"Volunteers are not paid, not because they are worthless but because they are priceless." - Anonymous

On this page are subjects that pertain to Tech Inspection in the Northeast Division, Sports Car Club of America.

* Tech Discussion at Roundtable *

2008 Runoffs Tech Team Invites You to Join the Team

The SCCA National Championship Runoffs has a great Tech Team returning for 2008 but there is room to include you in the plans. We invite you to be part of the exciting Runoffs: October 2 – 12, 2008.

Come to the Runoffs! See the cars – up close. Meet the drivers and crews. Meet other people with the same tech interest as you have. Make new friends. Be there 4 days or 10.

What we do:

1. At Express Tech we greet the drivers, make sure the car’s information on the tech entry card matches the specifications for the class. (instructions and specs are included for on the job training) and issue tech decals.

2. We do annual inspections on cars and issue log books for new cars.

3. We assist the drivers with post crash inspection to help get the car safely back on the track.

4. We work with the Category and Class Chiefs to make the compliance plan for post qualifying and post race. We make the plan and complete the plan.

5. We congratulate the winners and celebrate with our friends.

What do you need to do to join the team? 3 simple things:

1. Send an email to scrutineer@scca.com and let us know that you will be there and what you would like to do.

2. Register when SCCA opens registration.

3. Be at the Runoffs. See ya’ there!

Toni Creighton
NA Tech

Compression Ratio

TECH SEMINAR COMPRESSION RATIO (Word Document)

COMPRESSION RATIO MEASUREMENTS (Excel Document)

Master Switch Wiring

This switch must kill all power except for an electrically operated fire system, if so equipped. This switch must also shut the engine 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, 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 engine. 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.

It is actually possible to use a 2 pole switch, but the alternator “BAT” lead must be connected to the battery side of the switch, effectively connecting the battery “+” and alternator output together. This will isolate both “power sources” to the same side of the switch. The 6 pole is preferred since the alternator is not hot when the switch is off.

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. The switch should also be tested after running a session on the track. We have found that even if the car shut off with the first test, it might not shut off after a session at speed on the track.

For more Tech Info, contact Bill Etherington, Tech DA.

Last updated 3/21/08.