xpb Standard engine maps
02/24/2012
I n the last few days the rumor mill has been hot. A message haunted the forest that the FIA Renault and Mercedes had banned an engine program that, as in the previous year, allowed exhaust gases to be produced even when the engine was towed. A storm in a glass of water. First: During the test drives so far, everyone was using legal settings. Second, no one was banned from anything. Third: Renault was not involved at all.
Mercedes gives the FIA a tip
The truth looks like this. Mercedes engineers have discovered a loophole on how the FIA rules could be tricked and reported this to the world association. The FIA technicians reviewed Mercedes’s concerns and determined that there was indeed a way to produce exhaust by towing the engine. But at a high price. The fuel consumption would have risen dramatically, even worse than last year. And the intervention could have shortened the life of the engine.
This is exactly what the world association wanted to prevent, so that blowing on aerodynamic parts is restricted. Therefore the software of the standard electronics was rewritten in such a way that tricks should be impossible.
FIA adjusts regulations
FIA race director Charlie Whiting said: 'Our goal was to prevent the engine from producing exhaust gases when the driver takes off the accelerator. That is achieved through restrictions on ignition and injection. We have programmed all of these restrictions into the standard ECU. The ECU sets the limits for the engine people. You cannot program the maps outside of these limits. '
At least that's what the FIA engineers believed. However, the standard ECU allowed the mixture to be enriched between 50 and 200 percent on four cylinders in the so-called overrun, i.e. the phase of taking off the gas. Mercedes technicians have proven that extreme enrichment could result in delayed ignition.
This would have produced exhaust gases without the engine receiving torque. The FIA has now responded to the warning. The mixture may only be enriched between 75 and 125 percent in the overrun. 'We are on the safe side with that,' say FIA circles.
