leading, trailing, wth?
 

I keep reading posts concerning the different firing order of the spark plugs. Talk of firing one at a time, both at the same time, and more. Could someone explain to me why/when you are supposed change the configuration? why is this advantageous? any downsides?

Thanks in advance :)

Making your leading and trailing fire at the same time will produce more horsepower but will also increase combustion temp. You will need to have a EMS that is very accurate. If the trailing fires before the leading then mostly byebye engine.