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Old 09-12-2010, 03:22 AM   #1
royalnewjersey
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Default 2008+ 2.5i Lots of UEL questions!

Sorry in advance for the long winded post

As the title reads, I (and probably others) have a lot of questions about UEL headers on an impreza 2.5, specifically 2008 and above. Assuming the '08 '09 and '10 are all the same (?).

I have a 2010 impreza 2.5i, and I want it to growl....

First off, I would like to say:
I HAVE DONE MY READING.

I know there are a lot of posts about different subjects regarding UEL headers.
See posts below for further information if you have questions about this topic. :

http://forums.nasioc.com/forums/show...n+solution+uel

http://forums.nasioc.com/forums/show...=2+5rs+catpipe


Here's what I "know" so far.

- I have read up about power loss / gain etc. I understand that EL headers are the most efficient, but most after market headers will be more efficient than the stock ones (EL or UEL).

- I understand that you will have to either buy a new cat pipe (or modify the current one) to make it fit.

- I understand that you will need to extend the 02 sensors. Front one will fit fine, rear one needs extending.

- I have read that it is best to replace all gaskets when doing this swap, and not to reuse the originals.

- I realize that this modification is fairly pricey, and is MOSTLY for sound. I want that boxel growl. I don't care too much about power (which is why I bought an NA car). As long as I don't lose tons of HP, I would rather get the growl back.

now on to my questions. I hope these help other people as well:


1) Does anybody make a "2008+" UEL header? I have searched on ebay, searched online, searched in the FS section. I can only find 03-07. Do I have to buy an older model that "just fits" but is not advertised? Seems like the aftermarket support is slim to none for the 2008+

2) I probably won't be messing around replacing my WHOLE exhaust system until my warranty expires (2015 lol). But I can be persuaded. In your opinion what is the best sounding combo? Borla reps>rallisport HFC>magnaflow? RS UEL>WRX HFC>Tsuedo? etc...

3) I understand that you have to extend the 02 sensors. What is the best way to be safe with this? I realize that 05+ use the 02 sensors to help calculate gas usage. I don't want to get a CEL, but I also don't want to mess something up. Does extending the sensors solve all issues? I've seen certain "spacers" that move the sensor out of the path of airflow to correct CEL's, but have also heard that this can totally ruin your engine tuning?

4) I really really appreciate other's work in documenting this particular issue. We are standing on the shoulder's of giants. But seriously, when are manufacture's going to have a bolt on solution? I saw on rallisportracing.com that they were going to have a bolt on UEL header. Do you think this would be for 2008+? I would pay extra to have a nice bolt on solution for headers, HFC, catback etc. Anyone?

5) What about the muffler? Impreza's have HUGE stock mufflers. Is this mostly why my car is sooooo quiet? If I start by getting a custom muffler / exhaust tip will I greatly improve the growl factor? Also, could I put in a catback system, and then wait to install UEL headers once there's a good aftermarket solution?


Again, please correct anything that is wrong, and answer as much as you can. I don't want to start a flame war about why / why not. I'm just trying to get some answers to questions all in one place. Thanks everyone.
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Old 09-12-2010, 04:08 AM   #2
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Have fun spending $1,500 on something that will net you 1 WHP.

You should of bought a WRX.
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Old 09-12-2010, 08:45 AM   #3
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Have fun spending $1,500 on something that will net you 1 WHP.

You should of bought a WRX.
not the sharpest tool in the shed, are you?
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Old 09-12-2010, 10:14 AM   #4
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1) no
2) be prepared, rallisport gives alot of rasp
3) cut, splice, solder, heat shrink. spacer WILL NOT WORK 05+
4) nothing bolt on yet
5)can use any of the 08+ mufflers i think. they should all bolt on.
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Old 09-12-2010, 12:27 PM   #5
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well if you replace your headers it will void your warranty
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Old 09-12-2010, 12:51 PM   #6
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well if you replace your headers it will void your warranty
No, it won't.
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Old 09-12-2010, 01:26 PM   #7
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Quote:
Originally Posted by kewlboxer2 View Post
1) no
Thanks for the responses. But what about this post:

