To better explain on the bus:

Sourcing the fuel pump off the coil probably triples the power requirement of the stock 16AWG wire (ok, it's german, so it is NOT AWG but MIL - I digress...) and the battery is right next to the engine, so putting in a relay to power the coil straight from the battery eliminates probably 30 feet of 16AWG wire, and therefore gives a couple extra volts at start.