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Exhaust Noise
Dopdog - 20/4/12 at 04:37 PM

HELP, has anyone got a nice quick fix for reducing the db noise on my seven type car?


cliftyhanger - 20/4/12 at 04:50 PM

db killer? cheap, effective, saps power.
But I reckon handy for a trackday or similar, better than being sent home.


johnemms - 20/4/12 at 04:54 PM

I made a 10'' x 1.5'' long tube full of holes - support washers front and back
Wraped it with stainless wool ..
Stuck it just after the 4 into 1 ..
made a hell of a lot of difference

I changed the wire wool for stainless once i was happy with the db reduction..

Will go through IVA easy with that fitted ..

[Edited on 20/4/12 by johnemms]


snapper - 20/4/12 at 04:54 PM

As said db killer or repack exhaust if you can


pewe - 20/4/12 at 04:56 PM

Cut a disc out of mild steel the same internal size as the tail pipe but leave a couple of tabs around the diam. and bend those at 90 deg. Drill holes/file slots in the disc. Push it into the tail pipe and drill into it and fix using a couple of self-tappers through the tail pipe and into the disc tabs.
Alternatively a good wad of wire-wool up the tail pipe but if it's track-day or IVA they'll want a reasonably permanent fix.
Long term if you have a re-packable silencer Acoustafil really does the job - not cheap though.
HTH.
Cheers, Pewe10


Dopdog - 20/4/12 at 05:28 PM

thanks for the feedback, I did use acustafil but it just got blown to bits???? Just packed it with steel wire wool around the center core then some high temp E glass. Just tested with a db meter and 103 to 106 db. I have a sprint this weekend and not sure if I have time to find a bd killer!! will be stuffing some up the exhaust at this rate


ReMan - 20/4/12 at 05:44 PM

Get a substantial silkence made to suit?


steve m - 20/4/12 at 05:49 PM

I also have a rather loud exhaust, and while its fun annoying everyone in the day, i cant use the car for work as i need to leave for work aat 0630, and its unfair to my neighbours !

Ive also used acustafil, and imho its crap, and did not do a jot to quietening my 7

The only thing that has quietened it slightly was stuffing some wire wool up the chuffy bit, and sticking a large washer with many holes drilled into it, and wedging it in the tail pipe, worked quite well but power was down, and when it came out at about 50 mph, and about 5k revs, frightenend the live out of me!


Dopdog - 20/4/12 at 06:04 PM

been on google, has anyone used / got any feedback on decibel devils?

[Edited on 20/4/12 by Dopdog]


matt_gsxr - 20/4/12 at 07:53 PM

One of these (middle) reduced my noise a bit (nothing quantitative), but it reduced the boost from the turbo.



Some folk swear by Basalt (versus e-glass), but I have no experience.

I think you are going to have to go with a massive silencer.
These guys have a good reputation
http://www.raceco.com/silencers.html#
But its a lot of money.

Matt

[Edited on 20/4/12 by matt_gsxr]


ashg - 20/4/12 at 08:52 PM

I have a quick fix. buy and fit a bigger exhaust. I went from a silly bike sized can to a big 6inch one. my noise went from 103db to 92db instantly


Dopdog - 20/4/12 at 09:50 PM

again thanks for the reply's, Matt I did see raceco and as said a lot of money! but do have it as an option. With regards to the bigger can i already have a 26in by 6in can but will be looking at a larger one if i can fit it on? Trouble is i run 2 1/4 bore through the system and wonder if this may be the issue?

[Edited on 20/4/12 by Dopdog]


Chippy - 20/4/12 at 10:03 PM

With the size of pipe you are running you really need a 7" minimum dia can, and as long as you can get it. If at all possable try to get an aluminium one as they are quite a bit better than stainless at muffling the sound. HTH Ray


Dopdog - 28/4/12 at 05:57 PM

HI Guys,

on this subject can anyone recommend where to get a silencer made that is close to oxfordshire?


pewe - 28/4/12 at 06:09 PM

These guys might be worth a try . Not used them but when I was in touch a couple of years ago they seemed to talk sense but could be pricey. If you do then may be an idea to put up some feedback.Simpson Race Exhausts
Cheers, Pewe10


Dopdog - 10/5/12 at 07:57 PM

Thanks Pewe,

have my car booked in with them in the morning 11th so will give feedback once I have the car back