Running a 2.5L on a 2.2L ecu... Will I have problems??

smh0101 · Post by **smh0101** » Tue Mar 03, 2009 10:47 pm

I'm working on my engine build... And I'm going with a 2.5L shortblock and 20g WRX heads.

My question... Will I be safe running it on the stock 2.2L ecu without anything extra? Or will the extra displacement cause problems?

thanks!

PhyrraM · Post by **PhyrraM** » Tue Mar 03, 2009 11:03 pm

The larger bore might need more timing to be optimal, but I'm sure it will run fine if you keep the boost reasonable.

Keep some sort of engine management on the short list though.

smh0101 · Post by **smh0101** » Tue Mar 03, 2009 11:09 pm

It wont run too lean because of sucking in more air?

PhyrraM · Post by **PhyrraM** » Wed Mar 04, 2009 12:08 am

smh0101 wrote:It wont run too lean because of sucking in more air?

The AFM will take care of that, until it maxes out. Keep your boost under that limit and A/F ratio should be OK. Of course with that displacment change, that limit might only be a few PSI.

555BCTurbo · Post by **555BCTurbo** » Wed Mar 04, 2009 3:30 am

Keep in mind the manifold absolute pressure will not change...so I wouldn't worry too much...

impreza_GC8 · Post by **impreza_GC8** » Wed Mar 04, 2009 3:38 am

I am running a hybrid EJ25 turbo setup with an EJ22T ECU.

smh0101 · Post by **smh0101** » Wed Mar 04, 2009 4:22 am

Thanks guys! Definitly some good info here.

And yea, EM is next on the list once the engine is built.

impreza_GC8 wrote:I am running a hybrid EJ25 turbo setup with an EJ22T ECU.

And I take it all is well?

Post by **Legacy777** » Wed Mar 04, 2009 6:59 pm

Check out this thread
http://bbs.legacycentral.org/viewtopic.php?t=15368

Jason Grahn did this a while back, and I don't think he had any issues.

impreza_GC8 · Post by **impreza_GC8** » Thu Mar 12, 2009 4:36 am

smh0101 wrote:
impreza_GC8 wrote:I am running a hybrid EJ25 turbo setup with an EJ22T ECU.
And I take it all is well?

Runs like a top. It loves its gas though. 440 injectors, a VF8 and no ability to tune can be blamed for that though.

tahiti350 · Post by **tahiti350** » Thu Mar 12, 2009 1:18 pm

wouldn't the ECU be off due to the RPM and MAF conflict (IE, more air flow at all RPM's) or does it have enough latatude to adapt?

douglas vincent · Post by **douglas vincent** » Fri Mar 13, 2009 4:33 am

I have advised Spencer I will refuse to sell him a 2.5 unless he buys a PP6 first.....

smh0101 · Post by **smh0101** » Fri Mar 13, 2009 4:35 am

And I will do so

I'm working on it!!

impreza_GC8 · Post by **impreza_GC8** » Fri Mar 13, 2009 5:37 am

tahiti350 wrote:wouldn't the ECU be off due to the RPM and MAF conflict (IE, more air flow at all RPM's) or does it have enough latatude to adapt?

Like I said, it runs pretty well. I didn't do the engine build though. Its possible it is running the EJ22T RPM sensors and junk but if you think about it, it just takes the data from the sensors and makes an equivalent combustible air/fuel mixture from that data. Doesn't really matter if you flow more air or not.

legacycentral bbs

A forum for 89-94 BC-BF(BJ) Legacy Owners and Fans

Running a 2.5L on a 2.2L ecu... Will I have problems??

Running a 2.5L on a 2.2L ecu... Will I have problems??