I've been lurking on this site for a a long time and I want to do the piggyback wiring for the 2nd heat element that I've seen on here from tedbear, I was unable to find exactly how its done. What else is needed besides the high temp wire and ring terminals if anything??
Here's a link on the how-to article about adding a second 500W element. The only difference in the way I did mine was to run two short 3-4" high temp jumper wires to connect the ends of one element to the other. Ring terminals (remove the plastic insulator) and 14ga high temp wire.
A word of caution about making the holes in the heat shield. The thin metal tends to tear VERY easy if you use a large drill bit. One other member destroyed his recently when drilling the holes and had to order a new shield. The way I did mine was to drill it out to about 3/8" and then I use a cone shaped grinding bit to enlarge the holes to the right size.
On the autotune, you just need to run it once after you have installed the second 500W element. Put a couple of bricks or something wrapped in foil on the racks to simulate a load of meat in the chamber before you start, along with a bowl of water like you would do when smoking something normally. I think it takes about 1/2 hour to complete, if I remember right.