DTMR

if I remove or hollow out the cats in my car, will i still have enough back pressure without losing torque I have slp long tube headers with slp high flow cats and shorty x pipe and full borla cutback exhaust. people keep telling me that if i take the cats out I won't have enough back pressure and ill lose power and performance

tx_zstang

tell them 'watch my rear lights as I fly by, see if I have enough torque!'
B.S. You may loose a little bottom-end torque from the headers (less back pressure, sure), but you will make up for it on the top end.

ffk_pennywise

I recently installed cams and longtubes with an O/R H. I dynoed shortly after and lost zero torque from my original dyno with just and intake and delete plates. Hope that helps.

Franchi

No, you will be fine. Backpressure is required but not nearly as much as most people think. Long as you aren't running dumped headers, you be ok.

JCON

Anyone know what the actual gains are form removing the cat all together? I have a set of high flow SLP's that will be going on.

DTMR

Thanks for the information guys. I just wanted to hear it from everyone I have the high flow slp cats on it now but I keep hearing mixed reviews of its better just going without them

Franchi

I run a offroad H pipe on my 06 GT and it's just fine. Deleting cats will free up some power plus add noticable volume.

Mellowdien

I'm running O/R aswell, it's a fantastic sound, i'm you'll love it..
But it does get old, i'm starting to use my gt more as a daily driver lately, and it does annoy me sometimes. If that's something you can live with,go for it! I was on the edge of putting the cats back, then i went on a business trip for a week, came back decided to go for a midnight spin, and decided i love the sound more than it actually annoys me.

S197GT07

For an N/A application, here is my findings.

Bone stock with a Bama tune (with 87 octane timing tables) I dynoed 272/295

I went back with the tune corrected for 93, and with the addition of an O/R H. Numbers were 281/307

You do the math, its not that much. Also, I'd assume some of that power increase was from upping the timing to use the 93. I did feel the loss of the cats made the car more rev-happy. And I like the sound

808muscle

What mufflers are you running? I know it's loud as hell!