"Our 928 Porsche headers showed an astonishing 23% horsepower gain..."
#16
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
A Y pipe with the 928 International cat back exhaust - way awesome.
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
#17
Man of many SIGs
Rennlist Member
Rennlist Member
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.
#20
Rennlist Member
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.
Shop also found a couple of cracks in the headers recently near the collectors, patched them with welds.
#21
Administrator - "Tyson"
Lifetime Rennlist
Member
Lifetime Rennlist
Member
IIRC Jean-Louis Euro track car was stock except for headers, put down 270ish rwhp.
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.
#22
Rennlist Member
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.
#23
Rennlist Member
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
#24
Administrator - "Tyson"
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Per the WSM anything over 1psi is not ideal, so no it's not low
#25
Rennlist Member
#26
Three Wheelin'
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.
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
#27
Drifting
#28
Rennlist Member
[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]
I'll be glad to buy them if I'm guaranteed not 10% just 10 more rwhp.
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]
I'll be glad to buy them if I'm guaranteed not 10% just 10 more rwhp.
#29
Three Wheelin'
#30
Rennlist Member