Contemplating N/A 2.5 swap into 93 Leg
Posted: Mon Feb 28, 2011 10:49 pm
Researching right now about which direction to take on doing this swap. I am rebuilding an NA ej25 shortblock from a 98 RS and have a couple options. Just throwing this out there in case others who have done something similar can give their input and/or experiences ahead of time.
My 93 wagon is for the most part my DD, parts runner
and winter car, and always dependable (although the body is getting a little rough) so time to give it some love. This is not supposed to be a huge bells and whistles kind of thing, just a little bit of an upgrade in throttle response 
The first question that came to mind was would the Legacy ecu and injectors handle the increased displacement. From everything I have read so far the ecu's are pretty versatile and the injectors and fuel pump can handle the task most likely.
I am questioning which heads to use. I have a set of heads from an '00 OBS (EJ22). The valves, intake and exhaust are way bigger than the old school e22 heads. In fact they look to be the same size as the WRX valves. With this route I could do the higher compression but I'm stuck with single port heads, which I'll have to source an exhaust manifold and figure out which head gaskets to use.
The other option is to use the 2.5 heads and maintain the Legacy's cam gears/sensor's and what not, assuming that would work. I would imagine though that I will need the intake manifold as well to make it work. Not sure on the OBS, i'm guessing probably. From what I am seeing as long as I use the newer style head gaskets I shouldn't have to worry so much about it blowing?
I've also considered using the pink ej22t injectors and running E85 considering they are about 30% larger anyways if I got my numbers right, but then I'd have to worry about trying to control fueling and whatever else so I kinda put that idea on shelf for now.
My 93 wagon is for the most part my DD, parts runner
and winter car, and always dependable (although the body is getting a little rough) so time to give it some love. This is not supposed to be a huge bells and whistles kind of thing, just a little bit of an upgrade in throttle response The first question that came to mind was would the Legacy ecu and injectors handle the increased displacement. From everything I have read so far the ecu's are pretty versatile and the injectors and fuel pump can handle the task most likely.
I am questioning which heads to use. I have a set of heads from an '00 OBS (EJ22). The valves, intake and exhaust are way bigger than the old school e22 heads. In fact they look to be the same size as the WRX valves. With this route I could do the higher compression but I'm stuck with single port heads, which I'll have to source an exhaust manifold and figure out which head gaskets to use.
The other option is to use the 2.5 heads and maintain the Legacy's cam gears/sensor's and what not, assuming that would work. I would imagine though that I will need the intake manifold as well to make it work. Not sure on the OBS, i'm guessing probably. From what I am seeing as long as I use the newer style head gaskets I shouldn't have to worry so much about it blowing?
I've also considered using the pink ej22t injectors and running E85 considering they are about 30% larger anyways if I got my numbers right, but then I'd have to worry about trying to control fueling and whatever else so I kinda put that idea on shelf for now.