Hood cover to quite air intake noise

[lance]

I've been running a Yamaha 300hp 3.3 HPDI with all the Hydro Tec phase III mods for about 10 years. While it is not overly loud, the mods to the throttle body air intake system make it noisier than a stock engine especially on acceleration. The intake noise is considerable for anyone sitting in the back seat.

I'm considering trying a vented engine hood cover like a Tuff Skinz. Has anyone noticed if a hood cover quiets the engine somewhat? Also, does anyone know if Tuff Skinz is the only source for a vented cover for a HPDI?
Thanks

[InjectorService]

I'm no expert here, but I don't think anything like a Tuff Skinz will help. The only thing that would help would be some sort of better airbox. Is your original airbox modified or only the TB?

[Whaaaaat]

If its too loud, your too old.

[282]

I called tuff Skinz they said it quiets it down 10%. I have a carbon cowl on my 300xs and its loud for me.

[home made tunnel]

If its too loud, your too old.

Hahaha Nice one!

But really, the only thing that quiets NOISE is closing it in. Close up the cracks, add foam inside to stop the echo, More vents will make it lower. Bolting some pieces of rubber to the inside of the cowl to stop the cowl its self from amplifying the noise helps too. Like an old shoe sole, or a chunk of an old tire.

[SS Minnow]

Hahaha Nice one!

But really, the only thing that quiets NOISE is closing it in. Close up the cracks, add foam inside to stop the echo, More vents will make it lower. Bolting some pieces of rubber to the inside of the cowl to stop the cowl its self from amplifying the noise helps too. Like an old shoe sole, or a chunk of an old tire.

This right here. They sell acoustical foam, or padding that you can glue to the inside of the cowl. Also, the vibration transferring through the parts acts like a string instrument, or think of two tin cans with a string in between. Any solid points and it transfers noise. I save old motorcycle tubes and have used it for this type application on many different projects.

OH, and yeah, if it is to loud, you are too old!!!!!!!!!!

[flabum1017]

[lance]

Ya, maybe age has a little to do with it...

The factory air box, with oil drain back, is long gone. I have a larger throttle body, 1/2" spacer, and velocity stacks.

Thanks for your thoughts. I'll look for some thin under hood insulation instead of an outside cover.