What length velocity stacks?

[Finto_GX]

Hi.
Currently building a cg13 with cbr1000 itbs.
It has 272 degrees high lift cams , port and polished head .

Does anyone know how to calculate what length of velocity stacks I will need?
I know the longer They are the better it is for power higher up in rev range

 

[Agent_Sm1th]

It's short stacks for higher rpm power. Longer ones for low to mid range.

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[Low Rider]

You won't be pulling enough rpm to warrant shorter intake stacks. Go for as much length as you can practically fit in.

Jenveys are within 20mm of the bulkhead and they'd benefit from being longer.

 

[Finto_GX]

I don’t even know how’s much room I have to play with as I haven’t fitted my new engine with the itbs on yet . We have made them shorter than normal itbs by eliminating the silicone adaptor so hopefully I should have more room