that im going to use them, might as well sinse i already have them..