Harmonic Vibration

[Guest]

Hey guys,
I think I found the source of my harmonic noise when I am crusing down the highway. I have my dual Falcon exhausts bolted tight to the frame in a custom setup, with no room for expansion or vibration. Hmmmmm. Not good. Think the thing is singing. Gotta figure a way to interject some rubber somewhere to dampen the vibration. I am sure it is not good for the manifold.....Even thought of getting some stainless flex pipe to install somewhere on the headpipes.

Bill

 

[Bugeye58]

That will definitely do it. At certain RPM, the resonant pulses in the exhaust can be telegraphed through the body in a hard mounted system, with the body acting like a megaphone. Commonly referred to as 'exhaust moan' in the NVH business.

And,you'd be surprised at the amount your exhaust will "grow" when hot. That expansion needs somewhere to go, hence the need for flexible hangers and isolators.
Jeff

 

[vagt6]

Great find, guys.

My foreward resonator is tucked between the frame rails and contacts the frame, also resonates.

What's a good insulating material to fit between the resonator and the frame to stop the noise?

thanks!

 

[MDCanaday]

Mark, try header wrap, as long as the metal is not too sharp the wrap should stop the "ground-out" vibrations for quite a while.
MD(mad dog)