Will do the ground upgrade hopefully this coming weekend, but I only adding 4 awg wire to bat neg to chassis, block to chassis and chassis transmission, but the wire goes to the bat + to fuse box to alternator will be untouched, is this make any difference to the upgrade at all? Coz I really don’t want to mess this wire and i think its hard to replace.

 

you can just do the grounds and you will get some benefit. grounds are the weakest part of the OEM wiring.

you don't replace the factory batt + to fuse box to alt. you run a new 4 awg wire from batt + to alt directly, with a fuse at the batt. basically, you introduce a parallel path for current.

 

great thanks! will buy another set of wire and a fuse, what amp should i use for this wire (batt + to alt)

 

i used a 100A MAXI fuse since my wire was in parallel with the factory wire (current is split between the two wires). but as a general rule - size it for the wire.