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"Our 928 Porsche headers showed an astonishing 23% horsepower gain..."

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"Our 928 Porsche headers showed an astonishing 23% horsepower gain..."

 
Old 08-29-2008, 02:29 PM
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A Y pipe with the 928 International cat back exhaust - way awesome.
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Old 08-29-2008, 04:06 PM
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I have the MSDS headers into a Y pipe on my 78 widebody. I am very happy with them and it feels strong but unfortunately I dodn't have a dyno to back it up. Sorry.
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Old 08-29-2008, 04:17 PM
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What kind of performance gain could be expected with these kind of exhuast mods (headers & Y) on a 300 hp Euro (81)?
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Old 08-29-2008, 05:12 PM
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If it gave me 10% more power I would be surprised and ecstatic.
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Old 08-29-2008, 05:21 PM
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I should note that my 10% is probably being generous to the headers...the entire exhaust setup I have was about 10% on the 5.4L (no intake mods or forced induction)...MSDS -> 3.5" Y-pipe -> Random Tech cat -> 3.5" -> Borla XR-1.

Shop also found a couple of cracks in the headers recently near the collectors, patched them with welds.
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Old 08-29-2008, 05:22 PM
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Originally Posted by Rob Roy View Post
What kind of performance gain could be expected with these kind of exhuast mods (headers & Y) on a 300 hp Euro (81)?
What exhaust manifolds does your car have?

IIRC Jean-Louis Euro track car was stock except for headers, put down 270ish rwhp.

Originally Posted by Rick Carter View Post
If it gave me 10% more power I would be surprised and ecstatic.
Since your car is boosted you really should measure the backpressure in the exhaust. If you have more then 1psi, a free flowing exhaust will free up power.
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Old 08-29-2008, 05:51 PM
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Originally Posted by Rick Carter View Post
If it gave me 10% more power I would be surprised and ecstatic.
Originally Posted by Hacker-Pschorr View Post
Since your car is boosted you really should measure the backpressure in the exhaust. If you have more then 1psi, a free flowing exhaust will free up power.
I've never measured exhaust back pressure 1psi seems very low. How much does it vary over RPM, boost and load range? My exhaust is designed to scavenge with the Tom Cloutier Y merge collector, similar to Burns Stainless.
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Old 08-29-2008, 06:02 PM
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No dyno to back me up either, but my seat of the pants tells me that my Euro with the headers breathes and runs a LOT better than the Euro that does not have the headers. YMMV
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Old 08-29-2008, 06:03 PM
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Originally Posted by Rick Carter View Post
I've never measured exhaust back pressure 1psi seems very low. How much does it vary over RPM, boost and load range? My exhaust is designed to scavenge with the Tom Cloutier Y merge collector, similar to Burns Stainless.
Per the WSM anything over 1psi is not ideal, so no it's not low
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Old 08-29-2008, 06:16 PM
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Originally Posted by Hacker-Pschorr View Post
Per the WSM anything over 1psi is not ideal, so no it's not low
Are you measuring at the O2 bung; what tool are you using to measure? Do meaure pre and post cat? I don't have a cat only a small dog.
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Old 08-29-2008, 06:24 PM
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I have a friend who had a GT with X pipe and 2.5" rear exhaust. It made about 320 rwhp max which is about normal. He wanted headers. He got a nice set of equal length headers and had them ceramic coated. I made a tapered transition to go from the 3" header collector to 2.5" X pipe and connected to the existing 2.5" rear exhaust. I'd say it would be about the closest comparison you could make between what you could do with the stock manifolds and again with headers. The best I could do with that setup was 316 rwhp. Sharktuned and all. The tests were done within a few days and no other changes were made. Maybe a different X pipe location would help some. Maybe something else would help. Once you have a good X pipe and rear exhaust, that's about all you can do. This on a GT and I have no experience with 16 v US or Euro so I can't say what the difference would be for those.

I have a set of MSDS headers for a 928. They are new, ceramic coated, and polished to look like chrome. $400 plus shipping.

Last edited by Louie928; 08-30-2008 at 02:11 AM. Reason: Added headers for sale
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Old 08-30-2008, 12:36 PM
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Originally Posted by Louie928 View Post
I have a set of MSDS headers for a 928. They are new, ceramic coated, and polished to look like chrome. $400 plus shipping.
Someone needs to buy these. That's a deal!
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Old 08-30-2008, 12:40 PM
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[QUOTE=Louie928;5751762]I have a friend who had a GT with X pipe and 2.5" rear exhaust. It made about 320 rwhp max which is about normal. He wanted headers. He got a nice set of equal length headers and had them ceramic coated. I made a tapered transition to go from the 3" header collector to 2.5" X pipe and connected to the existing 2.5" rear exhaust. I'd say it would be about the closest comparison you could make between what you could do with the stock manifolds and again with headers. The best I could do with that setup was 316 rwhp. Sharktuned and all. The tests were done within a few days and no other changes were made. Maybe a different X pipe location would help some. Maybe something else would help. Once you have a good X pipe and rear exhaust, that's about all you can do. This on a GT and I have no experience with 16 v US or Euro so I can't say what the difference would be for those.

I have a set of MSDS headers for a 928. They are new, ceramic coated, and polished to look like chrome. $400 plus shipping.[/QUOTE]

Originally Posted by 123quattro View Post
Someone needs to buy these. That's a deal!
I'll be glad to buy them if I'm guaranteed not 10% just 10 more rwhp.
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Old 08-30-2008, 12:47 PM
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Originally Posted by Rick Carter View Post
I'll be glad to buy them if I'm guaranteed not 10% just 10 more rwhp.
With your SC, you *might* get 10 rwhp. Pretty much depends on what you have for exhaust now.
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Old 08-30-2008, 01:11 PM
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Originally Posted by Louie928 View Post
With your SC, you *might* get 10 rwhp. Pretty much depends on what you have for exhaust now.
I have the Cloutier now, although it is only a single 3". If I could get Tom to make one in 3 1/2" or 4" it make give me more high rpm power.
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