teknopete

Can anyone thats done a head swap on a 93 wrx tell me,
Is it possible to fit STi heads ? If so what was involved in it?
Was it just a straight swap or were there other parts required?
Did u change to steel gaskets? Was there enough clearance for the pistons, did you need to shim the heads etc? Any info greatly appreciated folks, thing is though got an event comming up that I need 2 get this done b4
I`d heard that some1 had done this before but cant remember who Pat ? anybody ? Mail me offline if u prefer

Thanks
Pete

R19KET

Pete,

I've not actually done it myself, but since all of the "Phase 1 engines" are nigh on identical, it's not a problem.

It would also be worth changing the inlet manifold to the later one, so that you could either "straight entry" the TD05, or have the option of fitting a VF turbo at some point.

You don't have to worry about compression ratio, you just need to order the pistons, and head gaskets to suit the heads.

Cossie pistons will be the easiest to get hold of, and there are several choices of rods.

There are mixed opinions of the strength of the crank. Nearly all the cars in Aus' run a standard crank, regardless of the power. Same in the US, but over here, people seem to feel that they are good for circa 400ftlbs.

As for power, well that would depend on the turbo, boost, ecu/mapping, and how well the engine is put together.

Mark.

Stuart Knight

iTrader: (2)

Pete, I feel I may be qualified to answer this as I have done it to my MY94 WRX. While the engine was stripped down had the bottom end checked, but it was absolutely unmarked at 80,000 miles, so rebuilt it with just new shells/bearings. Had a slight overbore (wasn't necessary but my mate rebores engines, so it didn't cost much) and fitted Cosworth STi 4 pistons. Sourced some STiV heads (off a GTB Legacy actually, you only need to blank the oil feed to the second turbo) Make sure you get the cam wheels with them as the early ones don't fit (you will also need the later cam belt covers). I modified my early manifold to fit the later heads by sawing it in half and having 18mm inserted in the middle, and a couple of adapters plates made for the heads, but in hindsight I should probably have gone for the later manifold (at the time I was told it wouldn't fit, but I now know better). Head gaskets were STi IV (they are the thickest apparently). I think the exhaust manifold stretched enough without modification, but I may be wrong. Had the ecu remapped to allow the red line out to 7400-7500 (didn't fancy 8000). Just changing the heads and pistons and upping the rev limit did not produce any more power (Well 1 or 2 horses) but the car was running 293 bhp/275 lb./ft beforehand. The IDC of the 380 injectors was however 98% and the intercooler was struggling too. So I then put a PACE FMIC and changed the injectors from 380 to 440 then 550 (with an uprated fuel pump). Car now runs 330 bhp/300 lb.ft at 1.2 bar and is mapped very conservatively (i.e no knock on the knock link on very hot day, 5th gear full throttle uphill drags)

teknopete

Mark,

Thanks for that, jus what i wanted 2 hear
Yeah I`ll have a look at the manifold thing whilst at it,
(can hear sceems of pain from my ccard already ).
Was considering doing this as a 2 stage process.
I`ll mail u some info and if u get a chance let me know what u
think.

Cheers bud
Pete

dhorwich

teknopete,

Sorry to highjack the thread mate... but just got a question about a header tank....

Did you put the newer metal header tank on your scoob as mine has decided to leak again and im thinking of putting the metal one on so i dont keep getting this problem...

Would it be possible to let me know how you made it fit e.t.c....please:+pics

Any help would be great as im leaking...:

Dan

teknopete

Stuart,

U jus answered my mail b4 i sent it 2 Mark
That is identical to the plan The cars running 307BHP / 285 Lbft jnow @ 20psi (1.3bar) but could really do with a "bit" more, u know how it is
The FMIC is in place now (Pace as well) still have the old faithfull TD05 and the link running it all.
Is it possible 2 stage it ? IE heads first, pistons n rods
in a couple of months. Or does it all have 2 b done in 1 swoop?
Am i right in thinking the block doesnt need removed to do the heads (or i`m i jus being stupid)?

Thanks again guys, looks like I`m starting 2 get on track now
Pete

teknopete

Dan,

Got u r mail m8, sorry bout the slo reply (from last night), as u may b able 2 tell got a small prob myself jnow I`ll get some stuff 2 gether 4 u an mail u it (pix etc) k

L8r m8
Pete

ustolemyname??stevieturbo

iTrader: (1)

Ive mentioned before re-swapping the manifolds. The old TPS is a 4 wire, with a closed switch. The newer one is a 3 wire potentiometer only. The throttle bodies are not easiyl swappable, betweent manifolds, as the early TB would foul the ISCV on later manifolds. All other mechanical reasons, can be worked around. Im just not big on the electronics side of things. Will the 3 wire work OK as a pot. only on the old ecu, or will it freak at the loss of the throttle closed switch??
Suppose an aux closed switch could be added somewhere? just a bit messy tho.

dhorwich

Your a star mate... hope it all goes ok....

Looks like it will be pumping out some power when its done....

Good Luck

Dan...

Stuart Knight

iTrader: (2)

Block doesn't need to be removed to do the heads, be much easier with the engine out though. Don't know how the STi heads would work with standard pistons (compression ratio, clearance etc)