I am thinking about doing a 3" from the front into a 12" Summit glass pack with a turndown underneath in front of the rear axle. Will a 3" fit between the crossmeber and transmission?

 

Gonna be really really tight, man. Why are you wanting to do 3" diameter? 2.5" is the largest recommended for the power output range of our motors... and it sounds good too. I can personally vouch that there's a huge difference in sounds from the OEM size vs. just 2.5"

 

I mainly just want the 3" for deeper sound.

 

If you're wanting a deeper sound, stay away from a glass pack. You want a chambered muffler for that. Flowmaster Super 40 or a Thrush Welded would be better for that.

As far as the diameter of pipe, 3" is really overkill for getting a "deep" sound and, as I said above, will depend a lot on the muffler.

Here's some exhaust clips you can use as examples. The first 3 are my own Jeep, the second 3 are from a friend and fellow forum member (and moderator) Dukie564.

OEM exhaust manifold, 2.5" pipe going into intact catalytic, then 2.5" all the way back with a bend over the axle and tail pipe exiting under rear bumper:



Same setup as above, just an exterior recording of a cold start on a cold morning:



Now onto the current setup (well, almost). OEM exhaust manifold, 2.5" pipe going into punched out catalytic, then into Thrush Turbo muffler (not the same as the Thrush Welded muffler, btw), 2.5" pipe out over axle and exiting under rear bumper:



And for the DEEPER exhaust sounds, here's Dukie's 95 XJ 1995 4.0L HO, Flowmaster Super 40, Magnaflow Hi-Flow Cat, Custom Mandrel-Bent 2.5in Tailpipe:



And the same setup again, but with the addition of an APN header:


(btw, you can find his build thread here =====> https://www.cherokeeforum.com/f46/pr...r-cart-114924/)

So anyway, MY recommendation is 2.5" pipe and a more resonant muffler.

 

Anybody have any experience with Gibson vs. FlowTech for a header on the 4.0? Factory one's been cracked awhile and it's starting to grow and get louder...lol

 

double post

 

So I just picked up this set up (with the flowmaster super 40)
http://performance-curve.com/84-01ch...ailpipe-1.aspx

And I was wondering which of these cats would be best (i guess) to go along with this?
http://performance-curve.com/thunderbolt-spincat.aspx

Also looking at front pipes. I found this front pipe and was wondering if I should find a mandrel bent one instead or if this would do



Thank you in advance!

 

I think the notes might be wrong on that front pipe. It says CA emissions only, but I would think that pipe would be the same on Federal or CA. The Y-pipe from the manifold would be the only difference, right?

Just commenting... Sorry, can't really answer your questions.

 

Good choice with the exhaust kit. As far as the front pipe goes, you'll be fine with that. You won't notice any performance gains or harsh exhaust notes with those bends vs. mandrel bends.... if you want to test that theory, watch this video:


For the catalytic, get whichever one of those that fits the diameter of your pipe, and has the correct bung(s) for your O2 sensor. I really don't think there's that much difference in performance between one of those and a flowmaster or magnaflow unit.... but that's just speculation at this point. Might want to look up Thunderbolt vs. Magnaflow or similar search and see if there are any non-biased reviews or information on it.

 

Hey guys, I stumbled upon this video about the engineering aspects behind exhaust systems. Very insightful, give it a click:

 

So, I am going to be putting on a CAI fairly soon and replacing my injectors with some 4 holes and would like to my exhaust when I go home for spring break. I want something that is deep and will be noticed on the outside, but I would still like to be able to listen to my sound system and use my Bluetooth without struggling to hear it. I'm going to be ordering from performance curve and am trying to decide between magnaflow, flowmaster 44, or something from the 40 series(delta flow, super, original). Also trying to decide on a hi flow cat that won't break the bank or throw codes. I have a 2001 XJ Limited. Thanks

 

Lots of sound clips of what you're looking for in this thread...

https://www.cherokeeforum.com/f67/ch...thread-180356/

That's really the best way to determine it is to just hear it.

 

Thanks man! After I ordered the front pipe I started to wonder how it was going to connect to a cat that didnt have that 3 bolt flange on it. Looking harder at that front pipe, the O2 sensor is in the front pipe and the walker cat has that 3 bolt flange to match up to the front pipe, but its $151

 

OK team. I think I need to rethink this. I just did what I should have done originally before ordering a front pipe and crawled up under the jeep to look if it even matched what I have, which it looks like it doesnt.

Where the heck does a front pip attach in this hooha?!

 

I have a 99 Cherokee XJ with a 4.0.
My exhaust manifold has a crack in it and it's time to replace it...nothing crazy just a stock with flex joint type, Dorman, ATP, OMIX..any recommendations from what you guys have experienced with regards to cracking with any of these aftermarket replacements? Seems like ATP and Dorman have the best warranties, but quality wise, what's a good choice??