Interesting info Aeroman about the rear sports pipes - I was told this would pretty much preclude me from track days. It does seem loud (especially in tunnels!) but I've certainly heard a lot louder cars. Difficult to know. Perhaps the 105db claims are unjustified - certainly it's not massively louder than the sidepipes and if you're seeing 87 or thereabouts that's pretty much ok for just about any circuit..
As you know mr_tony from your car, the exhaust note on Aero's, and it's especially true with sidepipes, is at its noisiest under hard acceleration and also at the top of the rev range. I presume that this is probably something to do with the double-vanos system which also adjusts the timing of the exhaust cams.
When the revs settle at a particular level, such as 4/4,500 revs, the exhaust noise dies back and becomes much quieter which is what happened at Goodwood which was a stationary check. If they had done a drive-past noise test on the start/finish straight I am sure the Aero's reading would have come out much louder.
Maybe our Gyver can come out with something more technical on this?
