http://www.pistonheads.co.uk/gAssing/topic.asp?h=0&f=66&t=1096171&mid=0&i=0&nmt=David+Vizard+Interview+-+Port+Velocity+Dyno+Tests&mid=0 Informative Q & A with the great man who even replies to a number of posts on the forum too.
Needed to read it a few times before I could take it all in though.
Cheers,
Matt