pistons (6bolt) 8.3:1 vs 8.5:1

[javi-tsi]

I know I might be asking for a flame here, but I'm on 12hr patrol and once I start researching I get the z-monster on my back. So before this deal goes away:

I found some Wiseco and Ross pistons for sale, but they are 8.3:1 (0.020). I see folks here use the 8.5:1 (0.020) often. Which is better?

I plan on a set-up to run 20-25 psi boost and no nitrous.

 

[EVO-00X]

Either will do... but my choice will be on the 8.5:1 for better off boost drivability. Remember though, you've got to work to whatever fuel you are using. Out my way, the most you'll get out of 98 octane pump fuel is 22psi with a good tune. If you are looking at 25psi, you'll need to look at using race fuel like C16 for example and you cant run it everyday

 

[gurmanator]

if they are a really good deal then get them...you wont notice the difference between the two since you are forced induction already.

 

[blackGSX2g]

The higher compression your pistons are, the better off boost power you get, better gas mileage, and quicker spoolup. The downside is that with higher compression, you would be more prone to knock under the same boost conditions as a lower compression motor.

That being said, I run 25psi daily on pump gas with a 50 trim on 9:1 compression and love it. My average gas mileage with MAFT alone was about 23 mpg in the city with moderate boosting.

 

[dsmgrimreaper]

I'd run the 8.5:1 my self you can still acheive 20-25psi my friend has his set at 20psi as a daily driver and has had it at 30psi before not recomended it was an accident when playing with the boost controler, and you dont need race fuel to acheive that but it likes it a little bit more. in maine the highest octane is 94 and that works fine with 20psi

 

[javi-tsi]

That was easy enough! Thanks everyone!!!

Can't wait to get this project started!