http://forums.nasioc.com/forums/show...n+solution+uel

the first picture is UEL headers for his 08+. Where did he get those? Where do you buy them?
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Old 09-12-2010, 01:46 PM   #8
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Quote:
Originally Posted by royalnewjersey View Post
Thanks for the responses. But what about this post:

http://forums.nasioc.com/forums/show...n+solution+uel

the first picture is UEL headers for his 08+. Where did he get those? Where do you buy them?
Those are just borla reps, they are not 08+ specific. Ebay.
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Old 09-12-2010, 01:48 PM   #9
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Edit: Yeah, what he said. ^^^

Quote:
Originally Posted by royalnewjersey View Post
Thanks for the responses. But what about this post:

http://forums.nasioc.com/forums/show...n+solution+uel

the first picture is UEL headers for his 08+. Where did he get those? Where do you buy them?
If I understood correctly, they aren't for his 08+, they're a Borla replica for the 05 and under crowd.
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Old 09-12-2010, 02:42 PM   #10
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Quote:
Originally Posted by renyo View Post
Edit: Yeah, what he said. ^^^



If I understood correctly, they aren't for his 08+, they're a Borla replica for the 05 and under crowd.
Reps will work for 06/07. Mine were close to power steering lines and almost burnt through. bought real borlas and i have 2 inches of clearance there now xD. Just because they say it doesnt work for 06+ doesnt mean it wont work. It just means that is not an "easy" bolt on swap. you have to convert it back to sub 05 exhaust or get it custom made.
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Old 09-12-2010, 03:35 PM   #11
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Originally Posted by kewlboxer2 View Post
Reps will work for 06/07. Mine were close to power steering lines and almost burnt through. bought real borlas and i have 2 inches of clearance there now xD. Just because they say it doesnt work for 06+ doesnt mean it wont work. It just means that is not an "easy" bolt on swap. you have to convert it back to sub 05 exhaust or get it custom made.
Well, I meant as a direct swap, but yes you're right.
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Old 09-12-2010, 04:02 PM   #12
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Quote:
Originally Posted by nairbmik View Post
No, it won't.
:/ my subaru dealer said if i replace my headers my powertrain warranty would be void because "im tampering with the engine"
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Old 09-12-2010, 04:11 PM   #13
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:/ my subaru dealer said if i replace my headers my powertrain warranty would be void because "im tampering with the engine"
It won't void the warranty but they can refuse service if the said part is causing a problem. If they can find some kind of way to link a problem with your mod they will use it to refuse your warranted service. I believe the only way to completely void your warranty is if you take your car out of the country. But everything you do to prove that a problem is not caused by an aftermarket part would be a big fat hassle.

If they know you've modded your car, you didn't void the warranty...you just have less than what your warranty would cover. I'm sure they can blame a lot of engine problems on exhaust modifications tho.

P.S. I don't know this first hand but I've heard that UEL's generally lower HP as it does not maintain proper exhaust velocity. EL's are much more efficient in this respect.
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Old 09-12-2010, 06:26 PM   #14
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If your headers somehow malfunction which somehow contributes to your engine malfunctioning, and you try to take it to the dealer to get it fixed under warranty, they can DENY your claim. If your windshield wiper motor fails, they'll still fix that under warranty.

Nothing short of doing an engine swap or taking the car out of the country can VOID your warranty.
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Old 09-12-2010, 09:46 PM   #15
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wait what? you drive your subaru into canada or mexico and it voids your warranty? That's news to me.


I have currently on my car an EL header (and full exhaust) made for a 99-01 RS. The cat has moved from directly behind the radiator to the middle of the front doors. That is a looooooong way away from stock. It takes a while for it to heat up, and the car smells like gas even after it's been running for a while.

2 Months after putting the exhaust on my front o2 sensor (it was extended by solder and shrinktube) died. It could've been on its way out before installing the exhaust, so take that for what it is. If the new o2 dies next year, well I'll know the first one was fine until running extremely rich killed it.

