Racing 101 Cornering Question

The following is my speculation only and not speaking from experience.

I would hazard that the slow entry but fast exit would be the best for all three types of cars. It is perhaps the safest with the least chance of shooting off the course.

I hazard a guess that the differences between the three types of cars you mentioned may not be that much considering the chassis development that each of manufacturers have done to make the car neutral to gentle understeer in corners with oversteer featuring only on excessive throttle application.

The differences similar cars say 15 years back would be night and day.
A 80s 911 Turbo would be a wild ride for sure and would beg for a slow entry approach and gentle throttle out. A Ferrari 328 might be the most stable and go kart like while the similar era Corvette would be pretty neutral for sure.

Maybe the only corner where fast in and slow out may work is where you have long straight, corner than short straight where you maximizing the speed on the long straight and sacrificing the speed on the short straight.

 

Slow in and fast out is safer - usually, from my experience, that's where you draw the line on rules. So much depends on how the car is set up, tires, suspension, and entry speed relative to the optimal speed for exit all have to be factored into the ideal line.

Type 1 turns that lead to either faster corners and/or straights are crucial to good times and technique but whether you take them fast or slow - in will depend on where the car has just transited and you cannot draw a conclusion as to which type of design will work better on a fixed basis.

One thing I have learned though, is that rear wheel and rear engine is a better race car in almost all circumstances and speeds on a dry track than front engine and front wheel drive. With those two representing extremes, the remainder are going to have too many variables.

 

Fifty million folks will give you an answer, but as a Skip Barber instructor and a successful professional coach for two decades, I'll take a crack at your query...

The expressions "slow entry, fast exit" and "fast entry, slow exit" refer to the type of corner complex you are attempting to negotiate, regardless of the layout of the car. Examples of a "slow entry, fast exit" corner, which is WAY more important to master than a "fast entry, slow exit" corner are Summit Point T1, Savannah T4, Sebring T4 and T10, Road Atlanta T7, VIR T1, T4 and T12 (Oak Tree), Mid-Ohio T4 and T14 (Keyhole and Carousel) as well as T8 (bottom of Madness), Watkins Glen T9 and Laguna Seca T11.

Examples of a "fast entry, slow exit" that would be appropriate would be "throwaway" corners where the goal of increasing exit speed, at all costs, is mitigated by the fact that you must slow so soon after exit that there is no benefit to "slow entry, fast exit" and you are merely trying to maintain the greatest speed for the longest time in the broad range of the corner. Examples of a "fast entry, slow exit" are Lime Rock T1-T2 (Big Bend), Summit Point T5, BeaveRun T2-T3, Savannah T5A-T5B. "Fast entry, slow exit" is really the antithesis of the proper racing driver, as the goal is always to slow as little as you can, to maintain "fast entry, fast exit" above ALL else. <grin>

In analyzing each of the three configurations you've cited, and with the goal only of "slow entry, fast exit" or "fast entry, fast exit", the key is to utilize the centally mounted center of gravity of the mid-engined car to your best advantage by inducing rotation to get the car turned as quickly as possible.

The 430 may need to be "overslowed" more than the other two to initiate decisive and effective "turn-in", but should enable the competent driver to use more throttle, applied sooner than the others, due to the better traction of the mid-engine positioning, resulting in greater exit speed.

The rear engine 911 will brake better and more efficiently because of the way that the weight distribution significantly and substantially changes, but the light front end will require more driver machinations to get the front to hook up, such as more aggressive trail-braking (or "brake-turning") thus delaying that all-important throttle application.

The front engine, rear drive Corvette, specifically the current Z-06, is one of the most neutral, progressive cars I've ever driven and will brake well, turn-in well and allow modulated throttle to be fed as quickly as the steering lock is taken off!

In analyzing the data from the 997, the F360 (have not had time in the F430, yet <grin>) and the C6 Z-06, there is not much difference in the braking distances, corner entry or exit speeds between similarly street-tire equipped cars, but the way each of them do it is night and day.

To each his own and may all enjoy!

-Peter

 

Peter, your amazing knowledge humbles me, and color me wishfully hoping one day to know 1/2 of what you know. Wow.

 

Generally the quickest way through any corner is the slow entry/fast exit....especially if the exit is onto a long straight. If you overcook coming into a corner (fast entry)...you are going to either run out of road on the way out and have to back off, or you are going to have to scrub off alot of speed to maintain control.

I may not know alot........but I do know that!

