I recently bought a 2001 Impreza 2.5 RS with no mods on it yet. I'm looking to boost hp without doing anything too drastic (like swapping out the engine).

I'm planning on hooking up the hoodscoop with a cold air intake from PKZero as well as putting in a new muffler. I'm not looking for more sound from the muffler, just better functionality. Any suggestions there?

Any other easy and/or useful mods to give my scooby a little more punch? Thanks.

you will probably have more luck in here for performance mods :D

youc an start with a cold air intake, and a catback exhaust.

:D

Jay

turbo the sucker! :D I think someone is selling his ludespeed II kit in private for sale forum...

see the intake thread for info on the cowl intake based on the Cobb. Probably as good as it gets. But, without getting heads, you will hit the ceiling at about 200 hp with bolt-ons, even with fuel/spark management. That's a lot for an N/A 4 banger, but if you want real speed shell it out for forced induction. And be prepared to break expensive things in your transmission.

real NA power is cams and head work.

but little power is intake and exhaust. I'd get the exhaust and possible TWE headers if i were to start over.

Or just save up for a stage 3 ludespeed kit.

think of your goals, then work around that.

Thanks guys...

So what type of Cat-back systems does everyone have and how easily did they go on? I want a bolt on, rather than something I have to customize. Again, I'm looking for best functionality/gains, rather than sound.

Thanks again

Personally I love my setup... If I were to do it again I would not change one bit...

Let's start in the engine bay:

CAI - I bought Larry Ganz's CAI with a drop in K&N filter that alone made me smile. Plus it took no more than 15 mins to put in.(GET ANYTHING everything out there works better than stock. This will also mean that you'll lose some of your low-end power. Don't worry thought because other parts might help or just make it slowly decresse in power.)

UD Pulley - I bought an Unorthodox Pully. All it is a lightweight pulley that replaces the stock crank pully. There are other pulley kits out there I think AEM has one which replaces all the pulleys but I have no experiance with them. Advatanges are better throttle control/feel also slightly faster rev's. (With this mod you'll notice a slight dimming of the headlights at idle. If installed correctlly you will not put any more wear on the other parts or espcially your altinator or battery. Also, people fear with this mod they cannot install a stereo system MYTH! if you do install a big system you'll have parts that retain power so don't worry with this.)

Borla Headers - This you can put on in 30mins lucky us (love the subie). I love these headers because they are so unique. With their uneven lengths they give the muscel car sound and every muscel car owner thinks your a V8. Its great! I know you said you want versitlity over sound but this thing flows nice... If you think otherwise check out Cobb Tuning he uses it in his packages. (Fall back are just like the CAI loss of some low-end power.)

And lastly, the exhaust praise the lord for Stromnung! Buy the Stainless Steel and you'll be proud you spent the money. Get thier Mid pipe and the Dual tips its a nice and non-race'y look. It is bit louder than stock but since our motors have a larger displacement they have a deeper note also with the Borla headers they deepen the note more and then the Stromnung tops it off with their German grunt! (Like the CAI and Headers these all effect the flow of air which lowers the low-end power. Don't be scared, at idle I can get my car to get up and going in 3rd! I don't recomend it nor its not a common pratice but I highly doubt that you can do that in a 4 cyclinder.)

If your setting this up for drag, expect on a cool night (57degs) to do 15 flat... and avg of 15.2, and a 60ft of .879 and avg of 1.0 Its a great for drag racing on the streets. you'll beat all V6's like its your job and have fun with the honda's and other 4 cyinders Nitrous or turbo systems are fun too but you'll have some problems if you don't shift correctly and forget it after 2nd gear (our cars aren't meant for drag)

If your setting this up for Auto-x my car has all the power for close courses but expect to see the red. With all the flow in the world that thin line comes up fast. And shifting into 3rd is just like drag racing... its not fun

If you want more power you're looking into Head work or Cams. Other than that you're also looking into big power and expensive parts breaking in your transmition. With these mild mods you'll be happy and your gas mileage is still close to stock... 19.4 highway and city well most of the time I'm dicking around so I can't really say... but its still better than a owning a V6 or a turbo... This won't void your warrenty plus this makes gives you the cool factor from all crowds... V8 sound and beef to show for it... you'll get much respect...

