.020-.030 belt sheeve clearance is a safety margin. .005-.010 on a new belt is going to have the smoothest engagement. Set all mine up like this. The ramp rate of some weight will make engagement very hard with incorrect belt sheeve clearance. Don’t waste time clutching on a stand, do it in the snow. 4100rpm is a good rpm engagement for a turbo. Weights will not change your engagement rpm, primary spring start rate changes engagement.