I was wondering what sensors are used for fuel corrections when using TPS as your efficiency load? Mainly I was wondering if both Baro and IAT are used to compensate for atmospheric changes.
The documentation mentions intake air mass is calculated using the speed density algorithm in this mode so I would assume yes, but I wanted to make sure.
And a follow up question, since the documentation says speed density is used with TPS efficiency load, does that mean this tuning method is different than the typical alpha-n tuning method most ECU’s use when TPS is selected as the load source? I was just wondering because I’ve only ever heard of the speed density algorithm being mentioned when using MAP as the load source.
Thank you!
The efficiency load type is a setting that changes how the load channel is calculated. In practice, this changes what variable is on the table axis when it’s set to efficiency load.
The efficiency load type doesn’t change how the engine air mass is calculated.
The air mass is always calculated by using VE, MAP, IAT, and displacement.
If you want to use TPS as the load on the VE table and have baro correction, you can use MAP as a baro sensor.
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Awesome, thank you for the info!
Follow up question, when you say use the MAP sensor for baro, is this a setting I have to enable or something the ecu does automatically if there is no baro sensor installed? Does it just measure the current barometric pressure when the ECU turns on before the engine starts?
Also is there any advantage to having a dedicated barometric pressure sensor over just using the MAP sensor for it?
Thank you!
Configure the sensor as MAP, but leave it open to atmospheric pressure.
This will multiply the fuel by the MAP value, which in reality will be baro pressure.
We will be expanding the fueling model in the future, so we will try to make this kind of setup more intuitive.
A dedicated baro sensor will give you better measurement resolution. Using a 300 kPa MAP sensor with 12-bit ADC provides a measurement with a resolution of 0.1 kPa. That is 0.1% of fueling resolution (0.2% at the top of the Pikes Peak) based on atmospheric pressure. I don’t see a need for a better resolution than this.