Factory 3.5" Exhaust <vs> 4" Stainless Exhaust...cat back only??

[Pathfinder22]

What's the benefit of installing a 4" Stainless Exhaust on my all stock F250, where I am not removing the Cat Conv and I really don't care about performance sound coming out of exhaust???

I assume other than some slight improvement in exhaust flow volume, which may have a slight increase in reduced exhaust temp, there would be no need to shell out the $800 or so for this add-on.

Is this a fair assumption??

[cam406406]

ya i am with u i cut cat out and now i am going to cut out muffler for some sound i think it flows plenty

[Pathfinder22]

ya i am with u i cut cat out and now i am going to cut out muffler for some sound i think it flows plenty

What benefits did you get with cutting Cat out? How did you notice those benefits?

Also, are you putting an after-market muffler in or just having straight pipes?

Still wrestling with this one, as I'm all stock and not looking for throaty or performance sound by any means....

[cam406406]

better mpg with cat gone and am goint to strait pipe it

[smokersteve]

If you have a 4" turbo back you will lose some low end torque, that is where the mpg is. The truck will have a "throaty or performance sound". It will be loud. People like the 4" for the sound and that it is ment for upgraded turbos and inj.

If you keep the cat on you can even go to a 5" becaue that cat is restictive.

The stock system is 3" down pipe to a 3.5". With a muff and cat delete pipe the truck will gain power and still hold low end touque. This is good for stock or even slightly modified.

With cat and muff delete pipes or any other system, the egt's will drop a good amount and be a benefit to the truck because of the less restrictive system. The remaining factor is low end torque.

[Pathfinder22]

With a muff and cat delete pipe the truck will gain power and still hold low end touque.

Smokersteve;

Thanks, as that's the info I'm looking for. Since I don't care about sound & my system is all stock, I assume there is no need to upgrade to 4" exhaust.

I am very interested in doing the cat & muffler delete, and curious - what will that do to the overall sound?? I don't want it any louder, and if it will be...maybe I should do the cat delete??

Can someone point me to where I can purchase the cat & muff delete pipe?? Gonna go that route.

[Pathfinder22]

I think I found what I'm looking for and assuming the local muffler shop has some 3.5" pipe they can use if muffler replacement is done...BUT I don't want to lose the muffler if it's gonna be too loud???

03-07+ Ford 6.0L Powerstroke Diesel Cat Delete Pipe

[HOTWHEELS34]

If you lose the cat and muffler it's going to be loud. One of the main reasons people go to a larger exhaust is to lower EGTs.

[wesjones]

Let's back up here.......$800 for a 4" cat back exhaust? I think you need to do a little more shopping there, they arent all that expensive. Mine is aluminized steel and it has held up fine.

[smokersteve]

Originally Posted by Pathfinder22

Smokersteve;

Thanks, as that's the info I'm looking for. Since I don't care about sound & my system is all stock, I assume there is no need to upgrade to 4" exhaust.

I am very interested in doing the cat & muffler delete, and curious - what will that do to the overall sound?? I don't want it any louder, and if it will be...maybe I should do the cat delete??

Can someone point me to where I can purchase the cat & muff delete pipe?? Gonna go that route.

This ws not intended for sound but it worked very well.

I purchased a tip from kregan auto parts that had 2 layers of metal.
In between the to metal layers there is some kind of wrap, like fiber glass or something. The inner metal layer has perforations. This decrased the exh noise. I also cut the last exhaust bend to face the rear of the truck, not the side. That also decreased the noise.(to the cab)