all muffler and exhaust questions go here!!!!!!
#4726
Member
You want to build a complete one from scratch or install a new complete system? Building one from scratch, well.... basically just requires skill and the correct tools. You won't get a TON of torque out of an exhaust system on a stock 4.0 liter though, but to get the most out of it, go with an aftermarket header, 2.5" pipe throughout the system, a hi-flow (non-restrictive) catalytic converter, and your muffler of choice. The key thing though is opening up the restriction. The 2.5" pipe is perfect for that especially when combined with the aftermarket header. The exhaust pulse of the stock manifold is a little restricting in itself.
Combining the exhaust system with a overbored throttle body (about 62mm) will also help. All of these mods though will only net you about 10-15 ft/lbs if that.
Combining the exhaust system with a overbored throttle body (about 62mm) will also help. All of these mods though will only net you about 10-15 ft/lbs if that.
#4727
Newbie
Join Date: Mar 2015
Location: north NJ or Easter shore VA
Posts: 18
Likes: 0
Received 1 Like
on
1 Post
Year: 95
Model: Cherokee
It's originally "indented" for driveshaft clearance. The smooth one would be for a 2wd application (no driveshaft).
As far as performance goes, I really don't think the dents are going to make a huge difference, TBH. The major "restricting" factor is that the downpipe is 2.25".... so it almost acts as a "choke" between your header collector and 2.5" pipe from the downpipe back.
As far as performance goes, I really don't think the dents are going to make a huge difference, TBH. The major "restricting" factor is that the downpipe is 2.25".... so it almost acts as a "choke" between your header collector and 2.5" pipe from the downpipe back.
I understood that with the clearance thing. Would you happen to know what the correct part number would be the one without the restriction? I know if you go by Walker, they have the down pipe listed for 1993-1995 with that restriction #54488. After that they list a completely different downpipe for the '96 #55277 which I am actually eyeing but it doesn't look exact in length.. Does anyone know?
Thanks.
#4728
No, I don't lick fish.
I understood that with the clearance thing. Would you happen to know what the correct part number would be the one without the restriction? I know if you go by Walker, they have the down pipe listed for 1993-1995 with that restriction #54488. After that they list a completely different downpipe for the '96 #55277 which I am actually eyeing but it doesn't look exact in length.. Does anyone know?
Thanks.
Thanks.
If you're really that worried about it though, look up "Jeep TJ Downpipe" setups on google and consider converting it to that style. PITA if you ask me though because it is in the way of dropping the oil pan if you ever need to.
#4729
No, I don't lick fish.
I was watching the latest episode of Engine Masters on MOTD (sorry guys, can't see it on YouTube yet) and it occurred to me that a lot of the exhaust questions asked in this thread have been addressed in the show.
Pretty cool content on the show, surprising results at times, and it takes the guesswork out of things because well, numbers.
Here's a link to the whole playlist:
https://www.youtube.com/playlist?lis...t5dIHutSOu7srE
Dents in headers (can be applied to exhaust tubing as well)
Exhaust tubing size (people ask a lot about increasing to 2.5 from the OEM 2.25... this pretty much squashes the worry about loss of torque.... especially from such a small increase in diameter)
Pretty interesting information about headers... not quite as applicable to our motors because I don't believe there is an aftermarket cast-iron header option for it, but still good information in general:
Good one about mufflers.... IMO with such low power output-ers such as our 4.0's, it really just boils down to budget and sound level:
Check out the channel and the show, guys. It's like **** for gearheads.
Pretty cool content on the show, surprising results at times, and it takes the guesswork out of things because well, numbers.
Here's a link to the whole playlist:
https://www.youtube.com/playlist?lis...t5dIHutSOu7srE
Dents in headers (can be applied to exhaust tubing as well)
Exhaust tubing size (people ask a lot about increasing to 2.5 from the OEM 2.25... this pretty much squashes the worry about loss of torque.... especially from such a small increase in diameter)
Pretty interesting information about headers... not quite as applicable to our motors because I don't believe there is an aftermarket cast-iron header option for it, but still good information in general:
Good one about mufflers.... IMO with such low power output-ers such as our 4.0's, it really just boils down to budget and sound level:
Check out the channel and the show, guys. It's like **** for gearheads.
#4730
Newbie
Join Date: Jul 2013
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2001
Model: Cherokee
Engine: 4.0
AFE Header for 00 or 01 XJ
A couple of years ago it seemed AFE advertised the 48-46202 header for Cherokee's I called them last week and now they say this only fits a Wrangler. Has anyone put the AFE header with the 00 01 stock setup?
Thx
Thx
#4732
::Regional Moderator::
Join Date: Jun 2012
Location: clackamas,or
Posts: 422
Likes: 0
Received 1 Like
on
1 Post
Year: 1992
Model: Cherokee(XJ)
Engine: h.o. 4.0l
Ok so my new jeep only has a cat right now and before I start driving it I want to do some exhaust work. My plan is step up to 2.5" after cat in to a gaspack style muffler then run it over the axle but dump it out in to the passenger side rear fender well. Dose anyone see a problem in this?
#4733
CF Veteran
Join Date: Oct 2013
Location: Greenville, SC
Posts: 5,920
Likes: 0
Received 190 Likes
on
165 Posts
Year: 1999
Model: Cherokee(XJ)
Engine: 4.0
Originally Posted by 89limited_hero
Ok so my new jeep only has a cat right now and before I start driving it I want to do some exhaust work. My plan is step up to 2.5" after cat in to a gaspack style muffler then run it over the axle but dump it out in to the passenger side rear fender well. Dose anyone see a problem in this?
#4734
::Regional Moderator::
Join Date: Jun 2012
Location: clackamas,or
Posts: 422
Likes: 0
Received 1 Like
on
1 Post
Year: 1992
Model: Cherokee(XJ)
Engine: h.o. 4.0l
Probably turn it down and out so its not facing the tire and give clearance for the tire to move free from it.
It won't need to go through emissions or vehicle inspection
It won't need to go through emissions or vehicle inspection
#4735
No, I don't lick fish.
Keeps it up higher and lessens the chance of pinching the tailpipe.
#4737
No, I don't lick fish.
Gotcha. Yeah you probably wanna just stick with your original idea then. I don't see much of a problem with it other than what Hen noted... but I think you can work around that.
#4738
::Regional Moderator::
Join Date: Jun 2012
Location: clackamas,or
Posts: 422
Likes: 0
Received 1 Like
on
1 Post
Year: 1992
Model: Cherokee(XJ)
Engine: h.o. 4.0l
Thinking about it I could sleeve the 2x6 area with a section of 3" pipe where the exhaust would fit in to along the uni frame and add a hole in the bumper for the exhaust to exit and would be protected. If that make sense.
#4739
No, I don't lick fish.
Makes sense... I've thought about it before as well... my thing it exhaust rattle. Just my luck, I'd get it all together and the stupid tailpipe would hit as soon as I accelerate, or at low idle, or on a right turn..... or a bumpy road.