Rear o2 is fine, and it runs with an extension harness that's been linked here several times you can buy one easily. Extending the o2 wires solves nothing except allowing you to plug in your sensors in their new locations after installing a new header, as the stock cat is very close to the front of the car, while all older header designs have the cat farther back, where the cat used to be in pre 05 engine configs.

I do believe most of the UEL headers will only move the cat back a couple feet... in which case it's probably better off than mine. The front o2 will not need to be extended as long as the cat stays somewhere under the engine bay, if it goes beyond that, relocating the connector won't buy you enough slack to hook up the sensor.

Extending the front wire is not necessarily bad... depending on who you talk to, it's a mixed peanut gallery on that. Some say it's fine, others say it's not.

as for throwing codes... you know, honestly, my car has not thrown any exhaust codes with my particular exhaust. The only code thrown is when the front o2 died. But then again, I heat wrapped and painted my header to make sure it heats up as fast as possible and retains as much heat as possible, given the location of the cat on this header.

Every year the cars get some new doohicky for emissions and this makes it more and more difficult to put on the older headers in my opinion. The design of the headers changed in 05+ to accommodate new stuff going onto the engine so the stock header is optimized to work with the new stuff, while the older headers may still work mechanically, but a ton of new things happen before it gets to the old part, so lots of things can happen.

I would try a catback first... it doesn't mess with sensors and a well tuned exhaust can still give you grumbles/growls. My EL header and exhaust still produce a burble/rumble below 3.5k and above it roars like a normal EL header. You can still hear burbles slightly at higher RPMs but it most definitely does not sound like a honda.
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Old 09-12-2010, 10:50 PM   #16
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Originally Posted by Sir-Knight View Post
I would try a catback first... it doesn't mess with sensors and a well tuned exhaust can still give you grumbles/growls. My EL header and exhaust still produce a burble/rumble below 3.5k and above it roars like a normal EL header. You can still hear burbles slightly at higher RPMs but it most definitely does not sound like a honda.
Awesome. I was thinking about getting a catback exhaust first, and then upgrading to UEL headers etc in the future. This way it's cheaper, will be easy to swap if needed, give me better sound, and I can still add the rest later.

Any suggestions for a very typical "subaru" sound? I've heard good things about Tsuedo exhaust. Magnaflow? What do you have?
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Old 09-12-2010, 11:14 PM   #17
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Originally Posted by GT11 View Post
Have fun spending $1,500 on something that will net you 1 WHP.

You should of bought a WRX.
The correct way of saying that is, "You should have bought a WRX".
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Old 09-12-2010, 11:20 PM   #18
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borla makes a sexy growl but i myself am having a dilemma, borla has a 2.25' inlet 4.25 outlet catback but what difference would it really be other then just sound? magnaflow has a catback for 08+wrx thats a 2.5' inlet with 4' outlet not sure about sound tho i havent really looked at youtube but im not sure if the 2.5' will bolt up w/o having to deal with modding anything
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Old 09-12-2010, 11:22 PM   #19
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The correct way of saying that is, "You should have bought a WRX".
sometimes wish i would have but i bought my impreza for 20.5k off the showroom floor and the only wrx they had was in orlando for 27k and they would charge me 2k just to ship it to me so i figured id rather invest 9k myself into the engine
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Old 09-12-2010, 11:43 PM   #20
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Quote:
Originally Posted by Sir-Knight View Post
I have currently on my car an EL header (and full exhaust) made for a 99-01 RS. The cat has moved from directly behind the radiator to the middle of the front doors. That is a looooooong way away from stock. It takes a while for it to heat up, and the car smells like gas even after it's been running for a while.

2 Months after putting the exhaust on my front o2 sensor (it was extended by solder and shrinktube) died. It could've been on its way out before installing the exhaust, so take that for what it is. If the new o2 dies next year, well I'll know the first one was fine until running extremely rich killed it.

