5 replies to this topic

[Daniel Loh]

Hey guys. I am posting because I couldn't find anything related to the topic above, there was but it wasn't too specific as to what EJ20 and an EJ25 from where. I'm running an EJ20K, version 3 with the early model "push type" tensioner on the timing belt (for reference) on my GC8. I'm interested in an EJ25 but I only managed to find one off a Forester SG5. Others were in pretty bad shape. The engine looks stunning and is in great condition (which is rare in Malaysia...) but I'm a little worried about swapping it due to the wiring. If the ecu sockets are the same, would I be able to swap the EJ25 over without much problem? Your anwers will be much appreciated. Thank you!

[allpaw4]

Generally, the engines changed at some point, someone else should be able to confirm this, but I beleive in 98, they went from a 4 bolt to an 8 bolt engine. So if you have the early one, the late model engine wont fit up to your gearbox.

Also, you will need to have the new engine loom patched into old vehicle loom, and the new engines ECU. Your existing ECU will not work with the new motor. As a minimum, Cam and crank sensor pickups are different between models and years, so you might get it to the stage of cranking, but it will not fire. This can be fixed by using your old cam and crank pulleys (providing both motors are DOHC). The other problem is the difference in capacity - the old ECU will only be giving enough fuel to power the 2L, which will starve the 2.5, and you'll kill the new engine as quick as look at it. As well as that, there will be numerous sensor differences.

If you have already bought the motor, you need to buy the loom and ECU as well.

 

Good luck, its not a small job.

 

Cheers,

Ben

[aekOne]

To add to the ecu issues with the original computer, the SG engine will also have TGV'S (which can be removed/modified) and AVLS.

This upgrade will require a new ecu and loom splicing

[Daniel Loh]

Man, sounds like a hectic job! But thanks for the input guys. Really appreciate it. But would it be possible if I use the SG wiring but modify the wiring for the interior instead? Such as the instrument cluster etc.? Instead of messing with engine wiring, mess with the interior wiring instead, I guess is a slightly easier option? Main thing that I have to get running is the engine, car doesn't have a/c or radio. Stripped down just switches for the fuel pump, radiator fans and etc. 

[93tzlegacy]

SG5 forester is a 2 litre, might want to confirm you are getting a 2.5,. easiest way to 2.5 your car is use your heads, and manifolds, then aftermarket ecu and a bigger turbo.

[Daniel Loh]

It's an SG body definitely. But I double checked and it's an EJ25. Other than the badge on the accessory belt covers, the block had the EJ25 badge on it as well. I was thinking of just getting the block and pistons and using the rest of what I have but it's pretty costly to do so as well.