PDA

View Full Version : cutoff switches


MazdaMatt
02-04-2008, 11:58 AM
I'm planning on adding a cutoff switch to my solosprint del sol. I believe that there are race regs specifying that a cutoff switch be placed where a marshal can access it. Do these types of switches typically cut the entire battery power, or do they just cut the power from the engine management thereby killing the engine?

I would like to place one on my dash by my start-up switches, and I'd like to place one either outside my C pillar, or on my rolbar mainloop. Any suggestions?

13inches
02-04-2008, 12:19 PM
Its like deja vu all over again. The same Q came up on the HADA board last week!

From the '08 race regs:

6.4 CIRCUIT BREAKER
6.4.1 Cars shall be equipped with a general circuit breaker easily accessible from outside the Car. This
circuit breaker will cut all electrical circuits (ignition, fuel pumps, lights, alternator, etc.) but shall not
affect the operation of an on-board fire extinguisher.
6.4.2 The location of the circuit breaker shall be clearly marked by the official international marking - a
red spark in a white-edged blue triangle and shall be mounted in the following standard locations.
The OFF position shall be clearly indicated at the master switch location.
6.4.3 FORMULA and SPORTS RACING CARS: In close proximity to the right hand upright member of
the main hoop and in a location so that it cannot be operated accidentally. It may be mounted on a
bracket welded to the inside of the upright member of the main hoop.
6.4.4 GT CARS: In front of the windshield on either the cowl or fender but close enough to the windshield
to be accessible if the Car is overturned. Alternatively it may be mounted on a bracket attached by
welding or clamps to the roll cage, easily accessible through the driver's side open window. Drilling
holes in the roll cage for this purpose is prohibited.
6.4.5 OPEN GT CARS: In any of the above locations.


Logically, you want a switch that the driver can get at, and a switch that the corner-workers can get at in case the car is on its side, roof etc.

MazdaMatt
02-04-2008, 12:40 PM
Okay...

although this car is not going to enter any roadraces, i will follow those specs for consistancy with what marshals are used to.

Question #1: What is the difference between a Sports Racing Car and a GT Car and which one is my Del Sol?

Quesiton #2: Why does one type of car have the switch on the right side and the other type of car has the switch on the driver's side?

ScotcH
02-04-2008, 01:10 PM
Okay...

although this car is not going to enter any roadraces, i will follow those specs for consistancy with what marshals are used to.

Question #1: What is the difference between a Sports Racing Car and a GT Car and which one is my Del Sol?

Quesiton #2: Why does one type of car have the switch on the right side and the other type of car has the switch on the driver's side?

You're a GT car (bacisally factory car based). No idea for #2. Most race cars have them placed somewhere on the left of the dash or A pillar so it's accesible by the driver as well a marshal through the window.

MazdaMatt
02-04-2008, 01:33 PM
So placing one beside my head on the main hoop, and one on the center console by my switch panel would cover me?

Do you typically run your (+) wire from the battery to the cutoff, then to your electronics? or does it run a relay?

ScotcH
02-04-2008, 02:28 PM
So placing one beside my head on the main hoop, and one on the center console by my switch panel would cover me?

Do you typically run your (+) wire from the battery to the cutoff, then to your electronics? or does it run a relay?

Unless you REALLY want to, don't bother with 2 switches. Just put one on the A pilar, right at the dash by your left hand. Make sure it's accessible from outside through the window.

As for wiring, you run the big cable into the switch, then to the rest of the car. Also, in most cars, you need to run the ignition power through the switch as well since the alternator will still keep the car running. This is the case in BMWs ... not sure about Hondas. A 4 pole switch works well for this (2 big terminals for the battery cable, 2 small ones for the ignition power).

MazdaMatt
02-04-2008, 02:38 PM
That doens't QUITE fit the description of the rules, but its a solosprint-only car, so i don't care. I just don't have any roll cage up front, so it will be on the dash.

Okay, now who wants to sell me a used or inexpensive cutoff switch? Preferably the "red mushroom" e-stop style button.

Mike Basden
02-04-2008, 03:30 PM
http://cgi.ebay.ca/MASTER-SWITCH-BUTTON-MOUNT-SCCA-HSR-HMSA-VINTAGE_W0QQitemZ360018682958QQihZ023QQcategoryZ107066QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

ScotcH
02-04-2008, 04:08 PM
That doens't QUITE fit the description of the rules, but its a solosprint-only car, so i don't care. I just don't have any roll cage up front, so it will be on the dash.


Why not? Both of our cars have it this way, and they both passed race tech.

ScotcH
02-04-2008, 04:12 PM
http://cgi.ebay.ca/MASTER-SWITCH-BUTTON-MOUNT-SCCA-HSR-HMSA-VINTAGE_W0QQitemZ360018682958QQihZ023QQcategoryZ107066QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

That's the ugliest thing I have ever seen :) This style is pretty common:

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

This one is cheap, but is a 4-post: http://www.pegasusautoracing.com/productdetails.asp?RecId=4913

MazdaMatt
02-04-2008, 04:45 PM
Why not? Both of our cars have it this way, and they both passed race tech.

Okay, that works, then... the rules stated either in front of the windshield, or attached to the cage inside the window. Obviously if yours passed, they should take the cage comment out.

MazdaMatt
02-04-2008, 04:57 PM
Does anybody use anything like this? I would prefer this type of switch... I may also get the kind that needs the key to reset so my car has SOME ability to not be stolen.

http://www.moeller.net/images/content/themenauftritte/safety/safety_notaus.jpg

Pete@Marcor
02-04-2008, 05:12 PM
Does anybody use anything like this? I would prefer this type of switch... I may also get the kind that needs the key to reset so my car has SOME ability to not be stolen.

http://www.moeller.net/images/content/themenauftritte/safety/safety_notaus.jpg

We have a couple of supplers that sell us switches. Most have a removable key. I am trying to find the Hella ones, but as a temporary picture:

http://www.taylorvertex.com/Products/pdfs/taylorcatalog37.pdf

Look at "The Switch" on the lower right of the page.