Do Mini Roots Blower/Superchargers have gear whine like 6-71/8-71's?

Yes the mini-blowers do whine, its the nature of the beast. I'm not sure of the gear whine on the small P600 ATI, but I have a D2R ATI which I know will have a whine when installed on my 468.

Thomas

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"Bomber" '67 El Camino, Beater comes back to life.
Was 350/TH350 14.90 @ 93mph, 360,000+ miles on car
Now 406 roller, 340rwhp, more hp coming, 3.08 gears
Street radials, left in drive, 13.20 e.t[email protected] mph
8/1/01 added Plum Mist '67 to collection
*New* 468 on its way - going Big Block!

On a cog belt blower drive there is air trapped between the cogs and the splines of the pulleys. With cog belt drilling relief holes in the pulleys should have an effect. Also, if a cog belt drive is just slightly out of line it will make more noise and wear drive belts prematurely. With a serpentine belt drive, as most non-race ATI ProChargers use, the noise comes from the step up blower drive (ATI refers to this as the blower transmission), the step up is usually a drive ratio like 4.44-1). The gears in the ATI ProCharger are of low helical design, just like big truck and M22 transmissions - by design they will be noiser, but stronger, than high helical gears.

Of course the fact of a blower/supercharger compressing air will make noise too.

Thomas