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Old 04-22-2012, 04:04 PM   #1
TonyT88
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Default this is what im thinking for my 07 2.5i impreza

heres the headers http://www.ebay.com/itm/CNT-EL-98-05...ht_2547wt_1113


and heres the exhaust. http://www.ebay.com/itm/OBX-SS304-EX...ht_2408wt_1347

i might do the uel headers not sure. what do you guys think
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Old 04-22-2012, 04:19 PM   #2
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My buddy has the obx cat back on his 05 rs. Sounds really good
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Old 04-22-2012, 04:24 PM   #3
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Let us know what you think about the set. I've been thinking about getting the OBX pipes myself, but I've got an 04 and can't seem to find any labeled for that year. Mind me asking how you plan to make it all fit together?
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Old 04-22-2012, 08:15 PM   #4
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Intredasting.....

I call shenanigans on the WHP gains of the header, that's a bit much, but it still rustled my jimmies. I say do it, let the rest of us 06-07 owners know if it fits.
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Old 04-23-2012, 01:02 AM   #5
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JNA performance is located in Connecticut, they make a really nice WRX/STI exhaust that with slight modification will fit an 02-07 2.5i/rs. I have this installed on my 07 2.5i and it sounds amazing! Its also great for the price, the midpipe needs to be reduced and the flange needs to be rotated.

http://www.jnaperformance.com/index....product_id=592

Also i have herd these headers would very nicely with the exhaust

http://www.jnaperformance.com/index....product_id=876
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Old 04-23-2012, 08:13 AM   #6
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i have that same link i want that exhaust because of the price and the tip is huge which is what i wanted but thats 3 inlet piping thats too big for our cars thats what everyone said. did you lose any back pressure. can you post a sound clip man cause that would be awesome. i would help me make a decision
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Old 04-23-2012, 08:45 AM   #7
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Quote:
Originally Posted by TonyT88
but thats 3 inlet piping thats too big for our cars thats what everyone said
Yes for the n/a engines you don't wanna run over 2.5" pipe. Many people actually just go with the 2.25" and are happy with it.
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Old 04-23-2012, 10:24 AM   #8
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Quote:
Originally Posted by TonyT88 View Post
i have that same link i want that exhaust because of the price and the tip is huge which is what i wanted but thats 3 inlet piping thats too big for our cars thats what everyone said. did you lose any back pressure. can you post a sound clip man cause that would be awesome. i would help me make a decision
Did not lose any back pressure, will post sound clip link in an hour or so
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Old 04-23-2012, 11:26 AM   #9
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Here is the link to the sound clip. This is just the JNA catback NO HEADERS. Also if someone could tell me what the hell that creeky sound when i hit about 3k RPM is that would be much appreciated, its been happening since before i even put the exhaust on .
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Old 04-23-2012, 06:29 PM   #10
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You guys and your back pressure shenanigans. You must understand how the exhaust works before you can tell if a header/catback will be worth the $ as far as performance goes.

Related question, how would you actually know if the "back pressure" changed?
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Old 04-23-2012, 06:36 PM   #11
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hey i'm just saying man everyone says don't put on a 3" exhaust on a 2.5i. what do you have
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Old 04-23-2012, 09:39 PM   #12
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A lot of guys on local Subaru forum i'm on are running this setup on their 2.5i's, ive asked them if they lost any back pressure from the 3" and they all said after a tune they came out with a +20-25 hp/tq gain, so i assume that the back pressure was not affected.
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Old 04-23-2012, 10:23 PM   #13
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thanks for the info man app. it
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Old 04-23-2012, 10:25 PM   #14
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Quote:
Originally Posted by TonyT88
hey i'm just saying man everyone says don't put on a 3" exhaust on a 2.5i. what do you have
I have the knowledge of how exhaust flows through the system. If you want details search and learn like the rest of us. The info is out there, most of it on this forum right in front of you.

Quote:
Originally Posted by ImprezaBromance
A lot of guys on local Subaru forum i'm on are running this setup on their 2.5i's, ive asked them if they lost any back pressure from the 3" and they all said after a tune they came out with a +20-25 hp/tq gain, so i assume that the back pressure was not affected.

A lot of guys who you both are taking to have no ****ing idea what they are talking about.

