Andrew928
New member
Long time lurker, 2nd post.
I have a 1991 Porsche 928 GT that I've modified with a 1.7l twinscrew blower among many other things. Until now, I've pretty much been runnng the stock exhaust (I had an x-pipe inplace of the stock cats).
In case you are unfamiliar with these cars, it has a 5.0l V8 with a tranaxle (similar to the new Corvettes). With the blower, the car is putting out about 450RWHP, and I think the stock exhaust has been a restriction.
Well I just got done installing a set of headers, and now am looking to completing the rest of the exhaust - but this is outside of my abilities. The headers are 1 7/8" (I think) primaries into 3" OD collectors (I measured).
Anyway, I am looking for suggestions and an estimate of what it would take to go from the headers to the back. I would like to incorporate an x into the system and I've heard that low-angle x-pipes are better at scavenging than some of the pre-fab 45° X's.
Anyway, here are pics of my car with a stitched photo of the underside (it looks crooked, but it's not) and some pics of a friends car in California that has a very similar setup (he has and "H" and an "X.")
I'm looking fro recommendations on a shop hopefully near Plymouth/Canton. I've got a call into Gautz, but they seem extremely busy.
What I'd kind of like to do is this. THis is my friend's car from CA. Same kind of car - Porsche 928. Similar headers except his come to a 2.5" collector whereas mine are a 3". He says there's no drone but it howls when hits the go-fast pedal (this is a good thing). His is dual 2.5" all the way through. His car is a 6.3l stroker putting out similar RWHP - about 450 to 475. I don't know if it would a be a good thing to keep dual 3" all the way through or reduce down to dual 2.5"? (yeah... his car is exceptionally clean.)
Anyway, thoughts and insights appreciated.
I have a 1991 Porsche 928 GT that I've modified with a 1.7l twinscrew blower among many other things. Until now, I've pretty much been runnng the stock exhaust (I had an x-pipe inplace of the stock cats).
In case you are unfamiliar with these cars, it has a 5.0l V8 with a tranaxle (similar to the new Corvettes). With the blower, the car is putting out about 450RWHP, and I think the stock exhaust has been a restriction.
Well I just got done installing a set of headers, and now am looking to completing the rest of the exhaust - but this is outside of my abilities. The headers are 1 7/8" (I think) primaries into 3" OD collectors (I measured).
Anyway, I am looking for suggestions and an estimate of what it would take to go from the headers to the back. I would like to incorporate an x into the system and I've heard that low-angle x-pipes are better at scavenging than some of the pre-fab 45° X's.
Anyway, here are pics of my car with a stitched photo of the underside (it looks crooked, but it's not) and some pics of a friends car in California that has a very similar setup (he has and "H" and an "X.")
I'm looking fro recommendations on a shop hopefully near Plymouth/Canton. I've got a call into Gautz, but they seem extremely busy.
What I'd kind of like to do is this. THis is my friend's car from CA. Same kind of car - Porsche 928. Similar headers except his come to a 2.5" collector whereas mine are a 3". He says there's no drone but it howls when hits the go-fast pedal (this is a good thing). His is dual 2.5" all the way through. His car is a 6.3l stroker putting out similar RWHP - about 450 to 475. I don't know if it would a be a good thing to keep dual 3" all the way through or reduce down to dual 2.5"? (yeah... his car is exceptionally clean.)
Anyway, thoughts and insights appreciated.
