I have a Nouvalari muffler on my car, but I also have a stock muffler which pumps out the usual white powder form the casing. Ideally I would want a stock exhaust muffler because I want the car to be as quiet as possible around the neighbourhood so I started investigating whether I could solve the white powder issue.
I examined the stock muffler and worked out that the outer casing is only attached in a few places so relatively easy to remove - which I did. Now check out the insulation material which is about 10mm think and just all in bits. With the top and bottom of one half of the outer casing removed the insulation just fell out of the remaining cover sections form the other end of the muffler.
With it all gone now I figured I can find a new alternative heat material in sheets, cut to size and slot it into the casing and reattached the casing sections I removed, tig welding in a couple of places as per factory.
So this is why you get white powder and there is a possible solution for rebuilding the muffler - these mufflers are not cheap (£1600-£2500) so are well worth saving and without a fix you will be cleaning your engine bay for ever.
