Standalone ECU Self Learned

[Lextreme II]

I have been reading the Autronic SM4. One of the functions that interest me is the self learned. What does it really mean and how effective it would be. For example I have 8-1000 cc injectors with dual walbor fuel pumps. However would it self learned?

 

[Peewee]

By Self Learned do you mean AutoTune ?

If so, all you do is plug a WBO2 sensor in, and tell the ecu to set the AFR to what ever you want (say 12.5:1).
And then you just drive, and the ecu will configure the fuel map to suit the target AFR.

 

[Lextreme II]

Wow.. that is interesting function. This is what I found at www.autronic.com


Autotune ™ Feature.
The Autotune ™ feature is available for the SMC and SM2 model ECU's.
Old models can be upgraded with a chip change and new software.

The Autotune ™ will tune the engine with no input from the operator. The closed loop air fuel ratio table is used as the target air fuel ratio table for the Autotune software. This table is setup with the required air fuel ratios at various RPM and Load points.

An Autronic exhaust gas analyzer or any other analyzer that provides a 0 to 1 volt "corrected" output, is connected to the ECU O2 I/P, this is used as the actual air fuel ratio input. As the engine is run through its various RPM and Load points the software will adjust the volumetric efficiency numbers in the main fuel table to achieve the target air fuel ratio.

At no time do you need to touch the keyboard on the Laptop.

After the tuning is complete the analyzer and 02 sensor is longer need. At any time after tuning is finished the values in the target closed loop table can be changed, and the engine will automatically run the new air fuel ratio, providing you do not make a change to the volumetric efficiency of the engine, e.g. fit a different camshaft, modify cylinder head etc...

If the engine is modified so the volumetric efficiency changes, then the analyzer and Autotune ™ software will be required again to re-tune the engine.

The Autotune ™ software is much faster then a good operator. It is not possible to manually tune as quick as the Autotune ™. A typical engine will take less than 20 minutes to fully map on an engine dyno.

The accuracy of the Autotune ™ can be setup in the software from 0.5% to 5.0% accuracy. The default value is 2% accuracy, this is generally a lot more accuracy then most tuners manual tune engines.

1. You cannot directly connect a 02 sensor to the ECU to Autotune.
2. The analyser you use must have a "corrected differential" 0 to 1 volt output. Most analyser do not have a differential output. This is required for a accurate signal..


Overview
Autronic Autotune ™ software provides rapid hands-tree tuning of Engine Air/Fuel mixtures. This automated operation frees the engine tuner, allowing total concentration on safe engine/dyno operation. On road tuning of motor vehicles is even possible.

This software uses a complex combination of math, including statistics, trigonometry and fuzzy logic to intelligently adjust the fuel delivery tables. Initial tuning is rapid usually occurring within 1 second. High precision can be achieved by allowing the Autotune ™ to operate for an extended time at each engine operating point. The operator has control over the balance between tuning speed and accuracy. Accuracy is ultimately limited by the accuracy of the attached Air/Fuel ratio measurement equipment.

The program provides visual indication of the tune status. Automatic and manual storage of tune status allows the user to monitor the tuning progress even if undertaken in several sessions. Tuning usually proceeds 2 to 5 times faster than possible by manual means. Fuel savings of as much at 90% have been reported. The considerable savings in engine life are obvious.

This program also has elaborate diagnostics facilities and allows simultaneous operation of the ECU internal data logger and external P.C data logging.

Versions are now available that have live engine operating data graphs while tuning, and a live 3D graphical presentation of the tuning process.

 

[rivmasta]

Question: It builds its own fuel map based on lambda sensor. How fast does it make changes to the map? Ie if it tunes itself doing city driving then you take it to the strip you're obviously not going to have the most correct tune for what you want it to do. So... How long to retune based on useage?

 

[UZZ30-Québec]

that thing is very cool for dummies like me who don't know a **** about fuel maps.

 

[cowboy bebop]

The AEM does the same thing with it's "auto mapping" feature.

Eric

 

[KDog]

There are a few points which need to be clarified.
1) You set the AF ratio map, the ECU then changes the Fuel map to match.
2) The ECU does NOT use a lambda sensor to measure the A/F ratio. It uses an A/F ratio meter, The Autronic Analysers are compatible. Most meters are NOT compatible for various reasons. If you try and use the incorrect meter your Autotune will not work properly.
3) If you don't understand fuel maps then this feature is not for you. See point 1.
4) Autotune is a feature which is designed to save the tuner some time. It is not there to provide a tuning function for people who do not understand tuning..

 

[quadcam boat]

Also auto tune dosen't work on boat engines. Ray Hall told me this himself.