View Full Version : 50HP?

09-08-2005, 03:00 PM
Alright, I know we've all done the "How do i get a more powerfull car" thread, but that's obvious and goes on forever.

My question is, What is the best bang for the buck to get 50 extra HP, preferably low-to-mid range?

Not just which parts, what brand, style, where to get it from, and generally just opinions is what i'm looking for.
I've got a 99 2.5GT with snorkusectomy and K&N panel filter.
I was thinking of putting in Borla unequal lenth headers, Xcceleration.com's hi-flow cat, Stomrung cat-back for the exhaust, just don't know the best place to get these for cheapest

Next i was thinking of a pulley set, or just a crank pulley, not sure on the gains you get from the other accesory pulley's, just look nice hehehe

Any ideas where i could get extrude honing on my intake anywhere near Tampa, FL and how much it would cost, realistic gains, or speculative just to get an idea if its worth it to do.

after that what would i need, engine internals? engine management?

I've already taken the jack, spare, and all other goodies out, i hear that every 100 lbs is like an extra 10HP?

So any ideas where i can get this stuff from, and what else i need to do to hit that 215HP mark. I just want to be able to run the the WRX's, not spank them..... i don't have the money for that, lol

And besides, not everyday that a N/A 4-cyl keeps up with a WRX :twisted:

Thanks guys

09-08-2005, 03:04 PM
wrx takeoff turbo kit. Less boost will go further in your higher compression 2.5

215na hp is gonna be a bit expensive, and won't add to the low/midrange.

09-08-2005, 03:21 PM
To get 50hp you need to do the whole exhaust, pulley, CAI and some head work. Every 100lbs removed fromn you car frees up 10hp, you dont gain anything extra. I been playing with the idea of boosting my Legacy, it would be cheaper but EVERYONE is boosting their Legacy (anyone that is truely modding their car). I plan on going N/A, you damn straight it's going to cost alot of money, thats where the fun is. I'll leave the boosting crap to my CRX :roll:

09-08-2005, 04:23 PM
My question is, What is the best bang for the buck to get 50 extra HP, preferably low-to-mid range?

N20. Easy to install, power is there on tap. :-D

09-08-2005, 08:56 PM
N20. Easy to install, power is there on tap. :-D


Would you mind explaining more please? :D

09-08-2005, 09:19 PM
he means a nitrous kit. f--k that.

And i don't want to do a turbo, from what everyone says i'll only be able to push 7 psi and after a lil while will need a new engine, cause this isn't the turbo-deck 2.5. <sigh>

ok, so nobody has answered the specifics...
What do you all suggest as far as exhaust goes, where should i get it from for the cheapest and best customer service?

Anybody know anything about extrude honing?

09-09-2005, 03:43 AM
Specifically you're going to have to do a hell of a lot to hit 215 hp in a ej25. I suggest a 2.25" exhaust, cams, some sort of ems, some burly valve springs, fresh (thinner?) head gaskets. That might get you fairly close to 215 crank hp. It's not going to be very fun to drive around town; it will shake at idle and be down a bit on tq.

Or, you could run 7psi on a wrx turbo. The area under the curve will improve significantly, and lag will be very mellow since you're not boosting much and everything is pretty tightly sized. Sure, you can't run as much boost, but your 2.5 draws a lot more air anyway, and your higher compression makes better use of it. I don't much care for turbo power, but it just makes sense in this case.

Or, swap in a ej20t. Sure, the initial investment is higher, but then you get all that power and you don't have to kludge everything together.

Or... you could enjoy your 165hp for a long long time without the stress of wondering when it will blow up, forcing you to spend even more money on your engine.

09-09-2005, 04:20 AM

ok, so nobody has answered the specifics...
What do you all suggest as far as exhaust goes, where should i get it from for the cheapest and best customer service?

It all depends on your preference. You want go power and willing to spend a lot of money? You want something that sounds good and is cheap? I plan on getting a Borla header, Stromung track pipe (cat-less) either a Borla or Stromung cat back. I'm still looking for a reputable machine shop so I can get head work done. All I can say is read what people say, hit up manufacturers web sites and read, read, read. Check out www.Boxer4Racing.com (http://www.Boxer4Racing.com) and www.RALLiTek.com (http://www.RALLiTek.com) two great web sites.

