Q: “Is it better to treat the double apex corner as a single apex corner or is there room for a little more brake release — or quick blip of the throttle — to gain a bit more “mid-corner” speed through the short stretch of track?”
A: I’m going to use one of my favorite answers: “It depends.” It mostly depends on the length of the corner you’re talking about. But in many corners that can be driven with a double apex, I like to think of them this way: Drive it in hard and deep, collect it in the middle, and drive it out hard.
If you think about a corner that is about or near 180-degrees (Turn 2 at Laguna or Thunderhill, the Carousel at Road America or Keyhole at Mid-Ohio), there’s enough time in these corners to drive in fast, get the car sorted out in the middle of the corner, and then exit fast. If you drive them with the classic “in slow – out fast” approach, you’ll be slow because you spend too much time being slow! The corners are long enough to drive in fast and come out even faster.
To use this approach, you definitely use more of a double apex. If you use a single apex, you’re probably entering slower than necessary. This approach that I’m talking about is also referred to a “diamond” line because you tend to enter on a diagonal, clipping past the first apex area, letting the car drift out a bit in the middle of the corner where you turn the sharpest (and therefore are at the slowest speed, at the point of the diamond), and then are on an increasing arc, clipping past the second apex and exiting the corner.
Watch drivers on a short oval track, and you’ll see this style used a lot because they carry a lot of entry speed, turn the car the most in the middle of the long corner, and then get a strong exit off the corner.