I went to the auto wreckers(a small country yard is cheaper) and picked up a plastic front spoiler from a Chevy (Astro?) van for $5.00. It will probably cost $40. I took it off myself, its cheaper. Everyone says it looks stock and it also does its job. If you want to know how to install e-mail me. Also a multi chamber, 50 series Flowmaster muffler with an add on stainless tip works, and looks really good with the right tip. Its a lot cheaper than a $500.00 muffler. Check out there website for sizes.

COBB cams are an awesome addition (approx 20HP for 500 bucks). I LOVE MINE. Combined with Borla headers (wrapping them is a must), catless exhaust (results in CEL) and you have one cool sounding RS. My exhaust is a little wierd, but turned out to be great. 2 1/2" (NOT mandrel bent) leaving the headers into a glass pack reduced to 2 1/4 (mandrel bent) to a stromung SS Dual Tip. Very deep and throaty (even deeper with the cams) with no buzz. My exhaust gave me the best of both worlds:Flow AND sound.

I can't properly describe the improvement in acceleration and feel when I added the EXEDY lighweight flywheel. If I had known what the flywheel and cams would do to my car I would have done them FIRST. Shifting is WAY quicker and soooooo smooth, no herky jerky in between gears. The torque is AMAZING, Throttle response is unlike anything I've ever driven with a 4 cyl.

Intake is a K&N filter in stock air box with a PDM intake pipe (similar to GANZ FLOW)

Cams are the cheapest HP for the dollar unless you count a Turbo Kit.

here's an attempt at a video with the exhaust sound.

http://home.hawaii.rr.com/dtitan/MOV01030.MPG

the mic was a little to close to the exhaust. I'll have to try again later.

hi

i also have a 2001 subaru impreza rs and was wondering what i should do to it. i have the ganza flow cai with the k&n filter i have 5zigen catback exhaust. what would be the best next step in making good hp gains. (not quite to sure about headers cause they break i hear).

I would go as far as to say the break... my defintion of break is something that won't work anymore....

Headers don't break... the crack.... do they still work??? YES... will you notice anything... not really (driving-wise) you'll notice that the CEL is on more than usual but it won't effect anything...

Also another way that you'll notice is if you have it on a lift and look for cracks... but that's it...

Borla 4th gen headers shouldn't *Crack also they have a lifetime warrenty so if you notice anything like Cracks you can have them replaced...

Next best thing would be UD pulleys or any pulley kits...

after that I'd go Cams and head work but... don't be suprised when you see the prices of product and labor...

YEah, the new Borlas should be just fine, and headers are the only other place left besides cams/heads to get power. With the Borlas, you will probably be over 185 at the crank, and the sound will improve tremendously.

I have a 99 2.5 rs instead of a 01 2.5. Wondering if all the mods work the same way?

Thanx

Originally posted by triman_82
I have a 99 2.5 rs instead of a 01 2.5. Wondering if all the mods work the same way?

Thanx

Yes, except that you want to avoid any and all aftermarket intakes and might have a problem if you were do to a full PEMS system like TECIII. Other than that, everything is identical.

Guys, don't forget... ECU tuning at the end.

That will sum things up and make your sensors and computer happy. Just be cautious, adding headers to a MY00 and up causes CELs to come up once in
a while. Even on my MY99 OBD code P0420 came on last month. Subaru computers are very sensitve.

Well, so far I have a Ganzflow, K&N, PROECM, Stromung Catback, Kartboy with Momo Airleather, 20MM Rear Swaybar, Whiteline Lock Kit, Hawker Battery, and some other mods. I've also removed about 150 lbs of weight off of my car. My cars pretty quick, but I have to get some Borlas, a Cobb Cat, Cobb Street Cams, N1 Style Pulleys, Fidenza 9 Lb Flywheel, and a ACT Clutch, and I may be happy.

Thanks again.

I'm now leaning towards a Cobb CAI and catback exhaust. Anyone have any suggestions/comments about them?

