Board logo

silencer packing
markyb - 6/3/09 at 07:44 PM

My silencer is a straight through one so not likely to pass noise tests come SVA.

I have a DB killer but cant fit it at the outlet of the silencer as I have an end piece insert that needs to go in.

I have a roll of loft insulation sitting here and was wondering could I use this to pack the centre of the silencer and then place (rather than screw in) the DB Killer near the end. The end piece insert would then hold the DB killer static whilst the DB killer would stop the insulation blowing out.

Obviously everything would fall out post SVA but was wondering if there are any issues with using this method to get the noise levels low enough

If loft insulation is not suitable could I use the same method except have wire wool instead ?

cheers

[Edited on 6/3/09 by markyb]


nitram38 - 6/3/09 at 07:50 PM

The problem is emissions testing.....they need to put the probe into the exhaust.


David Jenkins - 6/3/09 at 08:12 PM

I don't know if this will help, but it's worth a look:

Linky

I did this to my silencer - I wasn't able to measure sound levels before and after the modification, and anyway I had repacked it at the same time so measurements would have been irrelevant, so I can't say definitively that it's quieter... but the exhaust note has changed (it's lower) and it SOUNDS quieter!


westf27 - 6/3/09 at 08:21 PM

put mine in the entry to silencer


paulf - 6/3/09 at 09:13 PM

Loft insulation does work for a while but eventually blows out, I used it for a while but the last time I repacked the silencer I also wrapped the perf tube in a thin layer of stainless wire wool and packed it with some industrial basalt wool from an industrial fire blanket type material.After doing this it has lasted 2 years instead of a few months between repacking..
You need something in the silencer as an empty box flows worse than a correctly packed one.
Paul