Last Updated: 4/18/15
Flowmaster Mufflers 40 Series American Thunder made by Flowmaster

Reviews Mufflers 40 Series American Thunder Reviews & Discussions:

"RBP sells overpriced trash. Look at TRD, URD, Magnaflow, Gibson, AFE, MBRP and Borla. Flowmaster mufflers restrict flow."

Posted on 04-15-2015, 10:07 PM

"piece thats huck bolted to the box. I added a length of flex pipe between the muffler and the exit plate. It has a rock ripper header, no cat and ive used multiple magna flows, thrush, walker, and flowmaster mufflers with this setup."

Posted on 03-12-2015, 11:50 AM

"Magnaflow vs. Flowmaster mufflers :D"

Posted on 02-04-2015, 05:07 AM

"weekend and love it. It did sound loud at first, but even after a couple hundred miles it has toned out a little. I think sound is also something that you become accustomed to over time. I installed Flowmaster mufflers on other vehicles and thought what ha"

Posted on 10-11-2014, 04:28 PM

"You won't need anything, just find a shop that sells and installs Flowmaster mufflers and they'll have what you need and want. They can even help you with best choice for your application, how loud or quiet you want, tone and so forth."

Posted on 09-07-2014, 06:06 PM

"In the last picture above, you'll notice I have 2 exhaust setups. One has no cats and flowmaster mufflers. The other is the catalytics with stock cobra mufflers. I'm hoping with cats and stock mufflers the car ends up super quiet. But if its low on power I"

Posted on 08-25-2014, 05:26 AM

"face of the conventional belief that chambered mufflers don't flow as good as straight through mufflers. Even before the tests, I read a lot about the acoustic and flow design principles utilized in Flowmaster mufflers, and these guys are really doing thei"

Posted on 07-14-2014, 12:16 PM

"That's good to know. I found this cool video that shows how Flowmaster mufflers are made. It's a fascinating process. And something I didn't know, the tolerances of baffle placement need to be precise to cancel out just the right sound waves. Greg"

Posted on 06-23-2014, 05:33 PM

"most all Flowmaster mufflers will cause a power loss. on average, I see about 5 horsepower loss with a Flowmaster muffler."

Posted on 01-05-2013, 11:50 AM

"Flowmaster FTW! I've had flowmaster mufflers on 3 Toyota trucks and love the sound coming out the tail pipe!"

Posted on 08-23-2012, 01:47 PM