stock compression or not

[carolinakeyz]

Is it stupid to run 9:6:1 compression with a T3/T4 turbo or should i get lower compression pistons cause Im not sure. cause i gt a buddy with and S13 and his compression is 9:2:1 and he has a garret t66. what should i do?

 

[1slo1g]

With that high of compression you better make sure you have a dead on tune or else you will mess everything up!

 

[carolinakeyz]

ok im just tryin to make sure i have everything right with the motor so it'll run right casue im not really all that sure on it. so do you think i should have lower compression

 

[gijoe985]

Seems to me that with lower compression you can increase the psi that you are running and have the option of running a lower octane of gas if you chose to. Running higher compression you're kinda stuck. Correct me if I'm wrong.

 

[dsm-onster]

More compression means more work or power is extracted from the fuel you are using. More boost means more flow or more air to make power. It is easier to get more power from adding more air (to match to more fuel) than it is to get more power from a higher compression ratio. For this reason, serious drag racers opt for the lowest compression ratio choice and pour on the boost w/ a big turbo. Throttle response suffers, but more power is summed up at the wheels.

Knowing what compression ratio yur system can tolerate is the key. How is your combustion chamber different from the sr20 or ka24 that your friend is running? How much can his rods tolerate with respect to detontion vs. yours. How much stronger is his hed bolts vs. yours. All of these play a factor in determining suitable compression ratio for boost and your particular goal.

You cannot look and an arbitrary engine and setup and determine anything that will benefit your setup. Simply research what others with 420a turbos have done.

. . . Super over-simplified explination.