I just did it last week. It works great! 835hp at the wheels too! http://www.i-club.com/ubb-files/wink.gif

Nope, 2.0 vs. 2.5... I'll definetly go with the 2.5. http://www.i-club.com/ubb-files/smile.gif

Thanks Philippe... The fact they told you that the new EJ20 is going to be just as hard to do as the jap spec probably means the new US market EJ20 electronics will be the same as the EJ20's from japan. I was told that the problem is grafting the electronics into an RS...

I know of a few people doing this right now, there is CanJam which is close to you and I also think Mike Shields from SPD in Calif. is also trying to figure it out. There's more but those are the places i've contacted.

Certainly hope it won't be too much trouble to do the swappo! http://www.i-club.com/ubb-files/wink.gif

Thanks for the reply... any others know anything???

It's been my plan all along.. http://www.i-club.com/ubb-files/smile.gif

I've thought about this since I first heard of the Rex coming to us...

I think that it should be possible, with the only custom parts being the motor mounts.

Reason: <small>This is some long, drawn-out Eric-logic, so bear with me http://www.i-club.com/ubb-files/smile.gif.</small> The Legacy will be getting the turbo engine in the GT model (opinion; also mentioned in the Autoweek article about the H6-VDC Outback). The Legacy uses the same 2.5l engine that's in the RS. Now, if the turbo can go in the same space as the 2.5 in the Legacy, I'd expect it to work in the RS as well. Hmm. Now that I'm thinking about it, I'd expect the H6 to squeeze in as well.

My apologies if this has been discussed and squelched already, I've been away from the board for a couple months.

&nbsp;&nbsp;- Eric
&nbsp;&nbsp;&nbsp;&nbsp;'98 2.5 GT Wagon - <a href="http://208.9.184.110/MembersList/ViewMemberPics.cfm?MemberID=143" target="_blank">Pics</a> - <a href="http://www.jeneric.ws/eric/radioflyer.htm" target="_blank">Page</a> -

hey 8Complex... I think the 2.5 is the best car I have ever been in, but, I also believe it is a detuned subaru. I would love to think that I could have a sube with P1 or WRX like performance and the great looks of the RS. This would, if done properly, be one of the best street cars available... in the WORLD!

...hate to bash the 2.5... but it just ain't the same. That's why we're all here right... Trying to upgrade the RS to world standards?

thanks Radio Flyer!! you bring us all some hope!!

Rallysport-

It has been argued by many over and over that the EJ25 is a better starting point to make power. Why would you want to decrease displacement?

8-

Agreed. EJ25 all the way, baby http://www.i-club.com/ubb-files/smile.gif

Sean

Hey Sean, I appreciate your arguement about displacement... but i've also heard too much about the EJ20 as being the only engine capable of 280+ reliable horsepower. I have read Mike Shield's post on another board about the EJ20's iron block with hardened crank and such...just a better bottom end he said. That's why I would opt against turbo charging my RS. I plan on keeping my car for a long time and would like the reliability of a "purpose built" turbo engine.

I would totally agree with you if we knew the long term consequences of a turbo RS, but until then I would rather not modify my car.

I do know some poeple with a minnam stage one and they have had no problems, so i don't think it's the wrong way to go, i guess it just depends on how much you rely on the dependancy of your car. I wish i could 'tune' my own car but i can't so i'm not going to break something that's not broke!! http://www.i-club.com/ubb-files/smile.gif

edit -- iron, steel what's the diff? http://www.i-club.com/ubb-files/biggrin.gif

[This message has been edited by RallySport (edited September 01, 2000).]

Mike Sheilds also said a while back that intakes and exhausts don't do anything to our cars. Then the dyno proved him wrong.

I'm waiting patiently for the new WRX to come to the US so everyone can finally see how weak-kneed and overly stressed it is compared to a properly turbocharged EJ25. Why the heck would anyone want a soggy, low compression 2.0 liter that needs to be wound out to 7000-7500 to make full power when he could have a big, torquey, high compression 2.5 liter that makes much more power, spinning to a rod-friendly 6000rpm? And don't say reliability because we've all seen the kind of piss poor tuning abuse the EJ25 can withstand. Far more sturdy than the EJ20, in my opinion.

