Jaycar O2 Digital Mixture Display Kit

[altezzaclub]

Not that I've found, and a dyno run is $80 locally so I haven't done anything about it. I have two sensors, one for each carb, and they were a Commodore pair out of one motor so I'm assuming they are in agreement.

 

The carbs behave very similarly over the whole rev range with them.

[Twinky]

Well I guess that phrasing "calibrating the sensor" is a bit misleading. I'm actually calibrating the circuit to the sensor.

The circuit is made for a specific Bosch LSU4.2 oxygen sensor. Each Bosch LSU4.2 sensor has a unique calibration resistor in place.

You tune the wideband controller to read specific voltages from this calibration resistor. Being a unique resistance to each sensor this is why the circuits

need calibration as voltages would differ between sensors. For instance the input resistance has to be something along the lines of 312 ohms and the

unique calibration resistor has a resistance of 220 ohm you have to change the value via a resistor network to read 312 ohms. That would be done via a trim pot.

Anyway the wideband controller comes with a set of instructions on how to calibrate the unit.

 

Another point is that a car workshop that uses an 02 sensor to tune cars does not use it for the specific purpose of tuning a car but to see where they are in terms of fuel delivery.

Most tuners are now turning to gas analysers to fine tune fuel mixtures. Each engine has a different ideal fuel mixture and a gas analyser will tell you at what point that is by

reading the chemical composition of the gasses exiting the exhaust.

 

I am similarly using the sensor to see where my engine is at and fine tune it on the road in terms of power delivery.