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Old 06-16-2007, 01:59 PM   #1
stoney98
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Default Full OBX Exhaust? General exhaust questions.

Has anyone run a full OBX exhaust - Headers, hi-flow, midpipe, axle-back? I'm looking into at getting full intake exhaust system - Cobb CAI -> EL headers for power -> Hiflow cat ->2.25" midpipe->Hiflow exhaust. I'm trying to keep the decible level at least *somewhat reasonable.
My question re: the full obx is because the OBX headers look like they will not mate up flush with any other company's midpipes and back. (see images red circles).

Borla -
OBX -


Has anyone gone the full OBX route? What type of gains did you see? How loud was it? What did the exhaust note sound like? I'm trying to avoid the swarm of bees sound if at all possible.

I try to do most of my own work cash flow resons, so getting shop to cut up a mid-pipe is low on my list of to-do's. Going full OBX I can get away for under $900 with a CAI (AEM or Cobb based on availability/price).

I was also looking at the Ebay Borla knockoff's for ease of parts compatability, but I lose the gained HP from the EL headers. Going this route will put me closer to $1500 for the Ebay borla knockoff's, Stromung hi-flow cat, and a stromung catback. This is a bit more than I want to spend.

Any thoughts or recommendations would be appreciated.

This setup will be going onto this car, so power is my end target as this will become a dedicated track car at some point. When that time comes around, I will be ditching the hi-flow cat for a track pipe.
http://forums.nasioc.com/forums/show....php?t=1174602

Thanks,
-Mark
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Old 06-16-2007, 03:04 PM   #2
Cky47
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That bent pipe youare seeing is the cat on that car...

The obx pipe has no cat.
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Old 06-16-2007, 04:45 PM   #3
stoney98
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Then what is the second pipe of the obx header? Resonator?
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Old 06-16-2007, 06:08 PM   #4
Back Road Runner
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A small resonator. I assume it's there to terminate the secondary piping for wave tuning, but I'm just sort of guessing.

Anywho, don't worry about fitment. That's what exhaust shops are for. Just have a place weld up the exhaust for you. All you need is a cat(or two) and a muffler. If you have some raw pipe stock, you can use that too, but the exhaust place would just use their stock. You might want to shop around a little. Prices may vary...a lot. It shouldn't cost that much, $100-$200 kind of cheap. It depends how much work you want done. You could have seperate sections made up with flanges as opposed to one huge, long section. More work, more time, more cost. If they quote a $1000, you better leave...quickly.

That extra pipe can be used, but it doesn't have to be. You can just have a cat welded in its place...or after, whatever you want to do. You're pretty free to do whatever you want. The only real problem is putting in aftermarket cats when your stock ones work. I guess the law requires the stock cat(s) need to be damaged to be replaced, or be above a certain milage(like 100,000 miles or something). Some people apparently just punch a hole through them with a screwdriver or something, lol, hey look, it's broken. I'm sure people who have done the full exhausts can tell you more specifics about the laws.
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Old 06-16-2007, 06:10 PM   #5
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You can get a HF cat for that header setup, at least COBB offers one. Secondly, be prepared to sound more like a inline motor with that EL header setup, and it should be plenty loud, HF cat or no cat.

IMO, I'd do the borla replica header($200), used HFC($200), and your choice of CB's($200 used-$500 new ($350 ebay obx new )). The drop-off between EL, and UEL headers is 5hp tops, which is taking away low end grunt anyway, but added in at mid and top end. The sound from UEL headers is worth the extra 5hp, and with my described setup it will sound boss. I'd add a decent sized resonator to the midpipe by the way, as I like a mild sound.

I have borla replicas, and a used borla 2.25" CB, and it sounds amazing. I also have a RTech HFC in my garage which needs installing, but I'm not sure I will install. It will be too loud for my taste, I can tell already, but the power gains might make it worth it.

Gains are minimal with full exhaust, and CAI, at least for the money you spend. Get a crank pulley, and suspension mods (RSB, springs, and some bushings). Good tires, and a short shifter.

My $0.02...
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Old 06-16-2007, 06:38 PM   #6
RS Guy1513
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if you want something that sounds awsome go the uel headers and a stromung catback...i'm still running mine with the stock cat and LOVE the sound...but i've also heard piker's with a hfc and it sounds even better...maybe a little loud for my taste, but soooooo smooth.....el headers would be nice for the power, but as mentioned, it will sound a lot more like an inline motor (boooo)...but it really comes down to priority and cash flow
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Old 06-17-2007, 02:49 AM   #7
stoney98
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Since the end goal on this car is for it to become a track car, my primary concerns are power and weight, sound be damned (although a nice note would be enjoyed*). Since it looks like running the OBX header puts me sans cat, I'm probably going to have a shop weld up a section with a hi-flow cat to replace the second piece of the OBX header. I'd like to stay street-legal and not get pulled over for noise issues. The next question is which hi-flow cat and then cat back... Any suggestions for a hi-flow cat?
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Old 06-17-2007, 01:21 PM   #8
BoozeRS05
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OBX ebay catback, if buying new. Can't beat $350 to your door for stainless, and it literally comes off the same production line as exhausts for $500.

Otherwise, I'd wait out a used stromung, cobb, or something comparable. I've bought more then half my parts used, and saved significant money in the process without falloff.
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Old 06-17-2007, 02:54 PM   #9
jpbiker
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Was thinking of going the OBX way too, anybody knows the sound level of the complete setup ?
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Old 06-17-2007, 02:55 PM   #10
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And if the exhaust note is pleasant ?
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Old 06-17-2007, 08:31 PM   #11
BoozeRS05
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It all depends on the header you get...

-It will sound boss if you get UEL header, ie borla/borla replicas.

-It will sound like an inline motor, but with slightly better performance with EL header, ie Rallitek/OBX.

It also depends on if you keep a stock cat, or if you go with a HFcat...

-Pleasant with the stock cat.

-Loud with a HFcat.

These are my opinions, you might feel differently. Go to youtube, and search '2.5 rs exhaust'.
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Old 06-18-2007, 09:14 AM   #12
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Don't let the UEL header guys convince you that an EL header sounds bad. Because it doesn't. My car does NOT sound like a Honda with a mellon-shooter.

I have the full OBX Header back system on my car. I also have a Delta Cam Regrind. The combination makes for a great car. I'm afraid My car sounds great. Not too loud at all, and a great sound.. if you ask me. You can hear what my car sounds like here.

http://www.youtube.com/watch?v=BHbRDCMFPDc

I'm afraid I can't comment too much on the gains of the system. But.. I did notice a difference. I had a leak in my original cast manifold, and replaced it with an OBX Header and cat-delete pipe. That made a nice difference, with a small increase in upper HP. But I still had my stock midpipe and muffler choking my car. I then got the Delta Cams install. That made A HUGE difference. Then 1 month later, I got the OBX Midpipe and muffler. So.. Like I said, I couldn't tell you if the whole OBX system by itself will make a large difference or not.
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Old 06-18-2007, 11:39 AM   #13
piker28
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well ive heard the full obx, headers a custom hfc and a huge resonator in the midpipe and my thoughts?

it sucked, even with the small obx muffler its loud as hell, raspy, just overally i dont see its benefits
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