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EJ25 engine mods
Iwish4aSynchro - November 13th, 2008 at 06:47 PM

What mods can be done to the NA EJ25 engine?

Low cost mods like.
K&N Pod fliter
Exhaust system?
etc
Various Forums mention STI injectors and shit like that. HUH

I am not thinking internal mods unless they are relatively simple.

Ideas

Thanks


pete wood - November 14th, 2008 at 12:41 PM

first up, what series EJ25 are you talking about?

Secondly, I'm sure there are some basic things you could do to help the motor. Airfilter and exhaust goes without saying. Re the exhaust, what is worth considering is an aftermarket cat. I'm almost certain that the stock cat is a massive bottle neck in the system.

I think there is a lot that can be done with this motor. To give you an idea, I've heard people talking about the heads and mentioning flow figures like 300hp from stock heads. That is cosworth territory. I'd love to get my hands on another motor and get some proper cams made up for it along with checking out the bottom end for higher revs. Outfront motorsport does a series of kits for this motor. They start with a 200hp upgrade just by using a different exhaust and ECU. What I'd want to know is whether the ECU is a pure plug and play thing or if it needs to be put on a dyno to be tuned. Check it out here...

http://www.outfrontmotorsports.com/motor_matrix.htm 


GeorgeL - November 15th, 2008 at 09:52 AM

Quote:
Originally posted by pete wood
first up, what series EJ25 are you talking about?

Secondly, I'm sure there are some basic things you could do to help the motor. Airfilter and exhaust goes without saying. Re the exhaust, what is worth considering is an aftermarket cat. I'm almost certain that the stock cat is a massive bottle neck in the system.

I think there is a lot that can be done with this motor. To give you an idea, I've heard people talking about the heads and mentioning flow figures like 300hp from stock heads. That is cosworth territory. I'd love to get my hands on another motor and get some proper cams made up for it along with checking out the bottom end for higher revs. Outfront motorsport does a series of kits for this motor. They start with a 200hp upgrade just by using a different exhaust and ECU. What I'd want to know is whether the ECU is a pure plug and play thing or if it needs to be put on a dyno to be tuned. Check it out here...

http://www.outfrontmotorsports.com/motor_matrix.htm 


Since there is so much varience in installations, each one needs to be tuned. They can probably give you a map that is pretty close, but there are always gains from tweaking. The ECU is a fairly common aftermarket unit that is fully programmable. In fact, it is an Australian product:

http://www.enginemanagementsystem.com/frameindex.htm 

Note the little tilde "~" in front of the horsepower readings in the Outfront ad. That indicates "approximately" and while it may be possible to approach 200HP with a stock 2.5l engine and a programmable ECU I doubt that they are really going over 180 and probably blowing fuel efficiency out the window in the bargain.


Iwish4aSynchro - November 15th, 2008 at 10:21 AM

Ahh as for exact engine model, that's tricky as it was not my doing so all i have is 2001 outback. + Engine number. Writing from wrecker/importer on manifold is 2001 forester DOHC etc.

But since found out that's wrong because Subaru Australia didn't have the EJ25 in a 2001 forester unless it was a Twin Turbo. It definitely aint a 2x Turbo. HMMM 2xTurbo.

I have read elsewhere it is not a good idea to shove a turbo on a NA Subi engine.

Got he K&N filter downstairs, Gotta wait until end of month for money.

But as i suggested i am not looking for internal mods. I was thinking about the http://smallcar.com/index.php?act=viewProd&productId=51 

But US/AU dollar is up crap at moment, so buy the bends and flanges here in OZ and have them welded up in town.

Any hi-flow Cat will do?
What about muffler?


ratbug - November 15th, 2008 at 07:24 PM

On a normally aspirated engine, you will have to spend a fair few $$$ to get any real power gains. Any changes, such as cams and different injectors is going to at least need an aftermarket computer and tune.
I have an EJ20 N/A and gained nearly 20hp at the wheels by using an aftermarket computer (microtech). The exhaust and pod filter were already done prior to the dyno runs, so don't have any figures on the increases they did, but would say they would have been minimal.


kombi kountry - November 17th, 2008 at 10:22 AM

from memory (you'd want to check this though) a 2001 forester will be the 115kw sohc unit, same used in the liberty rx of the time, however, when the ej25 was first introduced to the forester, although still sohc, was rated at 112kw. This is all for Aust. delivered vehicles mind you.

