I have started this project to get the turbine/compressor RPM on my car. From there, I added more stuff to get a better understanding of our engine. In addition, I provided an alternate version of some formulas to accommodate the 2.4L platform.

I'm a software engineer, so you will see some weird tricks that I used to make this work with Torque Pro. I recommend to start with the easy equations and validate them one by one. It is quite easy to screw up a formula and get a bad result. Let me know if you find something wrong or just want to add a new gauge to your dashboard.

*: Replace the * by the multiplication sign (x) when entering the equation.

/: Replace the / by the division sign (÷) when entering the equation.

In order to create your custom PIDs, you need to go the "Settings > Manage extra PID/Sensors >... Add custom PID" menu.

**OBD-II Sensors (For reference only)**

[0b]: Intake Manifold Absolute Pressure (kPa)

[0c]: Engine RPM

[0d]: Vehicule Speed (km/h)

[0f]: Intake Air Temperature (C)

[33]: Barometric Pressure (kPa)

[34]: Bank 1 - Sensor 1 Lambda

[46]: Ambient Temperature (C)

For more information: http://en.wikipedia.org/wiki/OBD-II_PIDs

**Torque Pro Operations (For reference only)**

abs(): Absolute value.

{X:B}: Verify if the bit B is set within the X byte.

[pid]: Refers to the pid number of a sensor.

val{Long Name}: Refers to another equation using its long name.

**Air Density**

This equation gives the air density inside the intake. Used to calculate the mass air flow rate or as a standalone gauge. The relative humidity is assumed to be constant at 50%.

Unit: lb/cf

Equation: .0717*(303.15/([0f]+273.15))*([33]/101.325)

OBD Header: 7E0

**Sea Level Comp**

This equation computes a compensation factor to normalize your horsepower/torque values to sea level, 30 celcius, 50% humidity. Useful to compare your HP/Torque values with other members.

Equation: .0717 / (val{Air Density} + .0000001)

**IsBoost**

This equation indicates whether the car is in boost or not. It is used to filter unwanted results from other equations. It checks if the MAP sensor is between 96 kpa and 255 kpa which means a boost between -0.78 PSI and 22.275 PSI.

PID: 010b

Min: 0.0

Max: 1.0

Equation: ({A:7}+({A:6}*{A:5}))-({A:7}*{A:6}*{A:5})

OBD Header: 7E0

**IsRpmGT2048**

This equation indicates whether the engine runs at least 2048 revolutions per minute.

PID: 010c

Min: 0.0

Max: 1.0

Equation: {A:6}+{A:5}-({A:6}*{A:5})

OBD Header: 7E0

**IsRpmGT3072**

This equation indicates whether the engine runs at least 3072 revolutions per minute.

PID: 010c

Min: 0.0

Max: 1.0

Equation: {A:6}+({A:5}*{A:4})

OBD Header: 7E0

**IsRpmGT3584**

This equation indicates whether the engine runs at least 3584 revolutions per minute.

PID: 010c

Min: 0.0

Max: 1.0

Equation: {A:6}+({A:5}*{A:4}*{A:3})

OBD Header: 7E0

**IsRpmGT4096**

This equation indicates whether the engine runs at least 4096 revolutions per minute.

PID: 010c

Min: 0.0

Max: 1.0

Equation: {A:6}

OBD Header: 7E0

**IsSpeedGT128**

This equation indicates whether the car is going over 128 km/h in order to filter unwanted results from other equations.

PID: 010d

Unit: km/h

Min: 0

Max: 255

Equation: {A:7}

OBD Header: 7E0

**BSFC**

This equation gives the Brake Specific Fuel Consumption at WOT.

Equation (2.0L): (((-0.000025*[0c])+.59)*abs(val{IsRpmGT3584}-1))+(((.000029*[0c])+.40)*val{IsRpmGT3584})

Equation (2.4L): (((-0.000056*[0c])+.68)*abs(val{IsRpmGT4096}-1))+(((.000037*[0c])+.30)*val{IsRpmGT4096})

OBD Header: 7E0

P.S I'm still working to improve this formula based on the engine load when you are not at WOT...

**T-Outlet PR**

This equation gives the pressure ratio as seen by the turbo outlet. I used an average value of 0.5 PSI drop to compensate for the pipe/filter restriction and 1 PSI drop for the intercooler. Depending of your setup and what you want to monitor, you can change these values to accommodate your needs.

Min: 0.0

Max: 3.0

Equation: (([0b]*.145)+1.0)/(([33]*.145)-0.5)

OBD Header: 7E0

**T-Intake PR**

This equation gives the pressure ratio as seen by the intake manifold.

Min: 0.0

Max: 3.0

Equation: [0b]/([33]

OBD Header: 7E0

**T-RPM**

This equation gives an estimate of the turbine/compressor RPM based on the turbo pressure ratio of the td04-19t compressor map. The number is only valid while you are in boost.

