WOW! It will take a while to wipe this smile from my face. Team O'neil was great and on top of that I learned a ton. Sure it could be better by adding a little e-brake action to their curriculum but on the dirt it is not as important as what I learned. And what I learned was left foot braking.
Left foot braking really does work, and it works beautifully. Foot planted on the gas and the brake (simultaneously as I was driving a car with not so much power) to slide front wheel drive car. My prediction of keeping torque applied to the wheels so they don't lock up was quite correct. But I was incorrect as to why it would make a car slide. That is caused by the beautiful effects of weight transfer. Soft springs help exaggerate weight transfer front to back and side to side, which gives different tires more grip while removing grip from the other tires and it also loads the suspension so you can use the suspension to do tons of work for you. You can't even turn without left foot braking (or lifting with enough engine braking) in the Audi 4000s. The weight transfer from braking makes those front tires grip and it ends up turning the car. If enough weight is transferred to the front wheels and taken off the back a slide happens.
The concept of weight transfer leads into the Pendulum Turn, aka the Scandinavian Flick. You turn right to go left and vice versa. So you're coming in hot to a 90 degree left, what do you do in your front wheel drive Golf and you're on snow? Slide the car right. WHAT?! Yea, you want to load that suspension and scrub speed at the same time. Sliding is not super fast and it tends to slow you down (tons of friction compared to rolling wheels). But why slide the wrong way? Because that makes it easier to get a full 90 degrees or more of rotation the other way while scrubbing speed and now plowing into the apex of the turn. You use the potential energy built up in the springs of the suspension to help rotate you the other way. So post counter steer, when you get off the brakes (thats what caused the slide), the suspension unloads forcing weight to the rear and neutral side to side the rear tires bite, following in the footsteps of where the front tires are pointed. So that whips you around with some speed. But the unloading of the suspension does the rest of the work. Those springs push the car back around and they make it easy to spin right around (think 180). To make the car rotate even more in the flick just hit the gas for a moment when you come off the brakes. It will exaggerate the weight transfer to the rear tires causing them to bite harder.
In the VW Golf I kept coming into the pendulum way too hot, and you can see that on video. So I ended up taking a bunch of cones with me on my first few tries in the Golf. As always if you intend on practicing this do it somewhere safe.
Another big lesson and explains why I was trash with the golf in a pendulum turn was always look far ahead. Ive known to look ahead far on tracks and in karting, but when you're learning something new it can be difficult to look ahead. Look where you want to go, do not look at things you do not want to hit. So if there is a tree you're headed right for, look up the road you're flying off of, you'll have a much better chance of regaining control of the car if you're looking up. The instructor noticed I wasn't looking up when I kept forgetting to counter-steer early. He said I would have caught when to counter-steer earlier if i was looking further ahead because the cars frame would would make it more obvious as to where i was pointed. You can't rely on feeling sideways, you've got to see it. So with that my argument for video games as simulators is improved. And you can learn to look ahead by playing video games.
My looking ahead improved for tarmac driving (non-coned) after playing TOCA Race Drive 2 on my friend's computer (with wheel+pedals). My lap times were slow until I started looking far ahead in the corners, then I demolished my old lap times. I even out paced my friend. While It's not the same as driving for real, video games can help with certain aspects of driving, especially the hand eye coordination involved in driving.
The double clutching and heel toe downshifting I practiced weren't utilized this time around. We did most of our work in 2nd gear. The courses were set up, and it was slippery enough, that we didnt need 3rd gear. The VW and Audi motors weren't turbocharged so we didnt need to keep them where the power was. They had good torque for most of the powerband.
I have some video footage from the classes (not too much because I had plenty of other things to worry about) and that should be edited and put up on youtube/googlevideo at some point. One warning: video and fixed camera angles make cars look really slow. Also, my camera mount can get a bit shaky.
Overall I suggest you go, and tell them this site sent you :D Because I know I'm going back for 2 or 3 more days.
Showing posts with label pedal techniques. Show all posts
Showing posts with label pedal techniques. Show all posts
Thursday, March 22, 2007
Wednesday, February 28, 2007
Practice Makes Permanent: Pedal Techniques
Before I get to rally school I am practicing various pedal techniques. I'm doing this to accelerate the learning at the rally school and be able to focus not on what my feet have to do but everything else: How to approach a corner, controlling the pitch of the car with throttle and braking, etc...
