too late to franken swap?

[peacewize]

Ok so I swapped a 25 sohc from a 2001 Forrester and I love it. However with the awd trans and bigger tires I want a little more for the cheap. Can I put 22 heads on and still use my 25 wiring/ ecu?

[ShawnW]

I wouldn't even bother if you have it all up and running with the 2.5 heads.  It isn't enough extra to make the work worth it.  Maybe do it down the road if you have a head gasket fail or another reason to pull the engine out.  

[idosubaru]

I wouldn't even bother if you have it all up and running with the 2.5 heads.  It isn't enough extra to make the work worth it.  Maybe do it down the road if you have a head gasket fail or another reason to pull the engine out.  

 

+1.  you'd be like "i think it's got a little more power".

 

most frankenmotor engines involve Phase I DOHC blocks, you're talking about Phase II SOHC block. it's not as advantageous that way.

 

you can't easily use 2.2 heads, not the traditional "frankenmotor heads" anyway.  those aren't a direct swap.  different intake manifold so you'd have to swap your existing intake manifold wiring harness onto the 2.2 intake manifold but then it still wouldn't idle and perform correctly due to idle and MAP/MAF changes.

 

you can use 99-2001 EJ22 heads, your 2.5 intake manifold will bolt right to them so there's no wiring change at all, but you'd need the exhaust manifold to do it as well.

[peacewize]

Thanks for the info. I'm I bit disappointed that it's hardly a noticeable difference, of coarse in retrospect most people start with the 22 or whatever they had stock so it would be a major bump for them. I think I'm just going to do cams and.call it a day.