Phases of the Corner

In my last post talking about an iRacing IMSA race at Long Beach I mentioned corner phases. These were just stated as a matter of fact and not really explained. Thankfully they are pretty easy to understand. They are a way to consistently break down corners. Normally this would be something a driver and engineering team would work on forming together, but it is just me here, so this is how I like to think about corner phases.

I normally try to break each corner down into five parts. Phase 1 being initial entry to the corner, when I come off the throttle and start applying the brakes but have not really started turning into the corner. Phase 2 is the transition to steering into the corner and starting to blend out of the brakes. Phase 3 generally does not have a throttle or brake input and is just trying to balance the car's rotation through the slowest part of the corner. Phase 4 is effectively the opposite of phase 2, starting to roll onto the throttle and unwind the steering. Phase 5 is also effectively the opposite of phase 1, the steering is most of the way back to center and I am back to wide open throttle (WOT).

Phases of the Corner, Speed Secrets by Ross Bentley

The phases do not have to have the same length corner to corner or phase to phase. It all depends on what the driver is focusing on executing to maximize the corner. I have found that using desire / intention of the driver as the differentiator between phases makes communicating across a variety of corners significantly easier.

The number of phases can also be tailored to the drivers experience level. An inexperienced driver probably doesn't have the mental bandwidth to break the corner in to fifths while still driving at the limit. Breaking the corner into thirds, entry, middle, exit, can be a lot more manageable. At the same time a very experienced driver might want more fidelity to describe what they are feeling / asking of the car.

Hopefully this quick primer on phases of the corner and the way that I use them helps clarify that post This article will also be linked at the bottom of any posts in the future that reference corner phases.