I’m running aftermarket fairings with NO foam and minimal heat shielding. . . Doesn’t appear to make a scrap of difference, been on for 2 years 24,000kms, still good to go!DAnG!!! over a quarter pound ......... of FOAM! I still have all mine in on the busa. Makes the side panels feel nice and snug when I put them on I guess but I don't think it does much else. Maybe dampen fairing vibration? I never have lost a fairing screw on the busa but I still think they'd all be fine without the foam.