Bought the Flowmaster catback system 6 months ago...... nice tubing, fit together well, DRONES ALL THE TIME between 1400-2000 RPM, even when barely on the throttle, so much so that it gave my wife headaches. Amazing how good it sounded ABOVE 2000 RPM, and relatively quiet, even when mashing it to the floor. But the massive DRONE was not tolerable. Sounded like I had a 55 gallon drum for an exhaust tip, especially when pulling thru highway underpasses.

Swapped out the muffler for a DynoMax Ultra Flow, the next to largest one they make, and it is quite a difference. I wasn't expecting alot from the Ultra Flow because it is a straight thru design, but I figured anything had to be better than the DroneMaster. It is. About 30% less drone volume in the 1400-2000 rpm range, and moderately quiet at full throttle (in the cab at least). I can live with it, and more importantly, so can the wife.

I know that the FlowMaster in the kit was a 50 series, and they do make a 3 chamber 70 series that is allegedly good for RVs, but I could not find any opinions on it.

FWIW, the FlowMaster axleback kit we had on the '05 V6 Mustang worked pretty good, sounded great inside the car.

 

This is one of 1000's of posts complaining of drone from Flowmasters. Don't understand why they are still in business. Drone, below average flow #'s... who would want one.

 

What's the old saying, "Happy wife, happy life?"

 

I heard a flowmaster 70 big block muffler on a Titan, and to this day that was the best sounding truck ever. Those 5.6s sound really damn good. Too bad about the dana 35 rear axle.


I heard a magnaflow on a V10 once and sounded pretty good. From how short it was, I imagine it probably weighed about 50 lbs less than the stock muffler too...

 

I had an Ultra Flo on V10 gone now, dad had a Magnaflow. I have put on and run enough mufflers on V10s and packed mufflers are not where it is at. Have had nothing but Flowmaster 70 series mufflers since.(glad they have a stainless now) Buy a small capacity muffler and you usually end up with drone. FYI packed mufflers change tone and often times drone more as they age.