SMT8-FT TECHNICAL MANUAL

Perfect Power Online Manuals.

 

Support for your SMT8-FT Unit.

FULL INSTALLATION

This section provides information on pin locations for all units, as well as details of wiring in the harness for optional connections.

 

 

POWERING THE SMT8-FT WITHOUT THE ENGINE RUNNING

 

The SMT8-FT can get operating power from two sources :

 

From the injectors
The injector power may be switched off when the engine is not running

 

From the 12 Way connector pin 2
This wire can be connected to any fixed 12V power point, which is switched off when the key is removed.

 

The SMT8-FT will use the power sources mentioned above, if available.
The pin#2 supply is normally left open, but is very nice to have when you like to talk to the unit without the engine operating or on the workbench.

 

 

RECOMMENDED OPTIONAL WIRING OPTIONAL DEFLECTION (TPS, AMP) INPUT
(PIN 11 OF 12)

 

Wiring in the deflection can be a little difficult, but is highly recommended. It will provide a two dimensional map. The difficulty is to find the correct signal wire amongst virtually hundreds of other wires.

 

The definition of the deflection signal is : It changes its voltage in unison to the change of the gas pedal. This can be measured with an ordinary multimeter.

The deflection signal can be obtained from the TPS, ETC, or AMP, or MAF sensor.
The principle is the same : It goes up with increasing engine load.

 

There are many ways to go about finding the correct deflection wire :

Trace the wire (colour) from the TPS sensor to the ECU.
Trace the wire from the AMP sensor
Poke a needle into each wire and measure the signal in response to moving the gas pedal.
Locate an ECU connector layout from the vehicle manufacturer's service manual.
Get help from a qualified vehicle electrician.
Ask a friend.


Once the deflection wire has been found, you will then need to TEE the SMT8-FT AMPIN into it with the provided TEE-CONNECTOR. If you prefer to do the connection yourself follow the diagram below :

 

SMT8-FT - Tee-in Connection of the AMPIN signal

 

Try the installation of the deflection wire connection : Once the unit has been powered up, the cursor must move in unison with the gas pedal right to left. See the LetRipp II Windows Software Guide on how to use the software to operate this feature.

 

Note : If you don't have a multimeter, you can use the SMT8-FT input and display the result on a PC. The AMPIN input can be connected to any voltage EXCEPT the  IGNITION (high tension!) without causing any harm.

 

 

OPTIONAL ENGINE TEMPERATURE INPUT (Pin 9 of 10)

 

This sort of connection is for the very particular tuner, and when you would like to change the "COLD" behavior of the engine. Locate the engine temperature wire (best done by tracing) and TEE into it with the SMT8-FT's TEMPIN (pin 9-12) on the optional wiring harness. If you don't need the engine temperature, then leave this wire open.

 

 

OPTIONAL MAP SWITCHING INPUT (Pin 3 of 10)

 

The SMT8-FT has two complete tuning maps.

The second map (Map B) is activated by shorting the MAPSW wire (Pin 3 of 12) to ground. If left open, then Map A is active. This is indicated in the right upper corner of the display in the LetRipp II Windows Tuning Software. This feature is recommended when you experiment with the tuning. It gives you two different choices of tuning while driving the car on the road. An absolute must if you would like to do economy tuning.