 

Very nice write-up Peter!
I definitely agree with you on the Vette. I could easily match lap times between a C5 (even non-Z06) and an F360. I find the new Z06 a significantly more capable machine than the 360. I too have yet to get seat time in a F430 and that's with some disappointment after having spent all last weekend in the middle of them. Too many students to match my butt to a 430. Next time for sure

On T5a&b at Roebling - man, we do our best to make that a fast exit! Sure wish we could wring it out consistently. I've made a quick exit outa there a few times (quite a hairy ride through ) but have yet to find the magic dust to "know the formula" <hehe>

Thanks Peter!
Cheers,
Chuck

 

The proper technique is always fast entry - fast exit.

 

as Peter said it depends if you are coming off a fast straight to a turn or the corner leads to a fast straight were you want the highest speed exiting the corner so slow in sharp turn to a early apex then fast out

 

Peter,

Great post. I completely agree about the "fast entry, slow exit" corners you mentioned at Summit (T5) and Lime Rock (T2-T3). I was sitting down in turn 1 at Lime Rock a few years ago watching Auberlen and he was braking so much deeper than the rest of the field. Every time he wold break a little bit deeper (maybe a product of some Skip Barber training ??) and each time I thought this is it, he's going to lock up and go off. He never did and made up time on cars that were much faster down the straight.

I also think it needs to be mentioned that the "slow in, fast out" is more applicable to production based cars and that high down force cars such as Atlantics and Continentals don't need as much emphasis on the "slow in, fast out" approach since slowing too much reduces downforce.

There is also a huge contrast of driving styles in F1 and some like Button, and DC brake in the traditional straight line and then get on the gas slowly as opposed to someone like MS who doesn't brake in a straight line and adheres to the "fast in, fast out" principle. MS's has the uncanny ability to make the car rotate at the apex and adjust enough speed to make the turn but also to minimimze loss of time through the corner.

 

Jon said: "MS's has the uncanny ability to make the car rotate at the apex and adjust enough speed to make the turn but also to minimize loss of time through the corner."

That's the nail on the head!

Ted Wentz said: "The proper technique is always fast entry - fast exit."

True, but a lot easier said than done. <grin> Purpose built race cars help. Alot!

Steven, your video is great, and I have to tell you that your careful study and enthusiastic reporting of your adventures reminds me of why this sport, at whatever level be it track days or F1, is SO fun and addictive! You're doing great!

-Peter

 

Jon/Peter/and all the rest of you: You have a lot more experience than I do and are better drivers to boot. Thus, I'd like to follow up on a couple of points: (1) hitting a late apex, and (2) rotating the car.

Because most of my experience comes from motorcycles, where a slow in/fast out, late apex is the key to keeping the rubber side down and the shiny side up, this is my standard approach to any turn. Let's use a 90 degree left hander to illustrate. Here's how I'd do it:

1. I'd line up on the far right side at WFT.
2. When my nerves would fail me, I'll slam on the brakes and maybe bang a downshift.
3. When I can see through the turn, i.e., a late apex, I'd get off the brakes and pitch the car in towards the apex.
4. As soon as I turn in, I'll start getting on the gas to shift weight to the rear wheels.
5. Done correctly, I'd be at WFO at the apex and ready to bang an upshift at the track out point.

Hopefully, the result is that I'm at 9/10 on the turn in and at 10/10 on the track out. Comments?

When you mention rotating the car, are you talking about throttle steering? That is, you're at 10/10ths on the turn in so that you can rotate the rear by slightly lifting the throttle or push the front by giving it gas. In other words, are you transitioning between going 11/10ths on the front and rear tires. If so, do you normally take an earlier apex line?

Finally, when does four-wheel drifting make sense? I see it on the older cars, but it seems like the newer race cars rarely do this unless, of course, they are going in a 360 circle.

Dale

 

Dale, you say: "When I can see through the turn, i.e., a late apex, I'd get off the brakes and pitch the car in towards the apex."

Too late. That "when" takes time. Time that you're not on the brakes and not fully on the gas (most drivers aren't even on the gas from end of braking to nearly on top of the apex, even though they think they are), therefore there is a period of time between maximum braking and turn-in and a period of time between turn-in and seeing through the turn ("whacking" open the throttle, in your parlance).

To drive above 8/10 or 8 1/2 tenths safely and consistently, you must be able to position the car and "see" through the turn BEFORE YOU GET THERE. You must be so intimately familiar with the topography (radius, surface changes, camber gain and loss, inner and outer pavement extensions and curbing) of a particular turn or complex of turns that you know what is going to happen before you even get there.