Shiv

Out of curiosity then, what's the best turbo kit on the market... probably been covered before but are there any kits in anyones opinion that could put out 300hp -- reliably???

A strong bottom end is like insurance. Insurance against poor tuning. Like Shiv has always said (paraphrase) It's not horsepower that prematurely kills engines, it's detonation. In any case, I doubt that anyone who goes through the engine swap process will be happy with 215-225 hp (or whatever the US EJ20 will have stock). If you modify it, you'll go through the same risks as all of us with turboed EJ25. True, you will have thicker cylinder walls, piston oil sprayers, and other stuff that will allow the EJ20 to handle much more abuse (detonation) before it grenades. But you will also have to run much more boost (lower compression, less displacement) to get the same amount of torque/horsepower.

Personally, I don't think it's worth the cost and effort.

Maybe Shiv's kit?

Any of the turbos out there will do 300hp...just ask all the people on this board who have had no problems for years (Adam, Richard, etc).

Of course, Shiv's kit comes with the TEC-II, which is very nice to have, and IMO, increases reliability immensely.

By the end of this thread, you'll be an EJ25 convert too ;-)

Sean

Doesn't the JC kit use a T28, I don't know if that will flow enough CFM's for 300 hp.

hey who is this shiv guy and he has a kit now??? shiv is that web page done?

Shiv super duper website can be found at http://www.vishnuperformance.com .

I am curious to know how many others have thought about swapping their RS engine for the north american EJ20.

I know the US WRX is going to be slightly wider and longer than than the RS, but I don't know how this will effect the size and placement of the EJ20. Does anyone know if the engines can be swapped with 'minimal' modification...? I like the idea of having an emmisions legal, factory turbo for my RS, however, if the changes end up weakening the car, I would rather stay normally aspirated.

I just got my '00RS two weeks ago and so far it's the best!!


... doesn't mean I won't need more power later... when the funds become available! http://www.i-club.com/ubb-files/biggrin.gif

now way,... you guys just feel bad that you guys wased money on a fat RS. The truth is that the 2.2L is where it's at, up to 406 bhp
(not recomended though). you get a used L for 6000 and supe it up! tec-II $2000 and turbo (make one your self customized by Turbonetics!) $1700, intercooler $900, and pay a guy to put it in because you'll have no idea what the hell to do $2000 (guess...)

still comes out to a modest 12000-12500 not bad for a 280bhp (at normal conditions) car.

just felt like saying that, please don't shoot me!!!!

Hmmm, yes I did think of doing that, the plan was to wait for the USWRX to come out & swappo baby.
I checked w. a Sube dealer that has a rally car w. a 2L swap & they said, it's not going to be any simpler than doing a Jap EJ20 ... ??

Until someone has access to a USWRX's exact specs / construction details, I don't think we can know for sure.

Just thought I'd let you know what I was told anyways.

Good Luck
Philippe

Shiv, what about the Japanese or UK owners who have raised the EJ20's compression ratio or used the 2.2L conversion? They are running less boost and still retaining great performance. The 2.2L conversion is too expensive to consider right now but the raised compression ratio sounds like a better idea. The main thing is the costs involved in 2.5L engine. In order to add a turbo and clear up the tuning problems and the MAF then I will need a replacement ECU. That adds an additional $2K onto the price of a turbo kit for the EJ25. With the crap paint of the RS I would rather get the car repainted with that $2K. If a US EJ20 can be found for a reasonable amount then I will do the swap. Not looking to be the fastest Impreza but I at least want a car that is faster.

