I have serched but have not found any specific fittment help on a Borla or Magnaflow muffler to replace the stock pumkin.

Anyone have any info on which model may fit the easiest?

http://www.magnaflow.com/02product/s...e=main&id=9957

 

It's pretty doable if you have access to a good installer/welder. I used Gibson 5506S on my 86.5 You should be able to find the case size and locate a similar M-flow if that brand is your preference. Or, you might consider getting later model mids (S4/GT) and running with an 86.5 RMB.

 

It is kinda tough as the pumpkin inlets on the side and exits out the back. I was thinking the same style muffler in the pic only attaching it on behind the x pipe where the cats would be, then getting custom pipes made up side by side out to the stock location, maybe 2.5 all the way back. I am afraid it would be too loud though.

It is pretty loud now with stock exhaust and no cats, I am just thinking the stock pipes going to the pumpkin are a bit small for my boosted application. The current sound is great and almost no drone so that is good.

Like mentioned above, some have fitted the later exhaust and RMB but I think the battery box on the 85 needs a BFH treatment to get it to fit right. That is one problem with the 85, 32v motor and dual exhaust with floor pans designed for single exhaust.

 

I did that on my GTO, but used the dual/dual M-flow with the internal x. Worked well, still required two additional straight-through mufflers to keep the sound reasonable. I sold the car before getting a good sense of how well the packing would hold up against the heat so far forward.

Theres a thread showing fitment of a std case muffler,: https://rennlist.com/forums/928-foru...lex%2C+muffler.

 

Ted, the 86.6 has a different (S4)floor and the battery box is smaller. The exhaust also routed like the S4.. Unlike what we have, where both pipes are side by side.

 

ROuted like an S4, hence the need for the 86.5 final muffler or RMB.
Given battery box- I stand corrected regarding fitment of a standard case perf muffler in place of the stock pumpkin- though mine has several inches to spare.

The floor didn't pose any problem with respect to fitment of the dual(S4 style L/R) mids riding under my 83 Euro, nor did the 86.5 final muffler.

 

Yep that is correct. Only difference in the 86.5 is the pumpkin muffler with side exit vs the S4 with the rear exit. Some say the battery boy needs modifications to make the 86.5 and later exhaust fit properly but SMT states that he has done it on his 83 and it fits (that is good)!

Someday I want to do a 2.5" dual custom exhaust following the side by side routing I have now. I like having access to check and fill my transmission fluid on the passenger side without the exhaust in the way.

 

Do you have any pics of this setup?

 

I was looking, no dice on pics on the Euro and we are currently in different states. I have pics for the 86.5 but not the 83.

The way it is set up, per sig with OEM gt cats and the larger (than GT) S4 mids and 86.5 muffler, the Euro is darn assertive. I was very surprised.

On the 86.5 I tried X, high flow cats, aftermarket resonators in mids and factory final muffler, and it was pretty sedate.
With the Gibson factory muffler, its a bit over the top still.