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So, what can you really do with an NA Ej25 engine?
Posted: Thu Apr 13, 2006 9:01 pm
by Matt Monson
149.1whp and 148ft/lb of tq. This is on a dyno that has stock RS's pulling 95-98whp, so I am more than 50whp over stock, and putting down numbers that stock and midly modded WRX's do. The set up, for those not familiar with the car:
MY01 SOHC EJ25 engine
Cobb CAI
Cobb EL headers with high flow cat
Stromung SS cat back
Unorthodox underdriven&lightened crank pulley
Exedy 14lb flywheel
NGK PFR-5 platinum plugs
STI head gaskets
Bone stock shortblock
Cobb Spicy cams
CHR motorsports PNP'd heads w/3 angle valve job rebuilt by me. stock springs and retainers...
Stock 2.5RS MAP based ECU with no piggyback and no CEL's...

Posted: Thu Apr 13, 2006 10:04 pm
by bmxpunk
COngradulations matt!!! Thats ridiculous!!! and best of all, no lag. What about with a little engine management? Do you think 165-170whp is possible with a tune?
Posted: Thu Apr 13, 2006 10:14 pm
by Matt Monson
Guys are singing the praises of the Perfect Power and the gains they are getting, but I am not convnced it's really more than 5-8whp. I will leave it as is for now. I have some 11:1 CR pistons that I am going to be getting from Cobb and once I build a ew bottom end for the car, then I will consider going to San Diego and having I-Speed relfash the ECU. But for now, with no CEL's and really good driveability, why bother. I have never been about having the most HP, I want something that's powerful, but reliable and don't want to cross that line into where you start to sacrifice reliability. It's a fine line, and I think some of the guys pulling larger numbers are across the line.
BTW,
Here's my dead spicy cam...

Posted: Thu Apr 13, 2006 10:15 pm
by 93forestpearl
Think that torque curve could be smoothed out a little with tuning?
I'd like to see what 11:1 pistons with tuning would do with the rest of that.
Posted: Thu Apr 13, 2006 10:23 pm
by Project_Legacy
geez what happened to the cam? looks to me that it got TOO spicy.

Posted: Thu Apr 13, 2006 10:42 pm
by Matt Monson
What's not smooth about that torque curve? Also, the hosted picture distorts is a bit. It was rotated from landscape to portrait and the rpm band got smushed. That torque curve is really smooth, and the dip at 3400 rpm you see before it shoots up is the cam coming on...
Posted: Thu Apr 13, 2006 10:43 pm
by Matt Monson
Posted: Fri Apr 14, 2006 12:11 am
by DLC
Nice numbers, and it's great to see that, if done right, this kind of power can be had with the stock ECU and no CELs.
Posted: Fri Apr 14, 2006 12:16 am
by Matt Monson
DLC wrote:Nice numbers, and it's great to see that, if done right, this kind of power can be had with the stock ECU and no CELs.
That's what floored me. Before I had a CEL because is was so damned rich. Now I don't, most likely because it has leaned out a whole point across the board...
Posted: Fri Apr 14, 2006 1:42 am
by entirelyturbo
That's simply awesome. I first thought, before reading the mods list, that you had already put high-CR pistons in it. But the fact that you didn't, and got that much power with bolt-ons and some headwork impressed the hell out of me.
I can't wait to see what you do with the 11:1 CR!!
Posted: Fri Apr 14, 2006 4:28 am
by 206er
werent you running 12.5:1 before or was I hallucinating that I thought I saw you say that somewhere?
I bet its doable on pumpgas up here. Ive run 87 on my 10.8:1 but dont as a rule.
matt, time to go to some ITB's to handle that 11:1 squeeze.
some literbike ITB's 40-48mm and megasquirt should do you nicely. cut up a stock manifold and use some silicon hose as couplers. an injected bike will have a good TPS for MS.\
man, think of the sound with some ITB's and unequal length headers with a pretty open exhaust!!! drooool
Posted: Fri Apr 14, 2006 4:55 am
by evolutionmovement
Not to sound like the dork, but how does it do for mileage now? If a 2.2 fits in an EA81 ...
Posted: Fri Apr 14, 2006 5:35 am
by 206er
a motor like this would freakin rip in a light car like an ea81. mine is nowhere near as worked as matts, but I get about 26mpg taking it to 6k all the time.
Posted: Fri Apr 14, 2006 3:58 pm
by Matt Monson
Steve,
I haven't run enough tanks of gas through it to know yet. I will update once I have a good sample set of what it's going to be like. The RS is known for really crap mileage while the ECU learns. It takes a few tanks to sort it out. And of course, I need to get over the newness of the extra power and not bury my foot all day long and start driving normal again. That takes some time.
As for ITB's and other stuff, I am not interested. All along I have approached this with a certain philosophy. I don't want to be the guy with the most NA HP. I want to be the guy with the most streetable HP that will pass emissions (which I think it still will) and has an engine that will last 100k mi.
I am also not going beyond 11:1 because I travel a lot and go down to much lower elevations. I don't want that to be an issue. I never had more than stock CR, though there was a period where I was given some misinformation about the Cometic HG thickness, and thought I was at 11.4:1. I wasn't...
Posted: Fri Apr 14, 2006 4:26 pm
by Kelly
Load Weisco turbo pistons in it.
$435 w/ rings, shipped.
Posted: Fri Apr 14, 2006 5:18 pm
by Matt Monson
Kelly,
turbo pistons would make the compression go down, not up...

