hi or low compression pistons.

[blinkshome]

im in the process of building my motor. iv decided to go .60 over. i want that last little bit. as im looking for pistons, one of my guys told me that a lower compression piston would suit me better. being that the motor is boosted i would ward off a detination scenario. more room for air and fuel. whutdayathank?

[neverlift]

lol if you can tune and kepp detonation away you could ude high comp but noone wants the headache, GO WITH LOW COMP....

[lrb_2000]

low comp is easier to tune for I guess.... high comp you will see higher output numbers at lower psi.. but it has to be a perfect tune.

I say go low comp and turn the boost up!

[el tigre]

Low compression, but I hope you aren't going for crazy power, that block isn't going to like .060 over.

[spooled240]

perhaps 8.8:1 arias???

[480sx]

Have you already bored the block or bought the pistons? If i were you i wouldnt bore the block out that much, you would be stretching your cylinder walls really thin. .20 over is as much as i would personally go, no real reason to go any bigger. The risk outweighs the small power gain that you would get with such a bore.

But lower compression for sure if your running pump gas.

[kazuma]

I have a similar question. I bought ross 8.6:1 pistons with a 20 overbore. now when I put these in with my eagle rods Would I be able to hit 400whp on pump gas or would it be easier with the 8.6's on pump gas or the arias 8.8?

[S13FX]

I have a similar question. I bought ross 8.6:1 pistons with a 20 overbore. now when I put these in with my eagle rods Would I be able to hit 400whp on pump gas or would it be easier with the 8.6's on pump gas or the arias 8.8?

With a properly sized turbo and a good tune, you should be able to hit 400rwhp no problem with that comp ..

[spooled240]

i've been thinking about the benefits of having high compression pistons tho...a boosted ka with stock internals is pretty quick having the high compression when spooling but then VERY quick on even a low boost setup.

I say if you decide to go w/ a high cr of 9.5:1 and keep the car from detonating with a few tricks like water infection or those ceramic coated pistons or just have a damn good tune, you will have the best of both worlds: a quick low end and a really good top end. High compression is also better on gas mileage when cruising which is something to think about. Especially with a big slow-spooling turbo, I wouldn't want a slow-a$$ low end then take off around 4,000 rpm imo. Unless of course you have a tiny quick spooling turbo, which will ultimatley limit you from hitting high hp numbers.

I know it is easier to tune a low cr engine to prevent detonation, but if you can keep the engine from pinging, you could have a 400hp semi low -boost setup w/ some decent low end...