Subie Swap

My son's are looking to prepar their 98 Impreza for FSP autocross for 2012. Actually the suspension is all done (springs adjustable struts, etc.). However the engine has over 200K on it. It runs well with three cylinders at 172 psi and one at 165 PSI (after adjusting all valves). They are considering swapping in either:

1) A low mileage 2.2 (has a Phase 1 2.2 now)

2) an N/A/ 2.5.

What would be involved with dropping in the 2.5 and what are the differences between Phase 1 and Phase 2? I think the belhousing bolt pattern is different and I am not sure if the electronic fittings are the same between the 2.2 and 2.5. I think I nered to keep the engine 98 or older due to different airflow sensors (MAF on earlier engines). Looking for help.

If the transmission doesn't bolt up, thats where your problem will be. The other issues can be tackled. Sounds like it will be fun though.

what's wrong with the engine in there now.. the low PSI on the one cylinder is not bad. I would run what you have till it grenades

torque 2.5

Any EJ/EG/EZ engine will bolt right up to the trans.

Keep the donor 96-98 and grab the ECU for ease of wiring.

I don't see a low mileage 2.2 giving much of a power boost if that is the reason for the engine swap??

you're talking about a 7 psi difference in a single cylinder

quick math says that's a ~4% difference

This is well within spec for this motor.

Run what you got.

I'm not entirely sure that many of these swaps are FSP legal, anyways.

I wouldn't dump that 2.2 for a 7psi difference for the world.

As previously stated, any EJ will bolt right up to existing mounts and transmission.

If you're looking for more power, Delta cams (cheap!) will nab you at least an extra 10 ponies. If that isn't enough, you can swap in an EJ251 or EJ253 single cam long block under the 2.2's intake manifold, it'll run just fine on the 2.2's pre-existing electronics. You'll just need the 2.5's exhaust header.

EJ25D (twin cam) is a bit weaker and more peaky. It also will require a good bit more wiring work, and as such isn't really worth the effort in my mind.

ValuePack wrote: If you're looking for more power, Delta cams (cheap!) will nab you at least an extra 10 ponies.

Cam change isn't legal for FSP. Engine swaps are legal under the update/backdate rule as long as the engine was available in that car in a different model year. For instance, the 2.5RS motor would be legal.

...if it's on the same line in the 2012 rulebook. I think there were some fastrack mentions of the listings for those cars.

Looks like all Impreza non-turbo's are on the same line for FSP:

Subaru Turbo 4WD (all, NOC) Forester (non-turbo) Impreza (NOC) Legacy & Legacy GT

Per Schroeder wrote: ...if it's on the same line in the 2012 rulebook. I think there were some fastrack mentions of the listings for those cars.

http://www.scca.com/assets/11-fastrack-oct-solo.pdf

Yeah, looks like a proposal to bump all non-turbos back to DSP.

I think maybe the Fastrack item you're remembering is this one, from the October issue:

Per the SPAC, the following group of class listing changes is proposed for member comment (#5440): - Replace the DSP Subaru Impreza 2.5 listing with: Subaru Impreza (1993-2001) (all) Subaru Impreza 2.5, NOC - Remove from FSP: Subaru Impreza NOC

Note that this is just out for member comment, not an official rule change yet. But it would affect Moparman's engine choices if it were enacted.

I don't know why they are putting all the impreza's in DSP they are not competitive against the E46 BMW's.

mad_machine wrote: what's wrong with the engine in there now.. the low PSI on the one cylinder is not bad. I would run what you have till it grenades

Because they are shooting to dethrone me and my Neon as regional FSP champ.

Also, My son will be taking it to college beginning fall 2012. I would like hom to have a lower mileage engine.

jstein77 wrote: I think maybe the Fastrack item you're remembering is this one, from the October issue: Per the SPAC, the following group of class listing changes is proposed for member comment (#5440): - Replace the DSP Subaru Impreza 2.5 listing with: Subaru Impreza (1993-2001) (all) Subaru Impreza 2.5, NOC - Remove from FSP: Subaru Impreza NOC Note that this is just out for member comment, not an official rule change yet. But it would affect Moparman's engine choices if it were enacted.

I already wrote in defense of keeping it in FSP. Since I have direct experience with both cars with FSP suspension prep and, as is, their Impreza cannot run a quickly as my Neon, i think the SPAC will take my opinion seriously.

Hocrest wrote: Any EJ/EG/EZ engine will bolt right up to the trans. Keep the donor 96-98 and grab the ECU for ease of wiring. I don't see a low mileage 2.2 giving much of a power boost if that is the reason for the engine swap??

A little for a power boost, more for reliability and longevity.

ValuePack wrote: I wouldn't dump that 2.2 for a 7psi difference for the world. As previously stated, any EJ will bolt right up to existing mounts and transmission. If you're looking for more power, Delta cams (cheap!) will nab you at least an extra 10 ponies. If that isn't enough, you can swap in an EJ251 or EJ253 single cam long block under the 2.2's intake manifold, it'll run just fine on the 2.2's pre-existing electronics. You'll just need the 2.5's exhaust header. EJ25D (twin cam) is a bit weaker and more peaky. It also will require a good bit more wiring work, and as such isn't really worth the effort in my mind.

I looked up headers and am seeing the same part numbers for 2.2 and early 2.5's

Capt Slow wrote: I don't know why they are putting all the impreza's in DSP they are not competitive against the E46 BMW's.

They are not putting them in. It is a proposal, up for member discussion.