In my last post, I detailed how the relays in the ECU system allow the system to flip to a default engine map. This lets the team keep running, even when something fails, and it decreases the chances of the ECU doing something that blows up the engine. Here’s a short explanation of what exactly an ‘engine map’ is and what it does.
Drivers
NASCAR Numbers 2019: Part 2 — The Drivers
Sixty-four drivers in 46 different car numbers ran for 37 full-schedule and 10 limited-schedule teams in 2019. But how did they do? And how does that compare to 2018? In my last post, I examined […]
Aerodynamic Forces
Keeping Racecars on the Racetrack
Ryan Newman escaped NASCAR sanctions for his comments immediately after being discharged from the infield care center at Talladega.
“They can build safer racecars, they can build safer walls, but they can’t get their heads out of their asses far enough to keep them on the race track and that’s pretty disappointing, and I wanted to make sure I get that point across,” he said. “You all can figure out who ‘they’ is.” […]
Aerodynamics
The 2019 Rules Package: The Tapered Spacer
NASCAR announced the 2019 rules package last week. Reactions from fans ranged from wait-and-see to despair to a surprising amount of anger. […]
Good basic explanation. The ECU runs in either closed loop or open loop mode. In closed loop it is receiving info from all inputs (sensors) within correct parameters, and so follows the closed loop map.
If some sensors fail, or go outside the normal operational data parameters, such as a temperature, oxygen sensor, or air flow sensor (MAF) the ECU goes into open loop mode, ensuring the engine wont go way too lean or way too rich, for example, but follows a “limp home” mode for ignition timing, and injector pulse width..
There however is nothing it can do if a cam sensor or crank sensor goes bad, it will lose all timing reference for injector PW and ignition spark events and the engine will not run.
And if the TPS,( throttle position sensor) fails completely, the engine will either die or remain at idle only,, depending on the ECU programming.