Battery relocation to trunk + NHRA rules

[Zacho]

To be track legal you have to do two runs of wire the length of the car. If you just switch one wire going up front the alternator can still provide power despite the battery line being open.


Heres how I did it

[BeeGTR]

this is how it did mine, F*ing solid

What kind of battery and mount is that? Is it a custom mount? Dry cell? What does it weigh? Is the cranking power good? So far I have been super happy with Optima's. They can handle not being used for a year, charged then there good, or leaving them on a trickle charger. They have amazing cranking power, but they are heavy....

-Zacho-

Thanks for the diagram, it's what I figured u have to do... I have one gauge wire now, and am thinking of switching to 2 gauge to save weight. Anyone have any idea if 2 gauge will be to small for the distance? What about grounding to the chassis to save weight on running a grounding wire? Has anyone done the switch to a rear mounted battery and not run the ground wire, if so did you notice any loss of response?

[Zacho]

The weight difference between 1 and 2 gauge is miniscule. What you ate that day would have more of an effect. Also you don't need to run the ground up front. Just ground the battery in the trunk using a LUG to a bare metal contact. Then take your engine block ground and do the same in the bay.

EDIT: I also wanted to add to not forget about fuses. I see too many people putting in stupid high rated ones like 175 or 200A.

[frankiman]

its a dry cell type Braille Battery, the 11,5lbs model with about 900 cranking amp

positive is 00g marine cable, negative is 8g, run together underneath the car with a plastic protective jacket
negative is also grounded on the strut bar

the mount is a ready made, full aluminium, perfect fit mount from Braille themselves

it screw into the floor via 6 self-taping screws, very solid

even though the small 11,5lbs battery has enough power to easily start my RB26, it doesn't keep its charge long, so i can't event keep the radio on for 1 hour without the engine running,

so the 15lbs battery might be more suitable

[BeeGTR]

The weight difference between 1 and 2 gauge is miniscule. What you ate that day would have more of an effect. Also you don't need to run the ground up front. Just ground the battery in the trunk using a LUG to a bare metal contact. Then take your engine block ground and do the same in the bay.

EDIT: I also wanted to add to not forget about fuses. I see too many people putting in stupid high rated ones like 175 or 200A.

I have a fuze box but cant remember the size of my fuze. I think I'm running 100amp. Anyone now what I should run? Or where do drop down to to melt it and step up a few amps?

-frankiman-

Perfect, Thanks! I'm going to switch to that!

I'm just looking at the Longacre Racing computer scales.... will be perfect for corner weighting, I was looking at buying industrial cooking scales, but there a couple hundred each and I'd need four so its only a bit more for the digital ones instead. I wont be getting it till I can get shop space sorted out next spring, but I'll post the info to help.