How to Get Through the Apex

Posted on April 17, 2013

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How to Get through the Apex

And not sucking while you do it

By: Rob Oakman

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Luigi Ferrara neatly through the Apex at Misano CTCC
( courtesy touringcartimes.com )

You have successfully used your brakes to turn your chassis into the corner, but where are you aiming? “The Apex you Idiot” you are undoubtedly thinking aloud. Well, that is obviously the answer. But where is the apex, what is an apex, and how many are there, smart guy…or girl?

There is probably a dictionary definition for what an Apex actually is and where the etymology of the word comes from, but who cares. What we are interested in is how the word applies to Racing. Simply put the Apex is the point of the corner where you drive the furthest to the inside of the track. This is where you usually stop decelerating, start accelerating, and is what determines where you are going to end up at the exit of the corner, so if you get it wrong you cost yourself speed, time, and may end up eating gravel pit. Most people assume that the apex is at the middle of the corner…which isn’t necessarily true. The apex is however the point you are aiming for at entry, and there can be more than one.

There are four basic Radius and three basic subtypes of corner you are going to come across. Starting with Radius there is the Increasing Radius corner, which is sharp at the beginning then opens up wider as you go through it, the Decreasing Radius corner which gradually gets sharper, the Common Radius corner that stays the same all the way through, and lastly the Box or Square corner which is sharp at the entry and the exit, but opens a bit in the center. The basic subtypes are the Hairpin which is 180 degrees, the 90 degree Dog-Leg, and the Esses (Sometimes call a Rhythm section). These different types of corner determine where your apex is. Yes, we could break this down into more corners like Banked, Flat, and Off-Camber or fall-off, and then there are combos of corners, and we will, but let’s just keep it simple for now.

A proper racing line takes you from the extreme outside of a straight, to the extreme inside of the corner, and back out to the extreme outside of the next straight. Basically the apex is the sharpest point of the corner. In an Increasing Radius corner for instance, the apex is early where the corner is sharpest; probably in the first third of the corner. A Decreasing Radius corner has the apex late where it is sharpest; in the last third. A Common Radius corner has the apex in the middle…where a basic racing line is sharpest. A Box or Square corner has two apexes – yep, two; one in the first third and one in the last third. This is because a Square corner is a hybrid of an Increasing Radius corner connected in the middle to a Decreasing Radius corner. So..yeah, you apex at the two sharpest points of the corner…beginning and end.

At this point you are probably wondering why I didn’t just say that the apex is the sharpest part of the corner and move on. That’s because it sometimes isn’t. The apex is determined by the sharpest point unless you have a combination of corners back to back. See, I told you we would get to combinations.

Turn-15 Double-Apex at the COTA ( courtesy of circuitoftheamericas.com )

Turn-15 Double-Apex at the COTA
( courtesy of circuitoftheamericas.com )

In a combination of corners, regardless of how many are lined up in a row, you always set up for the last corner before the next straight. As I have discussed before your top speed on the straight usually has a bigger effect on time than any other part of a circuit so you want to get to the throttle in the last corner as soon as possible. If you have a 90 degree Dog-Leg left that leads directly into a 180 Hair-pin right you would Late apex the first 90 left so that you are on the extreme outside of the track for the entry into the 180 right. If you have a 180 left leading into a 180 right than you do the same and late apex the first corner. Esses are approached like this as well. Because they are just a collection of corners lined up one after the other– sometimes called the Rhythm section – you apex each one to set up for the entry of the next and so on until you reach the straight.

Banked, Flat, and Off-Camber corners, if they are constant in their bank – or lack there of – are approached like any other corner when it comes to apex. If however they are progressive – that is to say the amount of bank or fall-off changes as you go through it – then you change your apex to take advantage of the part of the corner with the most grip. Example, if the corner is a basic Hairpin but the banking is steeper at turn-in than it is at turn out-then you late apex. Because you get better grip in the banked section you can carry more speed on entry than you can on the flatter exit. So, you want to fly into the corner hard, braking as late as possible, and apex late so that you are straighter (Turning less) on exit when you want to accelerate. This allows you to carry more speed in but also allows you to accelerate hard on the flatter exit. The opposite is true if the corner gains banking as you run through. Apex early and get on the throttle hard to take advantage of the extra grip you get from the added banking on exit. Off-Camber works the opposite to Banking. If the track Falls-Off on entry than Flattens on exit you want to apex early. If it falls off on exit apex late. The point is to use the area with the most grip to gain as much speed and time as you can while minimizing the time lost in a low grip area.

This article has gotten a little long so I’m going to add a Part 2 to this. Next time we will get a bit more technical about how you transition from Turn-In to Apex seamlessly and give yourself the best exit for a fast run down the straight.

If you have any questions or comments feel free to send them along below and follow OakmanOnRacing.

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Posted in: How to Race