I am in the process of trying to plan out a custom turbo kit for my 2.5rs. I have a couple options and I am trying to find out what is going to be more upgrade friendly and which would ultimately be the funnest.

1- Legacy Turbo: exhaust manifold, crossmember, uppipe, IHI turbo, downpipe, any intercooler and BOV, custom midpipe/intercooler piping, plus minor modification to waterpump and thermostat. Pros: Almost completely bolt on.
Cons: Adapting WRX waterpump. (is it just a simple replacement?) Getting this to fit. Limited aftermarket support and upgrades.

2- Custom Fab: custom uppipe and downpipe (ie: JC SPORTS style), custom intercooler piping, any intercooler and BOV, any turbo, and any wastegate configuration (easiest to do integrated wastegate a la JC SPORTS).
Pros: No headache of matching parts, just build to fit. Lots of examples on the market.
Cons: On my own for design. Lots of fabrication. Custom piping can get expensive.

3- WRX: "borrow" WRX turbo components; exhaust manifold, uppipe, downpipe, IHI turbo, intercooler and piping, crossmember, (waterpump?), did I miss anything?
Pros: Completely bolt on. Complete aftermarket, especially with new WRX coming. (BPM, MRT, STI, SYMS, etc). Could actually build completly with just aftermarket items.
Cons: Availability of the parts; where do you find these things at a good price? Is the sizing going to be ok for my larger EJ25 motor? Could always build with 22B parts I suppose.

Right now I am leaning towards the WRX setup because of the aftermarket support I will have. However, I am concerned with the sizing of the components since it would be initially designed for the EJ20. On the other hand the Legacy turbo setup is easily found and readily adapted. It does not lend itself to upgrades though.

I dunno what I am going to do yet, so how about some opinions? Imprezer, Tim Prudence, Diz, efoo... what do you guys think also? If you had to do it again, what would you do? Anybody else out there contemplating this?

Thanks,

Jon

Um, the sizing for the WRX turbo, whatever spec of IHI it is, should be a lot closer to "right" than the one which was used on the Legacy Turbo along with the EA82 turbos!

Just a thought.

what WRX components are you borrowing?

The new WRX? the current WRX? STI?

I think the new WRX components would work great for a 280-300hp buildup.

Stimpy, the WRX setup is not really a bolt on. The header will fit if you use WRX/Legacy Turbo waterpump (some head dremeling might be required). The turbo will bolt on and so will the downpipe. Whole bumch of wires will have to be relocated out of turbo's way. Forget about using WRX IC and IC piping. NO GO. Its too long to explain, but it won't work.

I went WRX route simply because I wanted to be able to use those CUSCO part and be different. And, I have done (and still am doing) the entire job myself. The IC has been ordered so it won't be too long anymore.

Feel free to ask any question if you have them.

alex you could have saved yourself a bunch of cash and just got in on the jc sports gb http://www.i-club.com/ubb-files/rolleyes.gif

Ah, OK. That was some of the information I was looking for. Is the relocation of wires necessary because of the higher mounting location of the turbo? I noticed a lot of the aftermarket companies are locating their turbo lower than WRX's. Or is it just that SOA wanted to run wires there because there was no turbo occupying that location? (I've got no problems relocating wires)

Could you elaborate a little on the WRX IC not working? Is the intake manifold/TB different, engine not in there quite right, different firewall location...? After reading a little it sounds like the '97 sti intercoolers will work, but they still need custom piping.

I am assuming the WRX/Legacy Turbo waterpump needed for either the legacy or WRX headers? Tim Prudence mentioned that his legacy exhaust manifold had to be shimmed to fit properly, so I am assuming this is what the head dremeling would rectify?

I really like the idea of having full aftermarket WRX support if I did this. If you had to do this again, would you opt to go the same route or would you rather just save the headache and buy a pre-made kit?

Oh, what exhaust manifold did you end up using?

Thanks,

Jon

I know, Bill, I can't sleep because of that. http://www.i-club.com/ubb-files/biggrin.gif http://www.i-club.com/ubb-files/biggrin.gif http://www.i-club.com/ubb-files/biggrin.gif

I mean CUSCO or JC Sports? JCS, of course. Too bad CUSCO's bathroom break was much shorter than JCS's, so I got ahold of them earlier. LOL

Well for WRX parts, I was actually considering BPM, SYMS, MRT, and/or others. I think I will probably just use basic WRX parts for now, (exhaust manifold, uppipe, downpipe, intercooler, turbo) and then upgrade to higher components later. By the time I get the Tec-II going, it will be spring so maybe somebody will have already wrecked a new WRX. I don't know about part compatiblity between the old and the new, though I am assuming the entire exhaust section on either will be completely bolt on.

I am curious to see what I could get the upipe, downpipe, crossmember, and turbo for (JDM or Aussie parts).

Imprezer: Any answers to my questions in my previous post?

The IHI in the 85-90 Subaru Turbo is the smallest of the Subaru turbos that I know about. It uses a different pattern than the WRX Turbochargers The Legacy Turbo has a bigger turbo that seems like it might be just a bit smaller than the WRX one. It shares the WRX Turbocharger bolt pattern. Then there is a large variety of turbos on the WRX. You will need to ask someone else as I don;t know much about them.

The 85-90 seems to be good to around 200HP with intercooler, though your milage may vary.

The Legacy Turbo was 200HP in Japan and Euro spec versions. /i think this was due to computer tuning and running more than 7psi of boost over the 160HP legacy Turbo. The EJ-25 has MUCH MUCH better heads than either the EA-82T, or EJ-22T which will make more HP on less boost.

The WRX Turbos might not be that happy of a choice as I recall them running 17 psi for the 280 HP.