The pedal technique I was asked to practice by the rally school is Left Foot Braking. The name says it all, it is braking (modulating the brake pedal) with your left foot. Why? I don't actually know but I'm guessing its so the front wheels of the car (in a FWD/AWD vehicle) don't lock up under hard braking or lose traction under hard gas. For example, say I want to pitch the car into an oversteer and I'm in a Subaru WRX. WRXs are AWD cars, as all Subarus are. That means if I want to break the rear end loose by accelerating hard (applying too much power to too little tire grip) the same will happen to my front wheels and I'll enter a four wheel slide or start to understeer (aka plowing, the wheels are turned but the car is going straight). That is where left foot braking(LFB) comes into play. Since the brake pedal of a car brakes primarily the front wheels, LFB can keep the front wheels of the car from trying to apply too much power to the ground and lose traction. If you see a WRC(World Rally Championship) car driving in the dark, often the front brake rotors will be glowing, although this could just be from hard braking.
Anyway I've been practicing modulating the brake pedal with my left foot and at first I was very hard on the brake because my left foot was used to clutching, not braking. Over time I got the pressure difference down with my left foot and now it clutches and brakes just fine. I initially started practicing LFB in a safe, empty parking lot just like when I learned how to drive. Once I became more comfortable with it I started using it in daily driving.
Another pedal technique I had read/heard about that was useful for high intensity driving was Heel-Toe down shifting. A misnomer for most pedal setups, Heel-Toe down shifts are now usually done with the ball and outside edge of the foot. What part of the foot is used depends on the pedal setup. A heel toe down shift consists of a few steps. The first step is to start braking with the right foot. When the revs drop to a certain amount (depends on the engine and what exit RPM you want), the clutch is depressed and held down by the left foot. The third and fourth steps are done simultaneously: The gear selector is moved to a lower gear while, with your right foot still on the brake, you blip the throttle with the outside edge of your right foot to bring the revs up. While still on the brakes the clutch is re-engaged (left foot comes off the clutch). That explanation of a heel-toe is not entirely correct, when you blip the throttle you're tapping it to bring the engine speed to what its going to be in the lower gear at whatever speed you're going. But the key element to a heel toe down shift is always having your right foot braking during the downshift.
Why would you heel-toe? Because you want to accelerate as soon as possible out of the turn. As well as being able to accelerate, in a FWD/AWD car it keeps the front wheels powered which helps prevent them from locking up. Locking up your wheels on tarmac is not good for stopping, or for your tires. Properly executed Heel-Toe down shifts also keep the car more stable in a turn. An abrupt downshift puts a load on the gears in the transmission, this load tends to change the wheelspeed and engine speed in an unpleasant way. In normal street driving the car will jerk, which is mainly uncomfortable and promotes wear on your drivetrain. However in 'high performance' driving the balance of the car can be upset mid-turn, this is bad. With tires screaming and grasping for traction in the turn, putting a load on them can cause them to break loose. So with a RWD car an abrupt down shift could cause you to oversteer and spin. I'm not so sure what it will do with a FWD car, but I imagine it could cause some understeer as the balance of the car could be shifted to the rear reducing traction for the front wheels. So I have been working on getting good at heel-toe downshifts.
Another downshifting technique is the double clutch. The Fast and the Furious brought the term to the new generation of drivers. The Fast and the Furious suggested it was used for straight line drag races, although it would of course be slower to double clutch in a straight line for upshifts and pointless. Regardless of most new drivers not knowing what double clutching is/was, it used to be a required skill for driving. Older cars transmission's did not have synchromesh gears. This means that in order to succesfully downshift, the driver had to shift to neutral, take their foot off the clutch, blip the throttle and then put their foot back on the clutch and shift to the gear they wanted. It may read like a cumbersome extended process but it is actually quite quick when executed correctly. With synchromesh gears double clutching is not required. However double clutching's purpose is still valid in modern transmissions. Double clutching was required to sync the engine's and transmission gears' rpm, but synchromesh gears do most of the work now. Double clutching a downshift is still smoother than relying on the synchromesh and saves on some wear and tear on the transmission and is very easy to execute.
The final pedal technique I've been working on is Heel-Toe Downshifting with Double Clutching. The heel toe technique is the same with the right foot, but blipping the throttle does not happen until the car is in neutral and the left foot is off the clutch. Then the shift from neutral to the target gear happens all while the right foot is braking. I'm not so great at combining the two so far, but it will come with practice and I've only been practicing for a few days. As with any new pedal combo I try it in either a parking lot or a very empty road at low speeds. Baby steps and patience, combined with a very forgiving car make this learning an enjoyable experience.
As with any practice it makes bad habits permanent. Practice does not make perfect unless it is perfect practice.
Hopefully my nifty camera mount from Stickypod will allow me to document these techniques and post them here as video.
