I am putting a 2.5 RS engine into my L wagon. The 2.5 is a bare block with pistons. For now, I want to put in the engine and ecu so that I can start to upgrade my gas tank and dash and get it ready for the AWD and eventually the STI block that I have. For now, I need to know if I can use the heads and oil pan and everything that isn't a block with pistons from my 1.8. The only reason that I want to do this is so that I can put the STI engine together in the garage while preparing the wiring and stuff on the car. I don't really care about check engine lights and all. I am going to get all new heads and whatnot but doing this will make my life easier.

The bare question is: Will my 1.8 litre parts (i.e. heads and stuff) fit onto a 2.5 litre? What parts must I obtain from an RS to make the engine work for about a month?

Pan, pulleys and accessories will fit. The heads will bolt up but I am not sure if the intake manifold will still fit once they are bolted to the block. I only say "may" because the Ej25 manifold has a wider distance between sides and I didn't get a chance to bolt my 1.8 heads to the EJ25 block to see for sure. Others may know for certain. You may not need to change the ecu if you use the highest octane gas you can find. In fact, it may cause more problems trying to make the TB, IAC and emissions stuff from the 1.8 work with the new ECU.

The 1.8ECU can handle the EJ25 with EJ25 heads....even EJ22 heads. Hopefully you'll find that it all works with 1.8 heads too.

Jay Storm

1.8L heads on a 2.5 will give you a very high CR, talk to Matt he knows whats up with frankenstien engines. everything from the 1.8 will work on the 2.5 if you use the 1.8l heads including the Intake. Ecu will run the car but be careful.

If you also need to do a AWD conversion I wouldn't bother putting in the 2.5 block. It's not worth it. Sell the car and get one that is already AWD. It is a royal PITA and considering this is all going into the 94 that you have listed in your profile it's really not worth it as the chasis is more than likely pretty beat. In addtion to doing the AWD conversion it is highly recommend that you upgrade the entire brake system including SS lines.

Z

The SS brake lines and RS brakes are going on tomorrow with some dummy axles. The chassis is in great shape considering it's a 11 year old car. The rear crossmember for the LSD from the RS is going in tomorrow as well. I have a tranny out of the same car as the engine, but it has no rear LSD. I can find one at the yard for $50 but if someone can tell me whether I need a 4:11 or a 3:90 then that will save me some time. I have all of the drive shafts and the crossmember for the front (if I need it).

I also have the ECU for the ej25. Should I use the 1.8's ECU or the 2.5's? Whichever I use will make way in about a month for a stand-alone turbo manegment system.

Oh, and Steve. What did you mean by "be carfull"? I do plan to drive this. I think that I can prevent doing any monster burnouts, but I do need to get on the freeway and stuff.

the 1.8l ecu is not mapped to run a 2.5l. the 1.8l ecu doesnt have a knock sensor. most likely the fuel maps are way off and your frankenstein engine will have a CR of atleast 11:1. there is a good chance you will have detonation even on high octane fuel.

So can I fix that by using the RS ECU? For the 2.5, I practically have everything or can get it. I am in good with my local stealership so they will let me have all of these parts that they have laying around for cheap. I also have the full wiring harness. So can I put on all of my accessories and get away without too big of problems? I don't care about having a engine light or hard starting.

sure you can run the 2.5l ecu if you want to rewire everything and buy a complete 2.5l intake mani....thats the correct way to do a 2.5l into a 1.8l
Is your 1.8l blown?? I dont see the point of temporally installing a 2.5l block??

I am going to buy a STI block from one of my friends. All that he has is very high performance heads and manifolds and stuff. I don't have the 20K to drop into an engine swap right now. If I put in the 2.5RS engine in, along with the ECU and the wiring harness that I have, then it will allow me to start to change over everything to OBDII. More specifically, the gas tank and the AWD. I have this guy's old RS shell that he totalled. He has the engine and tranny still. I need to do this project slowly. I am going to start with the RS block with all of my crap on it. Then I am going to get a V8 STI block. Then the tranny with the block. Then the engine manegment... so on and so forth. You said that I would need a new RS intake, what did you mean.

I need to know what I need to buy, bare minimum, to get this car running with the least amount of down time possible. Also, what should the order of my upgrades be? Block then Stage 4 heads or vice versa?

Save your money and do it all in one shot. Although you think you'll be saving money by doing it the way you are thinking about doing your swap you really are not. Where you got 20k from is beyond me. If you wait for good deals to surface you'll be able to do your swap for easily less than half of that. I still think you're better off starting with a car that is already AWD.

