Was the EJ25 ever in a WRX STi? The company who built my engine (Outfront Motorsports) claim that is was built on a crate STi shortblock, but it says EJ25 right on it. In the bit of research I've done it doesn't appear that the EJ25 was ever in the STi. Others on here have told me it's an EJ25D based on the picture below, so i'm just trying to figure out why the company who built it is claiming it's from an STi shortblock.

 

 

All USDM STi's are EJ25's, yes. Specifically the EJ257 but the block will only say EJ25. In all likelyhood the company is being totally honest.

 

GD

Is there a video of that?

It's older phase 1 EJ25D heads and intake manifold.

 

If Outfront says it has an STI shortblock, it probably does, they are a reputable business.

Sti in USA is 2.5

Sti in all other markets is 2.0

2.0 is the better engine all around. In the US Subaru wanted something they thought could compete with Mustang, etc on accelration. On US pump gas, 2.5 did that better.

ej20 is solid deck, much better and more durable.

 

if you want the best built motor you can get, you use the EJ22T block with mixtures of the Sti build as for crank, heads, intake etc.

 

enjoy your motor. way sufficient for normal driving. Only time anyone needs builts stuff is for the track or rally race, normal driving on the street, legally, factory stuff is all anyone needs.

Edited July 31, 201015 yr by bheinen74

Thanks for the replies guys. Weird, my google fu must not be what I thought it was. IT looked like most STIs had the 2.0.

As for video, there isn't any at the moment, but I'll make one soon!

 

And as for performance, this buggy dyno'd at 220hp at the rear wheel and weighs only 1900lbs.

 

Oh and now that we've established that it's basically an STI engine, what is the factory redline? This buggy has autometer gauges so I have no idea what the redline should be. Seems like it starts to lose power around 6300rpm, just going off the seat of my pants.

Edited August 4, 201015 yr by Speedbuggy

That should be making more than 220hp, especially on a 2wd dyno. That's mildly tuned 2.0l power levels. The 2.5 should be putting out 280 or so.

I was going to say.. I thought the stock STi was putting out 300 at the crank? If it feels like you are 'losing power' at 6300 rpm that's probably a safe bet for a 'redline.' you could probably push a couple hundred more but why bother? (6800 i think is redline for a stock STi?)

As far as 220.. maybe they dialed the boost down a little?

Yeah - all USDM STi engines are 300 HP. 220 seems very low.

 

GD

Yeah - all USDM STi engines are 300 HP. 220 seems very low.

 

GD

 

That's 220rwhp. The engine dyno'd on an engine dyno at 300. Those number's don't sound right? What's the boost levels on a stock STI? I believe I'm currently running about 8lbs.

 

Then again, it scares me with it's current performance, I'm not sure I'd WANT more power!

Edited August 6, 201015 yr by Speedbuggy

I really couldn't tell you what the 'normal' drive train losses are.. but since you're running it as a rear engine with (likely) not a 'stock' transmission I would imagine 220 is pretty fair. I do think stock boost is 8-10 pounds. Someone please correct me if I'm wrong.

I really couldn't tell you what the 'normal' drive train losses are.. but since you're running it as a rear engine with (likely) not a 'stock' transmission I would imagine 220 is pretty fair. I do think stock boost is 8-10 pounds. Someone please correct me if I'm wrong.

 

Certainly not a stock tranny.. it's a supped up VW Beetle transaxle.

Seems to me stock STI boost was around 15 psi?

 

Most of the time you can figure a roughly 17% power loss through the drivetrain. So 220 at the wheels would be somewhere around about 255 - 265 hp at the crank. Which is probably about right at 8 psi.

27% drivetrain loss? Seems very unlikely. Most transmissions are in the 10% or lower range. Many lower than 5%.

 

GD

27% drivetrain loss? Seems very unlikely. Most transmissions are in the 10% or lower range. Many lower than 5%.

 

GD

 

Interesting.. sounds like I need to get it to a tuner sooon.

Hey Speedbuggy, can you give us some further specs on the build? Just about everything you've heard is speculation based on a stock STI. That thing is not a stock STI:banana:

 

Jacob

all transmitions loos at least 15% power

and awd transmition can loos up to 25%

all transmitions loos at least 15% power

and awd transmition can loos up to 25%

 

That's simply not true in all cases. The curve is not simply a linear progression - it's going to depend on the power that's going in as to what drivetrain losses you experience due to friction and heat.

 

For the most part, percentages are a very bad representation of power loss - the power that is lost in a transmission is dependant not only on the design of the transmission but also on how it is being used and at what speeds. To see the error in this thinking one only has to consider what happens when you *change* the engine but not the transmission. If I put a 200 HP engine in a car that was 100 HP before the swap - the transmission and nothing else having been changed - where is that extra power going? All things being equal and assuming an imaginary drivetrain loss of 25% - you are telling me that the transmission was using 25 HP before but now is using 50 HP? Now increased friction from torque, etc are going to exist for sure - but to double the HP being "used up" in the transmission under a constant load does not seem likely.

 

In any case I think we all agree that 27% on a RWD transmission like that is higher than expected. You'll want to be having that checked out and then get in another dyno run to see what it can really pull. Assuming the engine dynoed by itself to 300 HP - I just don't see that kind of loss from your setup.

 

GD

From what I found out the stock boost on the STi is 14.5 PSI.

I found a horsepower "guestimator" here: http://www.mk5cortinaestate.co.uk/calculator4.php

300 cHP w/ manual rwd = ~254HP at the wheels

300 cHP w/ auto rwd = ~239HP at the wheels

 

The reduction in HP may be due to the lower boost. Was the engine running 8PSI when it dyno'd 300cHP?

Hey Speedbuggy, can you give us some further specs on the build? Just about everything you've heard is speculation based on a stock STI. That thing is not a stock STI:banana:

 

Jacob

 

The only technical details I know about it are that it's running a Turbonetics T3/T4 around 8psi. The fuel injectors are low impedance bosch and it's controlled by an EMS Stinger ECU. I know the fuel rails are custom and I beleive the intake manifold has been reversed on it to facilitate the rear installation.\

 

The transaxle is a sooped up Volkswagen Beetle unit with Porsche 930 axles and CVs.

 

Oh and I should point out that the numbers I've been quoting are all from the previous owner. He purchased the engine as a 300hp but I don't know if it was ever tested an on engine dyno.

 

Does anyone know a good place to take it within 4 hours or so of Pittsburgh, Pa?

Edited August 13, 201015 yr by Speedbuggy

n any case I think we all agree that 27% on a RWD transmission like that is higher than expected.

Where did we come up with 27%?

 

A VW trans is not a RWD transmission. It's a FWD transaxle just like a Subaru trans. It's just mounted at the back of the car.

 

Does anyone know a good place to take it within 4 hours or so of Pittsburgh, Pa?

That place is big enough I'm sure there is a place right in Pittsburgh somewhere. Pick up the phone book and look for an automotive performance company. Or Google: http://www.google.com/#hl=en&source=hp&q=Subaru+tuner+Pittsburgh+PA&aq=f&aqi=&aql=&oq=&gs_rfai=ChX6JW99kTOLsIaPEywSP5IWMBgAAAKoEBU_QJHF9&pbx=1&fp=eb25b226ce9fcffe