Let's talk about exhaust drone...

My partner/driver is complaining about drone. This truck was a farm truck hauling grain 6 miles to the elevator. Fancy pipes are cool on a truck that is rarely driven. Now it is hauling grain to the river and we are wanting to run around 300-400 miles a day on multiple runs. Pipes are still cool but not when they give you a headache every day and it is so loud in the cab you cannot hear the radio.

The darn truck is noisy. The PO straight-piped it with a single under cab pipe going to a wye just back from the backline of the cab, then flex to the sides and 6 in pipes mounted on cab corners going up to heaven.

I have been reading lots of forums on drone and nothing is conclusive. I could replace the under cab pipe with a 51in, 10in round walker noisebraker or something similar. I could add those resonators from Iowa80 inside the side pipes to see if that helps. The side pipes are directly mounted to the cab so that is a source of concern. Lots of exhaust vibration can be transmitted thru the support mounts. Even read that motor mounts can be a source of drone.

Lots of questions, not many answers.

What have others done to reduce or eliminate drone? What works well, what does not?

John

 

We have 2 minor exhaust leaks where the flex joins at the elbow below the vertical stacks. We put new band clamps on them but still have some leaking. Guess we should give that another go. The elbow has a reduced diameter section that appears to be smaller than necessary to fit up to the flex.

thanks for the info on your setup and the suggestion.

John

On edit - going to try steel wool. The band clamp on the flex causes a crease in the flex under the bolts. Will loosen and stuff it full and see if that helps. If that eliminates the leaks I can then maybe spend some $$ on better fitting elbow pipes. We need to lower the pipes slightly anyway to fit into my 12ft shop door!

 

Over 12ft.

 

What is the difference between a resonator and the drop in baffles that I see here -

https://www.iowa80.com/pd/quiet-muf...4/?green=04E7ECF5-C650-5AAF-9569-931977B03C83

John