Skip to content

X-Tau Direct🔗

This module is responsible for compensating for the puddle of fuel that remains trapped in the injector ports rather than entering the cylinder.

It begins by calculating the following parameters based on engine speed and engine coolant temperature.:

  • x (fraction of injected fuel that remains trapped in the puddle)

  • tau (time for the release of the puddle mass into the cylinder) These parameters are then used to determine a number of other factors, including:

  • puddle fuel mass (the mass of fuel in the puddle)

  • desired fuel mass (proportional to the estimated air charge)

  • transient fuel compensation mass

  • fuel mass inducted into the cylinder

Manifold absolute pressure and throttle position delta are deciding factors that are used to enable and disable the x-tau direct system.