The fact that you post scores and claim to compete, and then ask a question as blatantly stupid as this one just baffles me. You want an answer and supporting evidence though, so here it goes.
You have the option of whether or not to fuse the Big3 upgrade because the factory didn't anyways. But not fusing a large gauge wire tapped directly into the positive lead that runs the entire length of the car is just stupid. With that long of a wire and it being so close to many grounds, it only takes 1 breach in the insulator to ground out. And depending on where it shorts, and how strong the connection is, you're going to have problems.
Most people don't understand how an electrical fire starts, so let me break it down for you. Think of it this way... any electrical device has some sort of resistance to it, and when a voltage is applied, electricity flows. To increase the flow of electricity, you either need to lower the resistance or increase the voltage. Wires are rated in amps, NOT volts. You can be pushing only a couple of volts through something, but if the load on the circuit is low resistance, you'll be drawing quite a large amount of amperage.
Now, imagine the wire is pinched, it goes through the insulator and grounds out. Now there is a 12V+ power source touched a GIGANTIC ground (your entire car) and it goes right back to the battery. Basically, the circuit has almost NO resistance and a 12V source being applied. That wire is now going to carrying an ASSLOAD of current. Far greater than it could possibly ever hope to manage.
But it's all good bro, shit happens, that's what the fuse is for. Fuse pops and the circuit is interrupted.
OH SHIT! YOU DIDN'T FUSE DID YOU?
Bummer, the wire is going to heat up so hot that it physically melts and catches the insulator on fire. And who would have guessed that was right underneath your car's carpet.
I think you get the idea, FUSE it or leave the forums //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif
