Hood Noise Insulation

[MikeCallery]

The hood has an OEM insulation piece for noise absorption that works relatively well.

I am wondering if it would be any benefit to remove it and replace it with some of the high-end sound mat insulation available these days?

I have the K&N FIPN kit, not the filter but the kit, and although I know I cannot reduce all the noise, I am looking at doing some additional insulation to help.

Any thoughts or ideas.

 

[fourZero]

If you're referring to CLD tiles (aka "Dynamat") they don't block sound per se, they reduce or eliminate resonance. If you wanted to reduce sound transmission you would need to use CCF (closed-cell foam), my big concern there would be finding something that would stand up to the heat in the engine bay.

Is your engine really that loud?

 

[MikeCallery]

The engine, on almost all levels, is reasonably quiet and I have no complaints. Adding the K&N kit, however, does cause an increase in noise that I can live with because it does give me better performance when hauling and acceleration on the highway. It does create a bit more noise however, and it might be resonance, but heck if I could tell the difference and how to go about determining which?

I do know that I had a 2006 Tahoe and I put the dynamat on the hood, it has a thin piece of cardboard baffling and I also used a sound insulation spray all in the back and that helped.

My objective here is to try and reduce the sound coming off the engine when I crank up that K&N.

It might be prudent to leave the hood along and look for any/all other areas where it is just metal and work on that first then.

 

[LukerDooker]

The engine, on almost all levels, is reasonably quiet and I have no complaints. Adding the K&N kit, however, does cause an increase in noise that I can live with because it does give me better performance when hauling and acceleration on the highway. It does create a bit more noise however, and it might be resonance, but heck if I could tell the difference and how to go about determining which?

I do know that I had a 2006 Tahoe and I put the dynamat on the hood, it has a thin piece of cardboard baffling and I also used a sound insulation spray all in the back and that helped.

My objective here is to try and reduce the sound coming off the engine when I crank up that K&N.

It might be prudent to leave the hood along and look for any/all other areas where it is just metal and work on that first then.

Resonance is vibration at certain frequencies - the typical car noise that bugs you will do it over and over again at certain speeds, & once you hear it you will know it well and expect it at those same (usually lower) speeds.

& also from tire type & driving over various road types; road noise from cheap tires can be quite loud and that hum will never change unless the tires change.
...or a long stretch of some nice grooved asphalt waiting for the final top coat = horrible low end rumble on 20" wheels that goes right into my ear and fills my head...nauseating between 30-40mph...BLLLEAAAHHHRGH!

 

[MikeCallery]

Thank you. Then it is not resonance but simply noise from the engine sucking in all that air from the K&N.

 

[fourZero]

yes, typically resonance occurs on large flat portions of unreinforced sheet metal (trunk, quarter panels) due to induced vibration (in my case, from a subwoofer).

There are high-temp CCF available, but they are uber expensive. http://www.marshbellofram.com/bellofram-silicones/products/bellofoam-closed-cell-silicone-sheeting/