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Redoing my entire Exhaust

Xjin85

NAXJA Forum User
Location
MA
Hey fellas,

I am in the process of buying the final components for my exhaust. I am replacing everything from the front exhaust pipe, cat, and tailpipe.

Magnaflow cat for my 2001 xj rear cat
https://www.amazon.com/MagnaFlow-51205-Universal-Catalytic-Converter/dp/B0086C16NE/ref=sr_1_1?crid=35IXYW5AIQGDE&keywords=magnaflow+51205&qid=1676237467&sprefix=magnaflow+51205%2Caps%2C101&sr=8-1

Flowmaster Super 44 with Madrel 2.5" inch tailpipe that I bought from performance-cure.com
https://performance-curve.com/84-01-jeep-cherokee-4-0-mandrel-bent-exhaust-w-flowmaster-super-44-muffler/

Adapter pipe
https://performance-curve.com/2-5-od-2-25-id-custom-exhaust-reducer-adapter-8942/

Mandrel Bent 2.25" front pipe
https://www.autozone.com/emission-control-and-exhaust/exhaust-pipe/p/brexhaust-exhaust-pipe-102-8920/150878_0_0




3 questions:

1).
-I need help finding:
*Gasket and end bolts that will fit the new front pipe at the header
*Gasket and end bolts for both sides of the new cat
*What clamps and how many will I need?

2.)
-The mandrel tailpipe that goes with the super 44 ends up being several inches short and ends under the truck instead of being flush with the rear bumper. There is about 8'' inches of missing pipe from the cat. So i need to buy a 2.5 extension pipe to cut and install in order to fill in the gap.

Would this work?
https://www.amazon.com/Walker-52356-Extension-Pipe/dp/B001AGP5WQ/ref=sr_1_1?crid=29FXWOPNLHY8M&keywords=walker+52356&qid=1676237256&sprefix=walker+52356%2Caps%2C338&sr=8-1

3.) What kind of hangers and how many should I use?

4.) Is anything else i am missing here?
 
I highly recommend adding one of these flex joints and clamps.

2.5" (2 1/2 in.) x 6" Flex Pipe Exhaust Coupling Quality Stainless Heavy Duty https://www.bearriverconverters.store/collections/2-5-flex-pipes-couplings

IMG_1413_zps33642f2d-1.jpg


IMG_1405_zpsf80ce0f6-1.jpg


Interesting pipe sizing that you have listed. Appears to be the opposite of mine from the factory.

The factory downtube on my 2000 XJ non-CA emission is 2.5".

I used a 2.5" Magnaflow converter, then to a 2.5" Center inlet/ offset outlet Flowmaster 50 Series Delta Flow (which is starting to rattle and corrode after 15yrs of use, I'll be replacing it this month with the same unit) and then a reducer to mate to the factory 2.25" tailpipe. There is science behind the scavenging benefits of a smaller tailpipe than downpipe, related to the exhaust flow as it cools and exists the system.
 
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I highly recommend adding one of these flex joints and clamps.

2.5" (2 1/2 in.) x 6" Flex Pipe Exhaust Coupling Quality Stainless Heavy Duty https://www.bearriverconverters.store/collections/2-5-flex-pipes-couplings

IMG_1413_zps33642f2d-1.jpg


IMG_1405_zpsf80ce0f6-1.jpg


Interesting pipe sizing that you have listed. Appears to be the opposite of mine from the factory.

The factory downtube on my 2000 XJ non-CA emission is 2.5".

I used a 2.5" Magnaflow converter, then to a 2.5" Center inlet/ offset outlet Flowmaster Super 40 (which is starting to rattle and corrode after 15yrs of use, I'll be replacing it this month with a Super 44) and then a reducer to mate to the factory 2.25" tailpipe. There is science behind the scavenging benefits of a smaller tailpipe than downpipe, related to the exhaust flow as it cools and exists the system.

Wow man thank you! I think that’s just what I was looking for!!!

I ended up buying BRExhusat mandrel bent direct for tail pipe from AutoZone. It doesn’t have any creases at the bends so it should have better airflow be the Walker and ATP tail pipe.

Question, what and where did you have to use extension pipes?

I don’t know what else I have to buy in order to have everything ready for install. One person on the other forum said I don’t have enough to connect from the connector flange to the intake of the rear cat. I’m not sure what he meant by that. Will the flex joint you recommend resolve that?

