Sti engine into WRX help
 

Hi people,
Ive just bought a JDM 2002 STI engine to fit to my 2002 WRX, now my question is what's the easiest way to do this, can the AVCS heads stay on and just not operate? or can the cams be replaced with the cams from the WRX or is it just easier to swap heads?
Ideally i'd like to leave the motor in one piece and just drop it in, i have seen a conversion to get the AVCS heads to work here http://www.importtuner.com/tech/0311...ion/index.html but planned on doing this at a later time if it was possible?
Whats your thoughts?

my limited knowledge says you will need a sti ecu and a sensor will have to run to the gearbox so probaly a wiring loom aswell.

But shouldn't if you don't wire the solanoids up on the heads?

You'll need a STI ECU and the transponder chip (to match) for your key, Then just follow the instructions in the link you posted.
I did the same a while ago and haven't looked back :D
If you're not confident with wiring then get an auto electrician to do it (I did).

So what your saying is it's just easier to change the heads, as i don't have the loom nor ecu

When did i mention changing the heads?
Buy a STI ECU and wire it up (most Subaru breakers will have one). It's really not rocket science!

advice with an attitude, i like it.

I know it's not rocket science, but your assuming im just after power when im not, my need is for speed, time wise nothing more

you will need the ecu mate, if your after just the power
get your car mapped. the engine will be stronger.

i've put an sti v7 block in my uk classic.but have different heads (sti v4)
works a charm, but as aboth, you need to source an ecu to make use of your new engine.

No, you all seem to be missing the point, i need to fit this engine now to get the car running again, im not bothered that it has STI heads i just want to know the quickest way to get it fitted and running, if i can leave the heads disconected and just run it like that then thats fine, i'l worry about wiring the heads up after

No you cant just put the eng in. your best bet is to swap the heads.

about to put that my self.
if you use the engine as is, you need all the wiring inc ecu, with the ecu you'll need the transponder.

where as if you use the block, and put another set of heads on, you'll be fine.
but may/will need a map due to different compresion ratios and set up

Ok so why? as the cams are obviously pressure driven via solanoids which presumably retards them higher up the rev range, what else is different?

If the solanoids don't operate then the cams are static again

your wrx ecu will flag a fault code up as there is no tumblers on a sti as mentioned there is on a wrx

Im using my manifold so that should be ok?

yes, I thought you were trying to use the whole lump, will get my coat lol

No didn't buy the inlet as i saw no point, just wanted the bottom end

Surely it's easier/faster to source a STI manifold/ECU and bolt/wire it in rather than swapping heads over etc
Tbh when I fitted an STI engine in to my WRX I'm sure I read somewhere that you can block up the AVCS oil feeds and run it without, Although the performance will suffer (but as you said your not that bothered).
Personally it makes sense to me to do it properly first time round, But I don't know your circumstances.
Seems a shame to lose the advantage of the AVCS.

Time and money are the key factor here, the motor thats in it now was forged recently but has spun a bearing, so after laying out for that then buying this new motor it's starting to weigh heavy on the pocket, ilooking at the STI motor i couldn't see any reason why it won't just slip in 'as is' oil feeds shouldn't need capping as there operated by solanoids so cams would just be 'flat' rather than 'dynamic' but that shouldn't matter, but it looks like no-body has actually done it

2002 jdm sti engine doesnt have an immobiliser. better to put evrything in including the harness

wire the avcs solenoid (5 wires) into the tumble generator valves (3 wires solenoid and 2 wires position sensors) - or swap the intake manifold over. or get an STi ECU.

for speed you need to swap the heads.

You could lock the cams in place but the car would need a remap to suit and iti s a pointless route.

You either need to fit the whole engine and wire the avcs in but assuming you don't have the sti injectors, turbo you will need it mapping anyway.

easier to just fit the wrx heads to that bottom end.

I would spend the slight extra and small amount of time to strip the short engine once heads off and replace the bearings though. As the pistons are different it would need mapping but in theory it should be okay on the standard wrx map.

Simon

Have you been down this route? its basically what the link i posted shows which is what i was thinking of doing but just not straight off, i just nee to get it mobile and quickly


Simon: why "lock the cams" presumably they are already set in position the solanoids just operate electronically and oil pressure then moves them? or have i got this wrong

I thought this was all about speed (time). the amount of time youve been on here you could have swapped the heads and had the engine in. you asked the quickest way to get it running and i told you along with others.

This is true, but i also have to wait for weather at present as im doing it at the side of the road due to circumstance!

Nor have i got a definate answer as no one seems to have tried just running the motor 'as is' or understand how the AVCS works! just comments

If no one has tried it, Then doesn't that tell you something!

Not really no, i asked for advice not sarcasm, but now perhaps i can see why theres so many Subaru forums and i thought the MLR was bad!

they are activated by the oil solenoid but may not be in the same position or remain in the same position and need locking so the timing doesn't vary..

but if you don;t have the sti manifold, injectors, turbo, ecu, etc it seems a bit of an outlay plus small hassle adding the wiring etc..

Simon

i'd swap the heads over and sell the sti's heads. Could make some money back:thumb:

Apparently not as Paul's had some for sale for ages and no takers, engine's fitted now anyhow, complete