Another Intake Length

[Brian Knowles]

>I've found in many books how I can calculate the optimum
>length for the intake manifold, but I cannot find any maths for
>the length  of  throttle to air filter!
>
>I think that this is important because with a standard intake manifold
>we can play with the distance of the pipe which "connect"  airbox - 
>throttle...
>
>Any suggestion?
>
Rule of thumb has always been that there shall be no obstruction within 
one throttle-plate diameter of the intake bell, and more is better, i.e., 
one throttle plate is minimum allowable..

Brian