Cut off switch installation Options

[jhynesrockmtn]

In my continuing efforts to bring this car back to life and be able to run some vintage race events I have to wire in an electrical system kill switch. The original builder went for a GT clone and installed a Bosch 2 pole switch but it was just for show and not wired to anything. He ran AX and a few PCA time trials and apparently didn't need it to meet tech.

This is a 6 cylinder conversion with a factory 6 dash and ignition switch.

I've read multiple threads with suggestions for 2 pole, 4 pole and 6 pole switches and various install locations. Frankly I'm confused and could use some help.

I'm looking for a wiring diagram and suggestions for either keeping and using this switch or swapping it out for something else. I'll keep it in this location.

[brant]

a lot of W2W clubs will want you to have one that is also accessible to the driver when seated and belted in the car

So that the driver can pull the switch while on fire.

a lot of folks run a 2nd pull cable... so the switch is accessible to both the driver and the corner workers.

Its a really good Idea to get a rule book and a highlighter
spend a few hours looking for details in the rules

brant

[GregAmy]

https://improvedtouring.com/showthread.php?...l-switch-wiring

[jhynesrockmtn]

a lot of W2W clubs will want you to have one that is also accessible to the driver when seated and belted in the car

So that the driver can pull the switch while on fire.

a lot of folks run a 2nd pull cable... so the switch is accessible to both the driver and the corner workers.

Its a really good Idea to get a rule book and a highlighter
spend a few hours looking for details in the rules

brant

Brant, thanks for the replies. I'm in touch with the tech guy for our club. I may do the cabin pull but it is not required. Care to share how your setup is put together?

The confusing thing for me in the threads I've read is the "need" to wire it such that the alternator is protected. Some say it is a necessity, others not so much. I'll check out the thread on the link provided.

[wndsrfr]

a lot of W2W clubs will want you to have one that is also accessible to the driver when seated and belted in the car

So that the driver can pull the switch while on fire.

a lot of folks run a 2nd pull cable... so the switch is accessible to both the driver and the corner workers.

Its a really good Idea to get a rule book and a highlighter
spend a few hours looking for details in the rules

brant

Brant, thanks for the replies. I'm in touch with the tech guy for our club. I may do the cabin pull but it is not required. Care to share how your setup is put together?

The confusing thing for me in the threads I've read is the "need" to wire it such that the alternator is protected. Some say it is a necessity, others not so much. I'll check out the thread on the link provided.

It's not so that the alternator is "protected", it's to keep the alternator from continuing to supply the ignition after the switch is disconnected, otherwise the engine will keep running which is a bad thing in a crash situation--safety personnel need to be able to kill the engine from outside the car. Collateral damage is that if the engine is running with battery disconnected it fries the alternator....so be sure to wire it properly because at the event tech inspection they will switch it off to confirm that it kills the engine.....make sense?

[stownsen914]

It's not so that the alternator is "protected", it's to keep the alternator from continuing to supply the ignition after the switch is disconnected, otherwise the engine will keep running which is a bad thing in a crash situation

It's actually both reasons. If you use a regular two pole cutoff switch, you're not giving the alternator a place to attenuate its output for the short time it's still turning after shutting off power. Normally the battery's resistance serves this purpose, but if you use a two pole switch the battery is isolated from the circuit when the switch is off. An unattentuated alternator can put out 20+ volts and fry its own diodes and possibly other electrical components.

[campbellcj]

I've had tech inspectors actually test it with the car revving, not at idle... you want to make sure it works even with a stuck throttle or whatnot.

[mlindner]

Yup, I installed a 6 pole last year. Little head scratching but worked out nice. Mark

[jhynesrockmtn]

This is done. I ordered a 6 pole switch. The battery stayed in the factory location so I got creative with routing and protecting wires. The tech guy for our club came to look at the car and gave me a few to do's but blessed the install.

[mlindner]

Good job.