BHMSC

I’m considering replacing the catalytic converter on my ’80 SC with a European pre-muffler once the car qualifies for “historic” status but I’m curious about other folks’ experience.

I’ve read about sound problems with the test pipes. Is a pre-muffler worth the extra cost compared to a “test pipe”? I want something a little louder than stock but not something obnoxious (inside or outside the car).

I would keep the oxygen sensor. Was it necessary to re-adjust the CIS mixture to compensate for the lack of a catalytic converter?

The most reasonably priced pre-mufflers seem to be from Performance Products and Fabspeed. Anyone have experience with either? Others?

Noel

Your exhaust will be louder. How much, depends on how blocked your cat is now. For me it was slightly louder than stock at idle. Eny time you change the exhoust system, you are changing how air flows through the engine, so would check the mixture. BTW, your car should run a little cooler without the cat.
I have the pipe from Performance Products and it is actually perferated inside the tube, si it does provide premuffling.

BTW, nice choice in cars. I too have a 80 SC and a 98 A4 as a daily driver.

KC911

I have a Fabspeed premuffler (along with a GHL 1 in/1 out muffler) which I REALLY like. You might find some older posts regarding Fabspeed fitting issues (I think they had a problem w/ their jig), but I had no issues at all. To be honest, the GHL had already provided a 'nice' rumbling (but not too loud) exhaust note, and I really didn't hear much of a difference after I installed the premuffler.

Keith

RANDY P

Best thing I've ever done to the car was a factory euro-premuffler and a single in and out Flowmaster, has a nice roar, much more responsive and noticable torque difference.

But then again, my cat was dead when I started. Just by sheer age you should have it checked out. No 02 sensor either, have my CO set to 3.5%. No more cruise surging...

wheatdog

I installed the Fabspeed premuffler with no problems. I couldn't tell if it changed the exhaust tone due to the fact that I also fabricated my own exhaust system downstream of premuffler using 3" pipe and 3" inlet/outlet cherry bomb glasspack. Took it to the next DE event and everyone was complimenting me on how good my '86 carrera sounded. When I told them how I did it, I received scathing looks of disgust. Oh well, it looks like a professional install, sound and runs great and only cost me $125.00 to fab.

Panhead Mike
'86 Carrera
'65 Shelby Daytona Coupe
'63 Panhead Harley FLH
'67 BSA Lightning
Fuji 12 speed
Radio Flyer Wagon
etc, etc

dma550

WHeatdog, got any pics of that muffler? I'm tricksy and dangerous with a mig welder, sounds like I could cook up a nice muffler too

-DMA

wheatdog

Dma550,
Once I get my son to show me how to work the camera and download the pics, I'll see if I can get some shots posted. The setup could be improved upon, performance wise, by using a flowmaster instead of a glasspack. There's enough room to fit one of the smaller size ones in without proximity cooking the rear valence. Although cool sounding, the cherrybomb can't compete with the flowmaster. Also, flowmaster probably sounds just as good. I just happened to have a left over muffler from a 440 Challenger project. Win/win situation for me. Min.$$$ spent and one more piece of clutter removed from the garage.

RMA

Ive got a FabSpeed pre muffler - I didnt notice "more" exhaust noise after I installed it.

The fit was great in my opinion.