BrandonH

Totally tangential to this discussion but something I found interesting as I come up the karting learning curve: Since a kart has no rear diff, it doesn't turn well, and will push right off the track under power. Consequently, the major suspension tuning is done with caster: positive caster to be precise, and lots of it. Reason being, when you turn the wheel left, the left front wheel kingpin is tilted so far back that the tire jacks up the left side of the chassis at the same time the right front wheel is rising. This has the result of lifting the inside (left) rear wheel off the ground. Now the kart is a trycycle, and can corner just fine. The net of all this is that the fast kart guys will dial in lots of lock at corner entry, in order to quickly get the inside tire unweighted. Then, they'll unwind the wheel leaving the tires pointed on the path to the apex. Ross Bentley actually mentions this in one of his books as a habit karters need to break when they switch to cars. As always, you want to be smooth and precise in a kart just like a car, but it has to be smooth, deliberate and firm. A gentle turn in with a kart just means understeer.

Back to the original discussion of sawing the wheel: as many have mentioned, at the limit you are making lots of tiny little corrections. Some racing school author, I think Carlos X in Skip Barber's faster, calls this "traction sampling," a method of nibbling away at the wheel to test in a controlled way exactly how much grip is left out there.

B

SundayDriver

Great comment. This is very noticable in the rain - breakaway can be sudden and the conditions are changing so fast you probably don't know where the limit is from lap to lap. The fast way around is to make sure you are always sliding in the wet so you know where the edge is. If it is the front that is sliding, you can drive it. If it is the rear, you will probably crash it. That is why you change setup, if you can, to severe understeer in the wet. You end up cornering with lots of steering corrections.

Geo

I think you'll find that it varies a lot by track and corner.

Bob Rouleau

Wow - what a lot of great input here. Just in case we've jumped over the basics and into PhD driving 603, I'd like to mention some basics we might have skipped over.

1) You should try and turn the wheel once without sawing. This is like the friction circle i.e. mostly theoretical. We strive for it but we don't always get it right.

2) You should pull the wheel instead of pushing it. We have more fine motor control when pulling so in a left hand turn your right hand should do most of the work, pulling the rim downwards.

3) Initiate the turn with a slow movement - the first ten degrees of steering wheel rotation should be done slowly then turn the wheel faster. That slow inititation transfers weight and sets up a better contact patch enhancing grip so you can add more steering lock without understeer.

Note, my comments are not to contradict what has been said by George, John and others. If you are driving at the limit, adjustments are a must. Our tires achieve maximum lateral grip just as they begin to slide. If you are truly at the limit your progress around the corner is a series of tiny slides and we need to make fine adjustments of the wheel and sometimes even the throttle. Note however, that most drivers who "saw" at the wheel are NOT even near the limit in my observations. I often sit next to a driver who enters a turn sawing at the wheel in spite of the fact that he is not carrying anywhere near maximum velocity. Some do it out of habit I think and it is a bad habit.

As to the comment about F1 drivers, plots from data loggers show that they have very smooth inputs. We see video of the wheel bouncing around but that's due to the very stiff suspension and bumpy tracks.

Best,

adrial

If you watch the in-car video for Fernando Alonso... you can see that he is a "sawer". At turn in he would just crank the wheel over...car would understeer (obviously). His front tires were holding up decently...the commentators were wondering how he wasn't demolishing them.

Geo

Thank you Bob, lest anyone mistake me for Colorchange or Ghettoracer. Nothing is absolute, but for sure minimal hand movements is a goal that is supposed to support the goal of quick laps. The reality is we almost always have little corrections near the limit. On a very smooth track the corrections are sometimes almost none if you're a really world class driver.

Again, thank you. I had visions of being labeled one of the Three Stooges (Ghettoracer, Colorchange, Geo).

I hate to go so far out on a limb because it may get cut behind me, but any instructor who tells you to constantly move the wheel is just dead wrong. A race car set up on the edge often needs constant small corrections, much the same as a fighter place which is always set up on the edge. But minimal movement (while still making the car do what you want) is still the best policy.

SundayDriver

Yes. The better the driver, the more corrections they are making. When you have a smooth track, the very best are making so many (tiny) corrections, that you can't see them. Us mortals saw visibly at the wheel but as skills progress, the corrections get smaller and faster.

RedlineMan

Hey guys;

Indeed, great stuff!

Never fear G. You can be occasionally cantankerous, but you are not myopic, ignorant, or blindly obstinant!

