SFT installation on the vehicle

The simplest device to indicate the gear change moment

The main objective of developing shiftlight SFT was to make the procedure of installing and setting the device up as simple as possible. I wanted to avoid jumpers, small DIP switchers, buttons and other such a common solutions, which would have excluded the corpus being splash proof, blemished the general design and added complexity.

Calibrated for most vehicle types

Selecting calibration, adjustment and operation mode was managed to realize with only one rotary selector. Turning it can be guided by a scale. Calibration means, that the device needs to be inserted, how many cylinders, injectors or ignition coils the engine has. This is necessary for measuring the rotation speed correctly and for the scale to match the tachometer. The device is able to guess the correct engine configuration itself if during calibration the engine speed is selected to more or less at one single value, which is 2000 rpm. This solution enables to use all kinds of internal combustion engines and the user does not have to count the coils under the bonnet.

The device can be connected to the engine in several ways

For connecting the SFT, there are three colours of wires in the cable: white (ground), brown (power supply) and green (signal). They are surrounded by a shield of fine wire, which is advisable to connect to the ground with the white wire.

The white ground wire can be attached to any point on the vehicle, which is connected to the negative terminal of the battery. It can also be attached to the ground wire (usually black), which is found in a plug on the Wasted Spark or COP types of ignition coils.

The brown power supply wire should be connected to the circuit turned on from the ignition lock. Here it is important to notice that there should be no power in the circuit after the ignition is turned off. It can also be connected to the power cable (often brown or red) in the ignition coil plug or in the case of a classical coil to the positive terminal. Using a multimeter, it should be verified, that there is a voltage of about 12 V between the white and the brown wire when the ignition is on and 0 V when it is off. If the power connection is correct, then the light flashes briefly when ignition is switched on with a key.

The green signal wire should be attached to the ignition coil or into the fuel injection circuit, which both are in proportion to the engine speed. In coil connectors, these wires are usually green or striped. In classical injection coils, the signal wire should be connected to the negative terminal. In case of using an injector, it is necessary to measure from its plug, which one of the contacts have power, and attach the wire to another contact. Of course, testing must happen when the ignition is on, but the engine is not. For a diesel engine, connecting to the injector is the only option.

Also usable in an external circuit

If the vehicle is equipped with a programmed engine management system, that has a special output for a shiftlight (Megasquirt, VEMS etc.), then the signal wire can be connected to this instead and change the operating mode. This process is described in the manual.