I have been thinking about removing my cat with a pipe and i have a few question... Should i buy the one from racing beat or get a muffler shop to get it done? How loud and how much better would my car be with no cat?

 

I don't recommend that you remove it since you live in Cali. I don't think any muffler shop in the US will remove your cat and replace it with a pipe either. You might be able to gut your stock pipe though but you will never pass emissions.

 

Loud.

 

 

It depends on the muffler I guess. I did it with RB's cat replacement pipe, before I put full headers on, and with a power pulse muffler it was not too loud.

 

I have the stock muffler with no cat. We put a pipe in place of the cat. It is louder then stock by a fair bit. But, it is not loud enough that I can't stand it, or have a conversation in the car while driving. Some people have told me it sounds like an outboard motor, some people have told me it sound cool.

 

I put in the bonez presilencer that is a direct plug in replacement for the cats, bolts right up to the stock manifold and stock cat back system and takes less than an hour to put in, most of the time jacking up the car. Much better power and gas mileage but more exhaust fumes and discoloration over the tail pipe. The sound is great, a nice low rumble, easy on the ears, neighbors and cops but still enough to let you listen to that sweet rotory exhaust. It was about $150 with gaskets, bolts and shipping from an RX-7 place in Texas, don't recall the name right now but I could look it up.

Ray

 

I have a homemade cat replacement pipe. It's loud, but not obnoxiously so. Heck, if I turn the vent on high, I can barely even hear the car.

 

Just a couple weeks ago, I installed the RB cat replacement pipe on my '84 GS. Using the stock muffler, the exhaust sound has increased, but not as much as expected. In fact, I was a little disapointed. I plan on adding a straight through Magna flow muffler to increase the sound and hopefully it will then, not be too loud.

Mike

 

Cat replacement pipe = loud and tinny sounding with stock muffler. It sucks.

If you're going to go removing the cat or installing headers, you need to get a better muffler, like an RB.

I just installed headers, and the exhaust shop removed my cat because the headers were too long. They straight piped it to the muffler and now my car sounds like a thousand homeless people banging on tincans at the same time.

Removing cat and installing headers = major performance improvement, really bad for sound
Replacing stock muffler with something better = good for sound, minor performance improvement.

Jon

 

Vipernicus, that's why the bonez presilencer is so nice, it works great with the stock exhaust manifold and stock cat back system (including the stock muffler, which really isn't a bad unit, I have two of them that are original to their 84 GSLs, so they must be pretty well built - from what I hear they are pretty much the same thing as an RB muffler).

And the sound is to die for, a nice rumble, none of that tinny sound you get with the header. The best part is the expense, you don't need to buy an RB header and RB muffler, what's that, about $500 saved? The bonez presilencer works for me, seems like a nice inexpensive compromise to many of the problems listed above.

Ray