[Cleancoupe]

I’m looking to add a set of CSP headers to my car & I’m debating whether to run the GESI Ultra cats or just connection pipes. I currently have a AWE touring non resonated catback exhaust.

How big of a difference is the tone of the exhaust with cats versus no cats?

[Z OH 6]

Not that much honestly, high flow cats are still quite loud.

[Joshinator99]

Originally Posted by Z OH 6

Not that much honestly, high flow cats are still quite loud.

Agreed 100%.

That setup will be pretty loud, FYI…

[JasonD]

I have gesi ultra cats on my car, with borla s type dual mode axle back. It’s loud! I wish the valves would stay closed in stealth mode. Before the valves open, it’s loud, but not overly so. The headers added a lot more volume! I can’t say how much the cats quiet it down, but I doubt it’s much?

[WillyZ83]

Can’t speak for csp headers but my TSP headers had high flo cats and they were pretty loud on a NPP muffler 1ss

[Cleancoupe]

So it sounds like cats really don’t do much for the tone of the exhaust so it’s probably not worth getting them unless you have to pass emissions? They are pricey, but seem to be the only ones that hold up.

I’ll probably end up adding some resonators because I know she is going to be loud. I’m just not looking for crazy loud

[ST1LE]

Originally Posted by Cleancoupe

So it sounds like cats really don’t do much for the tone of the exhaust so it’s probably not worth getting them unless you have to pass emissions? They are pricey, but seem to be the only ones that hold up.

I’ll probably end up adding some resonators because I know she is going to be loud. I’m just not looking for crazy loud

They make the tone deeper and cut out a lot of rasp. Loudness levels are very similar, but make no mistake there is noticeable sound difference.

We are all different on what we like, but I do NOT like the sound of a catless Camaro. This is primarily on the stock NPP, which is raspy to begin with, so other axleback systems may be better but then its getting too loud for my taste.

[Z OH 6]

Originally Posted by ST1LE

They make the tone deeper and cut out a lot of rasp. Loudness levels are very similar, but make no mistake there is noticeable sound difference.

We are all different on what we like, but I do NOT like the sound of a catless Camaro. This is primarily on the stock NPP, which is raspy to begin with, so other axleback systems may be better but then its getting too loud for my taste.

High flow cats do not make a deeper tone. Lets just clear that up. The only difference between catless and high flow cats is a VERY VERY mild decrease in sound. I ran high flow cats on my setup for a year and just recently removed them, the difference is barely noticeable. There is a difference in sound between no cats and stock cats, but its just volume, no tone difference.

[Z OH 6]

Originally Posted by Cleancoupe

So it sounds like cats really don’t do much for the tone of the exhaust so it’s probably not worth getting them unless you have to pass emissions? They are pricey, but seem to be the only ones that hold up.

I’ll probably end up adding some resonators because I know she is going to be loud. I’m just not looking for crazy loud

Correct and resonators would honestly shape the tone a bit more. They take some of the rasp out of the sound.

[kropscamaro16]

i have afe power catted headers and exhaust on my car and i get told my car is one of the loudest at the tracks



they told me only reason to do catless is if im running race gas or its an actual race car which my car is neither

[Camaro1973]

Originally Posted by Z OH 6

Not that much honestly, high flow cats are still quite loud.

Taking the cats off my car it’s unbearably loud. Loud as you cannot even hold a conversation inside the cabin. There is a dramatic difference in decibels from no cats to the gen 2 ultra cats. They are 400 cell cats and are much quieter with them on.

[Camaro1973]

Originally Posted by Z OH 6

High flow cats do not make a deeper tone. Lets just clear that up. The only difference between catless and high flow cats is a VERY VERY mild decrease in sound. I ran high flow cats on my setup for a year and just recently removed them, the difference is barely noticeable. There is a difference in sound between no cats and stock cats, but its just volume, no tone difference.

Yeah no. As I said I don’t agree with this at all. Maybe other high flow cats, but not the 400 cell ultra cats.

[Z OH 6]

Originally Posted by Camaro1973

Taking the cats off my car it’s unbearably loud. Loud as you cannot even hold a conversation inside the cabin. There is a dramatic difference in decibels from no cats to the gen 2 ultra cats. They are 400 cell cats and are much quieter with them on.

No difference at all with mine between the Gen 1 cats and no cats. The single thing that made the most difference in volume on my car was headers. It went from tame to loud ASF with headers.

[Camaro1973]

Originally Posted by Z OH 6

No difference at all with mine between the Gen 1 cats and no cats. The single thing that made the most difference in volume on my car was headers. It went from tame to loud ASF with headers.

There’s a difference with those too. Maybe your just deaf .. lol

Bigger difference with gen 2 though.