Since writing the post Never Late Apex in 2015 and then revising it here I’ve come to realize that people have different ideas about the term Late Apex. Time to get it straight. Of course, when an autocrosser says “straight” better hold onto your wallet!
I’ve heard racing experts say, when advising how to drive a particular track, “You want to late-apex almost every corner” and they mean to be talking about the fastest way around the track. The problem is, what exactly do they mean by late-apex?
I’ve heard autocross experts say two things apparently interchangeably: “You want to late apex this cone” and “You want to backside this cone” as if they mean the same thing. To them, maybe it does mean the same thing, but not to me. What it tells me is not that the instruction is incorrect but that they might not actually know what late-apex means, though there’s no question about backsiding a cone. Backsiding a cone is an easily understood way of driving around a cone. It refers to the angle of the car as it passes the cone with respect to the general direction of approach. (There, I almost defined it.)
Late apexing a cone? Late apex, when it comes to autocross, is an extremely hard term to pin down because you apex, either late or early, with respect to an entire corner, not a single cone. A single cone on the autocross course rarely forms a complete corner, with the possible exception of a single cone turnaround. (Even then I would argue the point.) And a single cone within a corner may or may not be the proper apex, though you can always be wrong (and slow) and make it the apex. So, when someone told me to “late-apex that cone” I was always sort of confused, being as slow in the head as I am, until I realized they just meant to backside it. Hey, I can do that! Why didn’t you just say so?
Frankly, and this may shock you, I’m not even sure it’s worth thinking about the concept of late or early apexing for autocrossers once we get it all straight. I no longer use these concepts at all when thinking about autocross driving lines. They have zero utility for me. Maybe I can get you to that point as well. Maybe if I take the time to write it you will find it worthwhile to spend the time to understand it.
I’ve come to recognize three definitions for Late Apex. Maybe there are more, but I think these cover most of the territory. Number 1 is a simple geometry concept that can become exceedingly not simple in autocross. Number 2 is an actual technique for taking corners on a race track (with dubious utility on the autocross course) and is the one I was taught at my first track day. It sort of uses definition 1 as a given. Number 3 is the newest and best one, the one that as far as I know became fully developed only with the publication of Brouillard’s The Perfect Corner in 2016. It fully encompasses definitions 1 and 2. Using definition 3 apexing late or early is always a mistake when it comes to the fastest way around the track. There is only one correct apex for a particular car and set of conditions. All others are incorrect, in theory.
When I wrote Never Late Apex I was talking about definition 2 and attempting to relate it to autocross racing, not trackday driving. It can be found in many books and articles on performance driving and I’ve seen it taught to novices at various trackdays. (However, at least one person who claims to be a track instructor has told me I’m crazy, nobody would ever teach it to a beginner or anyone else.)
If you really understand definition 3 your whole approach to performance driving may change. Or maybe not. There is much to recommend the technique of definition 2 for the trackday enthusiast who knows it’s not a competition and chooses not to inordinately risk car or health. But, I think that a deep understanding of definition 3 will inform your technique, broaden your understanding and allow you to be both faster and safer.
(This is the end for part one. As I’ve sometimes done in the past, I’ll keep iterating with additional posts as I create diagrams to go along with the narrative. I’ll probably end up with 3 times the number of words necessary, but that’s the way this type of writing goes.)
To be continued.