The McLaren P1 is a hilariously complex and deliciously expensive hyper car. However, there is a simple and inexpensive secret lying underneath its rear end.
Where you might expect to find some fancy torque-vectoring, power providing, hard working limited-slip differential, instead you'll find an open-differential setup. That's right, your $1.3 million spaceship for the road doesn't want you laying down some sweet, sweet 11s. Why is that and what sort of system is at play here?
Jason Fenske from Engineering Explained is here to tell us all about that. He explains that the open differential works exactly as you'd expect it to. Power is sent to the rear axle, and the open system sends 50 percent of that power out to each wheel.
This could be a problem in a high-speed turn, where the outside wheel has the brunt of the load due to shifting centrifugal forces acting upon it. That tire is loaded up and ready for more power, but the inside wheel is keeping that from happening because if it gets more of that 50 percent split it's going to lead to wheelspin.
To counter this, McLaren employs a brake vectoring system. The engine sends all of the power that the driver is requesting and uses the brakes of the inside wheel to hold that roller back from spinning. This way the outside wheel takes on as much power as it can handle, which still falls under the 50/50 torque split. It makes sense when you see it drawn out in the video above.
Still, even with the added tech to keep the open differential working well on this car, it's a bit surprising to find such a system in the P1. Cost isn't an issue here, but perhaps McLaren are using that system in an even smarter way. What if the draw on the brakes during a turn is providing a regenerative boost to the batteries for the electric motors?
Now that open differential starts to look like a damn good decision, no?