[69fordfastback]

I just installed the battery box in the trunk. It sits as close to the right rear tire as I could get it with out touching the back seat or quarter trim panel. Ive read a thousand different ways to run the ground. Some say to just ground it on the frame rail in the back, others say ground it to the front of the car and still others say ground in the back and in the front. What are your suggestions. Also, if someone could clarify this for me, when people are saying mount to the motor are they saing to run a ground from the neg batt terminal to the motor/front frame rail or are they saying to ground the battery to the back frame rail and run a ground wire from somewhere on the block to the front frame rail (thats what I took it as). And last but not least where would be the best place to mount the starter solenoid???? In the stock location, up under the driver/pass fender, or in the quarter panel?? I have a smoothed out engine bay as of right now so I kind of wanna keep it out of the stock location. I dont know if this makes a difference or not but I do have full lenght weld in sub frame connectors (some say it makes a difference when grounding).



Thanks guys!

 

[MustangBradley]

The best way (in my opinion) is to run a large ground wire up to the point where the original wire was grounded. Remember, when you are cranking, you are sending a couple hundred amps along that wire. So you want the least amount of resistance. While grounding to the trunk will give you a valid ground path, it is not the optimal ground path.

For safety's sake, mount the solenoid in the trunk near the battery. The reason this is wise is that the hot wire will only be hot while cranking. There are too many things that can go wrong if you have a wire capable of carrying a few hundred amps, run the length of the car, that is hot all the time.

You can run a second, smaller hot wire that has a main fuse in the trunk, that will run the car's electronics. Don't forget that fuse.

 

[need4spd90]

thats a good idea

i have mine done a little differently
i ran my battery ground out thru the hole in the floor for the gas filler tube and down to the rear frame rail,near the quad shock mount

then i took another piece of 2ga from the engine block to the frame rail up front,near the sway bar mount

and i also have 2 of the factory ground straps from the back of the intake bolts to the firewall,like they were from the factory(you can never have too many ground wires lol)

i left my solenoid up front where it was, and i have my master cutoff switch installed in the 12v+ from the battery and mounted out back to keep it nhra compliant

i wrapped the 12v wire in heavy wire loom to protect it from rubbing,and made sure to use rubber grommets anywhere/everywhere it comes near any metal edges

its been like this for over 2 years now with no trouble..only trouble ive ever had was charging with the stock alternator..worked ok for a while,but eventually left me with a dead battery..you'll want to upgrade to a 130a,especially if you run alot of electrical stuff and/or underdrive pullies

and make sure the grounds are clean,shiny bare metal

 

[Smurf stang]

thats a good idea

i have mine done a little differently
i ran my battery ground out thru the hole in the floor for the gas filler tube and down to the rear frame rail,near the quad shock mount

then i took another piece of 2ga from the engine block to the frame rail up front,near the sway bar mount

and i also have 2 of the factory ground straps from the back of the intake bolts to the firewall,like they were from the factory(you can never have too many ground wires lol)

i left my solenoid up front where it was, and i have my master cutoff switch installed in the 12v+ from the battery and mounted out back to keep it nhra compliant

i wrapped the 12v wire in heavy wire loom to protect it from rubbing,and made sure to use rubber grommets anywhere/everywhere it comes near any metal edges

its been like this for over 2 years now with no trouble..only trouble ive ever had was charging with the stock alternator..worked ok for a while,but eventually left me with a dead battery..you'll want to upgrade to a 130a,especially if you run alot of electrical stuff and/or underdrive pullies

and make sure the grounds are clean,shiny bare metal

I am more along the lines with Need on this. I also grounded my battery in the rear of the car with 0 gauge wire. I also made 2 ground straps on each side of the motor of the car from the engine to the frame rail by the sway bar mount. I also have the factory ground strap on the rear of the motor. And so far so good with the 3g alt and electric fan in Miami traffic.

