I have my SVA re-test on Friday and only job left is to reduce noise from 104db to 101db !!

I have foam filter so lots of induction noise and have no room for original airbox, I also think a lot of noise is comming from the engine because without the bonnet on it's 108db.

I was looking at insulating the underside of bonnet and side panel etc... has anyone tried this with success and if so what did you use, need help as running out of ideas ?

Cheers,
Kosmo

Do you have any air-conditioning/ducting companies near you?
They should have insulation that they stick on the outside of the ducts. It is basically rockwool with a silver foil covering and is about 20mm-50mm thick.
They also should have some 3m stickie pads with spikes and washers.
These stick to your underside of your bonnet and the rockwool is pushed onto the spike. The washers go on the spike to hold the rockwool on and all you do is trim the spike down.
Alternatively you could evostick it on.

db killer up the pipe

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Originally posted by westf27
db killer up the pipe

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Yes I failed twice on noise with my striker and lagging pannels with accoustic foam cracked it (108 dB first time) make sure you use motorsport stuff as the tester check that it was fire proof. Make sure you lagg the bonnet side pannels and inside the transmission tunnel.
Also if you have a digidash change the number of cylinders to 3 !!!! You atre more than welcome to borrow the foam as it s all cut to sixe if you can pck it up (london)

Ive got the same problem, at test the car was 103. used a baffle and a few pieces of dynamat and at re-test I had 109!!

Been looking at lagging engine bay. Cheapest stuff I could find is this:-

http://www.pipelagging.com/sound-proof-sheet-insulation-10mm-thick-plain-armasound-sheet-p-496.html


Sound insulation of any kind seems to be very expensive!

this stuff is the best on the market. i have used it in all my cars to date and it has provided significant db reductions

if you go on youtube and search for second shin there are demonstrations of i in action.

Second Skin

I lagged my bonnet with some left over solid wood underlay (looks like camping mattress). It seemed to help. My tester said nothing....

As with others - home made baffle (22mm copper pipe wrapped in steel wool)

Plus loads of carpet did it for me on re-test. Stuck carpet offcuts onto bonnet, sides of engine bay, underside of nose cone and lined scuttle/battery tray . Also carpet on floor infront of seats- couldn't believe the difference- incredible

OK, looks like I have a plan.... lots & lots of soundproofing.

Thanks
Kosmo