does anyone have the formula in their engineering book?

I googled it, and found a few sites for speakering building. but it gives me the answer in hz and i need it in rpm. because i dont know how to convert hz -> rpm

im trying to calculate it for an intake arm of a turbo.

 

i look around, no promises tho...

 

this what you want?
http://grapevine.abe.msstate.e....html

 

its really pretty easy 1 hz = a cycle per second.

so if you have 1 cycle per second you have 60 rpms.

If you have 2 cycles per second you have 120 RPMs.. make sense..

so take the hertz and multiply by 60.

Not sure if that helps at all... haha, just throwing it out there, most people know this.. but you never know.