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Old 02-24-2008, 10:06 PM   #1
Bluefoton
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Default OEM vs Borla UEL header - acoustics

I need your opinions. First, when I switched from the OEM headers to unequal length Borla knock-offs, I actually failed to hear a substantial increase in rumbleness. Granted, it was there, but rather meh - the stock catback prevented from seeing a substantial difference. On the downside, the engine bay became much more noisy, due to the headers being very thin.

Now I just got an Sti catback - and I praise it for the combination of an amazing sound, rumble and also being quiet. I dont know how much of it is due to the catback, and how much to the headers, so...

...my question: for those who , drive a model in which the headers were unequal length to start with, were smarter then me and upgraded their catback BEFORE the headers, did the Borla UELs still make a difference with respect to stock? Or can I go back to stock headers, get my engine bay silent again, yet keep the rumble?

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Old 02-24-2008, 10:50 PM   #2
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when i was N/A i did my catback first and it sounded decent but the borla header definitely made it sound better. I was UEL stock.
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Old 02-25-2008, 08:58 AM   #3
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Hmm... well i did my entire exhaust header-back at once but i can say that the header is what creates the rumble. stock/oem manifold rumbles a tiny bit the the borla/replica really rumbles. Catback systems only make it louder. and replacing the stock cats with hfc or none (track pipe) will make it ridiculous loud.

if the op were to put the stock header on and still use the sti catback it would be pretty much the same loudness only it would not rumble/pulsate as much.
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Old 02-25-2008, 09:41 AM   #4
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thanks! As I said, I'm really happy with everything BUT the thin-metal structure of the header. Don't want to wrap it to silence it, as it seems to be rather bad for the header... hmm, maybe will come up with a funky enclosure or something...
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Old 02-25-2008, 11:32 AM   #5
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Quote:
Originally Posted by Bluefoton View Post
thanks! As I said, I'm really happy with everything BUT the thin-metal structure of the header. Don't want to wrap it to silence it, as it seems to be rather bad for the header... hmm, maybe will come up with a funky enclosure or something...
you can do a wrap kit with the sealing spray if your area does not salt the roads bad. Maybe take them off and have the thermal coated buy like jet-hot or something. might quiet the headers down a bit and also help with keeping the p0420 code from tripping.
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Old 02-25-2008, 12:19 PM   #6
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Quote:
Originally Posted by drummerRS2505 View Post
you can do a wrap kit with the sealing spray if your area does not salt the roads bad. Maybe take them off and have the thermal coated buy like jet-hot or something. might quiet the headers down a bit and also help with keeping the p0420 code from tripping.
OP isn't too far from me, so I can say wrapping is pretty much out of the question up here. Lots of salt for months on end.
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Old 02-25-2008, 12:40 PM   #7
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I have an STI catback on my ej22 98 Legacy L. Along with the short ram intake the exhaust is the PERFECT volume for my dailer driver.....nice and quiet when cruising, yet when you get on it it produces a nice deep roar... I can only imagine running the Borla headers.

would they make the car any louder ???
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Old 02-25-2008, 01:54 PM   #8
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Not from the exhaust side. Though after youtubing the sounds of an STi catback + OEM vs Sti catback + Borla, there IS a difference.

The main increase in the volume is from the engine bay ... the headers are just soooo thin!
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Old 02-25-2008, 04:44 PM   #9
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i was surprised to look underneath my car this weekend [05 rs] to find that i dont have UEL headers iirc the 02-05 RS' had UELs?
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Old 02-25-2008, 04:55 PM   #10
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I believe they are un-equal, just not to the extent that the Borla's are.
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Old 02-25-2008, 04:57 PM   #11
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Well this thread is making me a little worried as I have a RT cat and borla headers waiting to go on. Now I am worried it may be to loud.
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Old 02-25-2008, 04:59 PM   #12
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Quote:
Originally Posted by drummerRS2505 View Post
...the header is what creates the rumble. stock/oem manifold rumbles a tiny bit the the borla/replica really rumbles. Catback systems only make it louder. and replacing the stock cats with hfc or none (track pipe) will make it ridiculous loud.

if the op were to put the stock header on and still use the sti catback it would be pretty much the same loudness only it would not rumble/pulsate as much.
I agree 100% with this.
You will have a little bit of rumble with your STI catback but not as much as you currently have. Most of the rumble comes from the Borla style header.
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Old 02-25-2008, 04:59 PM   #13
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i was surprised to look underneath my car this weekend [05 rs] to find that i dont have UEL headers iirc the 02-05 RS' had UELs?
all models of impreza up to the most recent ones(I wana say 06+) are quite unequal legnth...