Z

I understand what you mean by starting with an AWD, but I have my mind set on doing this. As far as being cheaper? I know that I will not find a better deal on the stuff he is selling to me (I am getting this V8 STI block for 600, and that includes the pistons and crank). When the guy had all of his engine and stuff in his RS he was making around 500 hp. He has a stand-alone engine manegment system that cost 1500 alone. I am ball-parking the 20k number.

So, any ideas on wether-or-not I'm going to need to buy anything to make it work? Please, not to be rude, but I already know what I am going to do, I just need to know if it will work.

P.S. How would I get ahold of this Matt franken-genius?

Bump.

sounds like your nuts... Im curious about the engine swap your doing right now, *the rs ej25* i would guess that if you used the 270cc ej25 injectors and an safc I/II you would be set. as for the awd swap. Yea... thats all yours. Using the ej25 ecu is pointless. Its was to much BS, you can get an safc for bettween $100 and $280. The problem is you will have 10.5:1 compression and terrable cams. Nothing you can do about that i guess. Plan on horsepower drop at 5500-6000 rpms. I have to say that in my honest opinion, build this car with the ej25 rs bottom end, keep it FWD and get another car to put build on. That way you will have a nice family mans daily driver while you build your race car. get your hands on a 95 impreza coupe

P.S. How would I get ahold of this Matt franken-genius?

I think the Matt they're talking about is Matt Monson on the boards.

Good luck with the project, sounds like a lot of fun. :)

Man! I am getting a lot of "You're doing what? Good luck." Where's the love? I personally don't think it will be that bad. People say that the AWD swap will be hell, but I have a tranny, drive shaft, clutch, halfshafts, full knuckles and rotors, gas tank, LSD, and rear crossmember. I have all of the mounts. I already have the clutch pedel and slave cylinder hooked up. I also am taking all of the wiring out of the RS and will be laying it down in my car to see what connectors I need.

Then the engine will be cake after that. I got all of the prices for this project, and by geussing high, I can have this car be a WRX for 6k. I can make it a beast for 20k. It is going to happen. You guys can choose to jinx me, or you can offer the emotional support. I am going to need all of the help that I can get. This is the NASIOC. We are the guys that say, "Take a FWD OBDI L wagon with 13in rims and make it a WRX STI. COOL!!!". We are the guys that people write magazine articles on. We are the guys that toast anything with a larger than 2 3/4 in exhaust.

I am begging you to please help me. Don't just bring me down. If you think "I'm nuts", then just say "Sounds cool, post some pictures." I already know I'm nuts, but at least I'm not doing this on my own.

Thank You.

Here is the list of stuff I have. Am I missing anything?

STI Block, no crank pulley? : $800
Heads (including Camshafts) : $500
Intake Manifold & 440cc injectors : $250
Link ECU : $900
Lightweight flywheel : $250
ACT Clutch/Pressure plate (used) : $100
Turbo kit (incl turbo, up/down pipe, BOV,
wastegate w/ 6psi spring, K/N filter) : $500
Intercooler : $200
(stock) Transmission w/ Short-throw linkage : $300
Brullen Exhaust : $250
Front strut tower bar : $40
Front skid plate : $40
Rear diff skid plate : $30
ProECM fuel/timing piggyback module : $30
EGT probe/gauge kit : $100
Underdrive crank pulley : $50


2.5 RS block, 1 cracked piston.
Stock flywheel
Used clutch/pressure plate?
Knuckle
Wheel bearing

Man! I am getting a lot of "You're doing what? Good luck." Where's the love? I personally don't think it will be that bad. People say that the AWD swap will be hell, but I have a tranny, drive shaft, clutch, halfshafts, full knuckles and rotors, gas tank, LSD, and rear crossmember. I

:lol: I don't think it will be that rough. I just hope it goes well. That's all I meant by "good luck".


It sounds like a cool project, and the nice thing about Subarus is the interchangablity of the parts. You can put them together pretty much any way you like... and it usually comes out working OK. :)

If you have the time and resources to do a swap like this then by all means do it. If you do not I would think twice about it as it is very time consuming and you will run into more problems than you anticipated.

Best of luck.

Z

Most importantly, I need to know what the order of mods I should buy as to limit the amount of problems I run into.

OK, why do you have the Link and the ProECM listed?

So that maybe someone could tell me whether or not I should do the PRO or dive right into the LINK.

I don't know much about the ProECM, but I don't think it will work with the Link too. A lot of people here have had bad luck with the Link on daily drivers. The element Hydra seems to be favored.