Unit: x1000

Min: 50.0

Max: 175

Equation: ((((val{T-Outlet PR}*80)-30)*(([0c]*.000015)+.91))*val{IsBoost})+(abs(val{IsBoost}-1)*50)

OBD Header: 7E0

**T-Inlet Air Temp**

This equation gives an estimate of the air temperature at the turbo inlet. This estimate assumes that 65% of the air entering the air box is provided by the intake air temperature and 35% by the ambient air temperature at 0 km/h (Idle). As you go, this ratio is changed to reach 100% of the ambient air temperature at 128 km/h. This model is based on data that I collected on my car last summer. You will need to create an extra PID reading this value if you want to convert it to Fahrenheit instead of Celcius.

PID: 010d

Unit: Celcius

Min: -40.0

Max: 215.0

Equation: ((([46]*((.005*A)+.35))+([0f]*((-.005*A)+.65)))*abs(val{IsSpeedGT128}-1))+([46]*val{IsSpeedGT128})

OBD Header: 7E0

**T-Outlet Air Temp**

This equation gives an estimate of the air temperature at the turbo outlet. You will need to create an extra PID reading this value if you want to convert it to Fahrenheit instead of Celcius.

Unit: Celcius

Min: -40.0

Max: 215.0

Equation: ((((((((val{T-Inlet Air Temp}+273.15)*((val{T-Outlet PR}*.2)+.8)))-273.15)-val{T-Inlet Air Temp})/.7)+val{T-Inlet Air Temp})*val{IsBoost})+(abs(val{IsBoost}-1)*val{T-Inlet Air Temp})

**IC Efficiency**

This equation gives an estimate of the intercooler efficiency. You will see a negative result when you are not in boost since the air entering the IC is cooler than the intake air temperature (the equation acts a heater in this case). If you do not want to see this, you can multiply the equation by val{IsBoost} to filter out the result.

Unit: %

Equation: (((val{T-Outlet Air Temp}-[0f])+1)/((val{T-Outlet Air Temp}-[46])+1))*100

OBD Header: 7E0

**VE**

This equation gives an estimate of the volumetric efficiency based on the RPM.

Unit: %

Min: 0.0

Max: 100.0

Equation (2.0L): (((.005*[0c])+81)*abs(val{IsRpmGT3584}-1))+(((-.005*[0c])+117)*val{IsRpmGT3584})

Equation (2.4L): (((.009*[0c])+53)*abs(val{IsRpmGT4096}-1))+(((-.006*[0c])+115)*val{IsRpmGT4096})

OBD Header: 7E0

**Volume Air Flow**

This equation gives the volume air flow rate of your turbo car.

Unit: cf/min

Min: 0.0

Max: 500.0

Equation (2.0L): (1.998*val{VE}*[0c]*val{T-Intake PR})/5660

Equation (2.4L): (2.359*val{VE}*[0c]*val{T-Intake PR})/5660

**Mass Air Flow**

This equation gives the mass air flow rate of your car.

Unit: lb/min

Min: 0.0

Max: 100.0

Equation: val{Volume Air Flow}*val{Air Density}

**Mass Fuel Flow**

This equation gives the mass fuel flow rate of your car. Bank 1 - Sensor 1 Lambda has been used to measure the A/F ratio.

Unit: lb/min

Min: 0.0

Max: 100.0

Equation: val{Mass Air Flow}/(14.7*[34])

OBD Header: 7E0

**Horsepower (At the crank)**

This equation gives the horsepower at the crank.

Min: 0.0

Max: 300.0

Equation: (val{Mass Fuel Flow}*60)/val{BSFC}

P.S Multiply this equation by val{Sea Level Comp) if your want to normalize the result to sea level, 30 celcius, 50% relative humidity.

**Torque (At the crank)**

This equation gives the torque at the crank.

Unit: lb.ft

Min: 0.0

Max: 300.0

Equation: (val{Horsepower (At the crank)}*5252)/[0c]

OBD Header: 7E0

**Torque (At the wheels)**

This equation gives the torque at the wheels based on the circumference of my 215/55/R17 tires.

PID: 010d

Unit: lb.ft

Min: 0.0

Max: 3000.0

Equation: ([0c]/(((A/60)/.0021)+.001))*(val{Torque (At the crank)}*.84)*(A/(A+.001))

OBD Header: 7E0

P.S Replace .0021 km (or 2.1 m) by the circumference of your tires for more accuracy.

**Fuel Instant**

This equation gives the instant fuel consumption of your car. I used 1.68 pounds/liter of gasoline at 25 celcius in the formula. The gasoline weight is compensated using the ambient temp.

PID: 010d

Unit: L/100 km

Min: 0.0

Max: 100.0

Equation: ((val{Mass Fuel Flow}*60)/(1.68/((([46]-25)*.00095)+1)))*(100/(A+.001))*(A/(A+.001))

OBD Header: 7E0

**Fuel MPG Instant**

This equation gives the instant fuel consumption of your car in miles per gallon.

PID: 010d

Unit: MPG

Min: 0.0

Max: 100.0

Equation: (((100/(val{Fuel Instant}+.001))*3.785)/1.609)*(A/(A+.001))

OBD Header: 7E0