Recently, I had request about ignition timing so this week, I will talk about that!
Timing is one of those tuning adjustments that can occur right up to the fire up in the water box. During a race, you might notice the crew chief with a small black box in the staging lanes or in the water box before they start. This is called a graphic editor or pro mag digital retard interface. The part number is 7570 from MSD. They use this box to adjust the timing map. Most crew chiefs will have several timing maps saved in the editor for various track conditions and can change the timing map very quickly in the car.
This editor hooks up to the the digital multi-stage retard controller part number 8971 from MSD via a small cable. The controller is what sends the timing map to the motor. At the hit of the throttle for the launch there will be a lot of timing in the motor 55 degrees or more. This is done to get rear wheel speed going but timing is then immediately being pulled out to control the rear wheel speed.
Too much timing will cause the car to smoke the tires and not enough can cause it to shake. Wheel speed is a very touchy issue and deserves its own blog. Some of you might wonder how the timing map is triggered in the car. In my car, I have a small air activated button under the gas pedal so when it is smashed all the way down it triggers the timing control along with the fuel system controls and clutch controls. Going back to the launch, we start pulling timing out of the motor at 1 tenth of a second into the run and continue to pull it out until 1.1 seconds in the run down to 35 degrees. From there we ramp timing back into the motor and at 2.0 seconds into run the motor might have 46 degrees or more back in it. Remember, timing is power and these cars are all about making power.