The pedal technique I was asked to practice by the rally school is Left Foot Braking. The name says it all, it is braking (modulating the brake pedal) with your left foot. Why? I don't actually know but I'm guessing its so the front wheels of the car (in a FWD/AWD vehicle) don't lock up under hard braking or lose traction under hard gas. For example, say I want to pitch the car into an oversteer and I'm in a Subaru WRX. WRXs are AWD cars, as all Subarus are. That means if I want to break the rear end loose by accelerating hard (applying too much power to too little tire grip) the same will happen to my front wheels and I'll enter a four wheel slide or start to understeer (aka plowing, the wheels are turned but the car is going straight). That is where left foot braking(LFB) comes into play. Since the brake pedal of a car brakes primarily the front wheels, LFB can keep the front wheels of the car from trying to apply too much power to the ground and lose traction. If you see a WRC(World Rally Championship) car driving in the dark, often the front brake rotors will be glowing, although this could just be from hard braking.
Anyway I've been practicing modulating the brake pedal with my left foot and at first I was very hard on the brake because my left foot was used to clutching, not braking. Over time I got the pressure difference down with my left foot and now it clutches and brakes just fine. I initially started practicing LFB in a safe, empty parking lot just like when I learned how to drive. Once I became more comfortable with it I started using it in daily driving.
Another pedal technique I had read/heard about that was useful for high intensity driving was Heel-Toe down shifting. A misnomer for most pedal setups, Heel-Toe down shifts are now usually done with the ball and outside edge of the foot. What part of the foot is used depends on the pedal setup. A heel toe down shift consists of a few steps. The first step is to start braking with the right foot. When the revs drop to a certain amount (depends on the engine and what exit RPM you want), the clutch is depressed and held down by the left foot. The third and fourth steps are done simultaneously: The gear selector is moved to a lower gear while, with your right foot still on the brake, you blip the throttle with the outside edge of your right foot to bring the revs up. While still on the brakes the clutch is re-engaged (left foot comes off the clutch). That explanation of a heel-toe is not entirely correct, when you blip the throttle you're tapping it to bring the engine speed to what its going to be in the lower gear at whatever speed you're going. But the key element to a heel toe down shift is always having your right foot braking during the downshift.
Why would you heel-toe? Because you want to accelerate as soon as possible out of the turn. As well as being able to accelerate, in a FWD/AWD car it keeps the front wheels powered which helps prevent them from locking up. Locking up your wheels on tarmac is not good for stopping, or for your tires. Properly executed Heel-Toe down shifts also keep the car more stable in a turn. An abrupt downshift puts a load on the gears in the transmission, this load tends to change the wheelspeed and engine speed in an unpleasant way. In normal street driving the car will jerk, which is mainly uncomfortable and promotes wear on your drivetrain. However in 'high performance' driving the balance of the car can be upset mid-turn, this is bad. With tires screaming and grasping for traction in the turn, putting a load on them can cause them to break loose. So with a RWD car an abrupt down shift could cause you to oversteer and spin. I'm not so sure what it will do with a FWD car, but I imagine it could cause some understeer as the balance of the car could be shifted to the rear reducing traction for the front wheels. So I have been working on getting good at heel-toe downshifts.
Another downshifting technique is the double clutch. The Fast and the Furious brought the term to the new generation of drivers. The Fast and the Furious suggested it was used for straight line drag races, although it would of course be slower to double clutch in a straight line for upshifts and pointless. Regardless of most new drivers not knowing what double clutching is/was, it used to be a required skill for driving. Older cars transmission's did not have synchromesh gears. This means that in order to succesfully downshift, the driver had to shift to neutral, take their foot off the clutch, blip the throttle and then put their foot back on the clutch and shift to the gear they wanted. It may read like a cumbersome extended process but it is actually quite quick when executed correctly. With synchromesh gears double clutching is not required. However double clutching's purpose is still valid in modern transmissions. Double clutching was required to sync the engine's and transmission gears' rpm, but synchromesh gears do most of the work now. Double clutching a downshift is still smoother than relying on the synchromesh and saves on some wear and tear on the transmission and is very easy to execute.
The final pedal technique I've been working on is Heel-Toe Downshifting with Double Clutching. The heel toe technique is the same with the right foot, but blipping the throttle does not happen until the car is in neutral and the left foot is off the clutch. Then the shift from neutral to the target gear happens all while the right foot is braking. I'm not so great at combining the two so far, but it will come with practice and I've only been practicing for a few days. As with any new pedal combo I try it in either a parking lot or a very empty road at low speeds. Baby steps and patience, combined with a very forgiving car make this learning an enjoyable experience.
As with any practice it makes bad habits permanent. Practice does not make perfect unless it is perfect practice.
Hopefully my nifty camera mount from Stickypod will allow me to document these techniques and post them here as video.
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