The major difference between people who do this for fun and people who do it for a living (not mutually exclusive, I've found <grin>) is the successful management of the transition between the end of major braking and turn-in/throttle application. The truly quick are those who can "slow down," in their mind, all of the force vectors acting on the car and feel intimately, through their fingers and their butt, the ability of the tire contact patch (the ONLY connection with Mother Earth!) to counteract the desire of the car to fly off the road! <very big grin>

The reason I say you (and most) are too late is that developing this "visualization," or plan of attack before you get to the corner, promoted by Bertil Roos, Ross Bentley, Skippy and other fine coaches, is extremely important. To minimize the "down time" between all control inputs, you must almost have an "out of body" or "looking down from above" vision of what you're doing before you do it and reach the level of confidence required to have no null or to drive the car at the edge of the famed "friction circle." This is the reason why we can (and should) practice as often as we can to develop this set of skills.

When you ask: "In other words, are you transitioning between going 11/10ths on the front and rear tires?" Yes, and that is the hallmark of all pro and really quick amateur drivers. That is what I strive for, in whatever I drive, more from corner entry-to-apex and mid-corner than anywhere else in (including the exit of) the corner! If you can fully apply the throttle nearly anywhere in the corner while you have (or need to have) steering lock (input) on, you're probably overslowing and/or you are not at the limit of the car and the tires. It is a fact that nearly every car on any track can be driven quicker by someone else. It's all in your head... It's an intellectual exercise, not a bravery test.

You ask: "If so, do you normally take an earlier apex line?" Ding, ding, ding! We've got a winner! Yes! Yes! Yes!

The whole idea is that as we learn, we take the safest route, brake in a straight line, drive deep, turn a lot, apex late and unwind the wheel as we apply power. For years and years, I was the slave to the "DE" (drivers education) line. I'd haul down the straights and do exactly what you did, slam on the brakes, paste myself against the belts and rob my passenger of his breath as the harnesses squeezed the air out of him, go deep, slow more than I thought I had to to retain control, turn in more than I thought I had to get the turning DONE and "whack the throttle" as soon as I saw my way out of the corner. It was fine, fun and kept me and my charge on the black stuff. As in most learning situations, I had plateaued, driving harder, but not really doing anything except wailing on the car and exhausting myself.

One day, I was teaching the classroom part of a professional school and a friend of mine (who had been on the front row at the RunOffs several times in a GT car) asked if he could ride with me. We went out and I did what I always did. He was aghast! He couldn't keep his mouth shut after the first lap. He started saying "brake HERE," "turn HERE", "gas HERE" and when I protested, he told me to "shut up and drive!" Hah! He said, "as good a report as we get out of the classroom of what you're telling people, you should at least be able to DO it!" Steadily, he brought my turn-in points further and further back, so that I was turning the wheel less and less to draw as large an arc throught the corner as possible. He also MADE me concentrate more on getting OFF the brakes than getting on them. He also told me "you've got the car control skills, if it steps out, FIX it!" and, as my confidence grew, everything started getting eerily calm in the car. All of a sudden, I found myself turning way earlier than I had been. I was eating cars up right and left, my brakes were not degrading, the tires were singing (a squeeling tire is a happy tire!), my throttle and steering applications were decisive, measured and aggressive, but calm. I learned more in that cold winter day sixteen years ago than I had before or have since.

In short, I learned to trust myself. I learned that it is most important to make the car do the work, without taking too much out of the car. I learned that the WAY YOU ASK THE CAR to do something allows you to transcend that "edge" and teeter in that netherworld of 11/10's without too much drama while still retaining a reasonable chance of not bringing back the car a smoking heap of rubble.

While the old cars definitely suffer slip-angles that would invite certain disaster in a modern car, all of the really quick guys are 'balancing" the car on the brakes, on the throttle and with the steering wheel every moment of every bend in the road. They are "drifting," because they are preserving speed or gaining speed. They are not "sliding" because that infers losing speed. As most modern performance tires and even racing tires function best at 5-12 degrees of slip angle, the answer to your question is that the quickest drivers are seeking to go beyond the "planted" approach we are all most comfortable with. That's what's so fun about this sport. The more you practice, the better you get! Good luck.

-Peter

 

Good read Peter - thanks for sharing your insight. Can we expect a book ala Caroll Smith ?

 

Hah! It'll be awhile <grin>, but I do enjoy being able to contribute to this thread along with Jon and others. I never realized how many ways there are to look at the same problem (getting around the course quickly) until I started working with professionals. Then, I discovered that they're human, too!

-Peter (back to PGR3 and my F40!)

