Spray foam for noise reduction

[PorchDog]

I have a 7 window front engine short bus with the all the seats removed and the floor covering removed down to metal. I have covered the dog house with KilMat.

I realize that a front engine bus is noisier. It has a DT 466 and the engine RPM at cruise will be about 2000 to 2100 RPM.

My question is-- for folks who have used spray foam in the walls and ceiling and finished the bus out-- is it significantly quieter after the conversion?

At the current level of noise--with the interior removed-- I have to question whether I would be happy driving it on long trips.

I have also considered noise cancelling headphones....

 

[nikitis]

The passengers would love it more. And notice a difference, you won't as much.

A product I'm going to use for my undercoating of my bus is 3M Rubber Undercoating which acts as a rust prevention, but because it's rubber also absorbs a lot of the vibration to make it quieter.

But beyond that and kilmat I don't think there is much else you're gonna be able to do.

 

[gollum-SKO]

It helps a LOT with the sound!
Adding furniture and things has dampened the sound a lot more, though. There's a lot less noise from the road when there are cabinets covering so much of the floor, a runner rug through the middle, etc. The weight also made the ride a lot smoother and less bouncy.

The stairs are a huge cause of road noise, so making sure all the gaps in the front door are sealed and adding flooring (ideally with rugs/doormats) helps a lot.

Other considerations are tires (my all-terrains are way louder than the highway tires it came with)... and your body mounts/bushings. New polyurethane mounts to replace the torn and cracked ones will make your ride a lot smoooother and a lot quieter (both from road noise and the jostling and shifting and shaking around inside). I don't have specific recommendations but they don't need to be the crazy expensive ones, just try RockAuto first.