You guys got it all wrong!!! Swap in that 3.0 H6! It will blow everything away! Shi why stop at 2.5? go with the 3.0 H6 too! I'm sure you can tune that Outback to eat up that lil RS project of yours right? afterall it has another .5l to go and 2 more cylinders. Hmm....why stop there? let's go all the way to 5.7l engine! http://www.i-club.com/ubb-files/rolleyes.gif http://www.i-club.com/ubb-files/biggrin.gif

Gambit:
The problem with that logic (joking or not) is that the 3.0 H6 is a fair bit heavier than either or the 4 cylinder engines. The 2.5, on the other hand, is just about the same weight as a 2.0.

RallySport: The EJ20 isn't steel... And Trey from Cobb Tuning will argue all day that the EJ20 (later, non-closed deck) engines aren't that different from the EJ25 that we get.

[This message has been edited by Marquis (edited September 01, 2000).]

WOW... You guys might be right... http://www.i-club.com/ubb-files/redface.gif Just to note, I had talked to someone about the 3.0 flat 6 conversion. They used the same arguement about displacement... but I wouldn't, like mentioned before, agree with slappin on the extra weight even though 300 super reliable horse would be nice.

Note to Shiv -- I love the Project impreza and I have followed along from the start... unfortunately, doesn't mean I could do what you have done. A mech-e degree and a lot more time in a shop might help!

Thanks for all the posts! Glad to know that a lot of you feel very strongly about the integrity of the EJ25. From what I heard from you guys I might wait for a few years till the warranty expires, than I will go ahead with a turbo kit...

...unless of course all your cars blow up by then!!! Just Kidding!! http://www.i-club.com/ubb-files/tongue.gif



[This message has been edited by RallySport (edited September 01, 2000).]

Uhm....the new H6 is less than an inch longer! It weights about the same apparently. And so Subaru claims. So there.... http://www.i-club.com/ubb-files/biggrin.gif

I knew about the length, which is good if you wanted to actually do the swap. But I heard that the engine is like 100 pounds or so heavier than the EJ25. Maybe my recollection isn't quite as good as I might think.

hey Gambit -- when i talked to the mechanic about swapping for the H6 he said, "of course were going to have to make modifications to squeeze it in, as long as you got the money" ... ... a little bit discouraging even considering he may not have been telling the whole truth. And besides who needs tire shreding horsepower. If 300 horse and superb all wheel drive is good enough for the WRC cars, than it's good enough for me!

With that much power and the relatively light RS you could wallop any stock (under $100K) and many tuned performance cars...

I still think your right though... in general, more displacement is 'better'. http://www.i-club.com/ubb-files/smile.gif

So, here's a thought I haven't seen discussed before...
Why not wait for some wrecked 02 WRX's and steal their turbo. Then you got the best of both worlds. A EJ25 with a subaru turbo.
I am curious to know what people think about this. I figure if you could get the stock USDM WRX ECU it would work. If not,my current plans include picking up one of Shiv's TecII's in a year or so amyways, and that could run it for sure.
Will this work?

It would quite likely "work", but it would not be optimal (IMHO, anyway). A lot of people (including myself) will argue that the turbo sizing for moderate boost on an EJ20 (read: stock turbo) isn't adequate to provide the CFMs necessary to get good power out of the EJ25 at higher revs. It'd likely make a pretty meaty midrange (not that the EJ25 needs any help as such in this area), but will start to be out of its efficiency range at a certain point in the revs.

Well, it has already been shown that there is not much you can do to up the max RPM's on the EJ25 because of the valvetrain.
What I figure you would be making here is a cheap 250-275hp turbo. I am sure it would definitely outperform that gutless EJ20 that they will be importing to the states. And a lot simpler than a swap that most people would be looking for ways to bump up that 230hp from the get go.

Matt,
From what I have seen of the valvetrain, it is not our bottleneck. The SOHC heads use roller rockers, stainless valves and should be fine well past 6500rpm. Unfortunately, the engine mangement system will not let us get there, and the current cams will not produce power up there.

I think our redlines are conservative, but since torque falls off rapidly past 6000RPM the engineers had no need to raise it.

I know I sound like a broken record, but air cooled Porsche flat sixes have a similar valvetrain without roller rockers and are good to 8000rpm. Its not a matter of design just materials and execution. The phaseII heads appear to be quality in both regards.

