Intake manifold: optimum length from slide to valve?

[bowser]

I remember reading somewhere the optimum length for custom intake manifolds from slide to valve but can't find it anywhere now.

Does anyone have any info on this?

 

[hoffman900]

I remember reading somewhere the optimum length for custom intake manifolds from slide to valve but can't find it anywhere now.

Does anyone have any info on this?

The closer the carburetor is to the valve, the stronger the 'signal' which usually isn't a bad thing. I guess you can get so close that the gas doesn't have time to atomize. Overall intake length from the bellmouth the valve matters though and depends on some some engine combination specific items.

 

[XSLeo]

As far as the length goes I think the factory had it about right.
I think in theory at the proper length the bike makes good power all across the rpms. Going longer moves the peak power up the rpms. Shorter moves it down.
You can't get much shorter but you can go longer.
Will it improve preformance? try it and see.
Leo