Saturday, October 27, 2012

[10/27/2012] HANSON School (DDT)

Event: HANSON International Driving School
Track: Mosport DDT, Skid Pad
Weather Conditions: 6°C, Rain

I just thought I'd stop by for a quick journal update since it's been a while. And before you ask, no there hasn't been any progress on my WRX since last time 

Last Saturday I was given the opportunity to help out the HANSON school as an instructor-in-training. This meant helping out on the skid pad. 

The weather was crap. Great for the students, but not so great for standing outside lol. I tried my best to spend as much time in student cars as possible to stay dry, but I still ended up soaked to the bone.

Even though I'm no pro, I noticed a lot of reoccurring errors from students when I sat in their cars. See if you make these mistakes. I know I've made every single one of them so it was easy for me to recognize since it wasn't too long ago.

Car Control vs. Going Fast
Rain plus skid pad is a very good way to find the limits of the car. There were many RWD cars (lots of FR-S!) and I noticed some of the guys were purposely trying to spin out or power oversteer. I asked them what their goals were, and found out that they wanted to get faster lap times. Drifting around a skid pad is great for car control, but ultimately it won't really help you set faster times. I switched their exercise from doing donuts to treating the skid pad like a big sweeping turn on a track. The new exercise was to imagine the pylon on the skidpad as the apex, and to try and take that corner as fast as possible before spinning out. That way, they could find the cornering limit while going fast in the wet.

Threshold Braking
Many instructors teach students to finish their braking in a straight line before starting to turn in. And for good reason too. On a track, trying to learn trail braking can get you into a lot of trouble. But for the more intermediate students who want to experiment or think they're read for trail braking, the skid pad is the perfect place to start. In addition to the exercise above, I noticed that students were braking WAY too early. They were braking 2-3 car lengths before the marked turn-in gate. If I was driving I would probably be braking 1 car length beyond the marked gate. So I tried to get them to push their comfort zone by braking later and using corner entry to scrub the remainder of the speed. This was easier said than done in the rain though 

Students who braked too early also had a tendency to turn-in too early. They would quickly realize they had more grip than they thought they had, and were moving into the centre of the skid pad too quickly. So, to adjust, they would turn the steering wheel back outward to "get back onto the racing line". Steering input should be one smooth arc, without many big corrections. Having an excess of grip like this means you can be going a lot faster into the corners, even in the rain!

Induced Understeer
The other thing I noticed everyone doing was trying to turn the steering wheel more and more once the car started understeering. This would result in the car vibrating (the tires are beyond its useful slip angle) and then occasionally going from understeer to oversteer once the tires regained grip. Everyone says that their cars understeer (especially on Subaru forums) but the real truth is that any car can understeer if you turn the steering wheel too quickly into a turn (smoothness) and/or point the front wheels past their useful slip angle. It's natural to try and turn the wheel more and more since we want to turn in that direction but the car isn't letting us! But the correct, and somewhat counter-intuitive thing to do, is to back the steering wheel off slightly, and once you feel the grip has regained (through your finger tips while modulating throttle/brake), continue to move the steering wheel back into the turn. The end result is many tiny back and forth corrections while making a turn. If you watch the hands of a race car driver closely you'll see them doing this.

F1 2011 - Mercedes GP - Onboard cameras with Schumacher and Rosberg in the MGP W02 - YouTube Skip to 1:25

Unfortunately I don't have any good photos or videos from this day as it was really rainy and I was too busy with students. But I did manage to get a good rip on the skidpad in my iQ lol. I can't believe how much grip that little car has, even in the rain!

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