TECHNOLOGY – SIMULATION
Talent show How to determine if your driver is the real deal By DANNY NOWLAN
O
ne of the most hotly debated questions in all of motor racing is how do you pick the drivers with talent? This is not just confined to the vehicle dynamics community. Everyone involved in motor racing, whether they are a punter watching on TV or an F1 team principal, has a view on this. Well, lately I have been working on some projects that bring these matters into very sharp relief so, with the help of a bit of vehicle dynamics knowledge and
simulation, let’s take a dive into the key elements that define a driver with genuine talent, and how we can quantify this. To kick things off in this discussion, it’s worth reviewing the force vs slip angle curve and self-aligning torque vs slip angle as the relationship between these two is where the adventure starts. This is shown in Figure 1. The blue trace is the slip angle curve, and the purple trace is the self-aligning torque curve. Note the gap between the peaks of both. The ability to operate within
Fig 1: Normalised lateral force and self-aligning torque vs slip angle
this zone of detecting when steering torque starts to get light and fuzzy is the first element that sorts the drivers with talent from those who are simply there for entertainment, or to make up the numbers. The late Carroll Smith put this rather eloquently in his book, Drive to Win, when he presented the graphic shown in Figure 2. In theory, this should be simple to quantify but, over the last few years, two things have come up that have well and truly muddied the waters.
Power added The first is the addition of power steering. Okay, that’s not so new. PAS in the racing sense first started to appear on Sportscars in the ’90s and early 2000s, thanks to the amount of downforce they ran. It then didn’t take long for it to work its way into junior formulae, and it’s always been present in GT racing. The problem with prodigious amounts of power steering is it can often mask that weird, fuzzy feeling drivers feel through the steering wheel when the car is on the limit. The second element is the widespread adoption of Driver-in-the-Loop simulation, due in part to limitations on track time. I realise this sounds counter intuitive for someone like me to say this, given DIL is a key ChassisSim selling tool, but let me go into this in more detail. Most DIL
Fig 2: The Carroll Smith breakdown of driver talent from Drive to Win
76 www.racecar-engineering.com APRIL 2022
Fig 3: Plot of normalised combined force vs combined slip
