Cat -beat the guts out?

[Tommy]

I`m installing a Diamond Eye cat back exhaust on my 05 F250 with a 6.0.Should I beat the guts out of the cat or leave it alone? The cat stays as I`m not giving up 10 grand in fines.I`m open to all opinions .Thankx

 

[Mike]

If your fines are that stiff then you may want to look into just exactly how your state tests the functionality of the Cat. If they shoot it with a thermal gun then beating the guts out isnt a good idea. If they just look for installed stock equipment then you are probably OK.

 

[Tommy]

Thankx,I`m thinking about beating up the cat.

 

[Roland_Jenkins]

I gutted mine but if I had it to do over I'd install a cat delete test pipe.

 

[cranknrods]

trust me, im not a stump humper or anything but why would you gut the cat? my dodge has a cat but the center of it is hollow. you can stick your arm through the hole. is the ford different. cause if its the same then i would just leave it. my favorite thing to do is get rid of the muffler and keep the cat. sounds real good and its cheaper to put a muffler back on if i ever want to sell then it is to buy a new cat.
these are just my thoughts.

ohh yeah...if you read any of David Vizard's horsepower books, he states that a gutted cat has alot more restriction on a flow bench then a straight pipe and slightly more restriction then a performance cat. the reason is that the pressure waves build up inside the cat and basically try to block the flow. so having said that. if you decide you dont want the cat then i would definatly not gut it but rather put in a delete pipe. if this is not legal in your area then you could do what D.V explains IIRC and gut the cat but then reinstall it with a pipe going through it inorder to keep the pressure waves from building up inside the hollow chamber. basically using the outside of the cat as a mask.

 

[tbirdfiend281]

ive seen a factory exhaust with a test pipe and a muffler delete installed. The truck was still a mellow sound being factory sized, but on the IDS i was seeing 27lbs of boost, so it definitely dropped the restriction in the exhaust a little bit im sure

id recommend a test pipe myself

 

[JohnBoyToo]

IMHO....
Just how much difference do you think the cat makes on flow, hp, 1/4 mile times, etc...

I would guess it is negligible unless you are going for the 1000 hp mark....
(yeah, right ! u did say a 6.oh)

I chose to leave the cat alone and spend the $10k saved on fines for a Walker BTM muffler for my rolling house they call an Excursion...

and it did run 8.9 in the 1/8th which isn't too terribly bad for a daily driver...

 

[Tommy]

Thankx for all the reply`s.I was a little afraid of gutting the cat because of lt`s size.I`ll probably just put the exhaust on and leave the kitty alone.

 

[cranknrods]

with the new cats i dont think you would notice a difference if you took it off. alot of the times the cat flows better then the stock muffler.