So I was considering upgrading my stock exhaust to a cat-back system. I did a little research and narrowed it down to the Dynomax VT and the MBRP XP. Today I went under my jeep to take a look around to see what the install had in store for me. That's when I saw the stock exhaust pipe extending from the cat to the muffler is one solid 2.5" pipe with no resonator. The pipes in both of the above systems are several pieces of bolt together 2.5" pipe. Now I'm new to Jeeps but not new to cars. I know that the less bends and joints in an exhaust pipe the better. Seems to me the solid stock pipe from the cat to the muffler with few bends and no joints would perform better than the clamped pipe pieces in cat back exhaust. Soooooooo...why not just do an axle back exhaust for half the price? (I know, I know stainless steel blah blah blah. I live in San Diego so corrosion isnt an issue so aside from looks I don't really need stainless.) Any exhaust gurus out there to convince me otherwise?

 

Oh hey.... Not an guru but know a bit.
So a couple of reasons for a cat-back, get that stock,bulky restrictive muffler out of its present location and tuck it into a safer location.
But since you are looking at our VT system, and I am guessing it is a pre 2012, because there is no gigantic resonator there. You could do just a muffler swap and keep it in the stock location or you could do a under the driver seat, but need to relocate the EVAP box, but this often times involves a muffler shop and a few mandrel bends from them. If you do go VT on a JK use an OVER 4.0 application 2.5" I/O It has a great sound on the throttle but dead quiet at speed. Made in the USA as well.
In regards to clamps, if properly tightened down good for most applications these days, a lot of vehicles coming off the lot these days are clamps and not welded.

 

Flowmaster makes a nice axle back kit, AFE makes 2 kits ( 2.5inch-3inch ) and rugged ridge does too.

both the flowmaster and AFE kits are high tuck so you don't see them much and the tips are tucked up higher for better departure angle. flowmaster claims 1-2mpg gain...

i have a dynomax muffler cut into the middle of my exhaust and i removed the stock rear muffler. lots of clearance out the back and sounds pretty good. Wish Dynomax made a axle back kit! lost 1mpg though ( straight muffler loses back pressure for mpg ). i might add the flowmaster kit to my jeep to see if i gain some highway power and mpg. not to mention when i do my regear soon my jeep will rev over 2200rpms on the highway. the exhaust starts to get loud...

 

Thanks for the quick response. I actually just sent you a PM. Now looking for and axle back system and looks like you only offer the Super Turbo Dual...any plans of doing an Ultra Flo or VT axle back in a single or dual in the future? 2011 JKU

 

Your not going to gain much in the way of power from a cat back or an axle back. The only reasons to do it in my opinion is to change the exhaust note to something you like or to increase clearance.

 

Check your PM.

But I will answer it here as well, I will be meeting with our sales and engineer to let people know that I often (all the time) get requests for an AXLE back and some sort of CAT back with the VT muffler.

I will after SEMA (and working out ULTRA4 2013 ) on a DIY video using a VT muffler in front of the rear axle with an EVAP relocate hopefully.

 

You will see gains, but nothing like 2 more cylinders will get you.
On stock exhaust/stock Jeep vs DynoMax exhaust/stock Jeep we saw gains in the mid single digits-to low double digits depending on the system. But then you throw bumpers/tires/lift and you are often back to clearance as you mentioned.

 

All I did was got a flow master 10 series, and welded on some pipe and a hanger, and clamped it to the stock position. It's pretty much as high as you're going to get it.