not mentioning any names, but a friend who uses a 16# lower pulley has recently experienced IMMENSE belt slippage.
how did he cure it?

replaced the Belt Tensioner Spring.

I look at it like this:
the tensioner is designed to be used with a stock DIameter Lower pulley. Well we all add larger pullies, therefore the tensioner pulley is moved CLOSER to the center of the engine putting MORE stress on the tensioner spring than stock.
after a prolonged time, I'd say the stock spring would wear out.

Before he replaced his spring he could squeeze the belts together (just under the blower pulley where they are close) with very little effort. Now with the new spring, it doesn't budge.

I don't like to re-invent the wheel, I just like it to work as designed.
replace the spring and then report back is my recomendation

 

Your right MENACE, not only do we add a larger pulley that adds stress to the tensioner but, we also add a smaller and tighter belt.

 

ha ha ha

 

Keep the tech coming. This one is turning out to be one for the archives.

 

sarcasm from Tim? Nah...

 

No, I'm serious. I'm interested in hearing more about the art and science of belt traction.

 

I've heard that using a richard racing pulley and a gatorback is belt sucide. I have heard of the pullies chewing up gatorback belts very quickly. Anyone else?