6 rib vs. 8 rib pulley setup

[takem2church]

Tried to do a search but came up with nothing. What are the advantages of running a 8 rib pulley setup compared to a 6?

[ROHANs99M3]

You get better traction for belt at higher rpm/boost levels. I went from 6 to 8 and made a world of difference. You should also consider Crank Pulley size and s/c size as well.

[jszy25]

Plain & simple: more contact area with the belt = less slip

[pbonsalb]

The better question is at what point do you need to go from 6 to 8 rib. Depends on the crank pulley diameter in part. Assuming 6.00 inch, maybe somewhere around 3.15? Depends also on the gearing of the blower (V1 versus V2) and thus the load.