One of the most effective products you can use to improve the consistency of your car is an automated shifter. Shifts are made at exactly the same point in every run, which eliminates one of the major variables effecting the E.T. of the car. While automated shifting improves all cars, two types of cars respond particularly well: heavy cars with low/medium power and light cars with high power.
• Low / medium horsepower engines need the transmissions’ gear multiplication to accelerate heavy cars. Shifting to high gear removes the multiplication, greatly affecting the engines ability to move the car.
• High powered engines usually have a peaky torque curve and run through low gear quickly when installed in light cars.
• Shifting early or late ends up with the engine being far away from the desired torque range at the shift point. In both cases, it’s easy to see that a slight change in the shift RPM makes a big change in the car’s acceleration rate which causes an even bigger change in the E.T.
• Safety plays a role also, particularly with high horsepower cars. An automated shifter allows the driver to grab the steering wheel with both hands and concentrate on keeping the car straight during a run. A straight run is safer and more consistent.
There are two ways to control the shift point of the car:
• The first is the tried and proven method of using an RPM2 switch module. This switch module determines the engine RPM by reading the pulses given off by the ignition system. These are the same pulses that are used by the tachometer. When the engine reaches the RPM that has been set in the RPM switch, the RPM switch activates your air or electric shifter.
• The second method is to use our “Shift Timer”. The Shift Timer is a device that starts timing when the transbrake is released and at the preset time, activates your air or electric shifter.
The Shift Timer works particularly well in cars that have “loose” converters.
• The engine in a car with a “loose” converter tends to run at a fixed speed until the converter locks up and stops slipping.
• Since the engine runs in a narrow rpm band near the intended shift point for a large portion of the run, the actual shift point can vary widely.
• The Shift Timer will allow the car to shift at a precise point during a run and the engine rpm doesn’t matter.
Another situation where the timer works well is on throttle stop timer equipped cars because the shift can be positioned in accordance with the throttle stop timing.
• Shifting while the engine is in the “stopped” condition greatly reduces the chance of tire spin when the engine goes back to wide open throttle again.
• To actually shift the car, two types of automated shifters are available, CO2 or electric. Both work equally well and are a matter of driver preference. The “shifter and accessories” section explains the advantages of each type.