would it be worth having it dynoed first to check it's putting out the manufacturers hp (i.e. make sure no problems with computer)??? although you'd hope the previous owner had this checked when doing the conversion?

has it got the original wbx 2.1. exhaust on at the moment?

btw: how do you find it performs in general? always been interested in an ej25 conversion on a T3. you've got the 5 speed right? ever feel like it could do with a bit taller gearing (i.e. taller tyres, after market r&P, or taller 5th ratio from a wbx 1.9 unit)


pete wood - November 17th, 2008 at 10:32 AM

Quote:
Originally posted by Iwish4aSynchro
Ahh as for exact engine model, that's tricky as it was not my doing so all i have is 2001 outback. + Engine number. Writing from wrecker/importer on manifold is 2001 forester DOHC etc.

But since found out that's wrong because Subaru Australia didn't have the EJ25 in a 2001 forester unless it was a Twin Turbo. It definitely aint a 2x Turbo. HMMM 2xTurbo.

I have read elsewhere it is not a good idea to shove a turbo on a NA Subi engine.

Got he K&N filter downstairs, Gotta wait until end of month for money.

But as i suggested i am not looking for internal mods. I was thinking about the http://smallcar.com/index.php?act=viewProd&productId=51 

But US/AU dollar is up crap at moment, so buy the bends and flanges here in OZ and have them welded up in town.

Any hi-flow Cat will do?
What about muffler?


I think any hi-flow cat is going to be better than the factory jobbie. Re that header setup, reading the spec on the site, it's about being COMPACT rather than flowing well. The primaries on that one look shiny but I reckon (from the little I know) that they are way too short. A proper 4-1 setup would be much better for power I think. A local exhaust shop could make you a much better setup but expect a $1k price tag for a custom exhaust. Outfront do this one...
http://www.outfrontmotorsports.com/exhaust_setups.htm#External%20waste%20gate...
But I suspect it's not at it's best for an NA motor.

Re the EMS stinger, yes it's an aussie ECU.


Iwish4aSynchro - November 17th, 2008 at 09:20 PM

OK so you guys have changed my mind. Gunna do the Hi-Flow cat and exhaust system + Pod filter K&N.

That's all. Too much stuffing about and i ain't a rich man i own 2 T3's.

Kombi Country.
Ahh mate i purchased vehicle from Yan at Wolfsburg Motors in Sydney, he did all conversion work and i picked it up on ebay, Bargain. Only a 4 speed though it does have the taller gearing not sure if for all cogs but definitely 4th. Rubber is 205/70 on a 15 I think maybe a 75. But either way sits on about 27-2800Rpm at 100K's I would like it lower, but hey too many mods.
Yes stock exhaust. Reversed Subi into VW Cat and Muffler.
Performance is what a T3 should have been to begin with.
It's just so driveable, cruises and has power left over. Want to knock it back a cog a 105+ sure use 3rd fly past and move on. Bloody beautiful. Gotta be steady on the throttle in 1st and 2nd but u get used to that. Wheelspin is not uncommon. Where u at? Mate drop by have a drive. I am converted. Too many advantages.

Pete.
Had the though of buying the bends and getting it welded up by a mate, welder fabricator by trade. Was thinking about an off set center between 1 2/3 4 and then running duel outs. Know what i mean. Might simplify the outlet points and mounting etc. Mount to the chassis rails. Exit each side less pipe better flow and better note. Sort of like Link provided but improved, I do like their header pipes though., buy them and then weld on. Hmmmm


kombi kountry - November 20th, 2008 at 03:38 PM

thanks for the insight...

yeah i had a good read of your original post when you bought it. you sure saved yourself a shed load of $$$ by avoiding the conversion yourself plus install of 4-speed, plus after market wheels/tyres.

just going off what i've read in the past, the 4 speed sounds better for the conversion anyway, plus i think aftermarket R&P's are easier/cheaper to come by.

very kind offer re the test drive, although i'm in Syd. never know, maybe if i'm passing by some time.

re the rpm's @ 100. that's about spot on what the ej25 does in the 5 speed liberty/forrester so engine should be used to it

i'm definately keen on the conversion although am going to have to cite the current economic downturn as reason for putting it on hold for the time being :)


Iwish4aSynchro - November 20th, 2008 at 09:38 PM

Mate offer is there if u get up my way. Bloody beautiful place up here in gods country.

Good to know that the stock subi sits on roughly same rpm at 100.