Subject: How to calculate the increase in HP of an engine with forced-air induction?

I'm interested in finding out what difference forced air induction, or ram-air 
systems are making to the overall power of my motorcycle.  My friends and I 
have been arguing about the various techniques used by different manufacturers 
and the massive gains they all purport to make as a result of their differing 
approaches.  My argument is that although using ram-air systems undoubtedly 
make a difference to the performance of an engine, it's not going to make all 
that much difference.  If this sort of system only makes gains at high speed 
(approaching 200mph) then below this the effects would be negligible so make 
little difference to everyday riding.  It would be interesting to find out 
though the use of hard science, rather then just guesswork, how much difference 
forced air induction is making to the performance of our machines, and how fast 
we have to be going before it makes any noticeable difference at all.

Re: How to calculate the increase in HP of an engine with forced-air induction?