Help!! In an attempt to improve gas milage and sound (a little) I had a Flowmaster50 DF (2 1/2 in/ 2 1/2 single out, standard side exhaust)installed 2 weeks ago. I got an instant 1 MPG increase. Now for the problem. I travel on the highway and try to keep it @65 MPH. At this speed (engine rpm = 1900)I have a very annoying exhaust drone that drives me crazy. Above & below 65 MPH, the drone drops off some. After a week of misery I took the truck back to the dealer . He swapped the FM50DF for a FM70 free of charge (what a guy). The FM70 is supposed to be quieter, and it is, except for the 65MPH drone. Absolutley no change, I was surprised. I returned to the dealer and paid for a full-bore resonator installed just ahead of the FM70. The dealer said that this would kill the drone. It now seems to be even louder with the resonator. Is this a Flowmaster / F150 problem?? Would a different brand free-flowing muffler sound different?? Does anyone have a simliar experience or advice?? Again HELP!!!

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2001 4X2 S-Cab
4.6 V8
3.55 Gears
Dark Highland Green/Arizona Beige 2-Tone

[This message has been edited by YorkF150 (edited 04-17-2001).]

[This message has been edited by YorkF150 (edited 04-17-2001).]

[This message has been edited by YorkF150 (edited 04-17-2001).]

 

That sounds weird. I've got true duals on my 5.4 with 50 DF exiting the sides and and no drone at all. I can sort of hear it if i turn off the radio and really listen for it. SI/DO? Which exit are you using?
Really that shouldn't happen though.

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2001 SuperCrew ORP 5.4L Gen I
MODS-Ramsey Brush Guard and Pro Plus 9000 winch, MAAP steps, Airaid, True Duals w/ 50 series muffs, Line-x, bugflector, and huskyliners.
http://albums.photopoint.com/j/AlbumIndex?u=1508480&a=11420452&f=0

 

York150: Here's a tip I've used a couple ties in the past. It will dampen a drone inside the cab a little and it cost about 5 bucks. Go to the local home center a get some pipe insulators. Get the 6'foam versions and get a couple of different diameters (1 1/2", 2" etc.). Work them long-ways between the back of the cab and the front of the bed. Mash them down as far as you can and put in as many as you can. This gets rid of the sound waves funneling up
between the cab and bed. It helps a little and only cost $5.
Winder
2001 Screw, 5.4L
Superchip, air box mod, Gibson SS,Scorpion Zeros.

 

Look and see if the muffler is under both heat shields.I have very little drone but I also have the 4.2 not sure if it makes a diffrence.But I had my flowmaster installed further back so it was under the heat shields and more under the bed than the cab.Hope that helps.

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------------------------- 99 SILVER XLT/REG.CAB/4.2/5SPD/3.55/K&N/Flowmaster 50 series Delta Flow/Westin Black Nerfs/SuperChip/Hellwig Rear Swaybar/Energy Suspension Front Swaybar Bushings and Endlinks/Trenz Billet Antenna

 

My stock exhaust has weights down the length of the system. I wonder if yours had them stock and now without them ya get the drone.