I believe differentials distribute power to the other wheel right? Where would the power go to if both wheels are braking?
In: Engineering
Everyone’s talking as if this can’t happen. In fact it’s the usual method of braking for manual cars, hitting the brakes while the engine and transmission are still coupled.
Your assumption is that the engine somehow can overcome a braking force on its own and it’ll break something. That assumption is just false. It would stall before that happens. Engines operate on a torque/rpm ratio, and when you press on the gas pedal, what you’re really increasing is the torque.
As you press down on the pedal, more fuel mixture is thrown into the engine, alongside more air. This increases the engine’s torque output. If the output exceeds the torque needed to keep the car at its current speed, the engine’s RPM is able to increase, and the car accelerates.
Conversely, if you take your foot off the pedal, the engine’s torque output will decrease, and if it’s no longer enough to maintain the current RPM, the engine will slow down. So, how does this behavior factor into braking?
When you apply the brakes, you increase the torque needed to rotate the wheels tremendously. Such a sudden increase overwhelms the engine’s current torque output and, as explained above, the RPM drops dramatically as a result. When it drops under a certain threshold (around under 800 RPM for gas engines, around 650 for diesel), the engine is in a critical operating state where it may no longer be able to sustain its own rotation and might stall. If you apply the brakes suddenly enough, it most certainly will.
Does this apply extra strain on the shaft, clutch and other internal components? Yes. Is it enough to break them? Not by a long shot. Not if the internals are in decent condition anyway. Learning to drive manual would get you used to this concept, considering how often instructors will just slam the brakes while in traffic without hitting the clutch, and stalling the engine.
Latest Answers