long bat cable

i know you can't run too long a + cable with out current drop, but can you run a long ground with no issues ? i'm thinking of off switch at rear of car for the ground

 

The ground is just as critical as the pos. cable to complete the circuit.

 

The longer the wire the more resistance {ohm's} it has, a larger diameter wire will have less ohms per foot, than a smaller diameter wire, also the more strands inside the better{less ohms} and more flexable it will be.

 

so i guess its a no go for off switch back of car. the ground would have to go back to the switch then back to the battery (up front)

 

Just a couple of thoughts. Why not put a disconnect switch under the hood by the battery. Open the switch and lock down the hood.

If you ever need long cables it is better and cheaper to get them made up at a local welding supply. They charge by the foot for really good multi strand cable and they will crimp on the cable ends for you.

 

The cable could go from the battery to the switch, and then to chassis, couldn't it?

 

I have done mine like this for some time

 

I think you are better off having the disconect switch on the positive lead. And the easier it is to get to the switch, the more you'll use it. If batery is in trunk, why not a good ground at the battery to a lug on the frame, and a ground strap from motor to frame??
Both could be short wires.

 

I mounted a master disconect on a dragster and ran a morse cable to the switch from the back of the dragster. That way you do not have to run a bunch of battery cable. Might work for your application. Still meets NHRA specs for the cut off at the back of the car.

 

This is the best way to go.