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912+STi v8 Spec-C motor
Posted: Wed Nov 09, 2011 3:55 pm
by 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
Re: 912+STi v8 Spec-C motor
Posted: Wed Nov 09, 2011 4:00 pm
by RonW
motor delievered
adapter plate
crossmember
mounted
motor mounted
turbo header mockup
turbo brace

Re: 912+STi v8 Spec-C motor
Posted: Wed Nov 09, 2011 4:25 pm
by 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.
Re: 912+STi v8 Spec-C motor
Posted: Wed Nov 09, 2011 6:53 pm
by Steve Arndt
Ugg with all the JDM spec 4 + carry the one.
Cool project though!
Re: 912+STi v8 Spec-C motor
Posted: Wed Nov 09, 2011 6:54 pm
by Steve Arndt
You can weld a -6 AN fitting directly to the end of the aluminum Subaru fuel rail.
Re: 912+STi v8 Spec-C motor
Posted: Wed Nov 09, 2011 7:15 pm
by RonW
heh, thanks steve. i'll take a look at it physically and see what you are referring to
Re: 912+STi v8 Spec-C motor
Posted: Wed Nov 09, 2011 9:00 pm
by 55superbeetle
I like what I see! Why no megasquirt, seems like you had it down?
Re: 912+STi v8 Spec-C motor
Posted: Wed Nov 09, 2011 10:28 pm
by 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.
Re: 912+STi v8 Spec-C motor
Posted: Thu Nov 10, 2011 1:09 pm
by 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....
Re: 912+STi v8 Spec-C motor
Posted: Thu Nov 10, 2011 2:07 pm
by Steve Arndt
All the acronyms and letters. It was just a light hearted joke.
Re: 912+STi v8 Spec-C motor
Posted: Thu Nov 10, 2011 5:02 pm
by ambrynmc
Duh, now I get it....
Re: 912+STi v8 Spec-C motor
Posted: Fri Nov 11, 2011 8:23 am
by 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
Re: 912+STi v8 Spec-C motor
Posted: Mon Nov 14, 2011 12:41 pm
by 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.
Re: 912+STi v8 Spec-C motor
Posted: Fri Dec 02, 2011 7:01 pm
by RonW
Re: 912+STi v8 Spec-C motor
Posted: Fri Dec 02, 2011 7:26 pm
by supaninja
I WRX stands for World Rally Cross Country
Friggin sweet, keep this thread updated