 

Fantastic response Peter. I'm checking my calendar for my next track day. I can't wait!

Dale

 

Peter, when you say balancing the car with the brakes, are you talking about brake modulation. When your buddy thought you the correct way of driving, you said he showed how to come off the brakes instead coming on the brakes. Can you elaborate on this please?

 

he might be refering to Trial Brake Rotation. This is something we practied alot at the SB school I did last year. Basically instead of being hard on the brakes deep into the corner and then back on the gas, at turn in you start to very slowly come OFF the brake as you are turning the corner. The idea being you can carry more speed into and throughout the turning process. You feel at this point that you are about to loose it as you carry alot more speed into the corner but when done properly this trail braking action will actually start to rotate the car as you are cornering helping you to complete the corner and carry alot more speed out of it. How I do Peter?

 

Peter - if I might pick your brain a little; I hope to track our 1955 500 Mondial in the next two years, but have never driven a car of anywhere close to that vintage at speed - skinny, hard tires - and, oh, did I mention a non-synchro box, drum brakes, RHD, and a motor that is cammed such that there isn't much torque below 3500rpm but a bucket of torque @ 3501??? Looking at the old films of these cars being driven at 10/10ths, it seems that every turn was one continuous stab-and-steer slide.
Does your analysis of cornering change with this car, or do the same principles apply, just at a lower speed? Just a little nervous about this.

 

This braking technique has been a huge improvement in my lap times. I took a 1 day advanced course at Derek Daly school with data logging in a open wheel car (new to me!), and the instructor I had was a European youngster and was racing F3 and doing Jr WRC in Europe. He basically was happy with how I drive, and told me that I tend to be confused between "line" and "technique". I was asking a lot about lines and finding lines for a particular track, but he corrected me by saying my techniques was dictating my lines. And one of the biggest issue with my technique was braking. I was trail braking longer then I needed to, over slowing the car because I didn't roll off the brake smoothly, and since I have over slowed the car, I am also more abrupt on to the throttle and sometimes inducing too much throttle oversteer. He had me work on just that part of the technique and helped me break down each corner into sections with each section relating to a portion of driving technique. After I trusted what I was doing with the new perspective, the varying line options became visible to me. I start to understand how top drivers were able to make the passes on me where I didn't feel that the car can hold the line he had taken to pass.

I also noticed afterwards that I had been faster in a kart because I had already employed that technique natrually because 1 foot is dedicated to brakes and the other to throttle...explaining why I was keeping up with my friends in a kart and was always a few 10th behind in car.

I still feel that braking and truly knowing the tracks in detail (meaning walking the track remembering, the traction differences, surface changes, subtle changes in radius, elevation changes, banking or off camber corners and visual references) makes most impacts to my lap times.

 

These guys don't know what they're talking about. Just make sure that someone is going around the same corner on the outside, ram into him, and your car will careen around the corner at great speed.
Oh, this isn't NASCAR?

 

What an active thread!

Vivek, I define "brake modulation" as constantly altering the brake pedal pressure in order to reach the point of incipient (or "just about") front-wheel lock-up. Proper brake modulation is required in order to execute "threshold" braking. As in cornering, the most efficient use of the tire under braking is when it is rotating several percentage points less than the actual rolling rpm, unencumbered. "Slip angle" under braking, if you will! <grin> Brake modulation is only useful in executing the rate of attack (over time) at the beginning of the braking zone and for altering the amount of pedal pressure as the car slows (it will take less pressure to slow the car as the car itself slows) to keep the car, and more importantly, the tire, at the threshold of lock-up. That is NOT the important part, even though we are all taught that the brakes are the most underutilized capability in a modern car...

Jim forced me to move away from being seduced by by the sensation of doing something special by "slamming" on the brakes. He refocused my attention towards "squeezing" ON the brakes earlier and, more importantly, focused me on where and how soon I could get OFF the brakes. This reduced my natural tendancy to over-brake for the corner and allowed me to become comfortable introducing the slight instability required in order to begin the rotation of the car. This leads to the next phase, how to integrate the end of braking into helping the car to begin turning into the corner.

