Kill Switches

[dylan873]

Absolute beginner to the racing world, and I am wondering why race cars seem to have kill switches for all sorts of things that are automatic in stock cars, things such as fuel pumps. Why do these things need their own switch in race cars? Thanks and sorry if stupid question

[Mechanic Z]

I don't know anything about it, but I would guess that they have a switch on the fuel pump so, in the event of a crash, they can shut off fuel flow and prevent a fire.

[jimclark]

Originally Posted by Mechanic Z

I don't know anything about it, but I would guess that they have a switch on the fuel pump so, in the event of a crash, they can shut off fuel flow and prevent a fire.

Spot on.

[Dave Brand]

Originally Posted by Mechanic Z

I don't know anything about it, but I would guess that they have a switch on the fuel pump so, in the event of a crash, they can shut off fuel flow and prevent a fire.

There is an external electrical cut-of which switches off all electrical circuits (except any used by a fire extinguisher system) so there's no need to switch off individual devices in the event of a crash.

[Dom]

Many cars will have the manufacturers wiring loom and ECU replaced with a lighter, minimal setup. This also allows more control over individual items by the driver such as cooling fans and converting a greater amount of engine power into actually driving the car rather than running luxuries.

Another theory is that us drivers are often control freaks, and besides all those switches look cool

[Al Weyman]

I believe kill switches independant of the master kill switch are mandatory on the fuel pump stateside but not overhere. I have read they can be wired up to an oil pressure switch to turn them off if the car crashes or expires. I use a mechanical lift pump in one of my cars and I think thats the ideal solution apart from having to crank the engine over a few times to get the fuel up if the car has been left standing a while.

[GORDON STREETER]

Quote:
Originally Posted by dylan873
Absolute beginner to the racing world, and I am wondering why race cars seem to have kill switches for all sorts of things that are automatic in stock cars, things such as fuel pumps. Why do these things need their own switch in race cars? Thanks and sorry if stupid question

I take it you mean "road cars" also when you say "automatic" I assume you mean controlled by the ignition switch that in a road car doesn't isolate the battery.
In actual fact you need very few switches in a race car as you need to concentrate on driving.
Petrol pumps sometimes need to be switched off if the engine has flooded .
To make things more reliable like electric fans it's best to be in control rather than rely on a £5 sensor that could cost a fortune and the race