so in order to be scientific about this I've ordered a cheap decibel meter from Ebay which has a DC output of 0-1.3v representing 30-130 dBA which I can connect through my MS3X generic input board and datalog using Megasquirt. This will then let me do a scatter plot heat map of decibels vs engine load and RPM. If I mount the meter in exactly the same location each time it should let me quantify an improvements made.
http://www.ebay.co.uk/itm/111427851857
http://msextra.com/doc/ms3/genericsensors.html#wiring
vibrations/noise
Re: vibrations/noise
Having not driven the Dav yet I don't know what to expect, but having just looked at your picture, and referred it to my car you could be onto something, I think some rubber to insulate the A frame from the roll bar would be well worth while.
like you say the G15 mechanicals are all insulated from the body as they are chassis mounted and the chassis has rubber sandwiched between it and the body, hence no issues apart from exhaust and induction noise which to a certain extent can be tuned to taste, that said the engine in my G15 was only a standard sport with a Janspeed exhaust so not really a rip snorter.
like you say the G15 mechanicals are all insulated from the body as they are chassis mounted and the chassis has rubber sandwiched between it and the body, hence no issues apart from exhaust and induction noise which to a certain extent can be tuned to taste, that said the engine in my G15 was only a standard sport with a Janspeed exhaust so not really a rip snorter.
Re: vibrations/noise
Ordered a set of 8 x m16 rod end bearings tonight to make up a four link bulkhead mounted engine brace to replace the standard a frame. Will post pics as and when. Should be lighter than the a frame and I hope way quieter.