I started reading the first post and working my way down, the first thing that popped in to my head was "Good strong power". Those things suck up a lot of juice, especially at higher rpm's. Like anything, the harder you make it work, the more power it needs.
Also don't over look the need for a GOOD ground. Bad grounds can run you around the block. Because we drive in a salty/corrossive atmosphere it makes things rust in between the connections.
Good luck, RICK