Loudest High-Flow Cat Recommendations

[AJ88]

Looking for the best and loudest free flowing cat to free up my flowmaster 80 series a bit. Any high flow catalytic converter recommendations? Sound clips welcome especially if you run 80's series flowmasters. Thanks.

 

[Clone TIE Pilot]

I don't know how loud different brands of cats are? But I do know that GM cats usually have the longest life.

 

[454muscle]

If you want high flow cats, magnaflow makes them for any size -- I have 2 of them on mine, although I'm not sure I like the sound. However, if you're putting on cats, I would expect for any loudness etc anyways.

 

[AJ88]

Well will I notice an increase in exhaust volume after the installation of high-flow cats? Enough to make it worthwhile? Or for the money should I just swap over to 40 series flowmasters instead of messing with the cat?

 

[454muscle]

Well will I notice an increase in exhaust volume after the installation of high-flow cats? Enough to make it worthwhile? Or for the money should I just swap over to 40 series flowmasters instead of messing with the cat?

It will definitely NOT increase exhaust volume or flow. A cat generally adds a little bit of backpressure, which causes a slight performance increase in torque at low RPM, but you lose a few horsepower at high RPM. Purpose of cats is pollution control, not performance gain. The cats decrease exhaust flow, hence the invention of the "high flow" cat -- but it does not actually increase flow of your exhaust system (it's still a decrease).

If you want it to sound awesome and flow good, and you are emissions exempt, then **** the cats. The reason I have cats on mine is because by law (over here) the car should have cats if it came from the factory with cats, and because the car is so radical looking, I needed to be sure the cops don't bother me when I do plan to cruise.

Put on 2 Flowmaster 40 series and an H-pipe -- the H-pipe will cause the sound to be really low, when it resonates at certain RPMS (around 1500 - 2000 RPM). Like the old 5L Mustangs sound (they come with factory H-pipe). The H-pipe also increases torque.

Some people prefer the X-pipe, which causes the sound to be a bit more obnoxious and throaty-sounding. The X-pipe costs a bit more but increases horsepower at the top end.

 

[Clone TIE Pilot]

Well will I notice an increase in exhaust volume after the installation of high-flow cats? Enough to make it worthwhile? Or for the money should I just swap over to 40 series flowmasters instead of messing with the cat?

It will definitely NOT increase exhaust volume or flow. A cat generally adds a little bit of backpressure, which causes a slight performance increase in torque at low RPM, but you lose a few horsepower at high RPM. Purpose of cats is pollution control, not performance gain. The cats decrease exhaust flow, hence the invention of the "high flow" cat -- but it does not actually increase flow of your exhaust system (it's still a decrease).

If you want it to sound awesome and flow good, and you are emissions exempt, then **** the cats. The reason I have cats on mine is because by law (over here) the car should have cats if it came from the factory with cats, and because the car is so radical looking, I needed to be sure the cops don't bother me when I do plan to cruise.

Put on 2 Flowmaster 40 series and an H-pipe -- the H-pipe will cause the sound to be really low, when it resonates at certain RPMS (around 1500 - 2000 RPM). Like the old 5L Mustangs sound (they come with factory H-pipe). The H-pipe also increases torque.

Some people prefer the X-pipe, which causes the sound to be a bit more obnoxious and throaty-sounding. The X-pipe costs a bit more but increases horsepower at the top end.

It's the same over here, cars that came with cats must have them forever in all 50 states under Fed law. Some states are pretty lax with enforcement so people in those states get away with it, for now. Other states are strict with enforcement and you just don't even think about removing your cat.