batt cables

[racerdad]

so i am raplacing the batt cables in my daughters legends car. what i need to now is what batt cables should i use ? i wont them to be large enough but i do not wont too much weight.
also the power on & off switch had the power wire going to it. i have always been in favor of the ground to the switch because it will turn of power coming out of the batt.
is there a rule that sayes what has to go to the switch ( i could not find one ).
also were is every one running there ground to this car was grounded to the batt hold down and that did not seam right to me.
thanks cody

[Hoopy_boy]

 You might want to do a little research on normally open and normally closed ignition systems before you become in favor of  buying CDI boxes in bulk by cutting the ground instead of the power with the ignition switch... backfeed... some things are best left alone

~Gimpster~

[racerdad]

now you know i mean the big red switch on the rear fire wall. you said (ignition switch) im not talking about the switches on the dash. will this do the same thing to the CDI boxes?
thanks cody

[Hoopy_boy]

A normal motorcycle battery does not have the amps a car battery does... now if you cut the ground with a master shut off switch, you still have power on the positive side of the ignition lurking for a ground.  Any minor ground found wheather it be from moisture on an open terminal or what ever (static electricity also)... the power is there and will backfeed through the engine, it's mounts, the alternator or ignition system. Many of the components within the CDI electrically act as a one-way valve. If power is backfed through these components, with the amplified battery amps pushing it through the minor ground it finds the ignition box or even alternator regulator will be harmed.... positive cable power disconnect is the way to go..... eliminates any issue which could be caused by feeding the system in case it finds a minute ground anywhere

~Gimpster~

[Hoopy_boy]

 Bottom of the page on this link  http://www.rbeelectronics.com/wtable.htm is a base guide for battery wire gauge size per length required. Since your cables are to be used in a racing enviroment where more factors like heat and vibration variables are more extreme than under normal operating conditions, like loads required to start a hot hot engine etc.. I suggest at least one size larger cable than specified per length (if not 2 sizes larger). As far as the ground, the battery mounting stud is a great place to ground your battery. The cable can be shorter which amounts to less amp/resistance change. I do not suggest simply slipping the cable end over the mounting bolt and expect it to ground against the battery strap. A nut need be installed first to snug down the battery as well as used as a jam when the cable is placed above it , from the battery strap, and another nut over the top of the cable. This provides a solid cable ground compared to simply slipping it over the battery hold down strap. I have seen racers drill their frame and run a mounting bolt through it for the ground. I don't like this technique because it weakens the frame where drilled plus a longer cable has to be used and amp/resistance levels are changed for the worse. .... Just my 2 cents

~Gimpster~

[Hoopy_boy]

 OK, Steve was wrong. My opinion is not needed here. Apology for stepping on toes. Didn' t  mean to shut anyone up.  See ya around somewhere

~Gimp~

[racerdad]

i dont know what the last post was about but if you dont think that i appreciate when some one is trying to help me you are wrong. if thats not what was ment bye the last post never mind and just know i do appreciate every one helping a new guy like me.
thanks cody

[qweedqwag]

I ran 4 guage wire (red) for all power in the car from front to back, same with the ground wire only I used black, I have used the battery hold down to ground the car before, and I have also mig welded a stud to the frame which worked out very well, the threaded stud can be tricky if not prepped correctly.

Mike