Sound Insulation

[charisma]

I have a Westfield Megabusa that is loud. I want to make the car quieter. I want to be able to drive down the road and not cringe everytime I press the throttle pedal down slightly.

At the moment I have a Techcraft silencer that makes the exhaust quiet enough, but what I really want to do is reduce the 'under bonnet' noise.

There is a lot of induction noise that I can attempt to silence with various air filters etc, but my first stab at this noise problem will be with under bonnet sound insulation.

Does anybody know of any suitable material and/or supliers, the insulation needs to be heat resistant obviously!

[liszt]

I have a Westfield Megabusa that is loud. I want to make the car quieter. I want to be able to drive down the road and not cringe everytime I press the throttle pedal down slightly.

Being unhelpful, sounds like you chose the wrong car


I'll get my coat

[Kevp]

Try Ear Plugs.

[charisma]

I can't afford to buy everybody earplugs.

[Stig]

I used aluminised fibreglass matting. It's a fairly good sound insulator (though not sure how effective it would be in a Seven) and obviously shields heat pretty well.

Just stick to the underside of the bonnet.

[Avocet]

Most mass-produced cars looking to reduce noise fit fibrous undertrays beneath the engine bay. A great deal of noise is reflected off the road surface. For proper noise control you need something very dense. Years ago, industrial sound deadening used to be a sandwich of two different types of foam with a lead sheet in between. Nowadays you can get synthetic "lead" which is just as good. Do a search for "Halyard Marine" on the 'net. They sell sheets of the stuff (also try "ASAP supplies"). That said, the stuff is very heavy and about 30mm thick! It also doesn't like going round compound curves and may completely stuff the underbonnet cooling. Finally, beware of changing the air filter without checking the fuel mixture under full load. Although most air filters that will make it quieter will probably restrict the airflow, you might get unlucky and get one that allows too much through and this could dmagae the engine.

[accident]

you want it quiet then fit the bike airbox,it kills all that glorious induction noise.
but you will need to raise the bonnet bulge about 6".
then youll need the whole fuel map redoing.

[Spyderman]

Where does the induction pipe go?
If you could duct the induction to the front near the radiator it would help.
Try not to reduce the bore though.