Exhaust, Intake, & Engine.

[White2.5GTLimited]

Exhaust - I recently purchased a set of UEL headers (the Borla replica type) & a 2002 WRX aftermarket slant-end exhaust for my 98 GT. Now I know the headers will fit because I've had them before but what about the exhaust? I've never had an exhaust that was meant for another car before. All of my previous exhaust systems were custom made for whatever car I owned at the time (not cheap!).
This time, I've decided to cut costs & chose a system that would need little modification. My issue with that being where to modify. Some people tell me that it's the mid-pipe that needs lengthening & others tell me that it's the axle-back that needs to be stretched. Which one does it actually need to be? I've been searching for about 2 hours & nothing...

Intake - I want to switch out that 'torque-box' to something a little more direct flowing. People have been telling me about a $40 intake kit that supposedly works wonders. Are the parts needed something I can get at AZ/AAP or do I need to order this kit from Ebay? The intake kit for my last L is no longer in production.

Engine - Unable to find a replacement 25D or any 2.5 near me for an affordable price, I settled on a 1999 2.2. When the time comes for this 25D block to expire, I will be swapping over all of its hardware to the 222 (heads, intake manifold, coolant crossmember, etc). This will happen in a few months. I'm not looking for awesome power & speed yet, just something that will keep rolling until that time.

[anothernord]

Just lengthen the midpipe, the only reason to lengthen the axleback portion is if you have a WRX axleback with piping that curves around under the rear axles and stuff.

For the intake - they're the same as the Impreza, just make sure you get one with enough bungs for the IACV, breathers, PCV.

A Phase II Ej22 block with EJ25D heads will give you a lower compression ratio. If you're leaving it N/A, then that's bad; you'll lose power and gas mileage.

[White2.5GTLimited]

Just lengthen the midpipe, the only reason to lengthen the axleback portion is if you have a WRX axleback with piping that curves around under the rear axles and stuff.

For the intake - they're the same as the Impreza, just make sure you get one with enough bungs for the IACV, breathers, PCV.

A Phase II Ej22 block with EJ25D heads will give you a lower compression ratio. If you're leaving it N/A, then that's bad; you'll lose power and gas mileage.

1. The exhaust is for a 2002-2007 WRX (couldn't find any for my car). It's a full catback exhaust with 2.25in to 2.5in axleback & a slanted 4in tipped muffler w/silencer. It's called an 'N1', whatever that is.

2. I've been looking for the correct pieces to make a custom intake but can only find this -> http://cgi.ebay.com/ebaymotors/98-99-Su ... ccessories (http://cgi.ebay.com/ebaymotors/98-99-Subaru-Impreza-2-5RS-DIY-AIR-INTAKE-PIPE-OBX-_W0QQcmdZViewItemQQhashZitem2565be8fc5QQitemZ160620777413QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories) <- Would this work? I could easily come up with the rest of the pieces on my own & the air filter box would remain exactly where it is.

3. I know. I once dug myself a hole & didn't know that I'd need a turbocharger to make up for the loss of power/torque, so I made one & it took a long while too. During the process, I realized that I needed new gaskets & certain pieces needed to be swapped over like the coolant cross thingy under the intake & such. It ran pretty well but it did feel better than my 97' L for certain. It was just REALLY lazy in the lower RPMS. I took the block because it was near me & the only one I could find that had no indication of internal issues.

[anothernord]

That intake will work, all Subaru engines are the same layout, so N/A intakes are nearly identical.

[White2.5GTLimited]

That intake will work, all Subaru engines are the same layout, so N/A intakes are nearly identical.

Sweet! Heh, I just decided to purchase this then. As with the exhaust, for confirmation, I would only have to lengthen just the midpipe, right? This just made everything 10x easier for me.

[anothernord]

Lengthen the midpipe, and relocate all the hangars.

[Garrison]

I'm just going to chime in, as a person who went with a cone filter intake. If I wasn't in the process of boosting, I would stick with torque box. Yes, it is hideous. But, it's also super quiet; which, after you drive with the whine of a cone filter for long enough (SPT filter in my case) you may not like the noise it makes (literally louder than the exhaust).

[White2.5GTLimited]

My air intake is going to be a fusion of the stock filter box to the CAI pipe to the TB. I don't want a cone filter. I had one of those before & I'm not a fan of the 'boooooooming' sound at all.

[White2.5GTLimited]

https://sl-i.net/FORUM/images/imported/2011/07/223638_2140460464759_1043592276_2468060_-1.jpg

My little experiment so far. It came in little pieces, it's wicked cheap, & it's going to stay there until I can get a metal intake pipe for the upper portion. I'm going to see how it responds during the course of a week. I keep getting mixed opinions for a direct air intake so I'm going to see for myself how well it does.

[Garrison]

Looks good mate, I may end up doing that myself. I really don't enjoy the "roar" of the intake with the cone filter. I'm only worried about the lack of airflow thru the turbo. Anyone want to chime in as to whether that might be a problem?

[ouch1011]

^^ What turbo?

There has been a lot of rumors thrown around with no proof that I know of that removing the torque box and/or the silencer will have a massive effect on the MAF readings and cause the engine to run dangerously lean. The problem I have with this is that 1) the resonator attached to the airbox really doesn't have any effect on the airflow into the MAF, and 2) almost all of the EJ equipped Subarus built prior to the release of the 2nd gen Legacy didn't have a torque box, and many EJ22 equipped 2nd gens still didn't have it. My LGT has a stock EJ22 intake without the torque box and no resonator, and it runs exactly the same as it did with the stock intake, just much louder. I like the sound personally, makes the hair on the back of my neck stand up from 5000rpm on :)

[4n70n1n0]

https://sl-i.net/FORUM/images/imported/2011/07/223638_2140460464759_1043592276_2468060_-1.jpg

My little experiment so far. It came in little pieces, it's wicked cheap, & it's going to stay there until I can get a metal intake pipe for the upper portion. I'm going to see how it responds during the course of a week. I keep getting mixed opinions for a direct air intake so I'm going to see for myself how well it does.

You want to go cheaper? Go to a junk yard and take the intake pipe from an L. They don't have the BIG ugly torque box and just use the L pipe on your 2.5. That's what I have now and it looks so much better and works great. It didn't cost me $20 at the local junk yard