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Old 08-20-2006, 09:45 PM   #1
scubysteve
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Subaru Stars OBX Header problems

Hey, just wondering if anyone else out there has had problems with the OBX EL Headers rattling around 3K - 4K? If so what did you find to be the problem and what has fixed this? Thanks.
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Old 08-21-2006, 10:34 AM   #2
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Posted my 2c worth on the 2.5rs forum.
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Old 08-21-2006, 08:31 PM   #3
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you need a better resonator. I have an STi cat back on my car and the stock STi resonator was not enough. I think mine's 18".
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Old 08-22-2006, 09:47 AM   #4
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Old 08-22-2006, 10:51 AM   #5
Patrick Olsen
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No issues like that with mine, but I imagine it would be damn annoying since I generally cruise between 3 and 4krpm. When I shift at redline I get a little buzz, but that's it.

Pat Olsen
'97 Legacy 2.5GT sedan
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Old 08-26-2006, 02:20 PM   #6
ten80
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Quote:
Originally Posted by MrHankey
you need a better resonator. I have an STi cat back on my car and the stock STi resonator was not enough. I think mine's 18".
I disagree, at least in my case. with and without a big arse Flowmaster hushpower II resonator (very very nice piece!), I still get rattling from the merge collector. I pinpointed it with the car on a lift, and think it is due to engine movement and pipe resonance, causing a couple of the header primaries to rub/vibrate together. I'm going to try stuffing an old gasket between combinations of pipes and see if that stops the problem. If it does, then a little TIG welding could keep the pipes from hitting each other. otherwise, these are sweet headers!
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Old 08-30-2006, 12:16 AM   #7
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Im having problems with my OBX headers it seems I have an exhaust leak where they mate to the cat.... When i installed them it seemed the space between the flange on the end of the headers and on the cat was far apart. However it seemed like it came together fine as i tightened those bolts with the springs on them... anyone have a simple fix for this type of leak? Its really annoying
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Old 08-30-2006, 12:21 AM   #8
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Are you using the spring bolts? Before I installed my headers I had an exhaust leak where the stock headers met my custom midpipe. The springs were removed and the leak stopped. It is still that way with my OBX headers.
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Old 08-30-2006, 01:41 AM   #9
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I also have a leak at the header/cat pipe junction. I'm going to try some copper gasket maker and see if it shuts the leak up. Spring bolts are definately a no-go without a donut gasket!
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Old 08-31-2006, 10:58 PM   #10
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Quote:
Originally Posted by Patrick Olsen View Post
No issues like that with mine, but I imagine it would be damn annoying since I generally cruise between 3 and 4krpm. When I shift at redline I get a little buzz, but that's it.

Pat Olsen
'97 Legacy 2.5GT sedan
Pat, are you running catless? I can't figure out why some us would have bad buzzing and other would not. I would LOVE to be able to solve this problem on mine.
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Old 09-01-2006, 01:00 AM   #11
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I tried putting a large hose clamp around all four pipes right before the merge collector and it subdued the rattling... a little bit. I'm not so sure it is the pipes rattling together. group N motor mounts are going in next week, maybe those will reduce the vibrations (or make them worse!?). hmmm.
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Old 09-01-2006, 08:57 AM   #12
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Cool, let us know.
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Old 09-01-2006, 12:17 PM   #13
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will do! I'm also going to have them heat-coated next week- that might also help.
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Old 09-01-2006, 01:11 PM   #14
Patrick Olsen
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Quote:
Originally Posted by horrorbiz View Post
Pat, are you running catless? I can't figure out why some us would have bad buzzing and other would not. I would LOVE to be able to solve this problem on mine.
No, I had a hi-flow cat already (from my MRT header setup), so my exhaust goes from the header to the OBX resonator to the hi-flow cat (which externally looks like the OBX resonator - it's a little metallic substrate cat) into the mid-pipe.

Pat
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Old 09-01-2006, 07:56 PM   #15
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Hmm, so maybe it does have something to do with the lack of cat. Is anyone else running a HFC with their headers?

Thanks for the feedback Pat.
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Old 09-02-2006, 01:21 AM   #16
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Yep, magnaflow HFC + flowmaster hushpower resonator. The sound is definately from the merge collector, so I think it's not possible for it to be due to some exhaust part further down the piping.
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Old 10-10-2006, 10:55 PM   #17
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Ok, adding a bunch of tac welds to connect the pipes together near the merge collector has not improved the situation. It's definately not the pipes hitting together. Heat wrap helps, but the headers are so hot the the heat wrap is burning, NO KIDDING! I'm tempted to chop the headers after the merge collector and go to town on the inside with a dremel and sanding wheel, then a polishing flapper. I bet there's some crap in there that's vibrating.

I wonder if anyone's rallitek headers do the same thing, they look to be identical, however I doubt that rallitek would sell anything with poor quality control. I haven't gotten around to the group N motor mounts nor the ceramic heat coating- but I'm very curious to find out how they affect the noise.
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Old 10-11-2006, 01:20 AM   #18
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For what it's worth, my TWE equal length headers make a rattling sound at certain rpms too. After MUCH tinkering around I'm pretty sure it's not a leak or some of the pipes vibrating together. I do have a resonator which really didn't help with the rattling noise, but did quiet things down to a sane level overall. With the stock cat section there is a little less rattling, but not much. I'm convinced it's the headers doing it, so maybe it's just a side effect of equal length headers?
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Old 10-11-2006, 01:31 AM   #19
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Quote:
Originally Posted by ten80 View Post
Ok, adding a bunch of tac welds to connect the pipes together near the merge collector has not improved the situation. It's definately not the pipes hitting together. Heat wrap helps, but the headers are so hot the the heat wrap is burning, NO KIDDING! I'm tempted to chop the headers after the merge collector and go to town on the inside with a dremel and sanding wheel, then a polishing flapper. I bet there's some crap in there that's vibrating.

I wonder if anyone's rallitek headers do the same thing, they look to be identical, however I doubt that rallitek would sell anything with poor quality control. I haven't gotten around to the group N motor mounts nor the ceramic heat coating- but I'm very curious to find out how they affect the noise.
Actually header wrap is supposed to "cure", and during this time it will smoke like crazy and you will smell some "burning" scents in the car. It's supposed to do this. Guys use the stuff to wrap things like turbo downpipes and such, which get far hotter than our girly little n/a motors can get a set of headers.
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Old 10-11-2006, 02:17 AM   #20
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good to know, I hope it is indeed curing and not burning. car on fire = bad situation, eh!
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Old 10-11-2006, 02:26 AM   #21
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LOL, yes, smoke normal, flames bad.
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Old 01-05-2007, 12:02 PM   #22
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Is everyone still experiecing buzzing? Was there any solution? I'm considering the OBX headers.

I'm going to PM Patrick Olsen, I'd like to see picks of his set up.

Last edited by problemcat13; 01-05-2007 at 12:25 PM.
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Old 01-08-2007, 12:40 PM   #23
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No more buzzing, but I now have COBB headers with ceramic coating. I do have to say that the welds, flanges, and overall finish of the OBX headers is much nicer.
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Old 01-08-2007, 02:44 PM   #24
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Are you sure it's a rattle and not a leak? After I installed my borla's I had what I thought was a rattle, ended up being a leak at the header->cat flange. Have someone hold a rag over the tailpipe and look/listen at idle. I ended up putting a new gasket in and that solved my issue. By the way, the cat/header gasket should be the metal one with the lip that gets crushed to seal.
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Old 01-08-2007, 09:11 PM   #25
555subaru
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borlas do the same thing

Last edited by 555subaru; 01-09-2007 at 12:22 AM.
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