Steering
This will be a three-part blog series on feel, what is actually is (through the controls and the vehicle itself) starting here with steering then to brakes and throttle all including “seat of the pants” which is the literal backside of the feel part, make sense?
We’ve all collectively laughed an exasperated laugh when we see photos like these, how, why, who…we have so many questions, how can someone not feel this?
It seems like many things in motorsports everyone assumes everyone already understands these seemingly basic interactions with the car but when you dig in a level deeper in a conversation or watch someone steer in the opposite direction on a skid pad (which really really gets you attention!) or more commonly how people steer more for understeer blissfully unaware that they are decreasing front grip (read my past blog titled “Passive Overdriving”) that these basic understandings are not as universal as we assume and of course realize this “basic” stuff is well, basically everything in interacting with the vehicle but it often gets glossed over because, well, it almost seems silly to talk about.
Feel is everything. It is the both the information you use to drive the vehicle at its respective true limit and then the confirmation that you are using all the road at the same time, we use it for everything. Our eyes gather visual information continuously but our feel is the confirmation and real time information on whether the information was accurate, it’s where confidence comes from (check out the “Feedback Loops” blog).
People love looking at data post session and drawing all sorts of conclusions about the squiggly lines and how they compare to one another. All sorts of things are reveled and decisions made on what to do next session to go faster still, sounds about right correct? It’s not, the data is there to quantify feel, the data should only be confirmation of what we feel not a revelation about what’s going on out there. Data is for confirmation not information, let that sink in. Engineers use data to measure objective things the vehicle and driver are doing…they (at top levels) track the vehicle in real time see the terabytes stream Matrix style across their screens and for things like oil pressure that’s super handy but… they still value the communication to driver via the radio for gauging how the car “feels” it’s the summery of all the data (minus the oil pressure and like things that you can’t feel but are vitally important). The driver hears a weird noise from the powertrain and asked if the engine/gearbox is OK and is relieved to hear back all is well but the stuff that makes the vehicle go faster than the other vehicles is the drivers skill set (helping set up and actually racing) and the connection and resulting confidence they have in the moment with how it all feels. So, what the heck is feel as it relates to vehicles? I am careful not to just say “cars” because this is applicable to most speed sports but will often, for very obvious reasons, use cars as the example.
Steering is a great starting point because if you are even just an enthusiast you hear reviewers often mention whether a vehicle has good steering feel or not so what can we feel through the wheel and why is it important? Incidentally in parallel for Sim racers steering feel is a massive selling feature of the wheel bases because you are of course missing all the physical cues of being in an actual race car an on the sims this stuff is all nearly infinitely adjustable which can be a good thing if you have the experience to adjust things or can go horribly wrong if you don’t. In the sim you (and the sim software manufacturer) have to adjust for all the vehicles because yes, they are all different, it’s fair to say the steering feel is different in every vehicle you drive, ride or pilot. Even within the same manufacture the feel is different, there are general best practices that everyone at least loosely follow like luxury vehicles have a lot of boost to them (which makes the effort very light and intentionally filtering out the very feel we need to drive the vehicle effectively at its respective limit) and then heading across the sliding scale to land at performance vehicles where the effort is much heavier and all the feel is theoretically left in. So, what is the luxury car missing? What is actually there in the wheel to feel?
To understand this you have to know what’s connected to what, in simple terms it starts at the tires contact patch with the surface and ends at the steering wheel itself, so; tire, wheel, hub, tie rod, steering rack, steering column and steering wheel. In between we have the tire itself, suspension/subframe bushings, suspension geometry, subframes and chassis flex, all sort of somehow attached or influencing that connection between the road and your hands. There may or may not be some sort of power steering pump that reduces steering effort which can be important for all types of vehicles. There is much talk these days centered around the electric systems that are now, by far more prevalent (because they help fuel economy) and their distinct lack of feel, the switch on and off and act generally less linier not just because of the electric pump but because as soon as you hook a computer to a mechanical system engineers can’t help but mess with everything and as usual you end up with something that now has latency and is non-linier in its responses and our brains hate that especially is they have been exposed to more transparent, predictable, faithful and granular steering systems that are analog hydraulic steering assist systems. You can mess them up to they are not all better but generally speaking you’ll always get more feel and finer granular feel from a well-designed hydraulic system (or better still no power steering at all). If you want the gold standard of steering you strangely have to go cheap, a kart or a Formula Ford are about as good as it can possibly get in the car world, why? Because they have no rubber bushings, heim joints from hub to steering wheel in the case of the kart no suspension at all to muddy the waters just pure unfiltered everything right into the palms of your hands… the steering wheels on karts and simple formula cars is literally alive in your hands. OK, so what’s there?
