With a lot of help from members on here, I was able to get rid of the awful drone I had after putting on a Magnaflow 18". I also removed my resonator. After doing the math, I determined 33" was optimal length. I designed this to adjust anywhere from 26" to 36" by loosening the exhaust clamp.

 

2nd pic

 

Nice job. Did you do it yourself or have a shop do it for you?
If the latter - what did they charge? Looking to have the same thing done. I have duals on mine and about 1600rpm on the hwy the drone is bad. When Im alone - I just crank the tunes, but w/ the wife in the car shes not a happy camper.

 

I had it done at a local shop. They charged me 142.00 and supplied the materials. I took pics from this forum so they had something to go by. It eliminated the drone more than if i had put the resonator back on.

 

I would change that clamp out to a good band clamp so it won't crimp the pipe...

Good job.

FYI, guys, the lengths are important as they affect what frequencies are eliminated/canceled.

Location can make a difference too.

 

Whats is the purpose of this "drone" ?

 

It sounds good now, but I still want to test it at different lengths. I will have it welded once I am satisfied it is the best length.

 

Correct me if I'm wrong but if you left the resonator on wouldn't it have not needed the j pipe?

 

same question as above^. plus how did you get your math to tell you how long you need it?

 

The math came from this thread from people much smarter than me.

https://www.f150forum.com/f38/exhaus...208112/index4/

I didn't want to put a resonator because I like the sound coming out the tailpipe, I just wanted to get rid of the volume in the cab. This method cancels out sound waves that carry into the cab and the resonator is like a small muffler, it would have quieted the exhaust note more than I wanted. It has a low rumble now and when I put my foot in it, you can definitely hear it while still being quiet in the cab.