Tim

[This message has been edited by boxerman (edited September 01, 2000).]

Matt-

You can not just throw the US WRX ECU onto a EJ25 based car, IMO. The injector sizes will be different. The injector's resistances might be different. The maps for fuel and ignition timing will be changed. Idle will be terrible, in all likelihood. Yes, it will probably "work", but not very well.

I'd like to hear more on the valvetrain debate...keep it going, guys http://www.i-club.com/ubb-files/smile.gif

Sean

Sean,
your point will become a non-issue if I've already got a TECII w/ the larger injectors. But it is all really just speculation at this point and we'll just have to wait and see what parts really are on the car once it hits the shores. It might work, it might not. I'm really just thinking out loud

As far as the valvetrain"debate" there have been numerous discussions previously that can be searched in the archives. I am one of the few here that really has little desire to jack the rpms to 8-9000rpm. If it makes the power down lower, I don't need those revs cuz I'm not looking to make one of those 300+hp monsters. The fact of the matter is that if there was a decent SC on the market that you could actually get delivered, I would go with 6-7lbs of boost on one of those and be happy. Ultimately it becomes a matter of to each his own.

Hey, Marquis. I live in Lansing, too. I have seen a white RS running around town a few times, is that you?

The 2.5 is a great engine to turbocharge simply because it will definitely get the turbo spinning a whole lot faster than any of the other Subaru engines. But I would hold back on dissing one of the most famous and proven powerplants in motorsports history. I don't know about you guys, but it was the EJ20 that got me excited about Subaru in the first place, that and AWD. I would think that the EJ25's bottom end was built to handle more than the amount of abuse a turbo would add. Take a look at Adam Bloom's RS. He ran his RS harder than anyone that I know of and all he kept saying was that he never removed the valve covers. I give respect to all of Subaru's engines and will love to see nothing but the meanest and cleanest Scoobies dominating the streets of America. If you want high RPM's, get a rotary. If you want useful and safe power get an RS, but buckle up and hold on tight.
ZEE
MYOO BRP

The 2.5 is a great engine to turbocharge simply because it will definitely get the turbo spinning a whole lot faster than any of the other Subaru engines. But I would hold back on dissing one of the most famous and proven powerplants in motorsports history. I don't know about you guys, but it was the EJ20 that got me excited about Subaru in the first place, that and AWD. I would think that the EJ25's bottom end was built to handle more than the amount of abuse a turbo would add. Take a look at Adam Bloom's RS. He ran his RS harder than anyone that I know of and all he kept saying was that he never removed the valve covers. I give respect to all of Subaru's engines and will love to see nothing but the meanest and cleanest Scoobies dominating the streets of America. If you want high RPM's, get a rotary. If you want useful and safe power get an RS, but buckle up and hold on tight.
ZEE
MYOO BRP

Don't get me wrong. I would never dis the EJ20. What I am dissing the the down tuned version they are shipping to the U.S. If we got a "real" WRX engine over here it would be a whole different story, but this topic is about the EJ25 vs TheUSEJ20 turbo.
If you we ever see widespread availability of J-spec EJ20's like you now have w/type R Honda B16's, I might be singing a different song about swaps. My last car was a Honda with a swap. I just don't think the USEJ20 can compare to what can be done with the EJ25 already in my car.

What makes you say that the "US EJ20" is not a great candidate for performance tuning?
ZEE

I never said that. I was sticking to the base of this thread, which was about swapping a USspec EJ20 turbo into an older RS(or maybe buying a MY02 turbo new). With either of those, sure you have a very tunable platform, but for a current 2.5RS owner is it worth it? My opinion is "no".
To buy the new car or to swap the engine is going to be pretty costly. I can get one of Shiv's complete kits for several K$ less than that swap(or the new car) would cost me.
But, then I got this idea that maybe I could save some money by salvaging a turbo from a wrecked US spec EJ20 and just using a TECII kit.
I am guessing here, but I think it is more than just emmissions do-dads that keep this US spec EJ20 turbo under 230hp. I bet the turbo is going to limit your output and you have to buy a bigger turbo to up the boost and hp. But, that smaller turbo might be just enough to make an EJ25 put out 275hp or so.
Just enough for a road touring street enthusiast like myself.

