by Jeemy » Mon 11.02.2013, 16:59
With respect to the other part of the puzzle - assuming unlinked to the A-panel fitment - your on-road vibration; the best (untested on my Elan as yet, but I have a 10-pack waiting to be fitted, and have had great success with other vehicles) thing to do is to fit sound deadening material.
Again this is untested on the Elan, but I did a full fit to a Merc Vito van and the cockpit is now Audi silent!
Dynamat is the big brand - for approx £145 you can get the lightest, thinnest version of their product called I think Supalite in a 10-pack. Its basically very highdensity EVA (I presume) foam, laminated to a thin metal sheet. The foam is adhesive, and you cut it to size and fit it to the inside of door panels, door cards, trunks, bonnets etc.
It stiffens the surface, reducing on-road vibration and although the technology is not sound (the best thing would be high density fibreglass packing the interior - which I have also done but cannot recommend due to water ingress problems - works incredibly well if you are sure you are dry) will audibly dampen down all such vibrations, the absence of hardly noticeable sounds you were quite used to gets quite spooky.
Its months away yet but when I finally rebuild my interior the floors, door ins and outs, rear bulkhead and anywhere behind the dash I can get to will be covered in Dynamat before being carpeted. Scraps from cutting to size will be fitted to smaller parts like A-pillar triangles (which I will be mounting speakers in); to give them some heft. Yes, it adds weight but the Elan isn't really that minimalist of a build anyway and its only a few kg; if that matters to you, you may have to put up with more in-car noise.
Sound treatment is big business for luxury brands like Daimler, Bentley etc - its a big part of the cockpit experience but the science is difficult in cars, especially at the lower or classic end of the market given water ingress issues, bad fitment, and the fact that you can never get an airtight seal anywhere.
Obviously the main sound leakage is through the hood but every little helps. There are plenty of other solutions about - if you go to talkaudio you'll find they've just launched a sister site dedicated to sound deadening, proofing and treatment and may have some opening deals - but the Dynamat is the best product, and the Supalite although expensive, is the most weight-effective.
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