What is speed density Subaru?
What is Speed Density? Speed Density is a tuning method where the ECU uses information based on manifold pressure and temperature using the MAP sensor and an added IAT sensor to calculate how much air is coming into the engine.
Is speed density better than MAF?
Speed density offers an advantage in that it is better at handling high-revving engines than a MAF sensor is. Speed density is still preferred by many modified car enthusiasts, because tuning is simplified and because the wire within a MAF sensor can become an obstruction at very high power-levels.
What sensors are needed for speed density?
Speed density systems do their work first by measuring the temperature of the inlet air and then the manifold pressure via a manifold air pressure sensor, or MAP sensor. They then calculate a density of air with which the ECU can calculate how much fuel it needs.
What is a IAT sensor?
The Intake Air Temperature (IAT) Sensor is used by the engine’s Power Control Module (PCM) to decide at which rate the engine should spark and inject fuel to obtain optimal performance. Check your car’s service manual to verify the location of your IAT sensor so that you are able to repair if needed.
How do you get a speed density tune?
57 second clip suggested1:25:22Speed Density Tuning | HP Tuners Live Training – YouTubeYouTube
What makes IAT sensors go bad?
Over time the sensor can “go bad” due to a buildup of oil and debris, or it just simply needs replacing at a certain point. Ongoing inspections can help keep issues involving the IAT sensor at bay.
Does speed density used O2 sensors?
Production-based Speed Density computers also utilize an oxygen (O2) sensor mounted in the exhaust tract. The computer looks at the air/fuel ratio from the O2 sensor and corrects the fuel delivery for any errors. Most Mopar fuel- injection systems have used Speed Density too.
Can you tune speed density?
Speed Density tuning relies on a calibrated “Volumetric Efficiency” (VE) percent for each engine speed (RPM) and air density (typically Manifold Air Pressure). In a forced induction application, or an NA application with proper resonance tuning, it’s possible to see tables where VE exceeds 100%.
What happens if my IAT sensor is bad?
A malfunctioning IAT sensor may cause your vehicle to take longer to start on cold mornings. The faulty IAT sensor tells the car’s computer that the air in the intake is a different temperature than it actually is and may cause the vehicle to not deliver the proper fuel mixture to the engine.
What does the IAT sensor do on a Subaru Outback?
The IAT sensor is responsible for measuring the air temperature and density to achieve the optimal air/fuel mixture for any condition. P0113 is specifically thrown when the Outback’s computer sees a voltage signal of 4.91 volts for over half a second at the Intake Air Temp Sensor.
What does the pre turbo temperature sensor do on a Subaru?
On a Subaru, there is pre-turbo inlet temperature sensor that is integrated into the MAF sensor that measures the temperature of the air as it comes through the filter and into the turbo. This is used for intake temperature based compenations. Speed density uses charge temperature as part of the caluclation of air entering the engine.
Where is the IAT sensor located on the SD?
The factory IAT sensor is in the MAF sensor assembly in a draw-through configuration (i.e. pre-turbo). While it is possible to tune SD with an IAT sensor in this location, it is more difficult and will require more tweaking of the SD IAT compensation table (because this placement does not take into consideration turbo and intercooler efficiency).
Is it possible to tune a Subaru MAF sensor?
Between the extra piping, turbulance and/or pipe larger diamter, its easy to see that the MAF sensor is operating well outside the bounds of what Subaru designed. It is certainly possible to tune for these changes but even the best tuner can only do so much on some setups. Enter Speed Density (SD).