Noise Reduction

[Iainl]

Getting ready for the Track Days, so therefore need to reduce my noise (still).

I was therefore thinking of lining the underside of the bonnet and the inside of the side panels with some noise reducing mat.

Has anyone got any recommendations such as Dynomat or Dodo mat?

Some of this material will be quite close to the exhaust manifold so will have to be fire retardant

Any advice will be welcomed

Cheers
Iain

[SPAXIMUS]

What are you trying to achieve? If it is induction noise that is causing an issue Dynamat will not help.

track noise really is in two parts, exhaust and induction. Bigger exhaust, well designed will sort most noise issues, sometimes at the expense of power. You can also have the exhaust coated which will help by an odd decibel of more and wrapping with tape helps.

Induction, good quality air filter and if you can inside a sealed bonnet with one inlet.

On my Westfield the induction is worse than the exhaust, but I have never been stopped even at coombe.

[Iainl]

Thanks for the reply Spaximus, I think I've sorted the induction noise by fitting an AB Performance air filter box which fully in closes the carbs, and the can on the exhaust is the largest diameter (6 inches) I can currently fit and was also purchased from AB last year

I was hoping the sound absorbing mat lining the underside of the bonnet and side panels would stop the chassis and body panels amplifying the noise

Cheers

[Lucky Ed]

All of the above will obviously help, but how much are trying to reduce the noise by?

I wouldn't have thought the matting would help the static exhaust test much, although it might help on the drive-by

Ed

[Facial Hair Optional]

All of the above will obviously help, but how much are trying to reduce the noise by?

I wouldn't have thought the matting would help the static exhaust test much, although it might help on the drive-by

Ed

I think you are spot on there Ed, they do the static exhaust noise test from half a metre directly in line with and at 45 degress to the exhaust pipe don't they? The matting wont help, might give you a qieter ride though I guess?

[fullpint]

I'm at 118db and have given up with the idea of track days.. Silencer is the word to reduce noise I need one twice as large or may be run a second can out the back  and put up with the reduced power..

[sanzomat]

118 That's pretty loud - you'd need to give out ear defenders to anyone in the vicinity if you drove it on a building site!

[Facial Hair Optional]

That is VERY loud! My Tiger was measured at Combe at 103 and I'm sure the guy told me that the sound level doubles for every 3dB it goes up?? I don't know what the ASBO is but I do know I have to fit the spare silencer that it came with to do track days 

[Gary RH7]

the sound level doubles for every 3dB it goes up??   

So does that make it five times louder than the Tiger

[SPAXIMUS]

I'm at 118db and have given up with the idea of track days.. Silencer is the word to reduce noise I need one twice as large or may be run a second can out the back  and put up with the reduced power..

That is a huge level. What motor are you running and what size silencer? There are many ways to reduce the noise but it will be trial and error somewhat.

Wunoff do a perforated pipe in their unit, which they enhance with like little scoops inside to drive the gas into the wadding.

I use Acoustafil and that reduce mine hugely as the previous fillings ranging from glass fiber insulation to very expensive matting didn't do the job

[Facial Hair Optional]

the sound level doubles for every 3dB it goes up??   

So does that make it five times louder than the Tiger

Well if what he said is true then yes, but I can't see it can you? I am sure Ian will explain it to us all soon enough, if anyone knows, he does.

[Facial Hair Optional]

I'm at 118db and have given up with the idea of track days.. Silencer is the word to reduce noise I need one twice as large or may be run a second can out the back  and put up with the reduced power..

That is a huge level. What motor are you running and what size silencer? There are many ways to reduce the noise but it will be trial and error somewhat.

Wunoff do a perforated pipe in their unit, which they enhance with like little scoops inside to drive the gas into the wadding.

I use Acoustafil and that reduce mine hugely as the previous fillings ranging from glass fiber insulation to very expensive matting didn't do the job

I have a Wunoff silencer on the Cossie Fury and it is a LOT quieter than the pinto Tiger. It's only held on by one jubilee clamp and is hung from the car by a metal strap affair. I guess I could rent it out for testing purposes?  I think the bore is 3 inch?

[Moleman]

If you get it sorted soon then there are still 2 spaces left for April Iain. 

[sanzomat]

There are two principal aspects to noise as measured by the dB scale. These are loudness (e.g. as perceived by a human ear) and sound intensity or the pressure made by the sound waves measured as the difference in air pressure between peaks and troughs in a sound wave. For every ten decibel increase the loudness doubles but the sound intensity (air pressure waves) increases by a factor of ten. So 118dB would sound twice as loud as 108dB and four times as loud as 98dB however the sound intensity at 118dB would be 100 times that at 98dB. Whichever way you look at it 118dB is VERY LOUD (sorry for shouting!)

[fullpint]

Its very loud!!! Hence why I wear a lid AL THE TIME plus ear plugs if on a long run

[paintman]

I'm at 118db and have given up with the idea of track days.. Silencer is the word to reduce noise I need one twice as large or may be run a second can out the back  and put up with the reduced power..

Bl**dy hell that is high!

Dixie got new silencers for his Cobra which is 4.6 litre and now it's about 95db I think or lower!

[Iainl]

Thanks for all the replies, I only have to drop a couple of Dba to get though the static test

So hopefully some sound dampening mat will sort that out and if I fail the drive past I'll have to not press the loud pedal so much

Iainl