I know this is a repeat question, but I am considering cutting out the cats and welding in straight pipes. I have a Flowmaster Delta flow 50 series muffler, and Gibson SS shorties. The truck sounds real good when you get on it, but is not real loud at all for normal driving. I like it because there is no resonance in the cab. If I remove the cats am I going to get alot more noise in the cab, or just a louder exhaust note? Now to the real question, what is it going to do to my power? Am I going to lose low end due to loss of backpressure, will it help at all. The truck only has 65k on it so I doubt they are clogged. Does anyone have any before and after numbers?

 

Any ideas??? or experiences???

 

You will lose low end and have quite a bit more interior resonance but it will sound badass. It will sound like it does when you first start it all the time. It will sound good I will be cutting my high flow cats off and going back to catless when I put my lt's on. There just isnt any substitute for the sound you get. I love it. Get you some dynomax racing bullets they will be louder and wont have as much interior resonance as without cats.

 

I dont mind some interior noise, I just don't want to have a headache when I am on the interstate. Does anyone have a cat-less 5.3 with flowmaster??

 

i want to go catless to, maybe this weekend if i have time. i am also wondering about losing low end. i wont mind sacrificing some low end to gain high end. is this what normally happens?

 

I took the cats off mine, i have more power period to be honest. I get better fuel mileage and it sounds awesome as hell. When you rev it up, you can feel more flow, sounds stupid, but try it, you will see.

 

Unless you have a stall you will feel some loss of low end power but you will gain quite bit in top end. Since I have a stall low end doesnt matter anymore. As long as you get some kind of exhaust exit besides just dumps the interior resonance wont be so bad. Mine exit at a 45 out the back so most of the sound goes out the back. With my cutouts I have alot more interior resonance than when I didnt have cats and had the axhaust going out the back.

 

Hmmm I have a set of gutted cats I was trying to decide if I wanted to use or not. Guess they will be going on.

 

You know that gutted cats can cause turbulence in the exhaust and actually decrease hp right put a pipe through the cats to make it straight inside and you will have better results.

 

Yep, thats the plan. Thanks for the heads up though.