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Discussion Starter #1
Thinking of getting a set of either Manzo or Pypes headers. From what I have seen they look to be the same thing. Any advantage of one over the other other than price?
 

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I'd look into the OBX system.
I would too but didn't mention it because it's hard to find. I rarely see them come up for sale these days. The bargan exhaust IMO is the OBX system then add long dynomax bullets in the center and short ones to some Solo Axle backs.
 

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Both are the same and good if you replace the collector flange because they are only 2 inch. Pacesetter are fine if u don't mind the coating coming off and them rusting. Obx seem to be best overall bang for your buck imo. Of course you can pay a ton for the American made headers but in the end hp differences are minimal. I would personally look into the coated stainless JBA headers on eBay. I am running modded Pypes headers for 2 years now no issues. Made 377whp with the little 2in flanges lol
 

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Ok I'll go a different path. Why are you looking at headers? On the GT, the exhaust restriction is in the flex above the cats. , next would be the cats, then the output of the cats and further down the pipe there is a crimp near the tunnel brace. In theory, as you get further from the engine, diameter can be less as the exhaust velocity and volume decreases with temperature.

That all typed, knowing what I know now, if NA, I would use the stock manifolds - they flow well, much better than 10yrs ago, then have a exhaust shop fab up a "test pipe" to replace the cats - 3 In inlet and 2.5in ball outlet. Then get a true 2.5in catback. If you plan to go with boost later, then headers make sense, but as stated earlier, the manzo will need to have the collectors replaced for the headers to work. Be conscious of diameter - otherwise just poser headers.

Here is a article to learn about exhaust: Auto Exhaust Science

here is an example showing the restriction inside the flex:
 

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Discussion Starter #8
Ok I'll go a different path. Why are you looking at headers? On the GT, the exhaust restriction is in the flex above the cats. , next would be the cats, then the output of the cats and further down the pipe there is a crimp near the tunnel brace. In theory, as you get further from the engine, diameter can be less as the exhaust velocity and volume decreases with temperature.

That all typed, knowing what I know now, if NA, I would use the stock manifolds - they flow well, much better than 10yrs ago, then have a exhaust shop fab up a "test pipe" to replace the cats - 3 In inlet and 2.5in ball outlet. Then get a true 2.5in catback. If you plan to go with boost later, then headers make sense, but as stated earlier, the manzo will need to have the collectors replaced for the headers to work. Be conscious of diameter - otherwise just poser headers.

Here is a article to learn about exhaust: Auto Exhaust Science

here is an example showing the restriction inside the flex:
Thanks for the advice. I know quite a lot about exhaust system, headers, etc. On my 2006 GTO, long tube headers were worth 20 HP at the wheels confirmed by dyno runs. I have been thinking about getting the OBX headers exhaust since they don't have cats, are long tubes and include an x-pipe which is usually good for 5 to 10 HP.

I am just a bit concerned about it making the car louder than I want. While I wouldn't mind a little increase in sound, I don't want it to be obnoxiously loud.

Would the OBX system be loud with the stock axle backs?
 

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Thanks for the advice. I know quite a lot about exhaust system, headers, etc. On my 2006 GTO, long tube headers were worth 20 HP at the wheels confirmed by dyno runs. I have been thinking about getting the OBX headers exhaust since they don't have cats, are long tubes and include an x-pipe which is usually good for 5 to 10 HP.

I am just a bit concerned about it making the car louder than I want. While I wouldn't mind a little increase in sound, I don't want it to be obnoxiously loud.

Would the OBX system be loud with the stock axle backs?
X-pipes make power? I thought they only smoothed out the flow.
 

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Discussion Starter #10
X-pipes make power? I thought they only smoothed out the flow.
They do smooth out the flow and make the exhaust sound smoother. But both an H-Pipe and an X-pipe do add power. The H-pipe tends to favor TQ over HP but not by a lot. Here is an article about this exact subject: http://www.superchevy.com/how-to/exhaust/1504-x-and-h-pipes-add-easy-horsepower-but-which-is-best-for-your-ride/

Quoting from the last sentence of the article: "On a typical 400-horsepower street car, adding an X-pipe or an H-pipe to an existing dual exhaust system can add 7-12 hp. A smoother exhaust note and reduced interior resonance are added bonuses."
 

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They do smooth out the flow and make the exhaust sound smoother. But both an H-Pipe and an X-pipe do add power. The H-pipe tends to favor TQ over HP but not by a lot. Here is an article about this exact subject: http://www.superchevy.com/how-to/exhaust/1504-x-and-h-pipes-add-easy-horsepower-but-which-is-best-for-your-ride/

Quoting from the last sentence of the article: "On a typical 400-horsepower street car, adding an X-pipe or an H-pipe to an existing dual exhaust system can add 7-12 hp. A smoother exhaust note and reduced interior resonance are added bonuses."
What I've read is that H-pipes sound better and X-pipes flow better? Is there any truth to that? I know there's got to be something different between the two or why would they have a X-pipe and a H-pipe? Sorry for the questions.
 

