912+STi v8 Spec-C motor

[RonW]

time to start a thread here so i can start to ask some advise. inspired by Mario's Turbo I'm venturing into the turbo world. sold my t4 megasquirted motor and bought a JDM 04-05 STi Spec-C motor from JDMRacing in Canada. It arrived and looked almost like a new motor. i used an Outfront adapter plate to mate to the stock 901 transmission and I used a stock subaru outback motor mount that I trimmed down and used some leftover roll cage tubing and flat bar to make it join to the chassis. i got a header off of ebay that im hacking up and modifying to the turbo. ive cad'ed up a turbo support bracket to attach the turbo to the old A/C location.

turbo is the stock vf37 twin scroll that i clocked to work with my set up. i'll use the stock waste gate and stock bov.

in the back of the 912 there is zero air flow so no way to really use air/air intercooler so going to use a PWR 5x8 water/air intercooler that i'll place as soon as the turbo is solidly positioned.

since its obviously not an aircooled motor, i'll needs radiators. i will route the coolant lines thru the heater channel tubes the output right at the foot well which i'll run to the front right behind the headlights where i'll have to have custom twin radiators built to fit and will be plumbed in series.

i've got the wiring mostly figured out utilizing the stock engine harness and stripping down the chassis harness with the help of subaru wiring guy, Brian Keene, who merges harnesses for the subaru conversions (subaru motor in to another subaru)

pics to follow

[RonW]

motor delievered


adapter plate


crossmember


mounted


motor mounted


turbo header mockup


turbo brace

[RonW]

Question #1: I'm running the stock fuel rails and need a way to go from that to -6 AN fitting. I was thinking of some type of manifold to route the runner fuel line to then output to AN fitting. Anything out there already or recommendations?

Question #2: Turbo oil return line will need to dump to oil pain. what is the best way to do this? tig on a tube? i'd was almost thinkin there was a way i might be able to bolt on an AN fitting with a flange and do the same at the turbo.

[Steve Arndt]

Ugg with all the JDM spec 4 + carry the one.

Cool project though!

[Steve Arndt]

You can weld a -6 AN fitting directly to the end of the aluminum Subaru fuel rail.

[RonW]

heh, thanks steve. i'll take a look at it physically and see what you are referring to

[55superbeetle]

I like what I see! Why no megasquirt, seems like you had it down?

[RonW]

this motor has adjustable valve timing which I'd have to give up if I went with ms. the stock ecu is tunable with the proper interface while allowing start up just like my wifes mini van which i had difficulty getting right with ms. i'll miss tinkering with ms but having a stock ecu will be nice too.

[ambrynmc]

Hi Ron, Outfront sells a -AN adapter to the factory fuel rail. He also welds a -AN "weld-on" bung fitting to the side of the oil pan and runs the turbo oil there.

Hey Steve, what do you mean with the, "Ugg with all the JDM spec 4 + carry the one."? I'm not understanding....

[Steve Arndt]

All the acronyms and letters. It was just a light hearted joke.

[ambrynmc]

Duh, now I get it....

[RonW]

no worries steve, joke was taken as such but yes, lots of letters like its a secret hand shake heh. no special club forming, all the acronyms deciphered below

JDM = Japanese Domestic Market
vs
USDM = United States Domestic Market

STi = Subaru Tecnica International (their race division)
vs
WRX = not sure what it stands for but a turbo version of Impreza

Versions (i think)
versions 1-6 so 1994-2000
-7 = 2000-3
-8 = 2004-5

Spec-C is the homologation version for Group N FIA racing, that depending on the year with have higher compression or balance/blueprinted motor along with suspension mods/bigger brakes on the car itself.

correct me if any of the above is to the contrary please

[ambrynmc]

Instead of custom radiators, what do you think of using motorcycle radiators? They come in all different sizes and shapes (some are even curved). It would take some time to find the right size, but they would be significantly cheaper than custom units.


By the way, that engine is beautiful..call it what you like. By the way, if you want even more mumbo-jumbo, get the code off the bar code sticker on the timing belt cover. It has all the important information on the engine itself. Yours probably started with EJ207xxxxxxxx.

[RonW]

Well no kids or wife around to bug me so I was able to make some headway on the car. I didn't like the previous iteration of the exhaust, only 1-5/8" or how far it ended up sticking out back. I dumped it and started from scratch. This turned out much better at 1-3/4" and significantly more tucked up. Since the back of the car wound not have sufficient air flow for an air air intercooler, I took Mario's advise and went with a PMR water air tube style intercooler. Really nice quality and the compact size will allow me to position it to the passenger side without issue. Good to 450hp . Jamie Novak, a fellow RGrupper from Austin TX was in town and we hooked up for a few drinks and some standing about brainstorming. He has a 914 with a suby wrx motor and tranny so he has been thru some of this already too. Jamie suggested dual radiators just forward of the rear wheels and use a scoop to channel air from under the car toward it. Not much room in there with a max width of 6". We'll see. Still waiting on the flywheel/clutch/pp from Kennedy, taking forever!

[supaninja]

I WRX stands for World Rally Cross Country

Friggin sweet, keep this thread updated