Should I attempt a 94 WRX rebuild myself??

[GmsWorx]

Hi,
Yesterday I had crank problems when my 94 WRX died. It's been STI re-mapped to 280bhp with over fuel. She had started tapping about a month ago and got progressively worse.
I have got another engine to go in it but I was just wandering if I should attempt the rebuild of my original engine myself.
I've been a mechanic for most of my life starting with cars but then moved on to HGV's so I know my way round an engine. Only thing is I've never done much with boxer engines!
Would I be silly to attempt to recondition it myself or should I leave it to the professionals? Only thing is cost as I've just spent out on another engine.
If anyone has rebuilt there own EJ20 I'd like to know if it was difficult?

Thanks
G

[bugeye_bob]

Originally Posted by GmsWorx

Hi,
Yesterday I had crank problems when my 94 WRX died. It's been STI re-mapped to 280bhp with over fuel. She had started tapping about a month ago and got progressively worse.
I have got another engine to go in it but I was just wandering if I should attempt the rebuild of my original engine myself.
I've been a mechanic for most of my life starting with cars but then moved on to HGV's so I know my way round an engine. Only thing is I've never done much with boxer engines!
Would I be silly to attempt to recondition it myself or should I leave it to the professionals? Only thing is cost as I've just spent out on another engine.
If anyone has rebuilt there own EJ20 I'd like to know if it was difficult?

Thanks
G

Can I ask how you managed this ?

[STIDave]

Originally Posted by bugeye_bob

Can I ask how you managed this ?

Was kind of wondering the same...

[GmsWorx]

If you mean how have I managed the rebuild, I have'nt started yet. I'm putting the other engine in next weekend.
As for my old engine I'm a bit undecided as to what pistons and rods to put in. If I'm going to do it I want to do it properly.
But, apparently with the EJ20 the pistons and rods are not forged and the piston heads are held on with pins not bolts like the STI. My EJ20 engine is not an original STI it's just been STI re-mapped. They did'nt start forging the pistons and rods until the original STI came out, I think that would be EJ205 but I'm not sure.
So it's recommended not to take EJ20 engines over 300bhp where as mine is pushing out 280bhp with 0.8 bar of boost and has over fuel so it is pushing the limit slightly.
I did'nt want to do the rebuild and have the same problem 12 months down the line.
I think I'm looking for an EJ20 engine rebuild kit with forged pistons and rods if I can, but I can only find them in USA for some reason!

[bugeye_bob]

No, I wondered how it was "STi remapped"

[GmsWorx]

Not sure how they done it!
I bought it after it had loads of work done by Scooby Teknix UK.
Needless to say I cannot find this company now but the car came from Blackburn so I don't know if they are up north some where.

[bugeye_bob]

I ran a 95 wrx for a few years with over 300 bhp(On a mines ecu), I found the gearbox the weak part if honest,
From the sounds of it you need to look at just what ecu / mods the car has, this may point towards the cause of your bottom end failure,
also what fuel did it run on, they really, really dont like cheap UL.

[GmsWorx]

Well, yeah it has been having tesco's unleaded!
As for ecu I'm not sure if it's been changed but I was under the impression it was re-mapped to stage 3 is it 280bhp 0.8 bar of boost.
Stage 2 being 300bhp 1.0 bar of boost
Stage 1 being 320bhp 1.2 bar of boost
If I got that the right way round!
How do I find out for exactly what's been done to the ECU?

[bugeye_bob]

Originally Posted by GmsWorx

Well, yeah it has been having tesco's unleaded!
How would cheap unleaded effect the engine compared to say premium?
As for ecu I'm not sure if it's been changed but I was under the impression it was re-mapped to stage 3 is it 280bhp 0.8 bar of boost.
Stage 2 being 300bhp 1.0 bar of boost
Stage 1 being 320bhp 1.2 bar of boost
If I got that the right way round!
How do I find out for exactly what it's doing? Do I have to take it back to the mappers??

Who told you crap about stage this or that on a 94 wrx ???
If your asking what difference fuel makes to these type of cars id be questioning if you should even own one, never mind be rebuilding one to do the same damage again,
this may sound harsh but I have never come across anyone who didnt know that imports needed good fuel or if you are desperate and you use cheap UL then you use octane boost to stop DET,

A standard Z4 ecu is 0.9 bar and if you are lucky you may make 280


hth

[GmsWorx]

I do know that that's why I deleted it!
Like I said this is my fist scooby and I only know what I was told when I bought it. So obviously I have been told a load of shite. So your right I need to know what it's actually doing!

Thanks