2.5 ecu questions

the_watts10 · Post by **the_watts10** » Sun Mar 02, 2008 7:10 am

ok guys first off i have a 1997 legacy wagon gt with a ej25 and plan to put my turbo, up-pipe, downpipe, etc. on the car and was wondering if the stock na ecu would reconize the turbo if so is there anyway i can fix this without switching to a piggyback ecu or chopping up the wiring harness and addind all of the necessary turbo sensors?

douglas vincent · Post by **douglas vincent** » Sun Mar 02, 2008 7:23 am

Unless you can get the turbo to hit about 4 psi max, no.

the_watts10 · Post by **the_watts10** » Sun Mar 02, 2008 4:12 pm

then how could i do it with out a piggyback?

vrg3 · Post by **vrg3** » Sun Mar 02, 2008 5:47 pm

The simplest non-stupid way to do it would be to install a high-output fuel pump and a rising rate fuel pressure regulator.

the_watts10 · Post by **the_watts10** » Sun Mar 02, 2008 9:54 pm

ok guys thanks but i think ive just decided to put a 2.5 (quadcam) in my car and just put the ej22t intake on it and current sti manifold uppipe downpipe etc. but thanks

BXSS · Post by **BXSS** » Tue Mar 04, 2008 4:46 pm

Just a heads up - a 2.2t intake manifold will not bolt up to DOHC heads, you'll need an Old style DOHC intake manifold (as '02+ WRXs have a different bolt pattern).

The phase 1 2.2 ports are much smaller than DOHC ports & the manifold will not line up with the heads.

Interesting enough phase II 2.2s have WAY bigger ports than PI 2.2e&t's & '02+WRX intake gaskets will fit (but have to be switched around - left on right & right on left - (I have WRX Hondata Gaskets on my PII 2.2e))

the_watts10 · Post by **the_watts10** » Tue Mar 04, 2008 5:46 pm

well its a 2.5 legacy outback will that work?

BXSS · Post by **BXSS** » Tue Mar 04, 2008 8:16 pm

You can use intake manifolds from a ej25 DOHC, EJ20H (TT Leggy), EJ20R (TT Leggy), EJ20G (JDM WRX), or EJ20K (JDM WRX) on a DOHC 2.5.

Matt Monson · Post by **Matt Monson** » Tue Mar 04, 2008 11:42 pm

the_watts10 wrote:well its a 2.5 legacy outback will that work?

The engines don't care what care they came out of. No 2.5l engine will accept an early 2.2l manifold. See the previous post to know what your options are.

Also be aware that you can run a lot more boost against an NA Ej22 than you can an Ej25. Ej25's are delicate engines under boost. crack. snap. kapow...

BXSS · Post by **BXSS** » Wed Mar 05, 2008 1:56 am

Yeah I did not even mention that, but 100% of the people I know with turbo 2.5s blew the engine.

Actually I only know 1 guy that had a AVO turbo-kit & the engine blew after something like 8k miles, the car had just 16k miles on it when cyl #3 lost compression (1 of 1 = 100%).

You may want to put 2.5 heads / intake on a 2.2 block to get something more boost friendly.

Matt Monson · Post by **Matt Monson** » Wed Mar 05, 2008 2:31 am

BXSS wrote:
You may want to put 2.5 heads / intake on a 2.2 block to get something more boost friendly.

That's a great idea...

asc_up · Post by **asc_up** » Wed Mar 05, 2008 2:31 am

Add another to the list. My friend blew up his RS with a Garrett T3/04. That's 100% of the people I know with a boosted 2.5L that blew up, too. Hahaha.

the_watts10 · Post by **the_watts10** » Fri Mar 07, 2008 5:22 am

well thanks alot guys becuase i am on the way to building my 85 camaro i am gonna have free time on my subaru so i think the 22 block and 25 heads would be great idea but would the 22 intake be better thatn the 25 and my stock turbo?

douglas vincent · Post by **douglas vincent** » Fri Mar 07, 2008 5:31 am

Or replace the 2.5 pistons with forged. Then you got plenty of torque AND it wont break.

BXSS · Post by **BXSS** » Fri Mar 07, 2008 1:52 pm

Again if you are using DOHC heads you have to use a DOHC intake manifold.

If you compare intake gaskets of the 2.2 intake vs the 2.5 intake you'll see the 2.5 port size is like 1.5 times the size of the PI 2.2 port.

I'd say that should work better.

Note: the CR with the DOHC heads may be LOW depending on the Heads / headgasket used.

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2.5 ecu questions

2.5 ecu questions