Indeed, students should be broken of the habit of sawing if they manifest it. They very much need to learn how much steering input is necessary for their car, in this corner, in these conditions, with these inputs. Try one steering input in this turn. BAM... frozen hands.

Try it this lap, at this speed, and see how your apex turns out. If it works, do it again. If it doesn't, analyze what you need - more or less input - and try that. Keep modifying it till you get it right. This is the only way they will learn how to analyze corner geometry, and what they need to do to make the car work.

Sawing around will never give them the FEEL of what works. They will never learn to feel those minute slips and wiggles in the chassis because it will be THEY that are inducing most of them.

If they start out sawing, they will never know how much input to use way back at the turn in point. They will never develope the skill of reading the corner, and will have to saw their way to the apex in perpetuity!

I have developed the "Broken English" style this year because of my new control placement. My new seat is fairly upright and distant for my long legs, and my steering wheel is extended 4" back and is fairly close to me. Reminiscent of Aussie Touring car for those who've seen it. This does not allow me to cross elbows because of the seat bolsters, but does allow a very high leverage ratio on the wheel.

Greg Fishman

One thing to add. The driver is making lots of small corrections but the car is taking a nice and smooth line. If you were blindfolded in the car you would not feel those corrections.

Geo

Whoa! Well put!

Quite right. One of the things I've observed is that too many people (including myself sometimes) try to go too fast too quickly. Yes, it's cliche, but it's true. I often have a hard time getting students to work up their speed over a few laps. Hell, I sometimes have a hard time getting them to take two slow warm-up laps, which can be used to try exactly what you are saying. Yes, slip angles change as speed increases, but that's also the reason for building speed slowly. I really have to remind myself sometimes. But the first few laps of any session is prime time for getting a feel for a smooth line through the corner. Increase speed incrementally and the sawing should be minimized.

Pretty much anyone racing something other than a formula car or sports racer of some sort will have to adapt the classic 3/9. Steering is just not quick enough in a production based car.

SundayDriver

Exactly Greg. Redline and Geo - all great observations.

One thing I do and teach - use the cool off lap to be precise. Drive it a 7 or 8 10ths, but hit every turn in point, ever apex and every track out. Be as smooth as possible because most of us have gotten at least a bit rough (with the exception of the two stooges - LOL) and that is the chance to clean things up.

Geo

Just to reiterate, two slow warm-up laps will set the basis for a really good session.

When I was at racing school I did my warm-ups at about 7/10 and 8/10 and they told me to slow down more. It was excruciating the first couple of times. But, I use it now. They explained that the warm-up is not only for the engine, dampers, bushings, etc., but also for the driver.

It's really tough to do two warm-up laps at 6/10 and 7/10 when everyone else is zooming by you, but it gives you a chance to refamiliarize with the track. Sounds silly if it's a track you're familiar with, but it does exactly what you're talking about. It gives you a chance to do two really clean laps with proper turn-in, apex, and track-out. Try it sometime. If you can get past the initial weird feeling of people zooming past you, you may find it can help you run better hot laps.

oldtimer

Hi Bob , just checking that you mean pull with left hand on a left hand turn ?

Thanks to all those who contributed to my initial post - its been very useful as I am due to go back on track at end of this month after an absence of 12 months .

MetalSolid

You guys forgot to tell him about the other steering control, under his right foot. Can sometimes be more effective for making those small corrections...

mitch236

This discussion brings up the old adage, "do as I say, not as I do". When I teach, I emphasize no sawing because at the speed the student is at, (s)he is nowhere near the limit. When I take that student out for a session in my car, often I hear the comment that my wheel is moving in the turns. Not big movements but it isn't static. I never really thought about it because when I drive, I am not thinking about such things but now in retrospect the wheel moves for two reasons that I can think of: one is the minor corrections required to keep the car's total contact patch as large as possible, the other cause is bumps kicking the wheel around in my hands. If I have to make significant corrections it is because I have lost one end (either under or oversteer). Once the suspension is set, I don't ever want to upset it with "sawing". I can't imagine this being faster, it may feel so but until I see proof it will be smooth for me.

As far as pulling vs. pushing with the hands, both hands should be involved. To use only one would remove sensory input. For your left turn, pulling down with the left hand gives strength but not much feel, the right hand gives feel but not much strength.

Geo is absolutely correct about warm up. I have a hard time sticking to it but when I warm up properly my hot laps are usually better. Not only that but my car is much happier.