Mark G
|
| posted on 21/4/10 at 04:55 PM |
|
|
Help!! Noise reduction ideas please?
Hi all,
I've got my first track day in the Indy on Saturday at castle coombe. Only I think it'll be too noisey. It's got at 893 blade
engine with an MK exhaust. I fitted the noise reducer that came with the exhaust on the weekend, only that increased the back pressure too much and
created a massive flat spot so I had to take it out again.
Does anyone have any locost ideas as to how I can reduce the noise by Saturday? I was thinking of welding something on the end of the can to redirect
the exhaust fumes back under the car. It won't reduce the noise at all but I'm hoping that it might trick the db meter.
Help?!
Mark
|
|
|
|
|
suparuss
|
| posted on 21/4/10 at 05:13 PM |
|
|
stuff the can with wire wool!
|
|
|
Davey D
|
| posted on 21/4/10 at 05:14 PM |
|
|
if you point the outlet of your exhaust to the floor will the floor absorb some of the noise before it bounces back up to the dB meter?
|
|
|
StrikerChris
|
| posted on 21/4/10 at 05:24 PM |
|
|
like wot he ^^ said and also an,erm hard to explain bit of metal tacked in the end of the exhaust has got us past scrutinears at rallys in the
past.twisted bit of metal,bout an inch in depth,imagine a 2 blade propeller side view.to try and swirl and disperse gas exit.only about 1db reduction
but was enough at the time
|
|
|
StrikerChris
|
| posted on 21/4/10 at 05:28 PM |
|
|
and lie about where your limiters at! 
|
|
|
rgrs
|
| posted on 21/4/10 at 05:34 PM |
|
|
Open it up and repack it, you will probably find that there is very little wadding in it.
Roger
|
|
|
Mark G
|
| posted on 21/4/10 at 05:52 PM |
|
|
Ok, so I've decided I may be better off doing a repack so I'm going to take the can apart tonight. Is wire wool really ok to put in the
exhaust?
|
|
|
Wadders
|
| posted on 21/4/10 at 06:00 PM |
|
|
bung a standard bike can on, they are very quiet. you do notice a drop in power tho.
Oh and tape up your bonnet scoop, induction roar is a big contributing factor on driveby.
Al.
[Edited on 21/4/10 by Wadders]
|
|
|
StrikerChris
|
| posted on 21/4/10 at 06:49 PM |
|
|
wire wool does the job if its not a majorly hot exhaust.carefull tho cause it will blow wire wool dust out that then rusts on what they land on!not a
problem on 7's really but gettin the t cut out on the back of my sx got annoying!
|
|
|
paulf
|
| posted on 21/4/10 at 07:17 PM |
|
|
You can use loft insulation it does melt eventually but would last a few hundred miles.Ideally you should wrap the perf pipe with a layer of stainless
wire wool as it doesn't burn and protects the glass wool.
Paul
|
|
|
Daddylonglegs
|
| posted on 21/4/10 at 07:40 PM |
|
|
Use stainless wire wool type material. You can get those pan scrubbers (waits for the witty returns ) that are stainless and shouldn't rot
down. I got some from homebase, 6 for £1
HTH
It looks like the Midget is winning at the moment......
|
|
|
LBMEFM
|
| posted on 21/4/10 at 07:45 PM |
|
|
Wadders, why doesn't your girly dance anymore?
|
|
|
Jon Ison
|
| posted on 21/4/10 at 08:14 PM |
|
|
Standard bike can, works every time hassle free and no worries about mods "dropping off" and been black flagged 1/2 way through the
day.
You will lose a little on top end but have more low down grunt with a much better power delivery.
|
|
|
andrew
|
| posted on 21/4/10 at 08:33 PM |
|
|
i made bafle out of a piece of tube about 2 foot longand stainless pan scrubs driled holes in tube welded mesh 2" inside tube put pan scrubs in
and wired them up tubeso they didnt just end up in end slid inside can held in with nut n bolt , that way if you fail noise just pop another pansrub
in or take out till your on limit
|
|
|
Mark G
|
| posted on 25/4/10 at 09:22 PM |
|
|
Had the track day yesterday. I'm very glad to say that after repacking with loft insulation the car came in at a very respectable 97db.
At SVA 1200 miles ago I think it was 100.7db so it was never quiet to begin with. Much better now.
Cheers all.
|
|
|
.jpg)
