jetrinka
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I posted a thread a day or two ago about installing this Magnaflow muffler before the plan was kiboshed by my better looking half. Well I never cancelled the order, the muffler came, and after some convincing I got it installed!
I wanted to originally post this thread as a review on the exhaust but also to see if there may be any efficiency benefits from it. The truck has about 6500 miles on it right now and through that time, during my normal every day driving (likely 60% highway 40% city) I've calculated, at the same fuel pump, around 11.5-12.5 MPG. I was interested in learning more about how the stock muffler on this truck is set up and tracking over the next month or so to see if any improvements are to be had. I don't expect any power gains - just more noise and hopefully a bit of efficiency.
The install is not very hard. Likely the hardest part is getting the old beast of a muffler out. It is heavy and the hangers suck to get to. However if you are planning to do this job, or any exhaust job, buy a pair of these exhaust hanger pliers. They make the job much easier. https://www.amazon.com/Lisle-38350-Exhaust-Hanger-Removal/dp/B0012S9A5U/ref=sr_1_2?crid=3IYQXHR3W0IFV&keywords=lisle+exhaust+hanger+pliers&qid=1640278420&sprefix=lisle+exhaust+hanger+plier,aps,175&sr=8-2
I did have to access the hangers for the tailpipe as well because I couldn't push it back far enough to clear the front section of the stock muffler from the crossmember below it. Once that was done though I tilted the whole thing down and hammered it off the tail pipe with a rubber mallet.
Install is an easier reversal of the install - it is helpful though to have someone at the back of the truck providing forward force on the tailpipe as well as aligning it while you tighten the clamps down
IMPORTANT NOTE!!!! - If you buy this kit do yourself a favor and immediately throw the provided clamps in the garbage. They are horrible and do not provide nearly the force needed to clamp the pipes together. I tried using them and when all the way tightened the pipes would easily move and rotate in each other. They look nice but are garbage. I used two of these instead and they worked great. https://www.oreillyauto.com/detail/...omotive-car-1998-toyota-corolla?q=35753&pos=4
Another important note on those clamps is since the pipes are down their length in 4 places (to provide the clamp something to clamp down on) be sure to install the clamps on the rearmost portion of those slots. As long as your pipes are installed in each other far enough clamping them here will help prevent any exhaust leakage past those slots that will happen if the clamp is forward of where they terminate.
Overall I am very happy with the product. I was able to adjust the tailpipe a bit to tuck it up a bit farther than stock (whoever thought of the tailpipe placement on these trucks should be shot.....) Sound is subjective but I will try and upload a couple videos of it. It is certainly a deeper tone but not as *thump thump thump* as a sound as you would get with a Flowmaster type muffler - a much smoother deep tone which I like. It is audible in the cabin but not overly so. I think outside the truck it sounds great.

There is a slight drone at cruising speed around 1600 RPM and when MDS kicks in the "helicopter" noise is more pronounced. I don't personally mind it but some others may. I am glad it retains the stock resonator because I'd imagine it would be much worse without.
Notes about the stock muffler - and I will get some pictures too. I thought because I had seen in pictures of the stock muffler on older 6.4's that I would be finding a flapper valve in the muffler. There is no such valve in mine. The muffler inlet and outlet are staggered and as far as I can see both the inlet and outlet open up at each opposing end into a sound deadening material filled cavity. I can only imagine these two cavities connect in the middle of the muffler causing the exhaust to make two 180 degree turns before exiting. I can shine a flashlight down one side but cannot see any light out the other side. Certainly seems restrictive.


I will update this again later. Thanks guys!
I wanted to originally post this thread as a review on the exhaust but also to see if there may be any efficiency benefits from it. The truck has about 6500 miles on it right now and through that time, during my normal every day driving (likely 60% highway 40% city) I've calculated, at the same fuel pump, around 11.5-12.5 MPG. I was interested in learning more about how the stock muffler on this truck is set up and tracking over the next month or so to see if any improvements are to be had. I don't expect any power gains - just more noise and hopefully a bit of efficiency.
The install is not very hard. Likely the hardest part is getting the old beast of a muffler out. It is heavy and the hangers suck to get to. However if you are planning to do this job, or any exhaust job, buy a pair of these exhaust hanger pliers. They make the job much easier. https://www.amazon.com/Lisle-38350-Exhaust-Hanger-Removal/dp/B0012S9A5U/ref=sr_1_2?crid=3IYQXHR3W0IFV&keywords=lisle+exhaust+hanger+pliers&qid=1640278420&sprefix=lisle+exhaust+hanger+plier,aps,175&sr=8-2
I did have to access the hangers for the tailpipe as well because I couldn't push it back far enough to clear the front section of the stock muffler from the crossmember below it. Once that was done though I tilted the whole thing down and hammered it off the tail pipe with a rubber mallet.
Install is an easier reversal of the install - it is helpful though to have someone at the back of the truck providing forward force on the tailpipe as well as aligning it while you tighten the clamps down
IMPORTANT NOTE!!!! - If you buy this kit do yourself a favor and immediately throw the provided clamps in the garbage. They are horrible and do not provide nearly the force needed to clamp the pipes together. I tried using them and when all the way tightened the pipes would easily move and rotate in each other. They look nice but are garbage. I used two of these instead and they worked great. https://www.oreillyauto.com/detail/...omotive-car-1998-toyota-corolla?q=35753&pos=4
Another important note on those clamps is since the pipes are down their length in 4 places (to provide the clamp something to clamp down on) be sure to install the clamps on the rearmost portion of those slots. As long as your pipes are installed in each other far enough clamping them here will help prevent any exhaust leakage past those slots that will happen if the clamp is forward of where they terminate.
Overall I am very happy with the product. I was able to adjust the tailpipe a bit to tuck it up a bit farther than stock (whoever thought of the tailpipe placement on these trucks should be shot.....) Sound is subjective but I will try and upload a couple videos of it. It is certainly a deeper tone but not as *thump thump thump* as a sound as you would get with a Flowmaster type muffler - a much smoother deep tone which I like. It is audible in the cabin but not overly so. I think outside the truck it sounds great.

There is a slight drone at cruising speed around 1600 RPM and when MDS kicks in the "helicopter" noise is more pronounced. I don't personally mind it but some others may. I am glad it retains the stock resonator because I'd imagine it would be much worse without.
Notes about the stock muffler - and I will get some pictures too. I thought because I had seen in pictures of the stock muffler on older 6.4's that I would be finding a flapper valve in the muffler. There is no such valve in mine. The muffler inlet and outlet are staggered and as far as I can see both the inlet and outlet open up at each opposing end into a sound deadening material filled cavity. I can only imagine these two cavities connect in the middle of the muffler causing the exhaust to make two 180 degree turns before exiting. I can shine a flashlight down one side but cannot see any light out the other side. Certainly seems restrictive.


I will update this again later. Thanks guys!
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