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Discussion Starter #1 (Edited)
I had a PM asking for some info on the exhaust in my sig. I figured after replying that I should maybe put the review up for all to see. Here it is:

My exhaust is 16665. My Hemi is a two wheel drive, not sure if it's the same exhaust for 4wd, but it probably is. It looks good, and sounds good. It's a much deeper tone than stock, and typically deceptively quiet. When you push 3k rpm, it starts to roar pretty dang loudly - I have a feeling at that rpm the roar is so loud in part b/c that's the area where my cold air intake would roar before i installed the exhaust. At wide open throttle, it'll turn heads like a souped up old GTO prepped for the drag strip. Other than that it's silent at idle once warmed up, and only noticeable if you know what to listen for when cold.

The only time I notice it when on cruise control is if MDS is popping on and off when on the highway. It's totally silent on cruise at 70 or 75 while running on all 8, but slightly noticeable when it bounces down to 4 cylinders. During what i consider to be normal and easy acceleration, it sounds virtually identical to most ram pickups with hemi's.

Installation is cake. Quite literally just lift it into place, push the welded hangers through the oem rubber hangers, then torque it all down (only three bolts). It attaches to the flange just behind the catalytic converters similar to how the oem exhaust does. The oem exhaust has two welded bolts, and the magnaflow has two true bolts instead. There's a compression sleeve that connects the rear resonator assembly to the forward muffler.

Much more difficult is getting the old exhaust out. I had to use a sawzall with a metal cutting blade (similar to a fine toothed hacksaw blade) to cut between the resonator and muffler in order to get it all out. I'd recommend doing this on a lift or with jackstands (not on the rear axle, but on the frame) so that the rear suspension isn't in compression. It'll give you way more room to wiggle the bent pipe from the oem setup out the back. If you do it on ramps like I did, that wiggle is truly difficult.

Unlike the oem exhaust, the tip doesn't point down at all, so clearance at the bumper is pretty slim, maybe a quarter of an inch. I've thought about extending the stock cutaway more to accommodate the new tip with more clearance, but haven't done so yet. I'm about half a thousand miles into the new exhaust, and there's no evidence of heat damage or physical banging to the plastic of the bumper yet so I'll probably just leave it alone.

Oh, one more thing...the first thing you'll notice after you install the new exhaust and take it for a test drive is the smell. It'll take a good half hour of driving to burn off the polish on the pipe sections, and it stinks. The muffler, resonator, and tip all stay a pretty polished stainless though, but the pipe sections will noticeably darken. It looks better if you make sure to wipe it down before starting it up after installation so fingerprint oils don't get burnt in.


I'd send pics but it's dark out now and I haven't snapped any yet.
 

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Discussion Starter #3
Thanks for the kudo's. One thing I didn't mention in my reply was the mileage...which leads to conversations I tend to shy away from. Mileage in my experience for everyday driving is so overwhelmingly dependent upon tire inflation pressure compared to anything else as to render any mileage comparisons that don't take it into account completely moot.

That little disclaimer being noted....

Immediately after installing this exhaust (with AFE CAI already in place), I drove ~60 miles highway to see my mother in the hospital followed by ~60 miles back home.

Trip to hospital: 20 miles at 75 on cruise, 20 at 65 on cruise, 20 at 75 on cruise with a hot inflation pressure of 39 psi = 20.4 miles per gallon stated on the evic with a reset before trip.

Trip home from hospital: 20 miles at 75 on cruise, 20 at 65 on cruise, 20 at 75 on cruise with a hot inflation pressure of 39 psi = 19.8 miles per gallon stated on the evic with a reset before trip. I attribute the difference to wind direction.

The other 800 or so miles since installation has been all to/from the office which consists of 15 mile 20 to 30 minute round trips and lunch ventures that include city, highway, stop sign, and roundabout traffic: bounces between 16.5 and 16.6 mpg with the same tire pressures.

I have the OEM tires and wheels and no lift or body modifications. I know this is somewhat not in line with typical tire inflation guidelines, but given the distances driven and temperatures when I've got time to inflate tires seems to be the best way to do it for me. the 39 psi hot usually results in 35 to 36 psi cold for me. If you don't believe that tire inflation has more impact on your mileage than anything else by a landslide, perform an experiment with just 2 psi cold inflation difference over the course of a couple weeks. I can just about guarantee the difference to be b/w 1.5 and 3 mpg difference.
 

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Great review, I've been waiting to pull the trigger on the same catback for a while. How hard was it to unbolt the old exhaust at the flange location? I looked at mine and the bolts/nuts are very rusty. What size socket did you use if you remember? I will most lilely end up doing it on ramps as well, my driveway is on an incline and i just dont trust the jackstands.
 

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Great review, I've been waiting to pull the trigger on the same catback for a while. How hard was it to unbolt the old exhaust at the flange location? I looked at mine and the bolts/nuts are very rusty. What size socket did you use if you remember? I will most lilely end up doing it on ramps as well, my driveway is on an incline and i just dont trust the jackstands.
I had no trouble unbolting the old exhaust when I installed my Magnaflow. If you are concerned just spray them real good with WD40 and let it soak for a little while before you try to take it off. Don't remember the socket size but since I had one it had to be a standard size. I did mine on ramps in the driveway and there is plenty of room underneath to work. I did have problems getting the rear portion of the old exhaust to come off. I had to do a lot of twisting and turning it before I was able to get it out.
 

