Topic: new style stacks

[mystic_1]

if anyone got any info/formulas on airbox design and sizing, I'd love to hear.

I've been reading up on helmholtz resonators lately.

http://en.wikipedia.org/wiki/Helmholtz_resonator

http://www.saltmine.org.uk/randy/airboxdesign.html

http://www.thunderproducts.com/AirboxesDynotech.htm

mystic_1

[kos]

In a very early attempt at an airbox, the original CB750 SOHC Hondas had a rather small airbox.  If one looks at the internals of the OEM air intake system on these bikes, air enters bottom of box, travels thru the filter into the open area on top , then is transmitted into the plastic air funnels (velocity stacks) and on into the engine.  I used these funnels only on, our production roadracer that I raced along with Gary Nixon with great results. Seam's like Honda did some testing/design work on these stacks. Don't throw the stacks away when you strip the airbox off...give them a try.

BTW....Nixon won Superbike race in Mod Ohio on this Historic Production bike.
KOS

[voxonda]

I defenitely agree on the OEM stacks, have used them for years and the bikes always ran great on them. On closed circuits that is, no filtration.

[Bill/BentON Racing]

Same stacks I ran on CB590.Worked real well and inexpensive!,Bill

[turboguzzi]

shame the stock rubbers will not fit my Keihin CR29's...

Made a quick measurement today and it looks like I could fit a 4000 c.c. airbox without much trouble,

I recall reading that current superbikes have a 10,000 c.c. liter airboxes. So 4000 cc is not quite the 1:10 ratio of displacement to box volume that sounds right, but is not that far off either.

Taking with a very experienced sidecar racing mechanic and rider (did GP's) he said that the first big gain would be from the carbs not sucking hot and turbulent air.

[Bill/BentON Racing]

Well that makes sense,keep us posted.Bill