Battery Switch

[BrianV8]

Ok so here is my problem, I am in the middle of a motor swap and am forced to relocate my battery to the trunk. Now here is my problem. I want to drag race the car and the this is the rule thats throwing me off.

"Rear firewall mandatory when relocated battery in trunk. If sealed battery box is used, must be vented outside of body. When battery is relocated a master power cut off switch must be installed on rear most part of vehicle."

Now we do have what would be considered rear firewalls correct? So i would assume i am good to go there. But the cut off switch is my real issue. Where is the rear most part of the vehicle? Would that be considered in the trunk beside the battery? Just an inline switch? Or do they need access from outside the vehicle or how would that work?

And another stupid question. Why do you even need a switch? There is no switch under the hood, why would you need one in a trunk?

Thanks Brian

[NismoS-tune]

Ok so here is my problem, I am in the middle of a motor swap and am forced to relocate my battery to the trunk. Now here is my problem. I want to drag race the car and the this is the rule thats throwing me off.

"Rear firewall mandatory when relocated battery in trunk. If sealed battery box is used, must be vented outside of body. When battery is relocated a master power cut off switch must be installed on rear most part of vehicle."

Now we do have what would be considered rear firewalls correct? So i would assume i am good to go there. But the cut off switch is my real issue. Where is the rear most part of the vehicle? Would that be considered in the trunk beside the battery? Just an inline switch? Or do they need access from outside the vehicle or how would that work?

And another stupid question. Why do you even need a switch? There is no switch under the hood, why would you need one in a trunk?

Thanks Brian

Brian, I'm in the process of doing something like this. I believe the metal seperation between the trunk and the cab is fine for a firewall as long as you don't remove the access hatch.

As for venting the battery, this is true for a led-acid battery as it releases hydrogen gases as the battery charges/discharges which are dangerous (it also must be mounted in the upright position since it's liquid filled and will spill). If you run an AGM battery (gel cell ok) then no venting is required and it could also be mounted in any position. No matter what battery type you used in the trunk, it must be mounted correctly and safely so it will never become a projectile in a collision or even when driving. Most race tracks required that you have an NHRA approved battery mount which I would suggest you do since the cheap crap is not always safe or reliable.

The battery should be grounded in the trunk and also in the front at the factory location to ensure a good circuit. For cable selection, an AWG #2 welding cable would be a minimum based on calculated current values though I've seen some cars run AWG #00 which is huge and heavy for nothing IMO.

Finally the battery disconnect is because of it being close to the fuel cell/tank I'm certain. I've seen people put a disconnect switch under the car, in the wheel well (not so good), even deleting the rear wiper and using it there. There are many options for what kind of disconnect switch to use.

Good luck.

[BrianV8]

awesome thanks for the info. Now to clarify the switch does need to be outside the vehicle. Not located within the trunk correct? And being a fellow skyline owner, where the heck do you put one so some random guy doesn't come around and flick you off when your parked on the street? haha

[NismoS-tune]

awesome thanks for the info. Now to clarify the switch does need to be outside the vehicle. Not located within the trunk correct? And being a fellow skyline owner, where the heck do you put one so some random guy doesn't come around and flick you off when your parked on the street? haha

I'm not sure if it MUST be outside the car. You may be ok if it's in the trunk but I doubt it. You may has to ask the track... Most people don't even do the switch lol. Oh ya, have the disconnect switch on the NEGATIVE side, not the positive even though both work, on a safety perspective, go with the neg unless you're far from the battery. If you're far from the battery, go positive otherwise the negative could get cut open/ground into over time and complete the circuit there!!

Battery mounting examples http://www.jegs.com/webapp/wcs/store...Id=10002&Nty=1 .

Disconnect example with remote actuator.

http://www.batteriesareus.com/index.php?main_page=product_info&products_id=10148

Manual disconnect

http://www.batteriesareus.com/index.php?main_page=product_info&products_id=10065

Skill check, which side of the battery do you disconnect first and reconnect last, always?

[mcfly]

awesome thanks for the info. Now to clarify the switch does need to be outside the vehicle. Not located within the trunk correct? And being a fellow skyline owner, where the heck do you put one so some random guy doesn't come around and flick you off when your parked on the street? haha

has to be on the outside and visible.
all the good ones have removable keys

[NismoS-tune]

There you go. Outside for you! You must use the positive conductor since you're far from the battery.

[nissanconvert]

is this for ashcroft or mission? pretty sure 90 percent do not have a shut off switch, it is for safety crew to shut down your car etc..

there are diff types of relocation kits you can buy- to give you the sealed package etc..

most of guys out there i don;t think get bothered... aka pj, my old rex etc, kent's 11 second rsx. So maybe check with someone at the track..

