I will give a short intake system a try.
But why should air in a longer tube have a higher resistance? What kind of resistance? friction? amount of mass? What you may get in a longer tube are unwanted turbulances because a longer tube could have more "traps" and edges if not well designed.
Don't forget the importance of the right resonance point.
Quoted from Wiki:
Designers exploit a property of air cavities known as Helmholtz resonance. Flow through the airbox is optimal at its resonance frequency, which depends on airbox volume and the inlet area and length of the snorkel. The resonance is typically chosen to be at a medium speed where torque otherwise drops, caused by valve timing overlap."
http://www.calsci.com/motorcycleinfo/Airboxes.htmlRegarding the heat, my new system does not run any longer in parallel to the metal water tube which indeed warms up the standard air tube a lot.