09-09-2005, 06:15 AM
You can reliably run 5-6psi on a stock block for miles and miles. You just have to do it correctly with the proper compenents and tune. I'd recommend taking a serious look at the AVO turbo kit sold by Rallitek. They will provide a basic map to go with your engine to correct fuel and such, and you can gain more power with a dyno tune I believe. The open deck block and result in some oil and coolant loss (not sure how this works, but this is what I've been told), so keep a close eye on your fluid levels. With a flywheel and cluth, you'll be putting down close to, if not more than, WRX horsepower.

Trying to do this while staying NA is going to rusult in a lot more money spent (valve spring kits are running around $2,000USD I believe, plus cams, intake, exhaust, headers, machine work to the intake manifold and heads, engine management). This type of HP from an NA motor will most likely result in a reliability issue that will be much worse than boosting the car at safe levels.

As far as the best pricing and customer service, Boxer 4 Racing (www.boxer4racing.com (http://www.boxer4racing.com)) has been my best source for parts. Dale and Patrick are really good guys who know their stuff and carry a wide variety of parts for our cars.

A guy on NASIOC made a good deal of HP from his 2.5RS with the following mods:
Modification or part (Where to get it)
Injen CAI (Boxer4Racing)
Cobb Equal Length Header and High Flow Catpipe with Cat removed (Cobb)
Cobb Catback (Cobb)
Cobb "Spicy" Cams (Cobb)
Walboro Fuel Pump (Boxer4Racing)
Exedy Lightened Flywheel (Boxer4Racing)
Exedy Racing Cluth (Boxer4Racing)
Underdriven/Lightened Crank pulley (Boxer4Racing)

The guy was making just shy of the same WHP that most Stock WRXs dyno for by about 10-15HP less. He still needed a set of Valve Springs (if you plan to push the redline up to harness the true power of the cams, you'll need stronger springs and rods) and Engine Management to correct fuel ratios and such. You'll need some pretty lightweight, yet durable wheels, as any extra weight you add to the drivetrain will compromise the amount of HP you're putting to the ground, which is true with any vehicle. I hope this helps.

09-09-2005, 10:10 AM
Cosworth offer a set of heads for $3000+.

www.cosworth.com (http://www.cosworth.com) (look under streetcars I think).

Basically your horsepower goal is unattaintable without spending a decent amount of coin...

But nitrous will get you that instant gain. All nitrous does is supercool your inlet charge (air). That's all. Run higher octane to prevent premature burn, and you'd be plenty safe.

Sounds like you're wanting allmotor power though, and N20 is classed as FI in drag racing anyway.

09-09-2005, 10:31 AM
I have always been told that nitrous was extremely hard on the engine and would grenade it over time. The more you use, and the more offten you use it, the quicker the engine dies...

If this is infact the case, then I would shy away from it.

If you want to stay N/A and push some high HP, then expect to spend along the lines of 10,000-12,000 USD. All that done properly should get you around 250HP. But would include a blue-printed block, full port & polish, higher compression heads, high lift cams, springs/valves, forged light weight internals, some sort of CAI, complete high flow exhaust system, upgraded engine managment, upgraded fuel system, better throttle body, strengthen the tanny to take the power and torque, etc. I probly left out a few things, but am at work and don't want the boss to catch me. :twisted: keeping the post short.


09-09-2005, 10:51 AM
Well of course reliability and longevity is a factor - but then NONE of these cars we talk about were built in an ISO9000+ environment, in a robotic factory, backed up by a production schedule of several thousand cars a year.

But I digress.
Of the many of the high HP Subaru's out there...how many are still ticking beyond 100,000 miles? A lot of the time a chassis is modified up the wazoo, only to be parted out less than a season later.

Nothing is forever, I guess.

If you want N20 facts, then a search on some physics sites and auto combustion principles is all you need to do. It's not for everyone, granted. I'm just being devils advocate, that's all.

09-09-2005, 01:21 PM
I've been told that running 35 and 50 shots on our motors is ok with the right plugs and high octane gasoline, but just as with anything else, if you use it, it will find and exploit any problem that is in the engine. If used properly, it CAN be safe, but using it properly is the problem. There's all kinds of books out there on the subject...I just have no interest in reading them or hooking up N2O to my car right now.

