Hey guys, I recently got my rebuilt 16V into my '84. I'm looking into exhaust options now. The flanges on the 8V cat pipe to the manifold are rotated, preventing me from bolting them up. Seems like I've got a few options:

1. Chop the flanges off the 8V cat pipe and re weld them at the correct angle. Though now that I think of it, they might be differently shaped triangles? I'm also not sure if the O2 bungs were the same thread from 8V to 16V.
2. Buy a used S cat pipe (does anyone know if the flange to the muffler would be compatible? My guess is no, but I have a dansk muffler that I'd prefer to keep.
3. Find a new aftermarket S exhaust. https://www.summitracing.com/parts/m...ons/submodel/s this looks like it would do it, but I'd have the same problem if the muffler flange is different.

Any suggestions? Also, will any 87 or 88 NA exhaust work, or are they different from the S?

 

O2 bung is standard M18x1.5.

Difference between 944 n/a and S is too small to have any effect with exhaust, you can safely use regular 8v exhaust.

 

Good to know about the bung, and yes, the diameters are the same, it's just the flanges that mess everything up.

 

If memory serves correctly, every single tube is different between the 8v and sixteen (different diameter). I found the same thing in my 88 8v, the sixteen stuff would have to be welded. Should be pretty easy to make the dansk exhaust work, I found the steel its made from welds really well with regular (non-ss) mig wire.

 

Thanks Noah. I hadn't realized they were different diameters, they looked very similar. I think my plan right now will be to run the 16V header, buy a DEC cat pipe and chop the muffler flange off of it and weld on the 8V cat pipe muffler flange so I can run the dansk unchopped out the back. I've heard the DEC cats lose their efficiency very quickly but I'm in michigan so as long as it doesn't affect how my car runs it's not a big problem for me.

 

i don't know if the 16v headers make up for it but the 16v exhaust ports are about 3/4" further to the rear of the car than the 8v ports.

i'd just cut and rotate the flanges.