Knock on wood :thumbup:

 

[PANTYEATR]

i would also say it's a good idea to run a "dedicated ground" system while your running all this cable. dedicated grounds basically bounce around multiple grounding points throughout the car that will be directly connected to the NEG on your battery. i like to run my NEG cable to the rear seat belt bolts, front seat belt bolts, the bare steel dash support under the dash, to the grounding poins on the core support and finally to the engine. that way you have excellent ground paths anywhere in the car. you may also notice brighter lights and things by doing this.

 

[cindys_sn95]

thats a good idea

i have mine done a little differently
i ran my battery ground out thru the hole in the floor for the gas filler tube and down to the rear frame rail,near the quad shock mount

then i took another piece of 2ga from the engine block to the frame rail up front,near the sway bar mount

and i also have 2 of the factory ground straps from the back of the intake bolts to the firewall,like they were from the factory(you can never have too many ground wires lol)

i left my solenoid up front where it was, and i have my master cutoff switch installed in the 12v+ from the battery and mounted out back to keep it nhra compliant

i wrapped the 12v wire in heavy wire loom to protect it from rubbing,and made sure to use rubber grommets anywhere/everywhere it comes near any metal edges

its been like this for over 2 years now with no trouble..only trouble ive ever had was charging with the stock alternator..worked ok for a while,but eventually left me with a dead battery..you'll want to upgrade to a 130a,especially if you run alot of electrical stuff and/or underdrive pullies

and make sure the grounds are clean,shiny bare metal

mine is just like this also. no problems at all and passed tech at all the tracks that i run.

 

[need4spd90]

mine passes at my home track which is NHRA, and one other track i hit up once in a while,which is IHRA

 

[69fordfastback]

Thanks a bunch guys, and gals!!!!!! Thats way more feedback then I thought I would get. I still have the ground strap on the back of the head to the firewall, and I added an additional one from the block to the frame rail near the sway bar when I did my 130 alternator last year. Ive got the box mounted in the trunk but before I run any wires I still need to finish up a few loose ends on the motor itself (need to put the upper back on, and the accesorie pullys). Im not familiar with drag strip rules and regs. I do plan on visiting the strip once I get this thing done. Is there a specific area the battery cut off HAS to be?

Thanks again everyone, all the replys helped out a bunch!!!!!!!!!!!!!!

 

[Smurf stang]

Make sure that the grounding areas are clean and bare metal so that they make good contact. Also make the ground strap of some nice heavy gauge.

 

[need4spd90]

NHRA rule book
Any car with a relocated battery must be equipped with a master electrical cutoff, capable of stopping all electrical functions including ignition (must shut the engine off, as well as fuel pumps, etc.). The switch must be located on the rear of the vehicle, with the "off" position clearly marked. If the switch is of a "push / pull" type, then "push" must be the motion that shuts off the switch, and plastic or "keyed" typed switches are prohibited. Also, the battery must be completely sealed from the driver and/or driver compartment. This means a metal bulkhead must separate the trunk from the driver compartment, or the battery must be located in a sealed, metal box constructed of minimum .024 inch steel or .032 inch aluminum, or in an NHRA accepted plastic box. In cars with a conventional trunk, metal can simply be installed behind the rear seat and under the package tray to effectively seal the battery off from the driver. In a hatchback type vehicle the battery box is usually the easiest solution, since the alternative is to fabricate a bulkhead which seals to the hatch when closed. At present, Moroso is the only company which offers an NHRA accepted plastic battery box, part number 74050.

But I drive on the street. I don't want a big cut off switch hanging on the back.
This solution takes a little work, but it solves the problem. Install the master cutoff inside the vehicle, positioned "sideways" so that the toggle moves forward and back. Drill a hole in the toggle handle, and attach a steel rod that will run out the back of the car, through a hole drilled completely through one tail light assembly. Have a spare tail light assembly on hand, so when you come home from the drags, you remove the rod and put the cherry tail light back in for street cruising. Next time you plan on going to the drag strip, swap lights and reinstall the rod. Since the drilled light is for the strip only, you can also have it marked "PUSH OFF" in big letters so the Tech Inspectors will think you're cool.