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9 Posts
Discussion Starter #1
I have a 2002 Impreza Rs2.5 and was wondering how to get more hp without a engine swap.
 

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Super Moderator
2000 RSTi
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274 Posts
High compression pistons, larger injectors, Delta Cams, and a standalone type device such as the Delicious Tuning Spork.
 

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www.jackstalk.com
‘98 RS, '00 911 Cab, '18 CT6 TT, '04 Escalade ESV
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5,499 Posts
For the amount of work and money youll have to spend to get decent horsepower gains, it is much more effective to swap in a WRX engine or just sell your car and get a wrx. There arent any cheap or easy ways to make noticeable power that dont require pulling the engine out anyway.
 

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Discussion Starter #4
For the amount of work and money youll have to spend to get decent horsepower gains, it is much more effective to swap in a WRX engine or just sell your car and get a wrx. There arent any cheap or easy ways to make noticeable power that dont require pulling the engine out anyway.
I’m going to buy an STI for a project car but I want to keep the rs for a daily just want a little more horsepower. I was hoping to get to maybe low 200s. I was looking at a cob accessport stage 1 but wasn’t sure if it fits the rs as the accessport is for Wrx/sti
 

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2000 RSTi
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The stuff I mentioned is what it takes to make the low 200s. Cobb doesn't make an AP for an NA car. I believe they either used to, or were talking about making one.
 

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Discussion Starter #6
The stuff I mentioned is what it takes to make the low 200s. Cobb doesn't make an AP for an NA car. I believe they either used to, or were talking about making one.
Is the tuning spork difficult to do if you have no experience?
 

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needs more cowbell
95L, 07 2.5i, R6
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9,297 Posts
You may be able to buy a tactrix open port and get it tuned, but will obviously need at least aftermarket cams to gain some ponies. It can be done, but cams aren't cheap and you may not be satisfied with the gain. Still it won't be an entire engine swap, just the cam installation and valve adjustment. It just depends on what you consider challenging, some people can pull the engine, swap in the cams and reinstall it in a matter of hours. Obviously higher compression pistons would net more power, but require the heads being removed to install. I would check with dyno tuners to see what advice they have and if they can use the taxtrix open port device on your model.
 

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Ex-Mooderator
2001 RSTi, 2011 WRX Hatch
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3,256 Posts
I spent thousands on:
New shortblock
Ported heads with larger valves
Larger cams
lightweight pulleys
equal length header
high flow cat
high flow 2.25in exhaust
Higher RPM, tuned ECU

I made about 20hp more than stock.


Just drive it as-is, or swap it.
 

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1995 EZ30 Coupe
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554 Posts
If you just want a small bump, I'd recommend slapping on a td04 with a vf11 wastegate. Keep up with the maintenance and you'll be fine running 5psi. More than that I have to recommend some form of tuning, and the rs block shouldn't be pushed past like 10-12psi anyway.
N/A power is a waste of money on a Subaru, plain and simple. I swapped an ez30 (220HP) into my coupe, and it's still not as fast as it was with a 1.8 block with 2.2T heads at about 10psi, and that combo will take much more.

Turbo or bust.

For a cheap yet badass motor, ej25 heads on an ej22 block. Mine was cooking at 18psi.
 

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1995 EZ30 Coupe
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554 Posts
If you just want a small bump, I'd recommend slapping on a td04 with a vf11 wastegate. Keep up with the maintenance and you'll be fine running 5psi. More than that I have to recommend some form of tuning, and the rs block shouldn't be pushed past like 10-12psi anyway.
N/A power is a waste of money on a Subaru, plain and simple. I swapped an ez30 (220HP) into my coupe, and it's still not as fast as it was with a 1.8 block with 2.2T heads at about 10psi, and that combo will take much more.

Turbo or bust.

For a cheap yet badass motor, ej25 heads on an ej22 block. Mine was cooking at 18psi.
 

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2002 WRX, 2001 Forster, 04 outback
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8 Posts
The spooly bois make an accurate point; there's only so much WHP to be gained, sticking with N/A. It seems to me that gains you can feel with the "butt dyno" require a lot of supporting mods. Finding four or five places throughout the car to pick up a few whp, to feel an actual gain when driving.

The "universally recommended"* place to start is, get the power you have, to the wheels and ground, as efficiently as possible. I'm not talking about rpf1 knock-offs and cheap federal tires. Lighter wheels will help, of course. and the options for coil-overs are plentiful, yet pointless for a daily. aftermarket struts and springs are just as easy to find and are used just as vehemently. From there its down to your preference. There's also power being lost to the bushings along the suspension and drive-line. lots of aftermarket support there too. Diff, carrier bearing, trans mount, and pitch mount bushings can be upgraded for smoother power delivery. Strut bracing is another good one for feel.
Because the chassis is shared with the WRX, most of the drive-line and bushing upgrades are direct fit and easy to find.

From that point, start making it breath better. Exhaust constraints are based on your need to pass emissions. you can still make power with a cat. but finding HFC and headers is getting hard. A good flowing header is the way to make more power. The debate is over UEL better sound vs EL better power. Either will make better power than stock.
A " cold air intake" setup, depending on which one, usually just looks cool rather than adding any real power. I like using weapon R when I can.

That's most of the OTS power bolt-on's. Now your car is: a little faster, louder, possibly bouncier, a little lighter, and has a check engine light. It's fun, sure, but it kinda feels Shitboxy. IT NEEDS A TUNE! but cobb is just for spooly bois and Haltech is expensive.

There is two tuning options I've been able to find for the '98-'02 N/A ECU's. The Delicious Tuning Spork and the Project Lambda tuner.
I have yet to actually get my hands on either of these. I plan to try both in the future, because of their ability. For now, there is a lot of info about them in these forums, from the time of development.

The ability to tune opens the window for internal engine mods: Higher Cr pistons, cams, valves, spring retainers.
at this point its a project car, with high hope of someday having the power of a stock 2.0 WRX.
 
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