The art of racing in the rain

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Rain, rain go away.... 😛

There is no denying that rain can be the bane of our driving existence . We cringe at the thought of raising the top and driving through puddles and rivulets on the roads, dreading the clean up in store and cursing the weather gods. It also doesn’t help that often times our car is setup for summer driving and inclement conditions result in unfortunate situations for those caught unawares.

The fear factor is amplified all the more when you are on track and the skies open up. Rain decreases traction, reduces visibility, increases stopping distance, and will put you into a tail spin should you have a lead foot. Driving schools, HPDE’s, Auto cross events etc. are all about teaching car control skills that translate to educated driving in the real world and yet people shrink away from going out on track when it is wet. Why? If driving in ideal conditions on track instills skills,  so should driving in rain.

Rain is my best friend 😉

I still remember being flummoxed before going to my first HPDE, when someone told me not to stay indoors if it rained, and to go out and enjoy the rain. Rain they explained was a great equalizer. In the rain it does not matter how powerful your car is or what mods you have on your car. What matters is how smooth you are with your steering inputs, gas pedal and brake modulation. I was still not convinced as driving on track meant driving with the windows open and getting soaked while driving at a high rate of speed. Well as things turned out, I was going up through the esses at Watkins Glen (in my Civic Si) having given pass by’s to several cars (on the front straight), when it started raining. As I got on to the back straight I could see a full line of powerful cars slow down their brake lights casting a red glow on the wet track. Seeing the traffic I lifted off the gas, when my instructor said “step on it” and guided me on the line to take in the rain. As I passed all these cars (E30/36 M3’s, Other 3 series cars, Volvo coupes, Corvettes) I now saw the light through the gloom. The astonished look on the face of one M3 driver that had just passed me a few moments ago made it worth the while. It helped that I was driving a FWD car with all season tires, but the point I am trying to make here is, on track, rain can be a great equalizer, and I’d gotten even. 😀

With that said, I scoured the Competition and Racing forum to see if I could divine further insight that could be summed up for track enthusiasts, and here is what I found:

1. Rain is an equalizer: It wont matter anymore that you are driving a roadster with a mere 240 HP on all-season tires with OEM brakes. The winner will not be the driver that is driving the fastest car, but the driver that is the smoothest.

2. Be smooth – You need to get this into your head now. Smooth and gentle equals faster lap times especially when the track is wet. Per S2KI member Naka “If you become fast in the rain, you will fly in the dry. It’s all about smoothness. If you don’t upset the car, your limits of adhesion will reach a higher level.”

No stopping at the bus stop chicane

3. Follow the rain line – Ask your instructor to point out the rain line to you and stick to it. Avoid any standing water and always brake in a straight line.

4. Tires – Rain typically means lower track temps which in turn means your tires will never get to their operating temperature. Since you cannot reach optimum tire pressure it is suggested to start with higher cold tire pressures. This will keep your tire grooves open and decrease the chances of hydroplaning.

5. Be situationally aware – In the rain lap upon lap will result in changing conditions. Keep your eyes peeled and stay alert to the feedback from your car. That puddle which you passed last lap may have gotten bigger. Look for the dry line and stick to it. While passing always make sure you are doing it on a straight.

I also came across the following post by S2KI member Naka and felt it would benefit all of us considering running on a wet track:
Low traction conditions will greatly magnify mistakes that may go unnoticed in the dry. Like jerky, sudden inputs to the pedals or steering wheel, or getting on the gas BEFORE you start unwinding the steering wheel.

So, the theory of dry weather applies. More than ever:
Smooth steering inputs. Unwind steering when rolling on the throttle. Always track out. Do not pinch the steering. Do not stab on the brakes. Progressively get off the brakes as the car slows down, etc. You know, basic DE stuff.


Line: The line for wet weather driving is different than for dry conditions. You’ll notice that the outside of a turn tends to have more grip than the apex. Try different lines and find which one is the grippiest at any given track. Experimentation is key. Also, due to lack of lateral grip, try to make as many straights as possible with slow small turns in between. Instead of long continuous turns. That way, you can be on the gas more. You know: gas, brake on a straight line, complete the turn as soon as possible, on the gas again. And so on.

Revs:As a general rule, you want the car to be smooth, not only in the turns, but also on acceleration.
Too low of a gear and you’ll easily power oversteer. Only recommended if your right foot is extremely smooth and sensitive. Also, at higher revs, beware of engine braking. You could easily spin by just lifting of the gas. And if you are not EXCELLENT at heel-toeing, the engine could lock up the rear end under braking.
Too high of a gear, and you’ll be slow (not necessarily a bad thing if you’re inexperienced). But if you like to use the gas pedal as an OFF-ON switch, then a higher gear will help you stay out of trouble (for the most part). You will rarely find yourself having to use the gas to catch a slide since that usually makes the car oversteer worse. Unless you are trailbraking or transitioning the car from braking to accelerating. You should try to avoid trailbraking in the rain, though, unless you are very proficent at it in the dry and your car can handle it without drama.

Temperature: The tires will not heat up nearly as much due to constant cooling from water from the track. Evaporation is a very effective way of heat dissipation. And the significantly less tire deformation due to lack of grip will make this situation even worse. Meaning, the tires will never be at their optimum operating temperature, worsening overall grip even further (unless you use specialized rain tires, which work at lower temps).
Pressure: Since you cannot reach optimum tire temperature, you should start with significantly higher cold tire pressures to be able to reach a hot number slightly higher than your dry optimum pressures.
This pressure will maximize your contact patch. There is no magical number. But the best way to find this number, is with a tire pyrometer (which is just as important as a tire pressure gauge). But as general rule, you want to run higher wet hot pressures, maybe 5-8 psi above your dry hot pressure. Hydroplaning occurs mostly with underinflated tires, when the tire deforms and allows a center longitudinal channel of water run through the contact patch. The faster you go, the higher the chances of hydroplaning. An overinflated tire does two things. First, it decreases deflection of the tire while rounding the center. And second, it helps keep the groves of the tires open, facilitating water evacuation. These two things will help you against hydroplaning. As a side effect the contact patch, and therefore traction, is reduced. But: It’s always better to have less traction than no traction at all (hydroplaning).

user posted image

Soft is better in this case. It will allow more progressive transition of weight balance, allowing you to have more overall traction. You won’t be able to change directions quickly, but in exchange, it will let you have more grip coming out of a corner.

As a side note:
If you feel intimidated by the rain, it means that you don’t know how to drive in these conditions. Get somebody who knows ride with you and instruct you. If you become fast in the rain, you will fly in the dry. It’s all about smoothness. If you don’t upset the car, your limits of adhesion will reach a higher level.

Hope that helps. Everybody else, please feel free to correct any inaccuracies I may have written.

Smooth and gentle equals faster

Now that you are enthused and  looking forward to running on the track, come rain or shine, let me direct you to the S2000 Racing and Competition forum. Should you have any questions about your first track experience, please feel free to read through their FAQ or start a thread requesting information.

I hope that you will begin to count the rain as your best friend. Good luck.

Images courtesy of S2KI member Tadashi. Also acknowledging all the posts on Racing and Competition with advice on driving in the rain. Thanks to Triple-H for sparking the idea and Naka for his informative post and all the rest.

NOTE: S2KI welcomes the opinions of its members on the S2000 and on all topics related to the S. Should you feel the creative urge to pen a few words then by all means do so and PM energetic, aashish2 or Onehots2k OR send us links to what you would like us to write about and we will feature you (or your community) on the S2KI Home Page.

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