[mcfly]

8:1 BATTERIES
All batteries must be securely mounted. Must be of sufficient
capacity to start vehicle at any time. Batteries may not be relocated
into the driver or passenger compartments. Rear firewall of .024-
inch steel or .032-inch aluminum (including package tray) required
when battery is relocated in trunk. In lieu of rear firewall, battery
may be located in a sealed .024-inch-steel, .032-inch-aluminum, or
NHRA-accepted poly box. If sealed box is used in lieu of rear
firewall, box may not be used to secure battery and must be
vented outside of body. Relocated battery(s) must be fastened to
frame or frame structure with a minimum of two 3/8-inch-diameter
bolts. (“J” hooks prohibited or must have open end welded shut.)
OEM-located batteries without complete OEM hold-down hardware
must be secured to OEM battery box/tray using the same 3/8-inchdiameter-
bolt hold-down method described in previous sentence.
Metal battery hold-down straps mandatory. Strapping tape
prohibited.

8:2 DELAY BOXES/DEVICES
Prohibited in all vehicles. A delay box or delay device is defined
as any device (electric, electronic, pneumatic, hydraulic,
mechanical, etc.) built for the express purpose of creating a delay
between release of transbrake or line-loc button, or release of foot
or hand brake, or release of clutch pedal/lever, and the resultant
action of the vehicle.
Changeable vehicle components, legal unto themselves (solenoids,
throttle-linkage components, hoses, springs, etc.), even though the
removal and replacement of that component may affect the
reaction time of the vehicle in relation to the driver action, is not
considered a delay device. Wiring may consist of a single (i.e.,
“one” or “1”) continuous wire from a power source to a switch (or
button), and a single continuous wire from the switch to the
transbrake or line-loc solenoid. Splices (no quick-disconnect)
permitted from the two-step to the solenoid (i.e., between the
switch and the solenoid), for data logger and/or nitrous only. All
switches, buttons, wiring, solenoids, etc. must be for normal
automotive use; i.e., not intended to create a delay (adjustable or
non-adjustable) between release of the button and the resultant
action of the solenoid. All line-loc/transbrake wiring before and after
the switch must be separate from any other wiring and fully visible.
Computer wiring, sensors, relays, and the like may not be wired to
the solenoid wiring. Two-steps or other rev limiters that are
adjustable by thumbwheel, replaceable chips, and the like may not
be within the driver’s reach and will preferably be located outside
the driver compartment.
Any system that does not fit the above description is prohibited
and must be corrected before the vehicle will be passed through
pre-event technical inspection. Further, discovery of a delay device,
adjustable or non-adjustable, at any time following pre-event
technical inspection will be grounds for immediate disqualification
from the event, loss of all NHRA sanctioned sport compact points
for the season, and suspension from all NHRA sanctioned racing
for remainder of season. Additional penalties may be imposed at
the discretion of NHRA. (See 9:1 COMPUTER, 9:2 DATA
RECORDERS.)
48 GENERAL REGULATIONS

8:3 IGNITION
Each car in competition must have a positive-action on/off switch,
capable of de-energizing the entire ignition system, in good
working order, located within easy reach of the driver. “Momentary
contact” and magneto kill-button-type switches are prohibited.

8:4 MASTER CUTOFF
Mandatory when battery is relocated or on any vehicle running
9.99 or quicker. An electrical power cutoff switch (one only) must
be installed on the rearmost part of each vehicle and be easily
accessible from outside the car body. This cutoff switch must be
connected to the positive side of the electrical system and must
stop all electrical functions, including magneto ignition. The off
position must be clearly indicated with the word “OFF.” If switch is
“push/pull” type, “push” must be the action for shutting off the
electrical system, “pull” to turn it on. Any rods or cables used to
activate the switch must be minimum 1/8-inch diameter. Plastic or
keyed switches prohibited.

8:5 STARTERS
All cars must be self-starting. Rollers and/or push starts prohibited.

8:6 TAILLIGHTS
All vehicles must have a minimum of one working taillight for night
operations. Strobe, flashing, high-intensity, laser, infrared, photo
sensitive, or other light-emitting/receiving device prohibited. See
also Class Requirements.

8:7 SWITCHES & BUTTONS
All switches and/or buttons must be standard, mechanical
connection type. Infrared, laser, retinal scan, fingerprint, lightsource,
or any other non-mechanical-type switch and/or button
prohibited.

8:8 SHIFT LIGHT
Shift light may only be triggered by tachometer output or ignition
output.

These are pretty much standard through usa/canada

[CanadianGTR]

If you're concerned about someone coming up and REMOVING the key while you're driving... you could always install a switch IN the car that bypasses the rear switch circuit. It's more wiring but it's not impossible to figure out.

[Terrh]

the main points in those rules there are:

Keyed switches are illegal.
Must be located on the POSITIVE side.

[BrianV8]

yeah i plan to do some racing in ashcroft this year and mission next year so i just finished putting the switch in. Rather not get hasseled over 50 bucks in parts. Its poking out nicely through the back bumper lol.

[nissanconvert]

out of curiousity are these rules for cars doing brackets/NHRA etc etc... OR do they apply to street legals.. Maybe clarification needed there..

[BrianV8]

from my understanding of the rules its all vehicles

[mcfly]

that's sport compact nhra rules. applies to street legals too.

[BrianV8]

yeah there is only one set of rules, if u wanna race you follow them otherwise may be **** out of luck.