How to Make a Magnaflow Muffler Sound Better

by Harvey Birdman

Magnaflow mufflers are popular aftermarket mufflers for truck and cars as well. They allow for smoother flow of exhaust gases as well as a deeper exhaust note. However improvements can also be made, even to Magnaflow mufflers. To make a Magnaflow muffler sound better you can attach a homemade echo chamber with a modified coffee can. The coffee can will slip over the tip of the muffler and bounce the exhaust note sound waves around.


Drive your car or truck to a clear area where you can work on it. Do not perform any car projects on the road side due to the danger of passing traffic. A garage or covered carport would be the best area to do this project.


Place an empty coffee can against the tip of the Magnaflow muffler. The tip will be round and protruding from the back of the muffler. Place the coffee can so that tip hole is flush against the bottom of the coffee can. The top of the muffler exhaust tip should touch the rim of the bottom of the coffee can.


Trace around the Magnaflow muffler exhaust tip onto the bottom on the coffee can. Do not worry about marking the tip of the muffler with the marker, stainless steel cleans very easily even from permanent marker marks. Take the coffee can away from the muffler and place it on your work space. Place a nail on a point on the outline and hammer it down, through the metal sheet. Repeat this hole punching along the outline you drew so that the outline is a series of holes.


Cut the remaining pieces of metal in the outline with a pair of shop shears. Snip at the metal bits that keep the inner metal circle still attached to the coffee can. Peel the metal away with a pair of needle-nose pliers and then smooth the edges on the coffee can with a hand file.


Take the coffee can back to the Magnaflow muffler exhaust tip and slide the coffee can over the tip so that the open side faces towards the back of the car or truck. Tape the coffee can into place on the muffler with duct tape. Wrap the duct tape around the can and onto the Magnaflow muffler itself, so as to connect both. Do not tape the coffee can to the underbody or to the suspension as the duct tape will tear when the car suspension is compressed or extended during a drive.

Items you will need

About the Author

Harvey Birdman has been writing since 2000 for academic assignments. He has trained in the use of LexisNexus, Westlaw and Psychnotes. He holds a Juris Doctor and a Master of Business Administration from the Chicago Kent School of Law and a Bachelor of Arts in both political science and psychology from the University of Missouri at Columbia.

Photo Credits

  • photo_camera Motorcycle exhaust image by Crisps85 from