Oh, and cooling the intake charge is not all that the stuff does. This is from another guy that I've talked to on ClubCav. Straight Nitrous (2 atoms of Nitrogen, 1 atom of oxygen) breaks down at a certain temperature. Oxygen of course allows for a stronger combustion, while the nitrogen keeps the engine cool. The more oxygen, the leaner you get if your fuel system can't keep up, causeing heat which is what breaks your pistons, etc. The Nitrogen, a cold substance by nature, keep the combustion cylinders cooler to a degree, but lean is lean, and hot is hot. Too much Nitrous and you'll sacrafice an engine. Again, this isn't knowledge I've obtained on my own, but second hand information. Someone else may be able to confirm it.

09-09-2005, 02:12 PM

that's exactly what I have been told...

09-10-2005, 10:30 AM
Will 40hp do? If so pick up the October issue of Subiesport magazine. It coverspart 4 of project 2.5RS. They list all the parts used and gains each one gave. Get ready to did deep though. They spent $3196 on parts and another $2000 on labor and Dyno time.

09-10-2005, 11:35 PM
Just shy of the costs of a good turbo kit, minus the dyno time if you decide to have a further tune done. The turbo kit will yeild more results for the money, but Subiesport still has some play that they can do with that car. If you can do all the installs yourself (they're pretty damn in depth), then you could save some money on your build by doing so. Good luck with whichever road you take.

09-11-2005, 03:55 PM
Well def dont boost too much. I was boosting about .6 BAR on my ej22 and my rings are taking a crap. I can't live without boost so now I'm migrating to a boost friendly platform to start over with.

09-13-2005, 11:56 PM
ok im gonna throw in my 2 cents here cuz this is where im heading with my car. and im a bit of a lurker :wink: ok so ive got the stromung catback, a peiced toghter intake and light weight pulleys. headers and high flow cat are comin. after that im getting the tech works street cam, wich ive have heard good things about, and they are also combatable with turbo, so thats a plus for future mods. all of those mods should get you your goal-ish.the cams will run you around 450 with core exchange. oh btw, frind of mine is arunning hks cams in his impreza wagon with a dohc 2.5 and he is running 150whp NA on stock exhaust and intake, so thats an option too. now, where to get them. boxer4 is awsome, ive done all my bussiness with them. but if your getting stromung, by directly fom them boxer4 is about 70-100$ over priced on there stuff. so yeah. oh and 1badlegacy, is your motor a ej22 turbo motor, or just an ej22?

05-14-2009, 11:59 AM
wrx takeoff turbo kit. Less boost will go further in your higher compression 2.5

215na hp is gonna be a bit expensive, and won't add to the low/midrange.

so are you saying that if you found a stock wrx turbo kit, you could pull everything off and have near perfect fitment to a comparable legacy?

05-14-2009, 12:44 PM
The two cheapest options to attain what you want are a WRX take off kit as mentioned earlier. Run about 5-7lbs, full catless 3" turboback, Perfect Power6.

The other option is nitrous on your budget. I've thought about it on my 2.2l as they are indispensable.

You're going to have to spend thousands to get 215 out of your NA.
Cams, PP6, hi flow cat, catback, pulley set, EL headers, and more. In my opinion its just not worth it.

05-14-2009, 11:55 PM
Don't forget supercharging. Simpler in theory, and would be very unique.

Here's a very through build on a 2000 2.5RS, using an Eaton M62, a Forester top mount, and a eManage Ultimate Em. I imagine it would be very similar on the DOHC EJ25.

http://www.ludicrous-speed.com/wiki/ind ... ild_Part_1 (http://www.ludicrous-speed.com/wiki/index.php?title=2000_Subaru_Impreza_2.5RSC_Build_Part_1)

05-15-2009, 10:47 AM
wrx takeoff turbo kit. Less boost will go further in your higher compression 2.5

215na hp is gonna be a bit expensive, and won't add to the low/midrange.

so are you saying that if you found a stock wrx turbo kit, you could pull everything off and have near perfect fitment to a comparable legacy?

Almost. You need the front crossmember for the uppipe to clear. You need to do some intake plumbing around NA intake manifold (rubber hoses work well).

05-15-2009, 12:48 PM
like reason said...lose weight on the car
you definitely dont need a spare tire lol

replace heavy stuff with lighter options

05-17-2009, 09:07 PM
if you want to beat up on WRXs and stay NA go with an H6 swap, ill have well under 2000 (probably closer to 1000 after parting out the donor car) invested when Im done, including the motor and many new parts for the motor (belts/pullys,gaskets), Group N mounts, custom radiator, and harness merge.

05-19-2009, 01:29 AM
Best bang for the buck would be a nitrous kit, now reliability is a different matter :twisted: