Wednesday, July 25, 2012

Red Bull's engine maps

Mark Hughes has a revealing explanation on the Sky F1 website of the engine map loophole exploited by Red Bull last weekend. As the regulations are written, the torque demand at full-throttle, at any engine speed, can be reduced from the maximum possible torque demand at those revs by retarding/advancing the ignition.

In fact, on the basis of the regulations quoted here, it would even be permissible for the full-throttle torque demand to decrease as the engine speed increases. There seem to be three relevant regulations in this respect, 5.5.3, 5.5.5 and 5.5.6:

5.5.3  The maximum accelerator pedal travel position must correspond to an engine torque demand equal to or greater than the maximum engine torque at the measured engine speed.

5.5.5 At any given engine speed the driver torque demand map must be monotonically increasing for an increase in accelerator pedal position.

5.5.6 At any given accelerator pedal position and above 5,000rpm, the driver torque demand map must not have a gradient of less than – (minus) 0.030Nm / rpm.

Now, 5.5.5 is a condition which applies at 'any given engine speed'. Thus, at any fixed engine speed, the torque demand must be a monotonically increasing function of accelerator pedal position. This does not entail that the maximum torque demand must be a monotonically increasing function of engine revs; 5.5.5 quite specifically applies to a function at a fixed engine speed.

Similarly, 5.5.3 requires that at each fixed engine speed, the maximum accelerator pedal position generates a torque demand greater than or equal to the maximum torque demand at that fixed engine speed. Once again, this condition applies to a function at a fixed engine speed, not to a function of engine speed. In fact, 5.5.3 is entailed by 5.5.5, and is, strictly speaking, logically redundant.

Perhaps the FIA had something else in mind...

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