Posted: Fri Apr 14, 2006 6:34 pm
by NuwanD
very nice work, I've done a very similar setup on a friends RS for solo events, works very well!
If you haven't heard tech works engineering made 300chp on a RS motor, albeit with high octane fuel, here's the link
http://www.techworkseng.com/News/Releases/09-20-05.html

Posted: Fri Apr 14, 2006 6:50 pm
by Matt Monson
I am well aware of it, but that's a race motor. See above post. This is why I will also not be doing the trendy '05 manifold conversion
I also heard through the grapevine that TWE fired their engine builder because he wasn't checking tolerances, and you know what happens there. Also, based on a friend's recent nightmare experience in trying to get some pistons from TWE. TWE was the hot new tuner on the market for about a year, but it appears that things are blowing up in their face (literally)
I will happily continue to give Cobb my business. They offered to warranty that cam, and I wouldn't let them. I don't think it was the cams fault...
Posted: Sat Apr 15, 2006 2:37 am
by DLC
Interesting info Matt.
I don't mind paying a bit extra for Cobb stuff because I know them, and I know how they are. Some people have had bad experiences, and some stuff hasn't worked out so great (2.5 turbo, 2.5 AccessPort), but I don't think anyone can blame them for sticking with the stuff that sells, and making damned fine parts while at it.
I'm anticipating your high compression results. As much as a turbo makes lots of power, I can't deny that 175-200 NA WHP would be attractive, even if it were significantly more expensive.
Posted: Sat Apr 15, 2006 7:29 am
by Kelly
Matt Monson wrote:Kelly,
turbo pistons would make the compression go down, not up...

I'm aware of that. Thanks.
My point, is that you will be told over and over that turbo is much more cost effictive, more tunable, and will net bigger gains.
Its true.
I build several motors a month. If your really that reserved about using turbos, use nitrous. It works well when proporlly tuned.
We built a motor two years ago that was raced every weekend, and ran a 50 shot on a daily basis. It never blew up because it was proporlly tuned. The only reason it was pulled out, was because the owner finally ponied up for an actuall turbo setup.
We also did a stage 5 techworks NA motor. 12.5/1 comp, heads, spicy racing cams. Like 10 grand worth of motor, and only ran on 103. It would light em up, but for half the price, I could do at least 100 more hp with a turbo on a two litre.
Posted: Sat Apr 15, 2006 7:48 am
by greg donovan
kelly, you are missing matt's point.
the point is reliable, streetable NA power w/no turbo lag on pump gas.
not to find the limit of NA power.
it is pretty exciting to know that you can get that much power from a ej25.
that would be an awesome PGT rally car. that would give a 02-05 wrx a pretty good run for the money.
the NA ej25 would have no resrictor to work around and better gearing than a WRX.
Posted: Sat Apr 15, 2006 5:10 pm
by Project_Legacy
heheh i love a nice built N/A motor. i was thinkin about doin somethin like this to throw in the legacy too. without so much money spent. lol. i doubt id have the gains you did tho.
Posted: Sat Apr 15, 2006 6:35 pm
by dzx
Nice job matt, you'll have to give me a ride sometime.
Posted: Sun Apr 16, 2006 5:20 pm
by Matt Monson
Greg Donovan,
Thank you. You get it. Kelly, you obviously don't have a freaking clue who I am and where my interests lie , and as has been your modus-operandi since you joined this site, you come into a thread and start talking down the members as a "tuner". I know you have built some really powerful cars. So what? I am not in the "my dick is bigger" power competition. Take it to NASIOC prooven power bragging if you want to strut your stuff...
As for people wondering about cost?
Cobb Stage II (CAI, H-back E,& pully) $1650
Cobb Cams $500
CHR heads $1200
Cobb Stage II Drivetrain $1150
Grand Total: $4500
It's not very often you see someone pull off a WRX swap for that price. The one that I did last fall cost the guy $6500, and I didn't charge him a cent in labor! Yes, he went straight to Cobb stage II, so there's and a TBE, an AP in that total. So, we can call it $5000 for a straight WRX swap.
So, even though day in and day out the parrots on NASIOC and the tuners like Kelly tell me I could make more power cheaper, I don't buy it. If it was about making the most power, I would have stopped playing with NA years ago. Would it be cheaper to make 300hp with FI than with NA? Absolutely. It really depends on what you personally want out of it. And that's why my next project is FI, and it will be even cheaper than this NA build. It will break the 300chp barrier, and will not use the standard WRX/STI formula. More to come....

Posted: Sun Apr 16, 2006 5:54 pm
by Project_Legacy
ahh! you always seem to have the fun builds. good luck with your next project!