I have the stainless steel Magna Flow in the stock location...

 

flowmaster 40 underneath sorry the pics arent that great

 

If I relocate the muffler under the driver seat is there enough distance between the evap canister and muffler? Is this something I should be worried about?

 

there is plenty of distance on mine... I wouldnt worry about it.

 

ahhhh, i can't decide flow 40 or 50. Anyone got a sound clip of the 40s? I can find the 50s one on youtube.

 

there is a nice flowmaster 40 clip in this forum somewhere...ah, here we go
https://www.jk-forum.com/forums/jk-show-tell-33/flowmaster-40-series-install-pics-vids-19596/

 

now i have to track down some headphones from a co-worker

 

go with the 40 series! I love mine

 

I posted this up on another thread, and though it made sense here also. I'm selling a kit, with a True Mandrel Bent Stainless Steel Pipe. If interested, please PM me.
This kit works on a 2 door, if you relocate the Evap Canister.

I have tested 5 mufflers in the last week. I've got video and sound for four of them. I'll post up video links as soon as I can.

I tested:
- Magnaflow 14377 14" X 4" X 9" Same side offset
- Magnaflow 10436 22" X 4" round Center in/out
- Magnaflow 11226 14" X 4" X 9" Center in/out and offset in/out
- Borla 40653 13.125" X 4" X 9.5" Center in/out and offset in/out
- Flowmaster 50 series 942554 17" X " X 9.75" Oval Same Side Offset

The following are my observations.

Both Magnaflow ovals, and the Borla sounded the same. I do not recall any difference at all. They all represent the most mellow deepest sound that I have heard on a JK.

The Flowmaster and Magnaflow round 4" both sounded very similar. Louder and and more ricey/tinnie/sharp sounding.

The Flowmaster is a very large muffler. The goal here was to see if a larger size created a deeper tone. Just the opposite turned out to be true... This muffler may be a good fit, if you wanted a louder muffler, and did not worry about clearance, or wanted to install in the stock location.

The Magnaflow and Borla with the Offset In, and Center Out would not fit in the location that I wanted to install the muffler. Both would be a good solution if you wanted to install the muffler in front of the Evap Can, on a 4 door.

Hands down the best muffler for the location where I wanted to install (just behind where the Evap Can was previously located) was the Magnaflow 14377. It has the best clearance, is well protected by the rear lower control arms and has as good a tone as any muffler that I've heard.

Picks of Magnaflow install

 

Just had the magna flow installed in the same location as the stock. very low profile, and my low end torque is way better for both trail and city speeds. Power band is more evenly distrubuted between 1500-4000 nice steady power increase. I have the auto and it imediatly shifted way smoother, meaning less. it will stay in 2nd all the way to 45 mph then shift and idle at 1400-1550 to hold speed at 45-50 mph. almost feels like an old 4.0 but i know its not. ok it almost reminds me of the 4.0 HO but I know its not. I love my JK but I still cry some nights lamentating of my lost love, my first TJ. ohh well back to the subject for 250. bananas I would say worth it.