Explain to me what "back pressure" is and why it's necessary.

A catback gains absolutely nothing from a tune on an n/a subaru. the gains from a tune are independent of the exhaust after the cat. it's likely that the same gains could be made from a tune with the stock exhaust, but they are not 20 lb-ft gains.
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Old 04-24-2012, 09:35 AM   #15
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Quote:
Originally Posted by RaceFaceXC View Post
I have the knowledge of how exhaust flows through the system. If you want details search and learn like the rest of us. The info is out there, most of it on this forum right in front of you.




A lot of guys who you both are taking to have no ****ing idea what they are talking about.

Explain to me what "back pressure" is and why it's necessary.

A catback gains absolutely nothing from a tune on an n/a subaru. the gains from a tune are independent of the exhaust after the cat. it's likely that the same gains could be made from a tune with the stock exhaust, but they are not 20 lb-ft gains.
Okay first off yes they do get 20 lb gains and secondly you would not get
ThE same gain with a stock exhaust..... You sir are a douche. Don't. One
In here out of no where and tell me that a n/a can't get a 20lb
Gain off a good tune..... Back to the original topic. I have never herd an obx on an 07. Do you have a sound clip? And those headers you posted are
More expensive but if that HFC is included
It's prob a better deal.

-Alex
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Old 04-24-2012, 11:43 AM   #16
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Quote:
Originally Posted by ImprezaBromance

Okay first off yes they do get 20 lb gains and secondly you would not get
ThE same gain with a stock exhaust..... You sir are a douche. Don't. One
In here out of no where and tell me that a n/a can't get a 20lb
Gain off a good tune..... Back to the original topic. I have never herd an obx on an 07. Do you have a sound clip? And those headers you posted are
More expensive but if that HFC is included
It's prob a better deal.

-Alex
Please, explain to me how a catback makes any difference on an n/a subaru, since you have such vast knowledge and complete understanding of the fluid dynamics involved. Seriously, I would like to read your detailed explination or at least see some dyno data.
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Old 04-24-2012, 12:41 PM   #17
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I'd be interested in knowing as well
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Old 04-24-2012, 02:19 PM   #18
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Quote:
Originally Posted by RaceFaceXC View Post
Please, explain to me how a catback makes any difference on an n/a subaru, since you have such vast knowledge and complete understanding of the fluid dynamics involved. Seriously, I would like to read your detailed explination or at least see some dyno data.
I don't have a dyno sheat for my car because it's not tuned yet. However HFC and a catback = less restrictive airflow. Less restrictive airflow = better gains with a tune. What exactly is your reasoning?
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Old 04-24-2012, 02:43 PM   #19
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The factory cat/catback are not a restriction with the factory headers. They are not really a restriction even with ideal headers like TWE.

My reasoning is that gains from exhaust parts are due to pressure wave tuning and exhaust velocity. To keep it simple... the headers determine both of these things. The factory cat/catback is more/less up to the task of giving the gases an easy path out of the system on an engine with stock heads.

before you call someone a douche, make sure you know what the **** you are taking about... Douche.

If you have no dyno SHEET, where are these 20 lb-ft gains coming from?

Last edited by RaceFaceXC; 04-24-2012 at 02:48 PM.
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Old 04-24-2012, 06:58 PM   #20
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My catback netted me 100 placebo hp on the butt dyno. True story.
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Old 04-24-2012, 09:21 PM   #21
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The stock Cat will restrict airflow..... And I'll get a Graph in a few days
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Old 04-24-2012, 09:58 PM   #22
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of course it does. the pancake resonator restricts airflow. cant wait to see the graph. quick question do any of you have your 2.5i lowered? if so what springs you using. and i don't car if it the wrong forum
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Old 04-26-2012, 12:54 PM   #23
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check out Rallisport UEL headers. Just got them last week
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Old 04-26-2012, 12:54 PM   #24
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check out Rallisport UEL headers. Just got them last week

What the........ posted 2.. sorry

Last edited by fpshked; 04-26-2012 at 01:13 PM.
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Old 04-26-2012, 03:16 PM   #25
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Quote:
Originally Posted by fpshked View Post
check out Rallisport UEL headers. Just got them last week

What the........ posted 2.. sorry
how do you like it so far?
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