Quote Originally Posted by BlueDevil
Well if I did it at all I would go with smaller. Top end means nothing to me. Its getting there in a hurry that means the difference. Besides on the track I rarely get over like 110mph anyway.
I think you have that backwards... Longer ones = more low/mid-range power. But like MileHigh said, our altitiude has a different effect on things. The density of air here changes the resonance of the box itself, not to mention the stacks and intake. This is partly why going to sea level is such a major improvement, there is a lot more air but modern engine intakes can use it better.

I've been studying a LOT on intake design. It's a black art insofar that very few people know about it, and the ones that do are typically paid a lot of money by auto mfr's to keep it secret. Short of having $50k in sun workstation and FLOW software invested it's all garage mechanics... But I have a shortlist of some calcs to figure out what lengths and volumes are best, and once you plug in air density to the formulas you begin to see how it should be. I've been playing with some different airbox designs on my superhawk (by changing the internals around, that's all I will say about it right now) and have been able to increase the power, so I'm onto something here. V-twins are nice to do this with, since there are half as many intake pulses as an IL4... :mrgreen: Makes the math half as hard, or something.