Q: “A friend shares his old Road & Track magazines with me and I really enjoyed your Oct 2019 article. It initially caught my eye with the tartan on the helmet of my life-long hero Jackie. It grabbed me further in covering another hero, Mario. And finally, something I’ve been thinking about a lot over the past few years, which is your main point (that you’ve made before) about brakes being useful for way more than slowing down, and especially rotating the car.
“There is something that doesn’t make sense to me about this with what I’ve read or heard from you though. I’m not sure if this just hasn’t “clicked” for me yet on the track, or maybe I’ve been doing it all along and am expecting more. Sorting that out will take more coaching at the track, but meanwhile, there is a teaching point I’d like to ask you about.
“My challenge is understanding the emphasis on release when describing rotating the car. Specifically, is there something about the actual rate of release beyond, (1) not over-slowing, and (2) keeping some weight on the fronts to steer in the corner? Also, isn’t this “trail braking”?
“I’m asking because I have experienced rotation in some corners with my 911 race car with an abrupt brake release while steering in the corner; this won’t happen with a usual more gradual release. It makes no sense to me, but somewhere I read that releasing the brakes, which were “holding the chassis back”, can cause the car to “spring forward” and decreases rear grip to rotate the car. Is that possible? This isn’t what you’re talking about Jackie, Mario and Colin doing, though, I assume?”
A: Yes, the rate of release is used to manage corner entry speed and load on the front of the car. If the brake release is too quick, it unloads the front and that might lead to understeer. If the release is too slow it can over-slow the car, and possibly overload the front tires. The best drivers use the rate of release to manage speed and load on the front tires.
Abruptly releasing the brakes, from a vehicle dynamics perspective cannot help the car rotate. In fact, by quickly unloading the front tires, it’s most likely going to cause understeer. And I’ve heard all sorts of reasoning for how it might help rotate a car (most of which I don’t buy into). The only way to explain why popping your foot off the brakes might make the car rotate is that if you’re using up all the front tires’ grip for braking, then begin to turn in, you’re asking too much of the front tires and they may begin to slide – understeer. If you then quickly release the brakes, you’re giving some grip back to the front tires to turn the car.
For sure, Mario, Jackie and Colin did/do not abruptly release the brakes.
I talked about this in a video on my YouTube channel a few years ago. Watch The Key to Being a Fast Track Driver: How You Release the Brakes.