Join Date: May 2016
Location: Winnipeg, MB
Car Year: 2003
Car Model: Forester STI
Feedback Score: 0 reviews
Well, I've driven the car all winter and it never left me totally stranded.
I've had a few unique issues, and a few recurring issues.
-The harness splice was quite easy. I still have the old EJ25 harness tucked away behind the RHS strut tower - the swap is completely reversible. The EJ225 ECU is in the stock location, and the EJ20K ECU is bolted into the glovebox.
-I had to use the turbo subframe and swaybar with the forester control arms. The two parts have different swaybar end link orientations so neither cars' fit. I need a 5" link with ends indexed 90º. I think the rear link off a mid 00's Elantra work. Do not drive around without end links when your axles are too short.... thats how you get exploding axles. Also the control arm hits the subframe right at the front inner bushing, but its not a big deal.
-STI rad is too thick, it would hit the belt covers. I just used the Forester rad (5/8" core) and I have had 0 cooling problems over winter :P.
-Power steering required some creativity. Wound up using the Forester pump (with some grinding), Forester rack and Forester lines (with some bending).
-Deleted the STI coolant reservoir since I used the Forester rad/overflow.
-Forester throttle cable was about an inch too short, but I flipped the cable bracket over (with some grinding) and it works great now.
-Had a noisy rear diff that took months to diagnose. Finally found it by putting it up on 4 jacks and removing the driveshaft. Found another mechanical rear diff in town and swapped it - now its quiet aside from the regular mechanical diff grindy noises. I tore down the transmission and transfer case three times trying to find this problem - I could have sworn it sounded like it was coming from the front. The bonus there is my trans fluid is clear instead of black because it has been so well cleaned and flushed.
-The engine, trans, driveshaft, and diff mount the same.
-Just fit up the 3" GC8 turbo-back exhaust. Needed custom hangers, but thats no problem. It cleared driveshafts, fuel tanks, sub frames, and bumpers.
-The AC doesn't work because the control systems are intrinsically different. I have not given up hope yet, though!
-The cruise doesn't work either. Haven't even looked into it.
-Can't put the cap on the clutch fluid reservoir because the intercooler is now in the way. Don't have a good plan for this - its currently just wrapped up in shrink wrap to try and cover it.
-Had the pins INSIDE the MAF break apart. Just resoldered them and its been solid. Bought a spare before I figured it out, though. The intake system on the GC8 doesn't really fit so I just put a mushroom filter on the end of the MAF.
-The axles from the GC8 are about half an inch too short, and as a result I have exploded the front left inner joint three times. I can reassemble it on the side of the -road in about 8 minutes now. This last time I lost a bearing outer race, so I will be buying 2002 forester axles, which have the female inner joints and are the correct length.
-I had a rear axle come out. Took me a few minutes of driving to figure it out...It feels like a slipping clutch except your speedometer keeps up. The axle actually slipped back in at one point and I sheared the splines off the tip of the axle past the circlip - just ground them off and popped it back in and its been good so far.
-Had one of the front brake pots stick really hard one day. Had to drive it to the side of the road with a locked tire in 1st gear at 15lbs boost. That also exploded the axle. Turns out the caliper piston is rusty. Might see if a local machine shop can make them from stainless for me. Seal kits are cheap.
-Using a wideband sensor to read AFR (because I was worried about fuel pump capacity - but its a non-issue) and it simulates the narrowband signal. I think the wideband is a slower sensor, plus its further downstream, plus its simulating a signal. I think these delays are causing my AFR to wander at constant throttle. Just enough that you can feel the car surge at like 0.25-1hz on the highway.
Maintenance this spring is rear struts, end links, brake rebuild, new correct length front axles, finishing up the gauge cluster, lighting the clock (pure reflective LCD was dumb, Subaru.), swapping Forester seats back in (GC8 sit way too low), front fender liners, and a few other little things!
I hope to get a few more winters out of it.
All in all, not mad about the swap - this thing is faster than my M3 now, but I would not recommend it to the faint of heart. Plan to take 2-3 months to do it.