Compression ratio

[wrxshotta]

Sorry for this question but i need a proper answer and i seem to find a different amount of answers...what is the stock compression ratio on a EJ 205...because i am ordering pistons tomorrow and i need to know what ratio to choose

[dumdum]

8.2:1 I would go with 8.5:1 as most companies just do half increments.

[baller_v24]

i thought it was 8.0:1

http://ken-gilbert.com/wrx/mans/3%20...C%20ENGINE.PDF

[dumdum]

/\ Your right.The STI's and 2.5L WRX's are 8.2:1

[wrxshotta]

but why is that?, i thought we want to lower compression why are most companies like weisco, cp etc rasing our compression?

[mosc]

Because 8.0:1 and 8.2:1 are really friggin' low. Look, turbos love low compression it's true but more compression does help. You want to find a middle ground that allows for full use of the turbo's efficiency range and utilization of as much of the air as possible. By modern tuning standards, Subaru's compression is on the low side even for a turbo car.

[wrxshotta]

gotchaaaa...thanks everyonee

[subarooster]

Originally Posted by dumdum

8.2:1 I would go with 8.5:1 as most companies just do half increments.

half increments?? wanna help me with that one lol??

[turmic]

You don't know math? Just kidding...they make pistons in half increments man. Think about it.

8.0:1
8.5:1
9.0:1

and so on....

[subarooster]

ohhhhhhh ok. thnx