[jinxergt]

Ok, I was thinking the other day about how stock GT cats and especially aftermarket cats fail and cause bigger issues. Then I thought about how GT500s hold up just fine with their stock cats in place. So I guess my question is what is different from GT500 cats from GT cats? If there is any.

I believe in 11 and up GTs and GT500s have a 2.75'' mid-pipe. So would a take-off cat with reducers welded onto a 2.5'' 05-10 mid-pipe of choice fit the bill better than taking the risk of running an aftermarket cat on a supercharged mustang running between 550 and 600 rwhp?

This could be a retarded idea. But I'm looking at this build with no harassment during inspections and to keep the noise down. I'm sure I will be flamed or thread ignored, but this is curiosity that bugging me.

 

[JEFF 1]

i do not think there is a difference except for pipe diameter in,through the "cat" and out. the question is what will that 1/4" restriction do ?
this should get some responses from high hp owners

 

[jinxergt]

I noticed you are using a GT500 mid-pipe.......how did you do that, isn't fitment different? I believe 05-10 GTs and 07-10 GT500s both use 2.5'' diameter mid-piping. And 11 and up GTs and GT500s use 2.75''. So if I was to use a 11up GT500 cat welded onto a 2.5'' 05-10 mid pipe wouldn't I be using a less restrictive cat and also using a cat designed from the factory to withstand 550 hp (I know it can handle a whippled GT like mine)?

 

[JEFF 1]

exhaust was updated a little over a year ago, all is 2.5" dia. stock "cats" for my HP works fine
yes your "cat" would be less restrictive, but it sounds like you are welding it to a 2.5" exhaust on the out flow side of the "cat" that would increase the back pressure in the "cat" a little. would that make the "cat" run hotter? just throwing out questions / guessing

 

[jinxergt]

If someone with a more understanding than us on flow dynamics could chime into this thread it would be great. I dont know if there would be increased backpressure if I did a 2.5'' reducer to the "in" side of the 2.75'' cat. and had a go back into a 2.5'' diameter reducer on the "out" side of the cat.