Calculator for Lambda
The DECS Lambda Calculator is a fully functional lambda calculator.
DECS default values are set for gasoline because it is still the most common fuel source for modern automobiles. But what happens if your exhaust analyzer reports a lambda number for gasoline, but the fuel being burned is really E85* Are the numbers you trust for accurate diagnosis correct? No.
DECS Lambda Calculator is been programmed with the appropriate values for multiple fuel types: USA gasoline, oxygenated gasoline, European gasoline, diesel, E85, CNG, and LPG.
The lambda calculator also reports air fuel ratio and % rich or lean. Red text warns the user of a result that could be undesirable.
Exhaust leaks and secondary air injection can discredit lambda values. An additional calculation added to the DECS lambda calculator is oxygen dilution value. The oxygen dilution value is provided to warn of possible air leaks in the exhaust system (or the presence of secondary air injection) that could skew the lambda calculator's results. If too much oxygen dilution could be present, DECS displays the oxygen dilution value in red and highlights any fields that could be incorrect due to the dilution in yellow.
Remember, the lambda calculator works for both pre and post catalytic converter gas samples. The results remain the same.
Calculator for Combustion Efficiency
If lambda is a measure of how well an engine was fueled, combustion efficiency is a measure of how well the fuel introduced into the engine was burned.
Just like the lambda calculator, the DECS Combustion Efficiency calculation accounts for multiple fuels. Most gas analyzers, and software, report CE based on gasoline characteristics. DECS takes all of the same multiple fuels from the lambda calculation into account. The CE output of the calculator also appears in red when the value is poor.
Unlike a lambda calculator, a combustion efficiency calculation is different for pre and post catalytic converter gasses. If the catalytic converter is functioning further combustion occurs in the catalyst. Therefore, a post gas reading should show a higher CE result than a pre gas sample.
Calculator for Volumetric Efficiency
The Volumetric Efficiency calculator determines the engine's ability to pump air.
Measuring VE helps you diagnose restricted intake systems, restricted exhaust systems, air metering problems, and/or mass airflow sensor issues. Questionable values are highlighted in red.
Calculator for Fuel Requirement
The fuel requirement calculation is automatically performed during a VE calculation. It can used to figure desired fuel quantity for a volume test when specs are not on hand.
In the screen shot shown above, a 5.7 liter engine operating at 4336 RPM would require approximately 1.66 liters per minute.
Its outputs reflect the required amount of fuel to maintain the correct air fuel ratio for the conditions and entered fuel type. A second set of outputs has been provided (+20%) to account for acceleration enrichment.
Calculator for Air Fuel to Lambda Conversion
The Air Fuel Ratio to Lambda Conversion Calculator is used to convert an air fuel ratio to a Lambda number. It is dependent on what type of fuel is being burned, so you must enter a fuel type. The calculator displays undesirable values in red. Fuel type selections include Gasoline, E85, Diesel, CNG, LPG, Methonal.
Calculator for Catalyst Efficiency
DECS catalyst efficiency calculation can be used to determine how well a catalytic converter does its job reducing each gas.
This calculation requires the measurement of pre and post converter gasses. Each gas is independently calculated and the results are a percentage output the represents the efficiency at which the catalytic converter reduces each gas.
Note: These results of this calculation could vary depending on engine operating conditions. For accurate results to be achieved the vehicle should be in good fuel control, and the catalytic converter should be fully warmed up, to insure proper catalyst operation.
Calculator for Emissions Reduction Goal Calculation
Useful for repair verification of an IM-240 failure when you are limited to a conventional gas analyzer.
Thd calculator helps you equate constant sampling gas analyzer information to common exhaust gas analyzers. Constant sampling systems are sometimes used by state emissions inspection programs. Since the constant sampling systems actually weigh the gasses in the exhaust stream the outputs are often expressed in grams per mile.
Common analyzers provide outputs in percent or parts per million. These two different readings make repair verification difficult. The goal calculator figures a goal based on the state's readings and a before repair baseline test drive.
