16v Exhaust system help!
 

Hi everyone

Finally able to use my 1981 4.5 auto after two years of body restoration and so now trying to sort all those little niggles etc!

I have original headers going into a Haywood and Scott Y pipe, then angled to a H&S small silencer and then to a 928 kidney which I thought was period correct but turns out to be for a 4.7 928S. I enclose a diagram and also photos of the kidney back box.

Im disappointed with the exhaust note/lack of V8 noise and wanted thoughts on what I should do. Sell the kidney and get a RMB? I like the black twin exhaust look and for originality would like it angled like it should be. Any suggestions for who could make something much appreciated!
https://cimg1.ibsrv.net/gimg/rennlis...3ed462b546.jpg
https://cimg3.ibsrv.net/gimg/rennlis...dc90f6a69b.jpg
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Claret, I don't think they make RMBs for the OB style cars. I had looked into that at one time for my '84. Two relatively simple and inexpensive solutions would be:

1. Have a muffler shop make a pipe connection to put in place of the center muffler. It would only be two flanges and a piece of pipe. Probably very inexpensive and would retain all the same stock look.

If that's not to your liking, consider..

2. Reinstall the mid-muffler and pull the rear muffler and replace with a pipe fabricates with dual black tips to retain the stock look. This approach would be a bit more difficult because the exhaust shop would either have to crush bend the pipe to get the angle right or piece together some mandrel bends to get everything to line up at the right angle. Either way, its a bit more labor intensive to get the desired result.

I bought a cat-back system from 928 intl. years ago for my '81. It is a bit loud (for me now) but a very good unit.

We do not make that anymore but the Borla system is well made and a great sound

had a BORLA cat back on my 81 , sounded great , even a little more HP

+ 1 on the borla, but with no cat I think you will find it to be too loud and too much V8 sound. I have stock headers-> Y pipe->cherry bomb->borla rear section. Sounds like a hopped up Camero. I really liked stock cat with the Borla cat back. Civilized yet aggressive.

My Euro 83 S has a LARGE first muffler (which looks like its got a non-original skin on it, but otherwise original), 2 out pipes to a 2-in 2-out rear pumpkin, and its pretty boomy at a fast idle, and around 1500rpm going through the gears. Has been known to set off alarms in adjacent cars in parking garages.
jp 83 Euro S AT 57k

http://www.nixsoft-consulting.co.uk/928spares/index.php?id=products

These guys make one for the S and S2 if that's any use. I have the S4 one (w silencer). Very nice.

Wait until after brexit and if the pound crashes you'll be able to get one for a few dollars.

This is not even close to being properly oriented (per original).

​​​​​​it is compared to whats on there now...
https://cimg5.ibsrv.net/gimg/rennlis...f4e079ce43.jpg
https://cimg6.ibsrv.net/gimg/rennlis...e05565ca34.jpg

That rear muffler is actually 'factory' original for a Japanese market 928.
It exits the body the same as the typical original, then turns straight back.
It can be 'cut back' to the original offsets & slant-cut tip lengths.

I came up with this early type RMB. Each tip has a built-in resonator.

https://cimg7.ibsrv.net/gimg/rennlis...2c57590fac.jpg
https://cimg9.ibsrv.net/gimg/rennlis...c3fa83bead.jpg
https://cimg5.ibsrv.net/gimg/rennlis...75af5f60d5.jpg

Good to know Jim. :D
^^now thats the ticket:thumbup:T

On my supercharged '79 I'm running OEM headers to a 928MS stainless Y-pipe into a Borla.

It's on the louder side, but why not hear that great German v8. Without cats it is a little stinky though.

https://cimg8.ibsrv.net/gimg/rennlis...b146a01ed0.jpg
https://cimg6.ibsrv.net/gimg/rennlis...5329471962.jpg
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