Throttle
This is the final control discussed in the three-part series on feel, in the first we talked about steering and the second brakes. That leaves us with throttle. What inspired me to write this is the same reason I always get motivated, I realize people are having conversation about a topic where everyone assumes that the other persons understands’ the topic but you notice after some observation that none of them really do, they’re just going through the motions. For example; everyone moans (rightly) about electric power steering systems being inferior but no one can describe what’s missing other than saying it lacks “feel” but that’s all! It kinda’ sets the stage for me to get frustrated or amused enough about it that here I am writing. I’m sure I missed some things you can feel through the car and controls so please “feel” free to add in the comments! I suppose in a way it all makes some sort of sense after all feel is not a conscious thing. All that information being pumped through the controls into us is very important but it isn’t really ever consciously acknowledged is it? I mean we want all the feel we can get because it subconsciously gives us information that makes us confident while doing something risky and that is a very good thing indeed. We balance that with our internal navigation system with our inner ear (6 axis gyro), the physical feel of g-forces and our eyes. As discussed there is overlap and redundancy there that when mashed together gives us a clear idea in the moment of how things are going…confidence.
The throttle, unlike the other controls doesn’t provide feedback per se but as we know it does effect the attitude of the vehicle in the corner and of course its primary mission, to shorten the straights. It’s different then, where the brake and steering both give actual information back the throttle is benign and numb. You may then just to the conclusion that you just monitor the attitude of the car and that is true but the throttle does effect the steering so in effect we can monitor steering to get another source of feedback on how the car is responding to the throttle. As a matter of fact it is the steering that will first warn you of too much throttle especially on a RWD car. Just as I described with the interaction between brake and steering we will instantly feel the steering lighten as the car starts to roll through neutral to oversteer as we start to rotate the rear, it’s due to the caster effect which is the wheel self-centering when you unwind it cause by the rearward lean of the steering axis which means you’re actually slightly lifting the car up when you turn the wheel, it is gravity’s (or loads) affect on the lifted front of the car that causes the self-centering force. The car naturally wants to settle down as low as it can get when a downward force is applied to it. So.. when you start to step the rear out the wheel will go light and start to unwind (as long as the car has positive caster and almost all do). If your good at picturing things you might now be saying hold on the front is getting lighter (reduced load) so the caster effect should be the opposite but there is a stronger force that makes the wheel want to straighten therefore get light. It’s the reason we like positive caster. It adds negative camber as you turn the wheel (that’s how it lifts the car), inside positive (which doesn’t sound good but it is, think about it) and negative camber on the outside wheel, it is the self-straightening tug on the wheels caused by the migrated scrub radius (that the caster caused) that we instantly feel. Now there is a whole chapter in Optimum Drive about the satisfying and very fast benefits of small amounts of beneficial driver induced rear wheel steering (as long as it is subtle, the wheel can’t go past straight, you start losing overall car grip at that point and you may be overheating your tires. Since straight is the limit I call this Zero Steer), we actually, ideally start Zero Steer just after turn and the slower the corner the more tolerant the vehicle (tire) is. I will conclude by saying something that will sound weird but it is subtle and important…You don’t actually need to be sliding to be doing this oversteer and understeer (and even zero steer) thing, it can all occur with the car not sliding when done right, you read that right, you don’t have to be sliding to have oversteer, understeer of Zero Steer, how? It’s defined by slip angle and the definition of a slide is more slip angle on one end vs. the other, it is just at some point the slip angle gets too great so the tire lets go and you now have a slide on that end of the car but before that happened the car was already understeering/oversteering/Zero Steering. It sounds very pedantic but this nuance is precisely where fast drivers earn their keep. If this distinction seems silly OK but how can you ever hope to be at that level if you are unwilling to see the subtle nuance that is required to be a great driver? Zero Steer is different than a four-wheel drift BTW, because the four-wheel drift allows for some counter steer, it’s plus or minus from straight while zero steer stops at straight and starts at the steering angle of the car going through the without any sliding. It’s a small but important distinction when you’re really trying to go fast. The particular slip angles in question are always variable, as we well know slip angle generates heat and too much slip angle generates well… too much heat but what that angle actually is littered with variables of the car and the tire, session length etc., all we do know is that we want to optimize it for any given situation.
This area is what some people call “throttle steering” and throttle steering always requires a reduction in front wheel steering. This as you can tell is all a delicate, granular balancing act the along with the brakes version coming in is the real joy of at limit driving. It all is hugely satisfying to have this level of control over the balance the therefore speed of the vehicle in any corner. As stated all of what the throttle pedal does is felt through the wheel and our inner ear and vision, all working tightly together to extract every ounce of efficient speed from the vehicle. On top of all of the sensations and information we can of course feel g-forces, all of this gets quite precise as we gain experience and confidence, as I often try to teach people a simple premise when driving, I want them to feel what fast is, real time in the vehicle, how it efficiently slips in and out of corners carving warping and tracking all due to deftly timed granular inputs that make the car willing to follow your instructions because it doesn’t have any resistance to any of it, you’ve seen to it by feeling, anticipating and refining everything every lap. Easy, logical, effective and devastatingly fast. Feel and Flow very much go hand in hand, Flow occurs automatically due to the accuracy of the feel that let’s our conscious mind to relinquish full control to our subconscious, simply, if it feels right we’ll flow. Feel puts it all in motion, enjoy the fast and efficient ride, you created it.