Also, Do I need additional extension pipes?
2.5” inch pipe from the cat to the muffler? From your experience using the same muffler and tail pipe did fall short? If so how short and how much extra pipe is needed so that it reaches the rear and is flush with the bumper?
I read that the tailpipe that comes with the Super 44 doesn’t make it all the way to the rear of an xj. I’d really like it to be flush with the bumper. Also, going to put on an exhaust 2.5” exhaust tip for looks.

Here’s a link to my thread on the other forum with the list of parts I’ve bought so far with the links: https://www.cherokeeforum.com/f67/redoing-my-entire-exhuast-268496/#post3692066

Only thing I didn’t buy was the Walker extension pipe bc I DONT KNOW WHAT THE HELL ELSE TO BUY TO MAKE THIS COMPLETE.

Everything I’ve preserved includes:
-BRExhuaust direct fit mandrel bent 2.25”” exhaust pipe (from Auto-Zone)
-Magna-flow Hi-flow 2.5” Catalytic converter (to replace rear cat)
-Flowmaster Super 44 with mandrel bent 2.25 tail pipe ( from Performance-Curve)

I’m STUCK on is what else I need to buy. What am I missing in between and What else do I need to buy so I have completed everything I need to install?

I’m sorry if these are dumb questions for you guys but I am really struggling with this and need to figure it all out so I can be sure that I have everything needed for the install without any hiccups.
 
You've got a PM

Thanks, fo all your help XJ deeper. I PM'd you back. I am about to buy the flex joint in the link you posted but where did you get the clamps that are with it in the picture? I looked at this site's inventory but they didn't have anything like that.

Also, Shouldn't it be for 2.25 instead of 2.50 since it's connecting my cat outtake (2.25 inch) to the adapter pipe that connects the Super 44 muffler (2.5
inch) intake?
 
Im not entirely sure what your expectations are with 2.5" pipe.
From my experience you will gain nothing over stock but .

I have fabbed my exhaust from header to rear bumper with 2.5" not because i wanted to. Because my pipe was ver baddly smashed, all of it.
I think i had 20ft of straight pipe on hand a combination of u bends and 45s spintech 3000 and used jeep sway bar brackets to fab exhaust hangers.
The spintech turned out loud as shit so i cut a second twister muffler in. This helped alot.

If a guy doesnt have fabb tools and knows how to use them i think this project would be overwhelming.

That is why many jeeps and pickups have exhaust kits bolted on but theyre rattling and dragging all over behind held off the ground by the rear axle.



Sent from my SM-G781U using Tapatalk
 
Thanks, fo all your help XJ deeper. I PM'd you back. I am about to buy the flex joint in the link you posted but where did you get the clamps that are with it in the picture? I looked at this site's inventory but they didn't have anything like that.

Also, Shouldn't it be for 2.25 instead of 2.50 since it's connecting my cat outtake (2.25 inch) to the adapter pipe that connects the Super 44 muffler (2.5
inch) intake?

As stated in my PM, my 2000 factory downpipe diameter is 2.50" at the location that I installed the flex joint on my rig. If your replacement downpipe is 2.25" from end to end, then you should order a 2.25" flex joint. https://www.bearriverconverters.store/collections/2-25-flex-pipes-couplings

My flex joint was installed over a decade ago, so I don't recall where I sourced the V-band clamp from, but you can do a Google search to find your preferred supplier. https://www.summitracing.com/parts/sum-694922?seid=srese1&gclid=CjwKCAiA9NGfBhBvEiwAq5vSy2VQIB2s1vIIhFuIQZ1PfrkHcQCqQR-VdEeBEmC7zweZJLKG97nfERoCo7wQAvD_BwE

I understand that you want to have a complete, end to end, bolt/weld together exhaust solution, but there are so many variables and with the XJ platform being out of production for 22 years, that does not exist.

A custom bent and installed exhaust for an XJ will run $500-700, depending on tubing size, cat and muffler type and where you live, so DIY is a $ saver, but you need to be prepared to modify the components that you buy as a trade off.

I suggest laying out all of your parts and mocking up the exhaust from downpipe to tailpipe and see if everything fits together. Then compare the mounting layout with your stock setup.

If there are places in the system which need to be adapted or extended, then use adapter joints at these locations and cut them to fit to achieve the desired layout.
 
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