ashg
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| posted on 22/2/10 at 12:11 PM |
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106db down to 99db
ok guys after getting 106db exhaust noise reading at my IVA i need to get the noise down. realistically how hard is it going to be to get a 7-8db
drop from my silencer by modifying it internally?
should i try or just get a new one?
it is a straight through type, so was wondering if i took it apart and zigzagged the perforated tube through it added a couple of baffles then
repacked it would it reduce the noise enough?
i know it will increase the back pressure but i will just have to live with that.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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ragindave
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| posted on 22/2/10 at 12:15 PM |
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Baffled
You want one of these.
http://cgi.ebay.co.uk/MOTORCYCLE-EXHAUST-BAFFLE-SILENCER-48mm-CAN-BAFFLE-NEW_W0QQitemZ350276156751QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item518e
15fd4f
Should do the trick
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MK9R
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| posted on 22/2/10 at 12:48 PM |
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quote:
Originally posted by ragindave
You want one of these.
http://cgi.ebay.co.uk/MOTORCYCLE-EXHAUST-BAFFLE-SILENCER-48mm-CAN-BAFFLE-NEW_W0QQitemZ350276156751QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item518e
15fd4f
Should do the trick
was going to suggest that, or alternatively take can apart and squash the perforated tube. Are you sure the can is packed correctly, i.e. not to tight
or too lose?
Cheers Austen
RGB car number 9
www.austengreenway.co.uk
www.automatedtechnologygroup.co.uk
www.trackace.co.uk
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smart51
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| posted on 22/2/10 at 12:52 PM |
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I took out the link pipe between my manifold and silencer and added an extra silencer inbetween. I had it made with 2" OD end pipes (rather
than 2" ID) so that it just slotted in. The can was 6" in diameter, the same as my main silencer but was only 5" long plus the end
pipes. My noise went down by 5db from 102 to 97 dB(a). You will need a longer one to get 7 or 8dB but that shouldn't be a problem.
The best thing is that this approach does not restrict air flow or power, unlike baffles or dB killers. And is saves your ears. 97dB is plenty loud
enough at full throttle.
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rgrs
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| posted on 22/2/10 at 01:03 PM |
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Which silencer do you have ? any pic's
Its a lot to drop, worth opening up your existing and seeing how it's currently packed.
When i opened mine up (mk eng) not a lot inside repacking it dropped me nearly 5dB.
The chances are the dB killer above won't fit if you have a swept bend on the exit of the silencer and it's only a quick fix not a long
term solution.
Also re: induction noise worth putting some sound material under bonnet and make sure when its re-tested the bonnets on, also on re-test get as far
away from the building as you can. If its tested in the exit from the speedo test i think its too close and could be affected by the building.
Roger
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big-vee-twin
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| posted on 22/2/10 at 01:36 PM |
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If you use the baffle from ebay it will need wrapping with fiberglass, to be honest I've used one on my bike, it didnt make too much
difference
Duratec Engine is fitted, MS2 Extra V3 is assembled and tested, engine running, car now built. IVA passed 26/02/2016
http://www.triangleltd.com
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spdpug98
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| posted on 22/2/10 at 02:01 PM |
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106db down to 99db
I had to the same with mine, well to 101dB but did get it down to 99ish
I used a back box from a Volvo about 9-10" dia, and fully lined my bonnet and body side panels with accoustic foam
My Blog: http://spdpug98.wordpress.com/
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boggle
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| posted on 22/2/10 at 02:24 PM |
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you can fit a bung in the end...
i had one on my subaru for its mots....
just because you are a character, doesnt mean you have character....
for all your bespoke parts, ali welding, waterjet, laser, folding, turning, milling, composite work, spraying, anodising and cad drawing....
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Werner Van Loock
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| posted on 22/2/10 at 07:16 PM |
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going down 8dB is an awfull lot, every +3dB is double noise, so going down is the opposite, so have fun
it's not a linear scale you know
http://www.clubstylus.be
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Dangle_kt
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| posted on 22/2/10 at 07:20 PM |
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errr...do you have a tacho that can be...errrr... calibrated?
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RichardK
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| posted on 22/2/10 at 07:40 PM |
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quote:
Originally posted by Dangle_kt
errr...do you have a tacho that can be...errrr... calibrated?
They can use their tacho though! Think its going to be a case of trailer it there or get there dead early and pack as much loosley packed steel wool
up there and hope it doesn't blow out! Together with sound deadening material under the bonnet and sides.
Good look mate its a lot to drop but doable.
Cheers
Rich
Or put a turbo on it that should deaden the sound a bit
[Edited on 22/2/10 by RichardK]
Gallery updated 11/01/2011
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