Just looking right now but I do have a question about pulleys. The kit come with a stock 3.33" drive pulley. This in turn rotates a 32 tooth cogged pulley and a 28 tooth cogged pulley on the SC itself.

When figuring impeller speed do you add the two drives together?

Example:


This equals 39,731 rpm


This equals 26,297 rpm. Add the two together and I get 66,028 rpm. Seems high...

Maybe if I leave out the internal step up on the first equation? This gives me 37,520 rpm TOTAL

Am I figuring this right???

 

Impeller speed= (Crank Pulley Ø / Jackshaft Pulley Ø) x (Cog Pulley Teeth behind jackshaft/Cog Pulley Teeth on headunit) x Internal Step Up Ratio x Engine RPM

So....

(5.75"/3.33")x(32/28)x3.54x6500=45,407rpms

You need to calculate the step up ratio at each point (you all ready provided the step up ratio within the headunit derived by dividing the input gear by the output gear).

In the case of my supercharger kit
(7.00/3.25)x(nothing because I don't have a jackshaft)x3.54x6500=49,560

With that in mind my custom supercharger kit should create more boost than the stock Vortech kit due to the larger crankshaft Ø I have.

 

Vortech has a calculator on the web site

 

Go here

http://www.vortechsuperchargers.com/support.php

Pick: Impeller Speed Calculator

Click " Go "

 

Thanks, didn't see that there...