The US WRX reminds me of the GSX eclipse and look at what that car can do with a little TLC.
ZEE

I figure, the choices we have (for those of us who want turbo) is to either go with the turbo 2.5 (and all the attachments required: knock sensors, fuel management, boost controller, horseshoe in ass... http://www.i-club.com/ubb-files/wink.gif ) or go with the EJ20 and add chip, intake, exhaust, protection from insulted i-club turbo-vendor members, etc. and be left with a perfectly good RS engine laying around. I guess the only advantage is with the engine swap you always have an extra engine if yours explodes!

...just joking http://www.i-club.com/ubb-files/biggrin.gif, don't want war... before i started this post I would have sworn turbocharging the RS meant trouble down the line, but now that i know more, i don't feel so sketchy about a kit, GREAT!

I guess what really influenced my opinion in the first place was the first time i heard the stage two minnam on the RS. It sounded horrible, obscenely loud, backfiring and such... it scared the ***** out of me! I guess that was the desired effect though... http://www.i-club.com/ubb-files/frown.gif

So... long post... I don't think either route is good or bad, but one thing is for sure... either way, RS TURBO GOOD! http://www.i-club.com/ubb-files/cool.gif

Rallysport-

Let me guess, you heard the Stage II with a Minnam 3" catback exhaust, right? That exhaust is insane. WAY, WAY, WAY too loud http://www.i-club.com/ubb-files/smile.gif

Sean

Hey Sean, yeah, now that i remember it had a grapefruit gun for an exhaust! Real intimidating though, especially when lightening shot out the back... (...can't really remember that detail http://www.i-club.com/ubb-files/wink.gif)

I just don't understand why the "pro EJ25" guys have to always give others such a hard time for merely suggesting an alternative. It seems to me that no matter how many times this is debated, the cost and complexity involved in "bolting" on a turbo to the EJ25 is always ignored. Like N/A said, bolting on a turbo to the EJ25 is far from simple, let alone expensive. In order to run any kind of boost, an auxilliary computer of some kind (S-AFC, ITC, etc...) or an outright ECU replacement (i.e. TEC-II) is needed. Both of these can be very expensive, adding to an already expensive turbo kit ($3000+). There are those of us that aren't sitting on a pile of money, nor do we want to throw $1000s at a car that only cost $18K, and thus we are open to other options.

I don't know about everyone else, but I wouldn't feel secure driving around in a car with three different computers altering signals to the stock ECU just to get the car to run right. Not that there would be a problem, but the risk is just too high IMO.

To me, the $/hp ratio and reliability is more important than absolute hp. So to many of us, a mere 220hp would be just fine. What engine that power comes from is yet to be seen.

Dave
'00 2.5RS Sedan
'72 Datsun 240Z

OT, but 240z, mmmmmm http://www.i-club.com/ubb-files/wink.gif Hold on to that!

I guess I probably should clarify my position. I don't think that the WRX ECU on an EJ25 would be a good idea, if it would work at all. My previous statements were mostly regarding the turbo off a stock WRX.

I just wanted to mention that the EJ20 in the new WRX(japan spec) makes peak torque(246ft lb) at 3600rpms. So anyone argueing that it lacks torque and is high strung is wrong. While the actual output figures should be less for the US, the peak torque should be made at about the same point.

Don't forget an EJ20 WRX should be lighter than a blown 2.5RS with all it's computer gadgets glory.
So handling is also affected. Nose heavy for the 2.5 http://www.i-club.com/ubb-files/frown.gif

Not to add to the confusion, but I would like to make some clarification to a few statements that I've made regarding this arguement in the past.

1) I do not hate the EJ20. Far from it.
2) For all-out performance, I still think the EJ25 (w/ good rods, pistons, etc) is your best bet.

