Tires Singing in the Rain

By Andy Wiest

“If you think it’s going to rain, it will.” – Clint Eastwood

Here in the Pacific Northwest, rain is a reality. You really can’t fully enjoy living up here unless you accept Henry Wadsworth Longfellow’s prose that “into everyone’s life a little rain must fall.” It’s why there is a disclaimer on all BMW Puget Sound Car Control Clinics (CCC) and High Performance Driving Education (HPDE) events, “We conduct our events rain or shine.”

Yet many drivers in all skill categories avoid driving in the rain and have a dim view of driving in it. Which, from my perspective (and the perspective of a number of high level professional driving instructors, such as our own Ross Bentley) is a shame, because, as I discovered, driving in the rain on a track is a fantastic opportunity to hone your skills at slower, safer speeds, push your car closer to limits, and try new approaches to things. I thank our own David Lightfoot for giving me this perspective when he was my instructor during a downpour several years ago.

Why do so many avoid the rain? The primary answer is somewhat obvious. Rain reduces traction on the track, especially on “the line,” as that is where there is significant smoothing of the track due to years of friction, rubber deposits, and sometimes fluids, affecting that portion of the track negatively for traction when it gets wet. Most tracks have a “dry line” and a “wet line” for this very reason. Water can also pool on the track and creates a hazard that must be avoided or planned for in your line. There is also a visibility effect from rain that can be viewed as reducing your margin of safety. Ultimately, besides the safety concern, rain causes speeds to come down which many view as “less fun.” But is high performance driving really all about speed?

I discovered early on that the most joy in HPDEs wasn’t about the speed on the main straight. Almost anyone can do that…if that is all we wanted - driving fast in a straight (or “close-to-straight” for Pacific Raceways!) line - we could just participate in drag racing!

I find the most joy for me in HPDE’s is executing corners correctly and as close to the limit of speed vs. grip that I can. The second level of that joy, for me, is in consistently doing it. An instructor once told me during one of my sessions that, with respect to variance from “the line,” the difference between novices, instructors, and professional level drivers is that novices think and execute in yards, instructors in feet, and professionals in inches. So, executing that Turn 9 apex at Pacific Raceways repeatedly a few feet from my right mirror and hearing the satisfying “whomp” of the air pressure through my right window each time is extremely satisfying. (I couldn’t imagine only passing it by inches. Maybe someday?)

So how do we build confidence and muscle memory? One way is to execute at slower speeds and with less grip, so that we can get the car closer to the limit so we can feel it, but at a slower pace. Water on the track is one of the best ways to do this! Think about the skid pad in a skills course or car control clinic. It enables us to push the car over the edge into oversteer or understeer well before the natural loss of tire grip on a dry track, so that we can understand what it feels like. The same principle applies on the track.

Let’s talk about some of the advantages of less traction on the track.

• Speed. Less traction means speeds must naturally come down. This makes the environment safer for practicing more challenging maneuvers. Less speed enables you to “train your brain” to think more ahead of the challenges you are approaching. Have you ever been having a quick day on a dry track and realized you were now thinking more “behind” the problem because your skill level was pushing you to have less time to think between turns? Hopefully this realization didn’t come after an off-track excursion like it has for some of us! In any case, this is one mental aspect that tends to keep us from pushing ourselves outside our comfort zone. Before we get to a state of muscle and brain memory that enables us to do things without actively thinking (how we typically drive around all the time), we have to use our active thinking to practice it to build the mental pathways. This is hard if you keep reducing the timelines for thinking! Speed coming down lets us build these pathways so that we will end up be better in the dry.
• Grip. Less grip can actually be a good thing. How many of us are actually driving “at the limit?” Not many. We tend to keep a lot of margin on the track for many reasons…inexperience, trepidation, or not fully understanding how to sense the car. Think about how professional drivers fight to stay right at the edge of traction during turns (watch an in-car video of a pro driver sometimes…it is instructive!). They listen to the tires, feel the G-forces, and have trained themselves to sense these things so that they can push right up to, but not over, the limit. The wet track lets us do the same thing by reducing the grip (almost) uniformly – more below. The slower speeds also reduce the risk if you do make a mistake because you have more time and more track distance to recover. It’s a win-win.
• Experimentation. Less grip and traction variance across the track forces us to change our approach to braking, turning, and acceleration. It’s like having a whole new track to drive on! Take advantage of it. Try new lines and new techniques. Almost everything can be translated into a dry track context.
• Track Congestion. OK, so I am actively scuttling my argument a bit with this one since I am encouraging you to drive in the rain which will put more people on the track, but I think there are still enough drivers that will sit out a rainy session that this will likely remain valid. The truth is, there are always people unwilling to go out on the track during the rain. This means you have the track much more to yourself. The last time I was out on the track in the rain, only four (out of the ten or so in our group) went out. In the whole 20-minute session, I think I saw another driver twice. As my instructor stated, “it’s like you have the whole track to yourself!” If you’ve ever been “stuck in traffic” or had a much better driver “breathing down your neck” you know that can take some of the wind out of your sails for that lap, at least until the pass-bys occur and you can focus back on your own line again.

So, driving in the rain can be challenging and rewarding. While speeds must come down, I would encourage you not to just decide to sit out your session if there is rain. Think of it as a new set of challenges to overcome to refresh your enthusiasm for driving! I know that I do.

(Let me add another reason: smoothness. Smooth is fast and safe in high performance driving. Driving in the rain is the best way to train yourself to be smooth. With less friction on the track surface, it is a real challenge to not break traction. Every input needs to be smooth. Practice in the rain! --David Lightfoot.)