Assume a target of 300 hp on a NORMALLY ASPIRATED Subaru street (not race) engine. Is it possible, and if so, how to do it and for how many $...?
I have in mind a "faux" Porsche 908 using a tube frame and Miata suspension. If my research is correct, the Miata and the 908 have very similar track/wheelbase. Seems like it could be a neat build...
stroker wrote:Assume a target of 300 hp on a NORMALLY ASPIRATED Subaru street (not race) engine.
Very heavy assumption. Cubic rpm, cubic dollars.
The EG33 in the SVX has 230 hp stock, I'm not sure how easy it is to get more power out of it.
Use one of the modern H6 engines rather than the H4. That should get you significantly closer. The older SVX is also available, but I think it could be harder to reach your target.
Buy an EG33, send the cams to Jon at Delta and tell him what you are looking for then buy some high compression pistons. You will may need a fabricated intake, an aftermarket ECU and almost assuredly some higher flowing injectors. The stock exhaust "headers" seem to flow quite well so the "bang-for-the-buck" modifications will probably be found elsewhere in the engine.
There is a thread on either nasioc or rs25 about a "time attack" 300hp N/A 2.5...of course tons, TONS of money is involved.
I'm trying to figure out if you could build a flat-8 with a custom crankcase...
MadScientistMatt wrote:I'm trying to figure out if you could build a flat-8 with a custom crankcase...
Why get so involved? Just build an adapter from rear flange on the front crank to the front snout on the rear crank.
There was a guy here built a drag car from a R100 with 2 13B engines. He modified a bellhousing to join them, had a clutch between the two. Start the rear engine, let clutch out to start the front one, stage, run 12's, turn around and do it again.
will the eg33 fit all of the manual subaru transmissions of the same years?
Andrew
digdug18 wrote:The EG-33 is a direct fit to any 5 or 6 speed that was mounted to any EJ engine.will the eg33 fit all of the manual subaru transmissions of the same years?
Andrew
The_Jed wrote:There is a thread on either nasioc or rs25 about a "time attack" 300hp N/A 2.5...of course tons, TONS of money is involved.
Search for "Gobstopper"
Eh, I was thinking about the wrong car. Gobstopper is turbocharged...
This might help a bit, but with an EJ25x motor you're looking at serious $$ to make that kind of power without turboing it. You also said non-race engine, so I'd have to say not with a 4 cylinder Subaru engine. One of the sixes may be able to be pushed that far IDK.
Wiki sez the 3.0 6cyl EZ30R is good for 245hp... 300hp would be only ~20% increase from bone stock, unless that 245hp claim is exaggerated. Wouldn't improved exhaust and porting make up most of that?
Streetwiseguy wrote:I know this was for a 908 not a 917, but the 917 engine was a flat 12 with the power take of in the center due to torsional vibration. I belive there is a replica in Australia that uses two flat 6 911 engines end to end with a center power take off, one engine runs in revers. If you really wanted to get fancy, follow the same thinking with two flat 4'sMadScientistMatt wrote:I'm trying to figure out if you could build a flat-8 with a custom crankcase...
Why get so involved? Just build an adapter from rear flange on the front crank to the front snout on the rear crank.
There was a guy here built a drag car from a R100 with 2 13B engines. He modified a bellhousing to join them, had a clutch between the two. Start the rear engine, let clutch out to start the front one, stage, run 12's, turn around and do it again.
modernbeat wrote:Eh, I was thinking about the wrong car. Gobstopper is turbocharged...
Just a wee bit, yes.
300hp is possible out of a N/A subie 2.5, if you look in the N/A section on nasioc.com, there is a build thread. That is the upper end of that engine though. The eg33 could go there using the same methods. The newer ez 6's have enough electronic stuff, you'll have to know your stuff with ecu's to get the power you would need.
You could also just go with a stock STI motor setup(but that is turbo) and have 300hp without modifying anything. It will likely be as cheap if not cheaper a route than trying to hit 300 N/A. It would also be far more streetable.
Build a killer low compression NA engine and the TURBO it!
I'd imagine it'd be a cranky, high strung, short lived, torqueless wonder.
In short, a race engine.
Any love for the overall concept?
I guess if you dropped the Subaru the only other real alternative would be to use a 911 engine...
Just wanted to say that Bob the Fabricator made ~220 whp in an eg33 impreza. Mods were intake, custom long tube header, exhaust, and hundreds of hours on a dyno. (It was one of the cars used for the EFI Logics tuning training.)
I personally believe that 300 hp NA is easily attainable with the eg33. The biggest downfall of the motor is that people who own them tend to buy a prepacked tune known as ECU Tune.
And yeah, sorry for the thread resurrection. 
The concept itself is great, getting it to completion... Not so much. EG33 or EZ30 are your answer. Subaru's flat fours have terribly shaped combustion chambers that hate the kind of timing advance necessary to make 300hp on a flat 4. E85 or race gas would make the dream worlds easier to achieve with an EJ25D/1/3, but a cammed flat 6 on pump gas would be more reliable and far cheaper in the long run.
Did you see the 2.5 longblock on the local CL, Stroker?
Go get it...mull it over, and when you don't use it you can sell it to me if I ever need it for my newly-acquired outback
Clem
