I have a Vortech Twin Screw and the belt slips under full throttle(11psi). I put a new belt on and made sure it was snug and it still slips. Anything i can do to help the matter. It has a 3in pulley right now and the crank pulley is overdriven.

 

Time to step up to a 8 rib set up

 

Already is

 

How much belt wrap do you have? Post up some pics, I've never seen a vortec twin-screw. I actually don't know if I've ever even heard of one lol

 

 

That took a whole 3 minutes lol... That's a nice looking setup, but I'm guessing theres a reason you don't see them on this forum?...

 

they have only been out a few years. not very many people know that they even made a twin screw. i have lots of belt wrap. it just started raining ill see if i can get some pics

 

 

You could have cross groves cut in the blower pulley to give it more "bite". There is a guy on eBay that offers this service.

 

Umm... I think I see a big no no in that last pic you posted... Is that a fixed adjustable idler pulley I see??? Those DO NOT work with blowers. The problem is, when you close the bypass on the blower and start making boost, you load the belt stretching it a LOT! with a ridged mount tensioner like that it won't keep the belt tight cuz it can't take up the slack. You need a spring tensioner that can take up the belt slack and still keep tension on the belt.

You need one of Magnuson 8 rib HD tensioner