Before we dive headlong into the actual feel I must make the point that this doesn’t work very well to not at all if the driver in gripping the wheel tightly. “Gripping” the wheel can come from anxiety (lack of confidence), aggression or bracing, none of these are good in their own right but greatly reduce to completely mute the information coming through the wheel. We have to use left foot bracing (in a production vehicle), proper seat fitting in a purpose built one. Never driving on hope or optimism (constant leaps of faith trigger huge anxiety) and non-objective “send it” aggression, all will have you flying blind, ignorant of this vital information even existing
So, now that we are calm sitting in the vehicle with a delicate grip on the wheel at 9 & 3 what information is there? Torque is number one, in simple terms torque builds with load, the greater the slip angle at the tire (let’s just focus on lateral forces now) the more lateral G you are pulling the more effort it will require to hold the wheel at that angle the fun part is when you approach the limit of grip, at first you feel a vibration, a resonance (this is happening quite quickly in most cases and is subtly or grossly different from vehicle to vehicle), this resonance is the warning, the very little juicy bit of information we need to stop the car/kart from understeering. Don’t you dare add more steering here, if you’re on entry you can chuck a little bit of useful load on the offending tire and then we can add some steering but we have been warned and as you might guess if we do add steering now without increasing load up front we will start to understeer and the steering will suddenly go light. You might hear some tire noise somewhere before the limit but they aren’t super reliable since it varies greatly from car to car and tire to tire (some make no squeal noise at all). What is squeal? High frequency resonance. So, the wheel in a good vehicle will load up slightly vibrate and then go light. What else is there? Well in a car/kart it’s a four wheeled vehicle so there is an inside and an outside tire, because of steering geometry (Ackerman, scrub radius etc..) and lateral load transfer the wheels don’t start sliding at the exact same time, usually the lighter loaded inside tire slides fractionally before the loaded outside tire…all of this can be felt in any good steering system and why enthusiasts/racers flock to simple pure systems. What an advantage to be keyed into this information allowing you to consistently be able to predict front tire grip without having to actually allow the car to understeer but at the same time knowing you are precisely at the limit, a huge advantage.
We aren’t done yet though, let’s talk about steering feel and braking, this becomes very important on mixed surfaces, most would assume (to simplify) that if you’re on a dry track that the grip is roughly the same across the width of the racetrack and this might be a fair assumption if you are still working on driving fundamentals, small percentage surface grip changes are far down the priority list well after things like line, braking and balance but at some point (hopefully) you get there and in that steering wheel under braking you can feel the slightest little torque differences (and front brake lock up) as the wheel is alive in your hands. I live in Colorado and drive in the snow and ice a lot, the amazing steering in my trusty Lancer Evolution is amazing at keeping me informed or available traction at all times. In a race car it is better still, you can instantly feel when you are out of the rubbered in groove which may just be the tiniest increment outside or inside but the torque will change at the wheel.
The trail brake entry phase (used in slow to medium corners) or in high speed corners (where the brake release is earlier) as you just tip it in start to laterally load up you get critical torque information about the most important piece of information available; available grip, most drivers turn in the same basic rate for all corners (and leave time on the table as a result) we should always use every bit of available grip right from the point of turn in…much time is left in the table by the “smooth is fast” crowd (you didn’t think this was going to be easy did you? One philosophy would work everywhere?), As the car loads laterally that wheel torque will build and load transfer will (not “weight” transfer, Google it), I mentioned the resonances/vibrations and potential sounds that would result as well as the torque but now we should mention seat of the pants with the back of the vehicle during all this because you can feel changes in the wheel and seat of the pants as the vehicle loads laterally and often if deceleration is involved, diagonally, if you can picture it you can see how that load would effect the torque through the steering wheel, any variance in load (how much trail brake, how quick the turn in) will have a tangible effect on rate of turn (yaw rate), these are the exact tools that make people fast, the seat of the pants tells us front vs rear slip angle as the rear intentionally pitches in with the turning we naturally reduce (to avoid getting to the apex too early) and this reduction of steering cause a reduction of torque felt at the wheel. All of these sensory inputs along with inner ear and visual cues (“spidy senses” are tingling away!) we have this super slow motion (in the moment flowing) feel, a very organic holistic feel (insert “one with the car” fluffy stuff here) as we use all the available grip to maximize turning rate (which gets you more radius, less pinching if you’re wondering why) and optimize balance as you hopefully efficiently carve into the corner with the wheel providing a large chunk of that critical timely information.
So… we’ve made it into the corner, congratulations but no time to rest and we (in low to medium corners) continue to add a bit of steering as we still decelerate the car (trail brake corners have varying minimal amounts of progressive steering since you continue to slow you can add more wheel proportionally), in fast non-trail brake corners we steer pure linier constant radius, in either case (but in different part of the corner) we will be thinking about throttle ASAP unless the corner is long in which case we will have a car balancing maintenance phase of some length (think carrousel type corners) so we are using steering wheel torque to know the fronts are optimally loaded and overall balance is on point then we open the wheel a hair and then start the acceleration phase, as soon as the load starts to transfer back we will feel the wheel going lighter and it will instantly go lighter still if we are rolling in too much throttle too soon vs. wheel opening (assuming rear or AWD). Just like on entry we’ll feel the torque go down a visually with inner ear we’ll feel the yaw rate increase and pull out some steering angle. If you haven’t read Optimum Drive, this granular critical fast balancing act is called “Zero Steer” (well by me at least! Hey if you invent/observe something no one has talked about, you get to name it!). You can feel rear slip angle build BEFORE the rear lets loose using these sensory tools, this is the key to it all, allowing a warning before the time lose occurs.
On the confirmation side, feel lets us know where the track limits are, obviously something as aggressive as curbing is very easy to feel but the more subtle finesse stuff to on a more granular level, cues like paint lines and hanging half a tire off the surface (where curbing doesn’t exist or over the curbing itself,) all is there at your literal fingertips allowing the confirmation that allows your subconscious to tick a box that in turn allows you to maintain your focus down the road on more important things
Imagine all that I just described without steering feel, how much more difficult driving a car at the limit would be, you are forced to attempt the high wire act of at limit car balanced with less sensory tools and how much more educated guessing (experience) you would have to rely on and how much less accurate that would inevitably be. Close your eyes now and imaging the purity of the sensory information that Kart or Formula Ford gives you and the accuracy it grants you…feel is everything to a driver.
To Be Continued…Part 2…Braking