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Discussion Starter #12
What I've read is that H-pipes sound better and X-pipes flow better? Is there any truth to that? I know there's got to be something different between the two or why would they have a X-pipe and a H-pipe? Sorry for the questions.
H-pipes tend to keep that American muscle car sound. X-pipes smooth out the exhaust pulses so it has a sound more like a Ferrari or car that has a flat-plane crank.
 

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H-pipes tend to keep that American muscle car sound. X-pipes smooth out the exhaust pulses so it has a sound more like a Ferrari or car that has a flat-plane crank.
I know this may sound stupid. But physically, the X-pipe looks like it would be a better performer {flow}.
 

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Discussion Starter #14
I know this may sound stupid. But physically, the X-pipe looks like it would be a better performer {flow}.
You are correct. While both the H-pipe and X-pipe both help, the X-pipe overall does flow better and have a slight edge in performance over the H-pipe.
 

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Thanks for the advice. I know quite a lot about exhaust system, headers, etc. On my 2006 GTO, long tube headers were worth 20 HP at the wheels confirmed by dyno runs. I have been thinking about getting the OBX headers exhaust since they don't have cats, are long tubes and include an x-pipe which is usually good for 5 to 10 HP.

I am just a bit concerned about it making the car louder than I want. While I wouldn't mind a little increase in sound, I don't want it to be obnoxiously loud.

Would the OBX system be loud with the stock axle backs?
I'm willing to bet it would still be pretty loud, I have the OBX system with Solo's and it's ridiculous loud. People love it but honestly for as much as i drive the car i'm wanting a set of GXP mufflers to tame it some.
 

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The OBX system with stock GT mufflers is NOT loud at all. In fact it's very stockish sounding. Now with the GXP mufflers it would be much louder than stock and a great option if you don't mind how loud it gets when you get on it. The Solo axle backs paired with the OBX is just too loud, you need to add a muffler or mufflers of some kind. The GXP mufflers are hard to find, it's why I mentioned the Dynomax bullets and the fact that everyone who listened to them liked that set up better than the sound of the GXP mufflers.

I'll have to try and make a video. Pacesetters (connection pipe flange taper cut off, so still 3") to 3" X pipe and 3" Dynomax bullets (I think 21" or so long) with 3" pipe to just before the axle back where it tapers to 2.5" (this is very much like what the OBX system does) then Solo axle backs modifed by adding the short dynomax bullets.

My set up is about the same volume as the GXP mufflers, just much deeper. This is why I know the stock mufflers are very quiet with the OBX, and the GXP mufflers are much louder than GT mufflers. Also the Yeti has the OBX and runs stock mufflers some times.

I have done an extensive amount of different exhaust set ups on the G8.......too many!
 

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I would too but didn't mention it because it's hard to find. I rarely see them come up for sale these days. The bargan exhaust IMO is the OBX system then add long dynomax bullets in the center and short ones to some Solo Axle backs.
OBX Full Exhaust Headers 08 10 GM PONTIAC G8 GT GXP | eBay

Would the OBX system be loud with the stock axle backs?
As someone pointed out, go with the OEM mufflers with the OBX system.

The OBX system with stock GT mufflers is NOT loud at all. In fact it's very stockish sounding. Now with the GXP mufflers it would be much louder than stock and a great option if you don't mind how loud it gets when you get on it. The Solo axle backs paired with the OBX is just too loud, you need to add a muffler or mufflers of some kind. The GXP mufflers are hard to find, it's why I mentioned the Dynomax bullets and the fact that everyone who listened to them liked that set up better than the sound of the GXP mufflers.

I'll have to try and make a video. Pacesetters (connection pipe flange taper cut off, so still 3") to 3" X pipe and 3" Dynomax bullets (I think 21" or so long) with 3" pipe to just before the axle back where it tapers to 2.5" (this is very much like what the OBX system does) then Solo axle backs modifed by adding the short dynomax bullets.

My set up is about the same volume as the GXP mufflers, just much deeper. This is why I know the stock mufflers are very quiet with the OBX, and the GXP mufflers are much louder than GT mufflers. Also the Yeti has the OBX and runs stock mufflers some times.

I have done an extensive amount of different exhaust set ups on the G8.......too many!
Nice post.

I eventually plan on going with the OBX system with high flow cats. and stock mufflers.
 

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Discussion Starter #18
I think I am going to stay stock for now.

By the way, the price on eBay earlier today was $595 plus $95 shipping. And now its been jacked up to $699 plus the $95 shipping. So screw those sellers.

For that price, I might as well get a set of SLP's or the Kook's mids with cats.

I may just get the Pypes and be done with it.
 

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I think I am going to stay stock for now.

By the way, the price on eBay earlier today was $595 plus $95 shipping. And now its been jacked up to $699 plus the $95 shipping. So screw those sellers.

For that price, I might as well get a set of SLP's or the Kook's mids with cats.

I may just get the Pypes and be done with it.
You're absolutely right! I saw it earlier this week and then I looked at it again when I linked it here and saw that it seemed higher. That's pretty nasty of them.
 

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Even at that price it remains the best bang for the buck. Kooks mids with cats is going to cost you a lot more and that doesn't address the mid section. The Pypes are not built as well and will not flow as well as the OBX. I would suggest grabbing them while you can, I wish I had done that but it was fun learning to weld and building my own Frankenstein exhaust too.
 
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