Exhaust Drone Cure
07-18-2014, 12:51 PM
#62
Network Engineer / Geek
I have the Roush exhaust on my 2013 with 5.0. Love the sound of this system, but the cabin noise is somewhat unbearable at times. I had the helicopter thomp at around 1500rpm as the motor lagged in 6th gear under certain accelerating circumstances. At around 1600 to 2000, had the dreaded drone that was most pronounced at 1800rpm. The Roush has a 3" main pipe. I installed a 3" side-branch with an effective length of just under 33".
All the cabin noise is gone! Now there is a nice rumble coming from the back of the truck, truly happy with it now.
Thanks to Buckeye Demon for the info in this thread.
All the cabin noise is gone! Now there is a nice rumble coming from the back of the truck, truly happy with it now.
Thanks to Buckeye Demon for the info in this thread.
Were you also getting drone at ~3,300 RPM under heavy acceleration? Has this modification helped that ?
07-18-2014, 10:18 PM
#63
09-20-2016, 08:22 AM
#64
Junior Member
For a 3" exhaust pipe, what size pipe is optimal for the helmholtz? What is the calculation to determine the proper length and diameter? Drone occurs in the 1800-2200 rpm range when hot. Also, from what I can tell it is best to position the resonator as far forward on the pipe as possible for it to be most effective, is this correct?
I just installed the Roush and it definitely drones in the cruising RPM range. What diameter pipe did you use? Would you change the length if you did it again? Do you still feel this has eliminated the drone in the 1800-2200 range?
Mine is not as pretty as Buckeye's, but it works. I could not believe how peaceful the ride home from the muffler shop was. My hat is off to you BuckeyeDemon, Thank you!!
I took BuckeyeDemon's pictures to the muffler shop and said COPY that. There was one slight deviation from his. I have the Roush exhaust (Resonator Delete) so I guess the piping is different. Mine is 18.5" from the flange to center and the pipe is 30" from center to end. If there is any drone it is at extreme acceleration and at about 3800 rpm but it only lasts until the transmission shifts back into 6th gear and then it is ALL good.
I took BuckeyeDemon's pictures to the muffler shop and said COPY that. There was one slight deviation from his. I have the Roush exhaust (Resonator Delete) so I guess the piping is different. Mine is 18.5" from the flange to center and the pipe is 30" from center to end. If there is any drone it is at extreme acceleration and at about 3800 rpm but it only lasts until the transmission shifts back into 6th gear and then it is ALL good.
09-20-2016, 06:29 PM
#65
Member
Thread Starter
For a 3" exhaust pipe, what size pipe is optimal for the helmholtz? What is the calculation to determine the proper length and diameter? Drone occurs in the 1800-2200 rpm range when hot. Also, from what I can tell it is best to position the resonator as far forward on the pipe as possible for it to be most effective, is this correct?
I just installed the Roush and it definitely drones in the cruising RPM range. What diameter pipe did you use? Would you change the length if you did it again? Do you still feel this has eliminated the drone in the 1800-2200 range?
I just installed the Roush and it definitely drones in the cruising RPM range. What diameter pipe did you use? Would you change the length if you did it again? Do you still feel this has eliminated the drone in the 1800-2200 range?
that's the beauty of having one that i can adjust. it's easy to swap in and out and get a definitive response of a change. i still recommend simply starting long and keep trimming back till you are happy. i believe the larger area pipe widens the bandwidth of attenuation. so i would recommend tending towards the larger size if you don't want to play around too much with hitting the frequency dead on.
09-20-2016, 06:58 PM
#66
Junior Member
did you get a chance to read post 1 or 38 by chance? after running this a few years, i will absolutely still says it works. i made several different lengths to test, even made a pipe in a pipe to see if i could narrow up the bandwidth of attenuation, and it absolutely did. I've still went back to the 30" length and running the other shorter size would start allowing enough of the drone back, that i didn't like it.
that's the beauty of having one that i can adjust. it's easy to swap in and out and get a definitive response of a change. i still recommend simply starting long and keep trimming back till you are happy. i believe the larger area pipe widens the bandwidth of attenuation. so i would recommend tending towards the larger size if you don't want to play around too much with hitting the frequency dead on.
that's the beauty of having one that i can adjust. it's easy to swap in and out and get a definitive response of a change. i still recommend simply starting long and keep trimming back till you are happy. i believe the larger area pipe widens the bandwidth of attenuation. so i would recommend tending towards the larger size if you don't want to play around too much with hitting the frequency dead on.
09-20-2016, 07:43 PM
#67
Member
Thread Starter
i just used a small body saw, die grinders, etc. tools i have available to me.
09-21-2016, 06:56 AM
#68
Junior Member
Thanks for the help, I appreciate it.
09-21-2016, 05:56 PM
#69
Roush Drone
I ended up putting the resonator back on mine and while it was there I had the muffler shop turn my tips to a side exit. I had the pipe modification and it was defiantly better but I had to depend on a muffler shop to do the measurements and welding. If you could do it yourself and keep playing with it then I believe you could get it. The resonator ended up being my best option.
09-23-2016, 07:47 AM
#70
Junior Member
I ended up putting the resonator back on mine and while it was there I had the muffler shop turn my tips to a side exit. I had the pipe modification and it was defiantly better but I had to depend on a muffler shop to do the measurements and welding. If you could do it yourself and keep playing with it then I believe you could get it. The resonator ended up being my best option.