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Discussion Starter #7
Stock nuts at the flange on mine are 15mm (just double checked on the old one sitting in my backyard waiting to be hauled to the scrapheap). The nuts weren't difficult to remove at the flange for me, but if you're worried a little WD-40 or PBlaster a few minutes prior to breaking their torque won't hurt.

It's a real pain to wiggle out while on ramps as stated in my original post. That being said, a couple sawzall blades would allow you to cut before and after the bends and it should fall right out once pushing the studs out of the hangers. My only metal cutting blade laying around was toast after my first cut, so it wasn't an option for me.
 

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didnt even think about more than one cut. I was actually going to cut right over the axle, but yeah it will definitely make a ton of difference if one cut is before and the second is after the axle, i'll just pick up a few extra blades. cant wait to put the exhaust on!
 

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didnt even think about more than one cut. I was actually going to cut right over the axle, but yeah it will definitely make a ton of difference if one cut is before and the second is after the axle, i'll just pick up a few extra blades. cant wait to put the exhaust on!
I didn't cut mine at all. But that might make it easier to get off. I wanted to keep the OEM muffler intact -- I still have it after taking it off almost 4 years ago.
 

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Discussion Starter #10
On ramps or jacking on the axle - there's no way the resonator can clear the axle moving it forward, and no way the coffin of a muffler can clear the axle moving it backward that I could detect.

I really tried, and grabbed the sawzall after much oomph was applied without success.
 

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On ramps or jacking on the axle - there's no way the resonator can clear the axle moving it forward, and no way the coffin of a muffler can clear the axle moving it backward that I could detect.

I really tried, and grabbed the sawzall after much oomph was applied without success.
Like I said, I did it without cutting but it was not easy.
 

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Discussion Starter #12
Maybe there's a difference in the size of the opening b/w the Dana44 setup on the rear wheel drives and the rear end setup on the 4x4's...idk...it was impossible for me and my brother giving it our all.

We considered jacking it up and unbolting the rear right shock and removing the fender well before spotting the rear AC lines that might get accidentally damaged during the wiggle out process...that's about the time I gave up on saving the stock exhaust, made life easy, and grabbed the sawzall. ;)
 

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So I finally picked up the exhaust, getting ready to put it on. Some questions on the install: what did you guys torque the two bolts at the flange to?
Also, I’ve read that a few people were concerned with how close the tip ended up to the bumper. Magnaflow recommends ½” clearance and it sounds like most of you are ending up with less that than. Anyone ever think of picking up a longer rubber hanger, just to create a bit more space?

Now off to the topic that I’ve been thinking about for quite a bit. 16665, as we all know, is smaller in diameter than the stock exhaust. Most other aftermarket exhausts are 3” in diameter, which is larger than stock. I understand the importance of backpressure to maintain bottom torque, especially on the hemi, but doesn’t it seem a bit counterproductive to actually reduce the size of the tubing? I’ve brought this up to the Magnaflow people and haven’t received a convincing answer. I mean their site alone states that increasing the diameter of the exhaust will improve the flow and performance, yet they choose to decrease it in this application. I do believe that there has to be a reason, otherwise they wouldn’t have done it, just want to know what that reason is. What are your thoughts on this?
 

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Thanks for the review sir.
He did a good one! Very accurate. I just got this same set up about 2 weeks ago. In my opinion, if there are still people searching out info, is it made it sound like it probably should have from the factory. Not too aggressive but can roar at higher rpms and seems to suit the style of the vehicle well in being a bit more subtle. But like I said, makes it sound like a 5.7 hemi for sure now.

At idle and even in the 2-3k range it is very quiet in the cab. I'm not sure how it sounds from the outside, youtube can help you there :) In the cab you can barely hear it at all. Same at higher speeds, you can now hear it roar but its still somewhat muffled in the cab so its nice. Low tone. Again, I haven't stood outside it while someone floored it...yet!

I had mine installed as I don't have a good spot to work on it and it was $150. Got the kit cheap & brand new for $450 Cdn locally, not shipped. By what I've seen it is very easy to install, I would have but I don't have a garage and it was -30 Celsius when I bought it :)

So far. I'm happy. I'm unable to test performance increases however if that's important to you. Finally, it will reduce your departure angle on the rear end off road. Good luck!
 

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I installed the kit as well and really like the sound. I wasn't worried about saving the stock exhaust so I cut it out from the get go and the install was super easy. I had to cut one of the flange bolts and the other one broke so no problems there either. I've only got about 1/4" clearance at the rear tip but so far I don't seem to be having any issues with it.
 

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I had to revive this thread since this is a great review and there's plenty of useful information for anyone considering the Magnaflow cat-back system. I just got mine in the mail today and hopefully will have time to install it this weekend. Thanks for all who contributed in this thread.
 
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Mopar Cat back for XK

Has anyone installed the MOPAR Cat back that they offer? I can get 30% off on that one. Thx
 
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