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conrod
24-01-12, 04:26 PM
Dear All,

There have been a couple of threads - see here (http://www.cobraclub.com/forum/general-cobra-discussion/41551-acoustafil-exhaust-packing.html) and here (http://www.cobraclub.com/forum/thames-valley/44752-acoustafil-exhaust-wadding.html) - on this unique packing material, and there's been very good feedback from my Thames Valley guys on it. I therefore decided to take the plunge myself.

You'll find a calculator on their website - Thermal Velocity (http://www.thermalvelocity.co.uk/product.asp?P_ID=425) - and also a more detailed formula in the first of the above threads. For a Dax with 3" perforated tubes I needed one square metre per pipe, each of which is 950mm long. They don't do a 900mm/950mm width as standard, but it's OK to use two widths side by side. As the 600mm width worked out the cheapest per sq metre, I decided to order three metres of this width, using a 1m length of 600mm and 300mm per pipe. That's 1.8 sq m rather than 2 sq m, but it's close enough!

As others have found, the people at at Thermal Velocity / Textile Technologies are very helpful. The normal price is £14.20 per metre plus VAT, giving a total of £51.12 for three metres, but they were happy to offer me a special price of £33.00 including VAT and delivery. They are also happy to offer this deal to other forum/club members. Just call 0161 367 1370, ask for Eddie Ashworth and say you're a UK Cobra Replica Club forum member to secure this special price.

If you have different sidepipes, or have a Dax with 2" perforated tubes, you'll need a different quantity - in which case just give Eddie a call and quote your measurements, and I'm sure he'll cut you a similar deal.

As our revered leader said in the second of the above threads, they don't call me "Tight Wad" for nothing! :D:D

Cheers.

Purple AK
24-01-12, 04:55 PM
Nice One Alan :cool: Maybe we need to speak to Rob about changing your user name! :lol:

cobrap
30-04-13, 05:39 PM
Well off the back of this Thread I gave the company a call yesterday and 5 metres of 500mm Acoustafil arrived today - £50 inc. delivery. --> :D <--

Why am I buying more when I only replaced my packing a couple of years ago...?

Main reason is that I chose to under-fill the cavity (I packed it to 100g per litre) when they recommend 130g per litre. So in essence it has moved about and the baffles have become annoyingly rattly.

So this time I'm going to go the other way and over fill to 150g per litre, which apparently might also marginally improve the performance. We'll see about that, but meanwhile I continue to extol the virtues of this product - not so much for its silencing properties (which are excellent), but its thermal insulation performance:

Since installing Acoustafil I have been able to travel on relatively long journeys, yet I can still touch the sidepipes with bare hands (or legs) without burning myself. Third Party Liability could be a thing of the past :!:

RogerC
14-03-16, 11:01 AM
Just ordered 3mx600 Acoustafil from the lovely people at Thermal Velocity.....prices have risen a bit since 2012 but they were more than helpful and let me have it for £63 delivered....a substantial saving on the website price.

hifihedgehog
14-03-16, 01:52 PM
Ah bugger I bought and fitted some acoustafil in Nov last year but missed out on all this and paid the full price :( however it appears to do what it says in the tin. The sound meter I borrow from work is away for calibration at the moment so I haven't re-measured the noise level however just going subjectively it is a lot quieter, a lot of the higher frequency noise has been removed so its just a low rumble now. My old packing was mostly intact and gave a sharp rasp at higher revs, now its just a nice smooth roar :D

Neil O
14-03-16, 02:17 PM
I have used this stuff on my Crendons.
It has to be said that it didn't seem to make either of them any quieter but the heat reduction was really noticeable.
Yes the side pipes will still burn your leg but your skin doesn't melt onto them quite as quickly.
I have tried packing loosely or tightly and found the noise levels similar but the heat reduction best when packed tightly.
Basically I wrapped around the central perforated tube twice which is about all I could get inside the outer tube.

RogerC
14-03-16, 02:58 PM
Sod's Law strikes again :-( Good to know as well that my skin will just burn not stick to the pipes.....
Just the cones to sort out now on my 2-3" conversion - keeping the old perforated tubes and packing in reserve. Have been to a local fabricator and am now contemplating some custom spun stainless 4 7/8" to 3" beauties that will relieve me of £60 but will be dead easy to fit and hopefully, with a much smoother profile will improve the gas flow a bit.


Ah bugger I bought and fitted some acoustafil in Nov last year but missed out on all this and paid the full price :( however it appears to do what it says in the tin. The sound meter I borrow from work is away for calibration at the moment so I haven't re-measured the noise level however just going subjectively it is a lot quieter, a lot of the higher frequency noise has been removed so its just a low rumble now. My old packing was mostly intact and gave a sharp rasp at higher revs, nowcones its just a nice smooth roar :D

RogerC
24-03-16, 02:02 PM
And the result is!
http://www.cobraclub.com/forum/attachment.php?attachmentid=32762&stc=1http://www.cobraclub.com/forum/attachment.php?attachmentid=32763&stc=1http://www.cobraclub.com/forum/attachment.php?attachmentid=32764&stc=1