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TECHNOTES -- ARTICLE 01
By: Bill Hughes -- NNJR Tech Chief
11 Jan 1998

It's that time of year again when we start thinking about what has to be done to our cars for the new season. There are no major changes for this year, however, there are two things I have been getting questions about. These changes are the removal of the grandfathering of Formula car and Sports Racer roll cages, and the addition of Improved Touring requiring a master switch.

For the people with the older Formula and Sports Racer cars, (registered prior to 1979), you are no longer exempt from the full Roll Cage rule. This means that the main hoop must now have forward facing braces. These braces should extend to, or as close as possible, to the front hoop. You are also required to now have a front hoop. This hoop must also have forward facing braces. These braces should extend as far forward as possible to protect the drivers legs. All of these bars should be attached to the lower frame rail, or triangulation is required. Also, make sure that all tubing size meets the current spec.

Now for IT drivers, a master switch is required this year. This switch must kill all power except for an electrically operated fire system, if so equipped. This switch must also shut the motor off, which means that you will need a 6 pole switch, not a 2 pole. If a 2 pole is used, two things will happen: 1) The car will keep running because of residual magnetism in the alternator, which will keep the alternator supplying power, and 2) the field being disconnected on the alternator will cause the smoke to leak out of your diodes, (and since we all know that electronics runs on smoke, the depletion of this smoke will render the alternator inoperative).

The mounting location for this switch is just in front of the windshield on either side of the car, below the center of the rear window, or mounted on a bracket attached to the roll cage (with the bracket welded or clamped to the bar, no bolts into the cage) in a position easily accessible from the open window. Don't forget your "OFF" decal.

The easiest way to wire an OMP 6 Pole switch, (available at Driving Impressions), on most cars is as follows:
Remove the battery ground, then disconnect the positive battery cable from the starter. This will be connected to one of the large terminals on the switch. Find the smaller auxiliary lead on the positive battery cable near the battery terminal and cut it off close to the cable. This lead will be connected to the second large terminal of the switch. Attach another battery cable to this second terminal and run this cable to the starter. Most auto parts stores will make this cable up for you, just let them know how long you need it and what size studs each end attaches to. Also, from the same terminal, run a 12 gauge wire to one of the terminals marked "1" on the bottom of the switch. The two terminals marked "1" are the Normally Closed contacts of the switch. The other "1" terminal will be connected to the supplied resistor. The other side of this resistor is connected to a good ground. This resistor is what protects your alternator diodes. The resistor should be tie wrapped to the other wires and the leads insulated. You have now succeeded in disconnecting your battery and protecting your alternator, now for shutting off your motor. There are two terminals left on the switch, these are marked "2". These terminals are for the Normally Open contacts of the switch. Disconnect the wire going to the "+" terminal of your ignition coil and attach this to one of the terminals marked "2". Run a 12 gauge wire from the remaining "2" terminal to the ignition coil "+" terminal. Now all that is left to do is to mount the switch and reconnect your battery ground cable.

After installing, start the car and make sure the switch will shut it off. With the switch off, check to make sure that the car will not crank, the fuel pump, wipers, and all lights will not operate.

When you have made all of your changes for the new season, don't forget to bring your car to one of our Once-A-Year tech sessions so we can check everything out BEFORE you get to the track. We also welcome any unfinished cars at these tech sessions to answer any questions you might have and to help steer you in the right direction.


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