Battery cut-off

[Ron McCall]

Where do you racing guys mount your cut -off switch? What type do you use? And do you have any pictures?

Thanks,

 

[Rob]

Hey Ron,
On my last car I mounted it in a spot I felt would be most accessible regardless of what kind of trouble I had just got myself into. Be it overturned, or against a barrier. I felt the tail panel was most likely the most accessible spot. It is one of those things I will always second guess, bottom line is it can't be right 100% of the time..I guess.
I was thinking about this for the GT40 just this past weekend, trying to plan ahead, and was looking through the "Ford that beat Ferrari" at many many pics, and noticed a common position was just behind the drivers door. Many had a notch out of the body panel (not that you would want to do that now....with the pretty paint and all.....)

 

[Rob]

forgot to add, the last two that I used were Moroso.

 

[Ian Anderson]

Are you going to race the car?
If so the governing body will probably have specifications and placement requirements.

If you just want a cut off switch we (Paul) mounted mine inside the rear clip on the ledge. Reach through the vent on the drivers side and easily switchable and remove key for "imobiliser" for SVA

Ian

 

[Malcolm]

In the UK the official place for cut off and fire pulls on the outside of the car are just in front of the driver below the windscreen, ie on the top of the front clip. If you think about it, this area is not ever going to be wedged against a tyre wall or if flipped, it is unlikley that the car will have crushed so much that a hand can't reach under and being on the drivers side, when a marshal comes to check out the driver, these controls are close to him at that moment too, in case the driver has not been able to trigger the systems from inside the car. This is in accordance with the UK MSA blue book I beleive. I have my controls in this position on my car so it can be done if wanted.

 

[John]

Battery Cut Off

Ron,

One of the cars I'm been looking at has the battery cut-off on the driver's door jam with a key. As you exit the car, you cut off all juice to the car and take the key with you. It also had a ignition disconnect switch near the gear shift.

Have you mounted your engine and transaxle yet?

John

 

[flatchat(Chris)]

Same here in Aus. Malcolm, and must be easily reached while strapped in the drivers seat. Aaaand don't forget to wire it to kill the motor, ie:-if the alternater is generating current while the engine is running -- it won't stop !
my tupence.

 

[Ron Earp]

Ron put it somewhere that you can get to it and a corner worker can get to it. I take take some photos of a few installations I've done, but I generally like them on a metal plate where the driver can get to it with his/her right hand. Since all track everts, even BMW track schools, require windows down, mounting it where it is accessable through the passenger window isn't a bad idea.

On the Jensen there are "three" cutoff switches. The main one is on a metal plate welded to the cage, a pull lever across the car that acuates the main one, and then there is a second one in line with the circuit that is at my gear shift. Too many? - British car, Lucas, bad bad bad!

The Miatas I put on a welded plate on the cage right behind where the passenger would go. Some Miata folks cleverly put them into the left hand driver's vent, or where the vent would be, which is easily accessilble for you and the corner worker.

I also have fire pulls in similar places.

Next car I do, the Lola, there will be a fire pull and battery on the outside of the car, and a fire pull and battery on the inside of the car. Both will be clearly visible and on the upper surface of the car, and marked with the usual international (which we found are not so international) icons. All those pictures of Mark Donahue running away from his Lola got me worried!

 

[Malcolm]

Ron, as if your reputation with car fires leaves Donahue relaxed!

To clarify, my opinion above was external only. Internals need to be easily reached by driver when tightly strapped in.

 

[Ross Nicol]

My switch is on the centre tunnel beside me and a hook in front of the windscreen is connected to a cable that pulls the internal switch off.

 

[Ron McCall]

Does anyone know if something like this
http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRF-30205&N=0&autoview=sku

would be acceptable to racing sanctioning bodies?

 

[Ron Earp]

It will, but, location might preclude using such a switch. Per the GCR:

"CLOSED SPORTS RACING CARS, PRODUCTION CARS,
IMPROVED TOURING AND GT CARS -- In front of the windshield
on either the cowl or on top of the fender, but close enough to the
windshield to be accessible if the car is overturned. Alternatively,
it may be mounted below the center of the rear window or on a
bracket welded, clamped or bolted to the roll cage or dash, easily
accessible through the open window. (Drilling of holes in roll
cage to attach the bracket is prohibited.)"

In these cases you want a switch type, not a button. Looks to me like the button type is more for the cockpit. But, the rules don't prohibit it. If I were you I'd run the button type in the cockpit, and put one of these outside:

http://www.pegasusautoracing.com/productdetails.asp?RecId=1464

Ron

 

[Ron McCall]

Thanks Ron.
I was just trying to get away from running the battery cable through the car.It looks like the Painless version can mount by the battery and you could mount multiple switches whereever you want them.

 

[Ron Earp]

You could do a negative cut if you like if you are afraid of running 00 or 000 positive, or whatever through the car. I've done both on cars we've built for SCCA, and both will work and go through tech. Clearly, if you run a negative cut you can't attach the battery post to the chassis as one might do, but through the switch. Either way, you'll still need to kill the alternator field or the ignition supply.

R

 

[Lee]

Or how about one of these. Remote internal and exterior buttons supplied. Cuts battery and alternator, with no long stretches of high amp cable to run. I think makes for much easier plumbing than the manual switches with remote pull cables.

http://rallynuts.com/motorsport/ARMTECH_Electronics_1856/Armtech_Hybrid_Battery_Isolator_95.asp

 

[David Morton]

I have my cutout switch right on top of the battery (rear compartment on the left and a cable pull to it in the cabin. The battery location is just inside the left intake on the rear bodywork with the usual sign on the outside so that you can pull the isolator from there as well. (Basically the isolator sits just inside the lower left intake) Virtually zero length of +ve cable to the isolater so when its pulled the balance of +ve cable from the isolator onward (starter etc) is completely dead. .

 

[David Morton]

Looks like this:

 

[Paul Thompson 'Hooligan']

Or how about one of these.

http://rallynuts.com/motorsport/ARMTECH_Electronics_1856/Armtech_Hybrid_Battery_Isolator_95.asp

Yep - I've used a few of these to date - they work well.

The best price for the last one I purchased was from Rally Design I think.

One thing though, any alarm/remote door locking circuits will require some thought as breaking the earth would isolate them too. I have previously run a separate fused bypass earth for alarms etc

Finally - don't leave the unit engaged (on) over a weekend as it will flatten the battery, the unit works like a relay or solenoid and draws 0.5A or so when engaged.

 

[Ron Earp]

That is a pretty cool piece of equipment. But, I'm on the cheap, so I'll stick with the $30 switch and $15 of wire! Nice to know about though if I run into one to wire that is difficult in layout, that would solve the problem.

 

[Phil]

Ron;
Ron and Ross definitely have the right idea...multiple cut-off with multiple access. I think I saw a nice unit also offered by Flaming River that has the switch with a linkage attached as well as the Lever. More's Law definitely applies here.
Cheers
Phil