The cats clogged on my 1985 GSL-SE, so I added a header and eliminated all 3 cats (mainly to save $1000 or so). The muffler is a newer cheap aftermarket one. Before the header addition and cat removal, the car was TOO quiet. Now it sounds like a weedwacker on steroids. Is there an INEXPENSIVE muffler that will be quieter, but not make the car sound like a LeSabre?

By the way, the header and no cats increases performance unbelievably!!

 

Whatever you do, don't throw away your old cats. It's likely that only the two smaller pre-cats are clogged, and they can be unclogged and re-used.
As for the main cat, those rarely if ever clog so it may still be good. They do split occasionally but can be re-welded. Keep it because it's replacement value (if your state ever brings in emissions testing--- a matter of when rather than if) is around $2000. Used ones are hard to find because recyclers scavenge them for the precious metals inside. Shops that install custom exhausts know this and will therefore try to keep your old parts unless you emphatically tell them to give you your old parts back.
The best option would be to have a header aft of which you could mount the external portion of both pre-cats in such a way as to disguise a custom-made straight-through pipe running through them in order to fool the emissions visual check. They usually won't pass your car unless all components are in place, including the air pump. The same could be done to the main cat but then it would be a neat trick to make it pass the actual emissions test on the dyno.

But back to your original question:
Install a pre-silencer just aft of the header. This should bring the noise down to an acceptable dull roar without sounding like your dad's Buick.
As for your muffler, many of the cheaper ones can't handle the rotary's exhaust for very long. Which one did you purchase?

 

same problem i had! keep the same muffler, and stick a cherry bomb on it as a resinator, thats what i plan to do.

 

A glasspack like a cherry bomb will only last about a month before the fiberglass packing all burns up and you are left with a useless shell.

 

The only presilencer I can find is the "PowerPulse" Presilencer from RacingBeat. It has a "six-port injection back-pressure pickup tube". What the heck is that? Should it be plugged or something? I assume I will also need gaskets.

Do you think this will do the trick?

http://www.racingbeat.com/FRmazda1.htm

Thanks!!

Tom

 

www.summitracing.com
www.jegs.com

Both sell lots of mufflers. For my turbo I've got a Moroso SpiralFlow for the presilencer. The car doesn't run yet though so I havn't tested it out.

You could get a Dynomax Bullet or lots of others, just make sure it's made out of stainless.

 

it's the tube that actuates your 5th and 6th intake ports. no it's not to be plugged, when you pull your old exhaust, you should see where it will connect to.

yes, new gaskets are a good idea.