In 100% stock form though, the EJ20s (at least the ones I've seen) are more suitable turbo motors. They have stronger pistons, thicker valve guides, etc. It's not a big difference, but if you want to be nit-picky, the stock EJ20 is built with forced induction in mind.

Now, I'm sure, due to the higher compression and larger displacement, a well tuned stock-internal EJ25 can prove to outclass some EJ20 engined cars. But, throw in some poor tuning, some unexpected detonation, or unexplained boost spike, and the stock-internal EJ25 is going to fail much sooner than the EJ20.

When I've made my statements regarding the EJ25 and turbo applications, I've always been thinking in terms of upgraded internals. I have to apologize, but this is just how my mind works sometimes. I still stand by my original opinion though, build a EJ25 right, and you'll blow away any EJ20.

In stock-internal form, my fear of the EJ25 are the pistons. The top ring is very high, and I've already pulled apart a few turbocharged EJ25s with broken ring lands. I feel this is where the first weakness lay, even before the issues of open-deck or rod strength.

For aftermarket pistons, you run into the issue with the EJ25 of very small compression height (distance from pin to piston top). This gives us very little room to move our ring package around. Since this engine was designed for non-turbo use, Subaru engineers knew they could push the ring package up high, and therefore could runs a very long rod, which is a proven design feature to add power. True, a better quality, stock replacement style piston should work well for 95% of turbo applications, but if you want some serious HP out of your EJ25, you're going to need to do more homework. It's not as simple as just sending stock parts off to a piston manufacturer and having them remake it with better "stuff".

I'm not saying there's no hope for turbocharged EJ25. We do have a solution which addresses these issues, and we'll make an announcement in the vendor section when it becomes available.

As for an answer to the EJ20 vs EJ25 debate, I don't have an answer if you're talking stock-internals. It ultimately comes down to the tuner and whole package. Throw away the stock pistons, rods and other crap and then we're talking about a completely different ballgame where Team EJ25, IMHO, is going to walk all over Team EJ20.

Regards,
Trey
CobbTuning.com

In response to some of the things said in this thread, if I did not own an impreza yet, and with the probable availability of both the 2.5RS and the WRX (based on what i've heard that is), wouldn't the WRX be the best platform.... I think it makes a nice well rounded starting point to begin work, and several modifications can be made at a later point. Alas I don't have a complete list of differences between the 2002 RS and WRX, but I'm assuming it goes beyond engine, and its looking to be around 3K more.....

Welcome to the board, Akirasoft!

If you don't plan on doing "serious" modifications to your car (i.e., bolt on mods only), you are absolutely correct.

The beauty of the new WRX is that you get to finance your turbo, and keep your warranty. http://www.i-club.com/ubb-files/smile.gif

"I'm waiting patiently for the new WRX to come to the US so everyone can finally see how weak-kneed and overly stressed it is compared to a properly turbocharged EJ25."

Right. Right.

"Why the heck would anyone want a soggy, low compression 2.0 liter that needs to be wound out to 7000-7500 to make full power when he could have a big, torquey, high compression 2.5 liter that makes much more power, spinning to a rod-friendly 6000rpm?"

I don't know.

"And don't say reliability because we've all seen the kind of piss poor tuning abuse the EJ25 can withstand. Far more sturdy than the EJ20, in my opinion."

That's fighting talk, Shiv.

First off I notice that Shiv sells a kit for the EJ25, so a factory turbo will be bad news for starters. Still, I don't know why he takes the existence of the EJ20 so badly - it's not a personal attack on you, Shiv, Subaru hasn't been building that motor for seven years just to annoy *you*.

The EJ20 isn't even sold in the US, so "weak-kneed", "wrung out to 7000 rpm+" and "[EJ25 is] far more sturdy" are all, well, his opinion. Perhaps an owner of a factory EJ20 turbo will tell you how weak-kneed his car is (although I'm not invalidating the belief that a blown EJ25 is unreliable - I'm sure it is).

And the EJ25 is a whopping 500 cc bigger - big deal, frankly.

Andy T