If you race enough, you will eventually find yourself racing in the rain. But with a little knowledge, the art of rain racing can quickly turn into a science
Indeed, it was a stunning 2018 National Championship Runoffs at Sonoma Raceway, with racers witnessing only the lightest of drizzles. But in return for such a majestic week, Mother Nature decided to soak several early rounds of the 2019 Hoosier Super Tour and U.S. Majors Tour, pounding the events with unrelenting rain. For these southern racers, many were left holding the umbrella in their paddock space and sporting a confused look – how do you race in the rain? Let’s answer their quandary.
“Depending on the weather, if I need to, I really like using good old Dawn dish washing soap,” says multi-time Runoffs winner and SCCA Pro Racing Trans Am racer Lawrence Loshak. Over the years, Loshak has certainly seen his fair share of adverse weather, with perhaps his rainy swan song coming in the 2013 Formula 1000 Runoffs race where he started last in a rain-soaked race at Road America and passed everyone at least once to take the National Championship.
“Just like you are waxing a car,” Loshak continues with his dish soap trick, “inside of the windshield, you buff it in. You don’t want to completely remove it. It will leave a little haze, but a little haze is a lot better than fog and not being able to see anything.”
While the layer of soap helps combat windshield fogging, keeping things dry, and moving air across the surface, is also useful. “In the Trans Am car, we do run blowers,” says Loshak. “But the most important thing in a GT car is sealing up the cockpit. Again, it’s moisture – you don’t want any water getting into the cockpit. Seal the firewall and all of the body panels so when you go through a puddle no water gets into the car. The better you do with that, the less fogging you’ll have. Blowers to blow on the windshield help, of course, but no blowers in the world will help you if you don’t seal up the car and put Dawn on the windshield.”
If you’re racing an open cockpit car, the recipe is a little different. While you can treat your visor to the same anti-fog formula as a windshield, managing other aspects can be more difficult. “You absolutely want to keep your helmet dry – dry, and already acclimated to the temperature that you’ll be racing in, because the shock in temperature change and moisture is what contributes to fogging up the visor,” Loshak notes. “You have to keep your hair dry – putting a dry helmet on your wet head doesn’t work. Obviously, you sweat but the helmet warms up with you.”
Blowers aren’t typically an option in an open-top racecar, so you have to use what you’ve got. “Once you’re racing, the air is your friend,” Loshak points out. “A lot of water doesn’t really get in your helmet; it will get on the visor, but it won’t get in the helmet. If you have a little circulation going through by the visor, that’s usually more than adequate.”
Car setup is another challenge, as most racers don’t get the opportunity to test and perfect a wet setup. “When we set up our racecars, how we choose the spring rates and shock valving, what we are doing is controlling the platform for the amount of grip that we found at the tire,” says Loshak. “The more grip you have, the more suspension control you need. When we are going to race in the rain, we are going to have less grip, so, ultimately, the suspension setup for the dry is going to be way too stiff to allow for any kind of weight transfer, or to allow the suspension to do anything. We want to have the car move around like it did in the dry. Generally, it doesn’t need to have a spring change – obviously that helps if you have time – but the easy thing to do is to soften up the compression and rebound on the shocks and softening or disconnecting swaybars.”
It goes without saying that tire choice plays a huge role in your success on a wet track, both in the tire that you pick and the tire pressures you set. According to Tim Gilvin, Hoosier Racing Tire’s Circuit Racing Product Manager, if you see the cars on track throwing up any water spray, its time to put on wet tires.
If your class allows it, you can also give yourself a leg up by changing tire sizes when you make the move to wets. “Narrow is the way to go,” says Gilvin. “Less footprint equals more weight-per-square-inch on the ground.”
Because of the loads, the speeds, and the fact that you’re splashing through cool puddles, the temperatures the tires see in the wet are going to be less than in the dry; consequently, you need to compensate for that by starting with increased tire pressures. “For cars, it is around 3psi more than your normal dry starting [tire pressure]; open wheel cars should start about 1.5psi more,” advises Gilvin.
Some road racing classes offer more liberal rules when it comes to tires, and this is another place you may find an advantage. “As much as Club racers hate to spend the money on another set of tires and wheels, intermediates are worth their weight in gold,” says Loshak. “For my 2013 Runoffs championship, it was a gamble to go out on intermediates – which is essentially a hand-grooved softer dry tire. I had to be very cautious during the first few laps, but as the track dried, I could drive a lot more aggressively while the other guys were babysitting their tires.
“Intermediate wet tires are perfect for times when it rained before the session, or it rained all night long, and you are the first session out,” Loshak adds. “You are much better off, and safer, to go out on an intermediate tire than chancing it on a full slick.”
With your car sorted, you now have to find your way around the racetrack – a track that’s suddenly fighting you every step of the way. “Just the way you can read 100 books on suspension tuning but still have no idea what to adjust on your car, the same can be said with finding the rain line,” says Loshak. “But you definitely need to read about the rain line and learn what the rain line is, and what makes the dry line bad. The dry line gets polished, it gets rubber down, and there’s some oil – it’s the stickiest part when it’s dry, but it’s the slickest part when its wet.”
While it should be easy enough to move over a few feet and find some unpolished pavement on corner entry, the challenge comes when you cross the dry line. “The traditional line is really basic to understand, but you are going to cross the dry line multiple times, so you have to have a plan for your path,” says Loshak. “You will get a little bit of slip when you cross the dry line, and it’s very important that you don’t panic – just drive straight past the line. When you get to the outside of the line, where you will have grip, you turn the car. And then you want to come back to the middle so you can put power down.”
Finding the wet line isn’t always as simple as just staying off the dry line, however. “Finding the wet line on any racetrack is different because there are a lot of tracks that have corners that work into corners, or chicanes, or esses, and things like that; you have to experiment,” says Loshak. “You’re always searching for grip. The grip will migrate back to the normal line as the track dries, so you always need to nip at it to see what you can get away with. There are certain corners where there is no rain line, so you kind of have to do the dry line, but I would always keep the car toward the middle of the track as I’m looking for additional grip.”
To that end, keeping track of how the racecar is reacting, and what the rain on your windshield is telling you, will help yield the best results. “Make a mental note of what the car did, and the next lap improve upon that,” Loshak says. “If the car reacts good or bad or indifferent, you can make a plan of how you are going to go through or improve that corner the next time. That goes though my head every lap, wet or dry.”
This featured appeared in the May 2019 issue of SportsCar magazine.