all muffler and exhaust questions go here!!!!!!
CF Veteran
Joined: Apr 2011
Posts: 14,553
Likes: 1
From: Carrollton, GA
Year: 1994
Model: Cherokee
Engine: Inline 6 4.0L High Output
I'll end up doing the swap if i get the money/ want to spend it on that. I just ordered the FM 44 for 2.25 pipe so ill run that for a while till i want to upgrade. I'd love to see proof of it, thats pretty significant
There is no muffler that will give you 15 hp and 2-3mpg. If your lucky you are looking at 3-5hp and maybe .5 to 1mpg. It is a different story if you swap the 2.25 piping out for 2.5 and add header, and hi flow cat. But even then you would be lucky to see 15 hp.
Thread Starter
::Regional Moderator::
Joined: Aug 2011
Posts: 4,742
Likes: 10
From: Jacksonville, NC
Year: 1993
Model: Cherokee
Engine: I6 4.0L HO
Actually mate you do gain morethen 3to 4 hp on the muffler like around 8hp.maybe 2mpg. Add a cai you will get those 15 plus and improved mpg. Add 2.5 pipe and ur good
CF Veteran
Joined: Apr 2011
Posts: 1,146
Likes: 0
From: Clayton, NC
Year: 1988
Model: Cherokee
Engine: 4.6L I6 Stroker with port matched +99 intake and 62mm TB
CF Veteran
Joined: Apr 2011
Posts: 14,553
Likes: 1
From: Carrollton, GA
Year: 1994
Model: Cherokee
Engine: Inline 6 4.0L High Output
I meant the piping not the muffler, sorry lol i know that a muffler wont do that.
Thread Starter
::Regional Moderator::
Joined: Aug 2011
Posts: 4,742
Likes: 10
From: Jacksonville, NC
Year: 1993
Model: Cherokee
Engine: I6 4.0L HO
If u redo headers back then yes nice gains won't give u 15 hp with just the pipeing. Add a good cai. And bored tb and u can get 15 horses.now the most ur gana see is a nice tourqe incress not a lot but a nice amount to knowtice
Yea... 15 HP is not likely... I've learned a thing or two since I got my *** chewed by jmm0122, toogreat and Kyle 4x4 4life for my horrible guess about HP gain from my intake and exhaust modifications... please see page 29 of this thread. Never again will I pull numbers from my ***... lol.
Haha it's all good.
CF Veteran
Joined: Apr 2011
Posts: 14,553
Likes: 1
From: Carrollton, GA
Year: 1994
Model: Cherokee
Engine: Inline 6 4.0L High Output
I got my new Flowmaster in today but i broke my clamp from the cat to the muffler, so is it alright for me to drive to the store to get a new one tonight or tomorrow? Just making sure the vibrations of the exhaust wont break anything else since i dont have the hangers on and the exhaust stops after the cat.
Im talking like power or MPG.


