rlaxton

Hi,

I am starting to investigate the possibility of putting a single or twin turbo version of Subaru's new 3 litre flat 6 as seen in the Outback in my MY02 WRX STi. Now I have found a source of new crate engines at around $4500 each so the base engine will not be a problem. What I am looking for is information on anyone who may have done this already. Now Mario Tobarac hinted that this had been done and that it fitted a few months ago now. There was also a car for sale on MRT site that had what I assumed was this engine stroked out to 3.2L (could have been an EJ33 from and SVX but I don't think that that would fit...).

So, anyone got any ideas? If it comes down to going it alone I am probably going to use the twin turbo Porsche engines as a pattern for ideas with two Garrett GT25 turbos running simultaneously through two separate FMIC then mixing in the plenum chamber. Autronic or Motec for the ECU seems to be the go. I am chasing a fat and streetable 300-350kW with good bottom end. I know that you can get that sort of power with the EJ20 but not nicely streetable.

Richard.

Alfer

Hi Richard,

I don't think using the SVX flat-6 is a good idea (1) its heavy, (2) its bigger. Dollars would be much better spent on the new H6 from the Outback.

As far as forced-induction, I'd be inclined to take the entire system turbos, ECU, MAF from a RB26 (Skyline GTR) and customise manifolds to fit... since they are proven to be fantastic twin-turbo setups.

K.

rlaxton

I agree about the SVX engine. It is also half as long again as the EJ20 and shares that engine's stupid bore ratio. The EZ30 is the go.

Interesting idea about the Skyline turbos... Do you have a plumbing diagram for a skyline engine?

Richard.

Alfer

Richard,

Since you are a Melbournian, lets take a cruise down a good tuning shop and check the plumbing out ... the place I go to has RB26s coming out of every crack.

K..

Alfer

Rich..

Here's what I think will work really well and would not be ridiculously expensive...

- EZ30
- De-compression plate and gaskets.
- Twin turbo system from RB26
- PowerFC / Autronic / Motec
- Water to Air Intercooler

Run it at low boost, 7 - 9 PSI..

That should give you around 500Nm of torque... maybe BP might contract you out to tow their fuel distribution tanks around town.

rlaxton

I was thinking more along the lines of:

- EZ30
- Forged pistons decompressed to 9:1 (or a bit less maybe)
- Two Garrett GT25 turbos, one per bank running at around 12-18 PSI
- Motec or Autronic ECU
- Twin air-air intercoolers

Budget is around $15000 over the cost of the engine (which is about $4500 new).

The water to air intercoolers actually are a bloody good idea. I could greatly shorten the path that the air takes. It would not be as good on the track but this is not for the track. A big cooler in front of the AC condenser would do the job.

Richard.

[Edited by rlaxton - 3/21/2002 3:00:24 AM]

Alfer

Forged piston is great! I don't have the kinda budget Hmmm.. wouldn't twin air-to-air intercooler increase the spool-up time ....

you said that you wanted a street car, wouldnt a low-boost, high-torque car more fun than an all out horsepower racer? i imagine anything over 1 bar is considered fairly high boost?

either way, i'm curious to check out the raw power of a twinturbo H6 gimme a yell when you do decide....

BugEyed

Hi Guys

Sounds a good project. What are you planning to use as a gearbox? I was under the impression that the WRX gearbox is fairly weak and wouldn't take that sort of torque in 1st and 2nd. Also, isn't the belhousing design different for the H6 engine and the WRX?

Duncan

rlaxton

The gearbox in my car is not weak. It is the new 6 speed with bigger everything ;-) I am not going to be drag racing the car anyway so don't expect gearbox problems.

Richard.

BugEyed

Richard

I'd better learn to read. The STi 6 speed should be strong enough!

Duncan