I'm also looking into getting the Cobb shift bushings and upgraded tranny mount. Good idea, or waste of money?

Another mod I've seen a few people mention was the lightweight pulley kit, which I'm going to get from vividracing.com. Will that actually boost hp, or just make the car idle lower and shift smoother? Any suggestions/comments about that mod?

Thanks in advance...

the pullies add power. how much depends on what else you have done. i believe the number to be... for every 1lb lost at the crank you gain 2.7hp (at the crank?) corrections are welcome.

Anyone have anything else to add? How about the bushings and tranny mount? Anyone have good/bad experience with either of those?

Anyone know the deal with the pulley "kit" at vividracing.com? It replaces all three pulleys. Is that necessary? Sounds like most people are only replacing one.

Thanks again.

Catback: Stromung midpipe, and dual tip axleback

Your scoop intake should be fine...

Headers: TWE will make the most power, but you'll lose deep boxer sound, and get a nice, RPM like race sound.. still boxer, but not deep. To get a little more power, but an AWESOME sound, go borlas.

Pulleys: replace with N1s, they aren't shorter diameter, they are lightweights.

Really, that's about it. Your car would sound really awesome. If you want to replace the cats, do so with 1 or 2 hi flow units, like Random tech. but stock should be fine really.

have fun, and watch your shifting into 2nd gear ;)

-Gagan

Do a tune up before any mods are done. Synthetic fluid, plugs, wires, etc.....Gotta make sure to get the basics done first :)

-scu

Well, I changed plans for my car and I'm going to put an arm and a leg out since I won't go turbo. Heres what I have:

Ganz w/ K&N - Replacing with Cobb CAI
Stromung Catback w/ Kartboy Hangers
20MM FHI Rear Swaybar
Kartboy Shifter w/ Momo Airleather
Sparco Pedals
PROECM Chip
Hawker 13 lb battery
Mr Joshs Pulley
Kuhmo Ecsta 712s

And heres what Im doing with my car:

Exedy 9 lb flywheel
Cobb Clutch
A Mystery Companies Cams (More aggressive than Cobb or JA HP)
5.5g titanium retainers and valvesprings
Brullen Headers
Bored TB
Ported Heads (Not Cobb)
SS Brake Lines
Koni Inserts
Cobb Springs
LW Bumper Beams
ECU Tuning and 8000 RPM Redline

Any more suggestions?

Well, I changed plans for my car and I'm going to put an arm and a leg out since I won't go turbo. Heres what I have:

Ganz w/ K&N - Replacing with Cobb CAI
Stromung Catback w/ Kartboy Hangers
20MM FHI Rear Swaybar
Kartboy Shifter w/ Momo Airleather
Sparco Pedals
PROECM Chip
Hawker 13 lb battery
Mr Joshs Pulley
Kuhmo Ecsta 712s

And heres what Im doing with my car:

Exedy 9 lb flywheel
Cobb Clutch
A Mystery Companies Cams (More aggressive than Cobb or JA HP)
5.5g titanium retainers and valvesprings
Brullen Headers
Bored TB
Ported Heads (Not Cobb)
SS Brake Lines
Koni Inserts
Cobb Springs
LW Bumper Beams
ECU Tuning and 8000 RPM Redline

Any more suggestions?

If you are going to open the block, how about throwing in some High Comp pistons to complement the heads, cams, 8000rpm, etc? That way you only have to tear down once....that should be it for the mods until you go bananas and do the bottom end up. Also maybe extude hone the intake as well as port match it to the TB and heads, maybe larger injectors and and upgraded fuel system such as Fuel pump and Vishnu fuel rails?

-scu

Anyone else have anything to add?

Thx.

Cobb intake/pulleys/catback of your choice. It'll give you a little extra punch and make it a more fun car to drive. Start with that, if you feel you need more, you can always do it.

JC

i got some ideas!!
make your ride look like this!!

Originally posted by washeretuesday
i got some ideas!!
make your ride look like this!!
check out my ride at
http://www.cardomain.com/id/mmmpreza