you would gain some AWESOME sound by switching to a borla header in your car especialy
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Old 02-25-2008, 05:09 PM   #14
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I have a brand new cosmoracing SRI, blue in color,if anyone is interested. PM me.
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Old 02-25-2008, 07:04 PM   #15
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just put borla UEL headers on my DOHC Leg GT, mated with stock midpipe and SPT Performance Muffler. The rumble is sweet on low RPM's but under throttle my intake deletes all sound. Im getting a louder muffler soon and keeping the SPT as a back-up. The intake may also be coming off if the rumble sounds good with the louder muffler.(which it will)
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Old 02-25-2008, 10:00 PM   #16
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Quote:
Originally Posted by IllNastyImpreza View Post
all models of impreza up to the most recent ones(I wana say 06+) are quite unequal legnth...

you would gain some AWESOME sound by switching to a borla header in your car especialy
the 06/07 2.5i is EL factory exhaust manifold (or header if you wish). they might not be excatly EL, but they are tuned somewhat to help the engine make power and it seems to be accepted knowledge that this was one important change that allowed SOA to make the few extra ponies on the 06/07's
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Old 02-25-2008, 10:32 PM   #17
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From running a couple of catback exhausts with header setup, this is what I can say.
Granted this is NOT the Borla headers, but some headers I made for my single port 2.2L Impreza. The catback section for NA's you'd have to put in a resonator along with a MUFFLER at the end if you don't want the raspiness. This applies to straight-through mufflers especially. Baffle mufflers are quieter.

Headers made the sound, anything after that MUFFLES it to how LOUD you want it to be.

I have one of the LOUDEST NA exhaust at the time, DEEP non-raspy when HOT, and you can hear it 1/4mi blocks away. I DO miss it in a way. This is the vid:
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Old 02-26-2008, 10:51 AM   #18
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wrapping the borlas/borla replicas makes almost all of that under hood noise disappear...plus it will help gas mileage a little by keeping the exhaust velocity up
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Old 02-26-2008, 10:59 AM   #19
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Quote:
Originally Posted by FuJi K View Post
From running a couple of catback exhausts with header setup, this is what I can say.
Granted this is NOT the Borla headers, but some headers I made for my single port 2.2L Impreza. The catback section for NA's you'd have to put in a resonator along with a MUFFLER at the end if you don't want the raspiness. This applies to straight-through mufflers especially. Baffle mufflers are quieter.

Headers made the sound, anything after that MUFFLES it to how LOUD you want it to be.

I have one of the LOUDEST NA exhaust at the time, DEEP non-raspy when HOT, and you can hear it 1/4mi blocks away. I DO miss it in a way. This is the vid:
awsome sounds goooooood

you ever get bothered by the cops at all ??
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Old 02-26-2008, 11:30 AM   #20
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Originally Posted by RS Guy1513 View Post
wrapping the borlas/borla replicas makes almost all of that under hood noise disappear...plus it will help gas mileage a little by keeping the exhaust velocity up
True! But if you do it in an area where salt, snow, and slush make your life miserable every winter, you just ask for the headers to disintegrate after a few winters
Not to mention the entire drop of oil + wrapping = fireball issue...
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Old 02-26-2008, 11:35 AM   #21
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Well this thread is making me a little worried as I have a RT cat and borla headers waiting to go on. Now I am worried it may be to loud.
It will be loud on hard accel but it will make you . I have the stromung single hfc pipe and i think the RT pipe has 2 hfc. Mine is quite tame at cruising rpms and almost not noticeable on the highway/interstate. Just don't romp on it around cops, especially if they are tards in your area, you'll be fine.
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Old 02-26-2008, 12:26 PM   #22
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Originally Posted by Bluefoton View Post
True! But if you do it in an area where salt, snow, and slush make your life miserable every winter, you just ask for the headers to disintegrate after a few winters
Not to mention the entire drop of oil + wrapping = fireball issue...
gotta spray em so they don't turn into a wick...i got my wrap in a kit with spray and metal bands...also putting a skidplate under em, so hopefully that will keep alot of the salt and **** off
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Old 02-26-2008, 01:19 PM   #23
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...Not to mention the entire drop of oil + wrapping = fireball issue...
fireball huh ? Never thought of that...
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Old 02-26-2008, 02:50 PM   #24
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Quote:
Originally Posted by IllNastyImpreza View Post
all models of impreza up to the most recent ones(I wana say 06+) are quite unequal legnth...

you would gain some AWESOME sound by switching to a borla header in your car especialy
yeah i think im going to pick up a set but not right now as im more focused on suspension and braking
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Old 02-26-2008, 05:58 PM   #25
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Originally Posted by IllNastyImpreza View Post
awsome sounds goooooood

you ever get bothered by the cops at all ??
I have never gotten pulled over for my NA exhaust setup. It'e LOUDER than my turboswap exhaust now; headers, DP & SPT catback. I think they hear it and think it's a motor cycle or a truck.....hahaha

I'll contact the person who has it at the moment. He's got the headers on his OBS. I want to hear that thing again!!
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