If I'm driving a new car (or bike/kart), or going to a new race track, or even if I know the car and track but just starting the weekend out my first task is to work through my process of figuring out how much grip I have.
When we think about "grip" we want to think about it in two ways:
- Braking and acceleration
- Cornering
For those that are astute with data, we think about these as longitudinal grip (braking/acceleration) and lateral grip (cornering). What we typically find is that the peak level of grip in one area will essentially be the same as the other.
For example, let's say your racecar can generate 1.5g's of grip. You'll typically find it can pull 1.5g's in braking and 1.5g's in a corner too (ignoring any anomalies on the track).
So, when I want to figure out how much grip I have I focus on one area: threshold braking. I will pick the corners on the track that require threshold braking and I'll pick a conservative brake marker to start.
As I start I'm hyper-focused on my initial brake application. Once I build tire temp and am comfortable my goal is to hit the brakes harder and harder each lap until I start locking up a tire or getting into the abs early in the braking zone. Once one of those things start happening I know I'm exceeding the limit of grip and I'll bring it back down slightly.
What the body does a great job of is feeling the limit of grip (g-forces) in one area and relating it to another. Meaning it does a good job at feeling how fast the vehicle is slowing down (how much grip I have in the brake zone) and naturally relating that to how much grip I'll have in the corners as well.
I like to build up to finding the limit and going slightly over the limit in the brake zones because it lowers the risk. By picking a conservative brake zone to start I can afford to lock a tire or get into the abs and then release off a little brake pressure to get it under control and still easily make the corner.