Subaru Impreza GC8 & RS Forum & Community banner
1 - 7 of 7 Posts

·
Registered
1995 Subaru Impreza L Coupe
Joined
·
5 Posts
Discussion Starter · #1 ·
So i just bought a 1995 Subaru Impreza L Coupe. I was wondering how much psi of boost can a 1.8l EJ20 handle with stock internals.
 

·
Registered
98RS, 98RS, 99RS
Joined
·
433 Posts
A 1.8l is actually an EJ18, the number stands for the displacement. Ive seen people run 5-10psi on here but the engine isnt really designed for boost. I read somewhere on here that the early ej18s had either forged internals or forged pistons or something but Ive never taken a block apart so I cant confirm that.
 

·
Administrator
2000 RSTi
Joined
·
1,802 Posts
You need to pick a turbo as well. Because 10PSI on a TD06 is not same as 10PSI on a TD04!

87518
 

·
Registered
1995 EZ30 Coupe
Joined
·
962 Posts
I believe the EJ18 is the strongest non turbo EJ bottom end. I ran almost 18 psi on an EJ18 bottom end with EJ22 heads, and I bet it would've taken more with better boost control and tuning. The larger combustion chambers of the 2.2 heads dropped the compression ratio a bunch to make boost safer. Definitely read up on things like engine management, injector options, gauges, lowering CR, etc. if you're gonna push it.
 

·
Registered
1995 Subaru Impreza L Coupe
Joined
·
5 Posts
Discussion Starter · #6 ·
I believe the EJ18 is the strongest non turbo EJ bottom end. I ran almost 18 psi on an EJ18 bottom end with EJ22 heads, and I bet it would've taken more with better boost control and tuning. The larger combustion chambers of the 2.2 heads dropped the compression ratio a bunch to make boost safer. Definitely read up on things like engine management, injector options, gauges, lowering CR, etc. if you're gonna push it.
will the EJ22 heads fit or will it need some modification
 

·
Registered
1995 EZ30 Coupe
Joined
·
962 Posts

Here's the PRIMARY thread that I followed for guidance:
 
1 - 7 of 7 Posts
Top