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View Full Version : ej22t running 9.1:1 CP how do I get there?


amorton
05-26-2007, 04:05 AM
OK EJ22T running 9.1:1 “or close to” compression ratio, with WRX, or RS SOHC heads what do I need to get it there? Rods? Pistons? The best I see is an 8.5:1 does any one make a higher CP piston? I don't want it enough to have custom pistons made, but if I can get it with off the shelf items then that would be preferable. Eagle

History trying to build a bullet proof very responsive 22t in the 300-400 HP capable and very reliable. Also trying to get as much torque and throttle response as I can get. Do you think running 9.1:1 is too high?

amorton
05-26-2007, 08:08 AM
bump, I posted this late at night

bmxpunk
05-26-2007, 11:30 AM
Hey man I am doing a very similar build right now up in wyoming. I wanted to run 9:1 but alot of people told me that was too high if I wanted to run anything over 10-12 Psi on Pump gas. I stuck with 8.5:1 and had custom pistons made which have quite a bit less dish than stock. My goals are very similar to yours but I am taking the response route over max power. I really think 300whp will probably be my limit.

It will also come down to your engine management it is harder to tune for boosted higher compression ratios from what I am told. I am starting off with an STi-RA ecu to get the car running and broken in but moving over to an autronic stand alone as soon as i can.

Brydon
05-26-2007, 05:51 PM
Hey man I am doing a very similar build right now up in wyoming. I wanted to run 9:1 but alot of people told me that was too high if I wanted to run anything over 10-12 Psi on Pump gas. I stuck with 8.5:1 and had custom pistons made which have quite a bit less dish than stock. My goals are very similar to yours but I am taking the response route over max power. I really think 300whp will probably be my limit.

It will also come down to your engine management it is harder to tune for boosted higher compression ratios from what I am told. I am starting off with an STi-RA ecu to get the car running and broken in but moving over to an autronic stand alone as soon as i can.

I am 9.2:1 and run 20psi daily. Don't let people tell you that you can't! Just another internet lie. If you tell enough people the same lie they repeat it enough untill everyone believes it.

As for the OP... over 8.5:1 will be hard without custom pistons. The 8.5:1 you probably saw was with the stock heads. If you use WRX head then the compression will be lower. like 7.7:1 with the ej22e thinner head gasket. With the 8.5:1 pistons you will probably only be up to 8.2:1 with the ej22e head gasket. If you use the ej22t head gasket you will not make it over 8.0:1. On the plus side I ran that setup with the stock pistons and ej22e head gasket daily with 30psi or more.

bmxpunk
05-26-2007, 07:12 PM
I am 9.2:1 and run 20psi daily. Don't let people tell you that you can't! Just another internet lie. If you tell enough people the same lie they repeat it enough untill everyone believes it.

As for the OP... over 8.5:1 will be hard without custom pistons. The 8.5:1 you probably saw was with the stock heads. If you use WRX head then the compression will be lower. like 7.7:1 with the ej22e thinner head gasket. With the 8.5:1 pistons you will probably only be up to 8.2:1 with the ej22e head gasket. If you use the ej22t head gasket you will not make it over 8.0:1. On the plus side I ran that setup with the stock pistons and ej22e head gasket daily with 30psi or more.

Man where were you before i ordered my pistons! I spoke with ron at axis in particular and a few other tuners and they were trying to shy me away from 9.0:1 daily driven, which was what I really wanted to do. SO i ordered 8.5:1 custom pistons built around the 22 block with 98 dohc heads and the stock 22t head gasket. THe engine builder here in town thinks I am crazy for going with the 8.5:1 with plans of around 17+PSI-that said he usually builds american v8 motors.
SO that leads me to the question that since my pistons were made around the ej22t head gaskets, what would happen if i were to use the the gasket from the ej22e?

amorton
05-27-2007, 01:28 AM
Ok so who makes affordable custom pistons for the Subarus? affordable being around $500 or less?

bmxpunk what are you going to run?

Brydon what do you have in your 22t? where did you get them?

Thanks for the help keep the good info coming. I did not think 9.1:1 would be too high it just means I have to run less boost which is fine by me I like small turbos better. you need any help.

bmxpunk
05-27-2007, 03:38 AM
I went with JE pistons on the reference of a local engine builder. I had Wiescos in mind and before I said anything he said he liked going with JE as they were the same castings as wiesco and he has had really good luck with them on motors that he did. We also checked into Mahle at the time and I cant remember if they weren't doing custom ones or if they were really backed up.

SO I just got my JE about a month ago and they took 8 weeks to get. I also had the crowns coated in ceramic and the skirts coated with their endurance moly coating. With all that plus some rings from total seal (conventional not gapless) It came to about $850

Some info you need to order them is
Bore (of course)
stroke
Length of Conrod
Deck height
volume of combustion chamber
Headgasket thickness
Cam lift

at least that all I remember right now

As far as turbos I agree with you i want the response so smaller is fine with me. I am going the route of either the VF37 or VF42 if i can get ahold of one