SMART TUNER SMT8-L - TUNING LAMBDA

Perfect Power Application Notes.

 

Application Note - AN 3

Introduction

This application note describes the various methods of tuning the CLOSED LOOP LAMBDA signal. Narrow or Wide band lambda can be tuned.

Purpose

Why would you want to tune closed loop lambda? Due to the ongoing emission problems, the demands for manufacturers to run permanent closed loop is increasing. What this means is that when you select settings for the engine, for example : tuning fuel, the lambda sensor will recognize these changes and the ECU will correct the air/fuel ratio back to what they were previously.
Using the SMT8-L, you can now tune lambda. This means you would run the lambda signal through the SMT8-L for Narrow band an tee onto the signal for Wide band. When you make a change, the ECU looks at the lambda and changes itself to your new settings. The standard ECU still sees lambda as correct but in actual fact the fuel settings have changed.

 

SMT8-L Features and Wiring

 The SMT8-L has a 384 site ANALOG map, which is added to three 24 row side maps of air temperature, engine temperature map and manifold pressure. The analog map sites are selected by the throttle position (or any other load signal) and the RPM.

 

SMT8-L Piggy-Back Unit - F6 - Lambda/AFR Modification

 

 The wiring of the SMT8-L for the NARROW BAND LAMBDA INPUT is shown in the diagram below.

 

 

SMT8-L Piggy-Back Unit - Narrow Band Lambda Input Wiring

 

 

The wiring of the SMT8-L for the WIDE BAND LAMBDA is shown in the diagram below.

 

 

SMT8-L Piggy-Back Unit - Wide Band Lambda Wiring

 

SMT8-L Lambda Setup

When intercepting a narrow band signal the "AFR Wide mod En" must be unchecked. Wide band modifications require this check box.
SMT8-L Piggy-Back Unit - ShiftF2 - System Definition

 

Conclusion

Most of us spend 90% of the time while driving a car "cruising" due to speed and traffic restrictions. The SMT8-L is the ideal tool to improve the cruising performance, while enhancing the power output at full throttle when overtaking. This can be done by intercepting the "CLOSED LOOP LAMBDA".