Rear o2 is fine, and it runs with an extension harness that's been linked here several times you can buy one easily. Extending the o2 wires solves nothing except allowing you to plug in your sensors in their new locations after installing a new header, as the stock cat is very close to the front of the car, while all older header designs have the cat farther back, where the cat used to be in pre 05 engine configs.

I do believe most of the UEL headers will only move the cat back a couple feet... in which case it's probably better off than mine. The front o2 will not need to be extended as long as the cat stays somewhere under the engine bay, if it goes beyond that, relocating the connector won't buy you enough slack to hook up the sensor.

Extending the front wire is not necessarily bad... depending on who you talk to, it's a mixed peanut gallery on that. Some say it's fine, others say it's not.
No need to extend the front if you pull the connectors back through the fuel rail area.
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Old 09-13-2010, 12:22 AM   #21
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Hmm some interesting things here. Let me first direct you to:

http://www.3gwrx.com/forum/index.php?topic=3898.0

and the bottom of:

http://forums.nasioc.com/forums/show...345720&page=59

to explain my background. I have driven about 10k miles with UEL headers on my 2008 2.5i. You seem to have the general idea, just know that this is only gonna work if you put the money into it. On top of all the obvious charges, this is especially true because, as far as we know now, the only ways to prevent the UEL headers from damaging the steering fluid lines that come very close are to either ceramic-coat (I used swaintech) your high-end headers (borlas from www.boxer4racing.com), or use a spacer, or both.

Other than that, I will reiterate that it is important to use a decent cat pipe (my stromung one died on me I think during a new england winter storm... might make the $500 randomtech one worth the money), and to not skimp on the details (wire extension, O2 spacer, and possibly higher quality oxygen sensors).

Also, since any 2008 impreza or WRX 2.5" exhaust is gonna need the midpipe extended, don't be stupid and get an expensive fart can cat-back (i.e. the agency power ones I bought). If you don't want a exhaust shop to fabricate the whole thing, you can either get a nice cat-back (like SPT or AVO) or, what I think would be best, is to get the AVO axle-back, and have the shop set up a y-pipe/midpipe with a long/beefy resonator.

Then, get yourself a tactrix cable, and buy yourself an e-tune (from Jeremy Estes, Phat Botti tuning, or Williaty). haven't finished mine yet, but I know the car runs rich under hard throttle. Finally, you should re-map the throttle, per Williaty's instructions (google it)

Hope this helps, let me know if you have any questions, and if you want my honest opinion, no it's probably not worth it. I had an AWESOME sounding car for about 6 months, but the system is clearly both costly and risky, making it an undeniably unwise investment. That being said, there is a boxer engine buried in there...
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Old 09-13-2010, 02:37 PM   #22
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No need to extend the front if you pull the connectors back through the fuel rail area.
like I said, it depends on the location of the cat, I can guarantee you that my wire had to be extended 14 inches even AFTER the relocation.
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Old 09-13-2010, 03:25 PM   #23
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Originally Posted by Battlesnake99 View Post
if you want my honest opinion, no it's probably not worth it. I had an AWESOME sounding car for about 6 months, but the system is clearly both costly and risky, making it an undeniably unwise investment. That being said, there is a boxer engine buried in there...

I'm kind of coming to this conclusion, not worth it. ESPECIALLY not while I'm still under my 6 year warranty.

I will probably end up getting a catback system though. Should be easy to bolt on, easy to take off, and make the car sound better. Any suggestions? I want a deeper "rumble" tone, but I don't want it to be super loud inside. And I definitely don't want it to drone on the highway.

Anyone have any good brands that won't break the bank?
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Old 09-13-2010, 03:33 PM   #24
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Get one custom made to your specs. Cost me $375 for a cat back with a muffler(magnaflow 12225) that I wanted. Going to go back and get a resonator or 2 stuck in and make a new cat section.
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Old 09-13-2010, 03:33 PM   #25
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if you want it cheap find a local muffler shop to make you a cat-back exhaust and buy some tips online or see what the shop has to offer i got quoted for like $350 with sport tips from magnaflow with stainless steel piping
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