[colljo]

Is there much of a perofrmance difference between factory CATS and high flow CATS?

[05SilverBullitt]

Good question. I'm interested, also.

Would it be advantageous to go from say a stock catted h-pipe to a JBA catted h-pipe? Is the price of the JBA justified? I mean, your really just replacing the cats, aren't you? Could you have a muffler shop move the stock cats and stay with factory h-pipe if you added long tube headers? Or, would it be just as cheap to buy the mid-pipe to match your headers?

What about sound? Is their a big difference?

Didn't mean to hijack your thread. Just thought I would expound on the question .

[06BlkMustanGT]

If the gains are anything they wont be too much (5HP max i'd say depending on exhaust set up) but they make the car louder because there is less resistance

[kj_cinci]

5 HP is about right, a bit more TQ.

Main reason to get them is for sound and if you have a high HP application. The stockers can 'fall apart' from the higher pressure and clogg, making your engine trying to push through and maybe grenade (has allready happened to one blown 05 GT...)

[05S281-71]

On my '06GT I saw a 6HP gain after adding magnaflow "X" with high-flow cats to axle back Flowmasters. F.Y.I.

[colljo]

The gains must be with the LTH. 6HP?

[kj_cinci]

Catted LTHs give almost 20 at the wheels ! ! !

The shorties gave maybe 8-10 and then an additional 6 I'd guess...??

[hawgman]

Originally Posted by kj_cinci

5 HP is about right, a bit more TQ.

Main reason to get them is for sound and if you have a high HP application. The stockers can 'fall apart' from the higher pressure and clogg, making your engine trying to push through and maybe grenade (has allready happened to one blown 05 GT...)

Oddly enough, the one I know about (Don_W) blew because an aftermarket cat came apart and clogged the pipe. Not a stock cat.
Personally, I am a bit skiddish of the aftermarket cats for the S197 cars. I have heard of just about every single brand on the market coming apart so far.

[Patience?!?]

I'm really curious about this topic too ... i've been seriously thinking about gettting LTs as well ... but, the one decision on what brand to get is holding me from doing so .... i definitely want an catted h-pipe ... but, if possible i would like to keep the stock setup (move the cats back if i have to) ... and just put in hooker headers ... the only reason i would buy JBA is because of them offering a catted-h pipe (and holley doesn't) ... I've seen people use the stock h-pipe, but cut off the cats ... i would like to know if there is anyone out there that has used the stock cats and h-pipe on a set of LTs ... so i can know if it is a do-able set up (and also safe ).