LEADASS

I'm in the process of installing 928 Motorsports headers,header x, and their hi-flo cats. I'm wondering about the cat back, I wasn't sure about muffler type or location but this looks promising back at the pumkin.

RichS 1986928

Matt, yes I've already had that battle with several shops including one that I took the car too
just for them to change their minds.
Currently I had to register with the CO DMV to have the car taken off the road beause I can't get it
registered without passing emmisions.

I need to find a 'custom' exhaust shop that will do this work.

dprantl

What about cutting the battery box out of a '86.5+ wreck, weld in place of the one in there now and use a group 48 battery instead of 49?

Dan
'91 928GT S/C 475hp/460lb.ft

RichS 1986928

Still got the heat shield to deal with, so I think overall it's less work to just use
2 dual in/out mufflers.

What's the difference between a muffler and a resonator?

Chuck Schreiber

John Curry just did this with his Euro I believe. I know he told me he did headers, an x, and a dual exhaust down one side of the car if I'm not mistaken. He said his car runs like a bat out of hell now.

Ping him and get him to respond. His Avatar is Soontobered. I'll give him a shout on his cell when I have a chance and have him respond here as well.

Chuck Schreiber

Just talked to Curry, He'll post when he gets a chance.

soontobered84

Sorry, late to the game here.(I hate when work gets in the way of my posting on RL.)

What I did is put MSDS headers on the stepson ('84 Euro). I wanted dual pipes all the way back like the Schwartz car has. Roger had an ANSA dual exhaust that he was not going to use, so I took it home. The ANSA system had a 1 into 2 adapter welded on the front end (for the original cat hookup) I removed that and had an X-pipe made that bolted between the headers and the ANSA system.

The car has a good throaty rumble at idle but is not too loud. HOWEVER, when you go WOT, it sounds just like the car that Porsche meant the 928 to be. No dyno figures available, but seat of the pants tells me 1)that my original cat was plugged up sufficiently to cause performance issues and 2) the Euros are bad scary SOBs above 4K RPM.

YMMV LOL

toofast928

Ohh now I have evil ideas. My 2.5 dual exhaust is only two years old but I really miss the sound of the single pipe. Plus I can't stand the passenger tail pipe wrap between the batt box and transaxle.

Curry sound clip pls...................

Landseer

Not perfect, but sure was the right thing to do in my case. All SS.
https://rennlist.com/forums/928-foru...ight=magnaflow
Its jacked-up from the Drivers side a little in this picture.
Nice and symetrical in a level view.
Guess it was routed in front of battery box, not behind. Oh well.

toofast928

Yep, my pipe is tuck up a little higher but regardless can still see from behind. I spray painted the rear piping with flat black. Blends into the underside

soontobered84

Tony,
I'll try to get a sound clip...newfangled electronic gear is not really my strong point, but then again, I'm still trying to figure out my strong point.

SMTCapeCod

Man, there is some ugliness on this thread....mandrel bends and stainless are good features!
As for the muffler- depends on whether you want stainless. Stainless designs are fairly limited, magnaflows do an ok job of taking out some noise despite being straight through- if you can fit a decent size. Regular Flowmaster impedes flow a bit, I'm not a big fan of the compact Hushpowers ........Hooker aerochambers are good but only in aluminized...Borlas are similar to magnaflows...Corsa are nice, but loud. I really don't like Spintech, after having one of the vendor's systems that utlized them.
I had a custom dual in/out fabricated to fit in place of the cats at one point, that was a decent solution. stainless-specialities.com or similar. Stainlessworks could probably do something too.

JHowell37

I modified a GT exhaust for my '85. To make it work, I cut out a section of pipe after the 90 degree bend on the driver's side. Then I welded the end back on.



At the front I cut off about 2 inches and welded on a piece of 2.5 inch pipe so it could slip on the end of the X-pipe and use regular 2.5 inch clamps.



It attaches at the rear cross member the same way the exhaust from 928 motorsports attaches to an '85. I even used the same hangers. I have heat shields from an S4 but haven't put them on. The heat really isn't too bad since there's no fiberglass stuffing inside to retain it. It clears the battery box (barely) without rubbing.