The 12C utilizes an active rear wing that rises at speed or in “active” mode, and flips up to near vertical under heavy braking to act as an air brake. To continue their engineering brilliance, the McLaren engineers were able to get away with much smaller and lighter motors since the design of the wing’s hinges uses the aerodynamic forces to change the wings position instead of using much heavier and stronger motors that fight the aerodynamic forces.
The Functional diffuser is one of the main reasons for the 12C to need a ‘heave-spring’ to combat squatting due to the downforce.
There are aerodynamic touches everywhere you look. Near the front and rear wheels are these deflectors which channel the air from under the car out to the sides.Even though the 12C is supposed to have more front downforce than a 458 (According to Sport Auto, the 458 has 70lbs of front lift and 68lbs of rear downforce while the 12C has 4lbs of front downforce and 136lbs of downforce at 124mph) it does not feel as neutral as the 458 and the front of the car could greatly benefit from more aero grip. Even a Camaro Z28 has noticeably more (front) aero than the 12C. This excessive rear grip does mean that the 12C is able to put power down extremely well for having over 600hp on street tires, but does so in a safe and understeering fashion.
Through Riverside, the 12C sustained an average of 1.10 G’s and a 95.9mph minimum cornering speed with front grip being the limiting factor through this sweeper.The real magic of the car is not only in its interlinked hydraulics of its suspension, but the active braking and “Brake Steer”. When entering a corner too quickly to the point where the front tires should push off the road; the ECU applies brake pressure to the inside rear wheel to help turn the car. The result is corner-entry balance that is very neutral and rarely pushy. To take corners quickly I found myself carrying slightly more entry speed, allowing the Brake Steer to work its magic and help turn the car better than it would have done mechanically, getting most of the turning done before applying throttle where I was met with understeer. In a sense, it kind of drives like a 911.
 |  |
Brake pedal feel is firm and cold bite is good, but once you get heat into the ceramic discs, the mu increases and the bite becomes much greater. When hard on the brakes, the rear spoiler flips to near vertical in the rear view mirror, creating a ton of drag like an airbrake to improve the car’s braking ability. This is a really cool feature and I find myself glancing in the mirrors under braking a lot more than I should be.
With the air brake deployed, the 12C spiked to an impressive 1.22 G’s of deceleration.In Track Mode, the traction control wasn’t intrusive and allowed for a slight amount of yaw angle in the car. It was difficult to get the car out of control which makes the 12C very safe and friendly for those with less experience on track. My biggest complaint was when the car got light over crests in the road, all of the power was cut until the car landed and recovered. This made it difficult to power over a few rises in the road at Buttonwillow like Cotton Corners and Lost Hill, but this conservative programming would probably save most drivers especially on a twisty mountain road.
After a few laps I needed to turn traction control all the way off. But this also requires a few hoops to jump through:
TRACTION CONTROL OFF:
-Push and hold the brake with your left foot.
-Press and hold the “Active” button for ~10 seconds.
(Once the dash prompts a TCS OFF confirmation):
-Release the “Active” button and push and hold the “Aero” and “Manual” buttons simultaneously for another ~10 seconds.
(The dash flashes red and confirms TCS OFF).
-Release the two buttons and now TCS is disabled.
*I would prefer just a simple “TCS OFF” button and preferably one that you don’t have to hold for over 5 seconds like most manufacturers do these days.
