I realize the best route for more power from the exhaust is to buy an x-pipe, but is there anything you can do to get more power from the stock exhaust. I have in mind to hollow out the catalytic converter. Is this difficult to do, my car is an 88 S4 with almost 180K on it?

Even if it won't be a horsepower gain would the exhaust note be more throaty?

 

Before you do that, have you considered a RMB instead? Do you have to get an emissions inspection there?

 

RMB = about 2 hp at most. Gutting cats = about 12 hp. Gutting cats AND rmb = too loud.

 

If it runs well, maybe you need a new look, not sound.
Sell those BBS and put some modern Porsche rims/tires on there.
Or even the stock discs.
It'll turn heads then, including yours.

 

Amen brotha.

 

So if I gut the cats and leave the RMB it wont be too loud right? Are there any tricks to gutting the cat?

I would love to add wheels to my car, unfortunately I don't have the stock ones and my budget is tight seeing as I just graduated from college. I just take comfort that my 16 inch wheels allow me to accelerate faster then someone with 17's or 18's.

 

Correct but my experiece is that is will be too loan in automatic cars.

 

with the small resonator cars it will be loud, too loud for most, with the bigger one like on my 87 they are just right.

 

Remove the cat, use a large pry bar and hammer to smash up the element. Very messy.

 

I'm not sure if the icon indicated that you were kidding and/or expecting flak for the suggestion?

Overall tyre diameter fitted, no matter what diameter wheels, determines acceleration rate along with final drive ratio and gearing. Standard overall diameter with factory fitment is just under 25 inches, so unless yours are different either way from that you won't experience much difference ... or speedo error.

 

I saved the cats as not to destroy them and had the local muffler shop build me my own pipes.
I have the O2 sensor in the crossover pipe and I tie strapped the cat temp sensors out of the way.

The Tone Is AWESOME, and I'm using the stock muffler (resonators in place)

 

On my 90 GT I got cats from the local junk yard, gutted em and swapped em out keeping the original cats. The car already had an RMB and was way too loud after gutting cats despite resonators. I didn't get pulled over, but after getting followed several times got a rear muffler from the same junk yard and it lowered the volume nicely. Same sound, but quieter.

 

I'm aware its not much different at all, but it is there. I'll take anything I can get.

 

No emissions here, just looking for more of a V8 rumble, and any horsepower I free up will be a bonus.

 

My car is an 88...does it have the smaller RMB? My dad's 79 has a flowmaster with gutted cats and it is really loud, and he has had no issues with cops here.

Also why does the automatic make the exhaust louder as compared to a stick?