[QUOTE]Originally posted by BlitzSRM

 

[QUOTE]Originally posted by tenblade2001

 

If Honda made the intake shorter, it wouldn't have made much difference regarding intake air temerature. It's in the worst place possible now.

Honda found the optimum lengh to maxmise the flow for the largest rpm range, hot air at idle was secondary. Hot air is a problem when your in traffic. and you don't need the extra power in traffic.

A better location to suck in colder air is what Spoon did with the snorkle.

 

[QUOTE]Originally posted by BlitzSRM

 

Whoa!.....This is a heady thread. I am glad I never took fluid dynamics.
-Lee

 

You may want to research Helmholtz's Theory/Helmholtz resonators. This is the primary equation used for intake manifold, plenum, and intake design. The length of the intake is a compromise between losses due to wall friction and gains due to both tuned ram effect and inertia ram effect. Of course, packaging constraints and getting the coolest air possible are big factors that influence the design as well. Many "cold air" intake designs such as the AEM show a h.p. spike near 4500 rpm. This is due to the tuning frequency of the very long intake tube. When the intake valves are closed, a negative pressure wave is created which travels back up the intake tube and once it hits the end of the pipe, it reverses direction and heads towards the intake valves as a positive pressure wave. When the rpm is at the tuned frequency, the positive pressure wave will enter the cylinder head just as the valves are opening. This creates a much higher volumetric efficiency similar to forced induction. This frequency (or rpm range) can be altered depending on the length of the intake tube.
Longer intake tubes can also create an inertia ram effect. This involves a column of air which has mass and therefore momentum that helps drive the air into the cylinder head. The downside to this is that it takes more energy to accelerate this column of air. This is why short ram intakes typically display better throttle response.

 

The resonance can also be had with a shorter tube, however, thereby reducing wall losses. The farther from the filter you can get, the closer to laminar flow things will become, but at what distance I cannot say offhand...there's obviously a point of diminishing returns.

 

Mugen DOESN'T feed stock airbox
they have the science your requiring.. a 55 million dollar wind tunnel
any way, even though this doesnt give a scientific formula, maybe it will help you find your answers

http://www.kingmotorsports.com/mugen_tech_s2000.asp
scroll down

 

[QUOTE]Originally posted by tenblade2001

You think?

 

[QUOTE]Originally posted by asu_lee
Whoa!.....This is a heady thread.