Jon observed the competitive advantage that Billy Auberlen has by his mastery of this technique when he says: "Every time he would brake a little bit deeper (maybe a product of some Skip Barber training ??) and each time I thought "this is it, he's going to lock up and go off," he never did and (he) made up time on cars that were much faster down the straight." Any yahoo can apply full throttle down the straight or even when he (or she) is exiting the corner, but it takes a real artist (and a lot of practice) to "meld" together the sensetive transition between the end of threshold braking, the inducement of rotation and then the instant, almost imperceptable (from outside the car) "balancing" by carefully using the throttle and the steering to stem the increase in the rate of yaw caused by beginning that rotation! Get's me excited just thinking about it!

bjm hits the nail on the head when he says: "You feel at this point that you are about to "lose it" as you carry alot more speed into the corner but when done properly this trail braking action will actually start to rotate the car as you are cornering, helping you to complete the corner and carry alot more speed out of it." Why? Because, as he says, "the idea being you can carry more speed INTO and THROUGHOUT the turning process." (caps mine)

Now, these are advanced techniques that can serve up a great deal more risk than pleasure, but it's a worthy goal for all trackheads (and required for success in most any form of racing) to aspire.

Brian, after my experience of driving 0418MD in Italy (and through the gates at Maranello... WOW!), I understand completely your trepedation, but I would propose that the adoption of these techniques are even easier in your car. Why? Because the car will give you a great deal more feedback and will telegraph to you it's intentions LONG before you get into trouble, IF you creep up on the limits we are talking about. The Dunlop, Englebert or even better, the new Blockley tires (oops, tyres) from the UK are bias-ply tires. They function at a much greater slip angle than the later, more modern radials. The tall sidewalls of these tires and the high Cg of the Mondial make everything happen more slowly, so you have time to adjust. I was much more aggressive in my control inputs with 0418MD because the two-liter car had NO throttle response down low and I WANTED to "stab and steer" the car. The difference (and the enjoyment) came from the fact that to sustain the slip angle, I used my right foot and hardly turned the steering wheel! <very big grin> You'll LOVE it! It's a real hoot.

Fuse speaks of his epiphany by saying "after I trusted what I was doing with the new perspective, the varying line options became visible to me," which is exactly why this is such a confidence game. The more practice he got and the more he analyzed his technique, (why his Daly instructor {who was it?} was trying to steer him away from his preoccupation with the "line") the more he could instead focus on "feeling" the car and "stringing together" the portions of the corner, aided by the factual data provided by the DAQ. The tangible benefit of this epiphany is what I spend my entire time at the track with my customers doing, to get them, as Fuse says "to start to understand how top drivers were able to make the passes on me where I didn't feel that the car could hold the line he had taken to pass." Bingo! It's NOT magic! <grin>

I spend a lot of time studying the tracks we go to, so much so that it's a running joke among people who know me to suggest, while we are walking around VIR, "now, WHICH is the blade of grass that marks turn-in for NASCAR?" You laugh, but I can do this for Lime Rock, the Glen, Summit Point, BeaveRun, VIR, Kershaw, Roebling, Charlotte (oops, Lowe's) Motor Speedway, Rockingham, Road Atlanta, Mid-Ohio and some European tracks like Monza, Mugello and others.

You cannot learn or know enough. Fuse is right on target when he says: "I still feel that braking and truly knowing the tracks in detail (meaning walking the track remembering, the traction differences, surface changes, subtle changes in radius, elevation changes, banking or off camber corners and visual references) makes most impacts to my lap times." You just have to realize that it's letting OFF the brakes that is the most important part of braking!

-Peter

 

I'll give Peter's fingers a rest. (It's amazing to me sometimes how close our communication can be, Peter - I felt like I was reading my own post! - referring to your 12:43 post - THANK YOU!!! )

bjm - You have the right idea! It sounds like you were very present to the message the Skippy School was conveying and apparently you were putting it to use as well. Great job!

The idea is to overlap the controls such that the car stays at the limit the entire way through the turn. This keeps the slip angle high, the speed up and efficiency at maximum - which all boils down to FAST. A tire gets its greatest traction when it is just beginning to slide (as counter-intuitive as that may sound to someone who's not experienced it.)

When I say overlap the controls, picture this:
Entering the braking zone (this is the period of time your foot is applying brakes and has nothing to do with distance markers on the side of the pavement, etc. ), you squeeze into the brakes.
As you are downshifting, where is your right foot? It's straddling the brake and the throttle for the blip - right?
So we use this foot position as a tool BEYOND any needed blips - I'll explain why in a bit.

Great so as we are reducing our braking, we are turning the wheel (overlapping the controls), and this is called trail-braking. It provides us the ability for an angular adjustment to our line based on the weight being distributed front-to-rear relative to the lateral forces on the car. Put simply we allow the centrifugal forces to rotate the car by turning and braking at the same time.

Now's where it gets interesting. Remember where the right foot is? It's over the brake and the throttle - allowing us to now overlap those two controls.
Yes, this means applying the brakes AND the gas at the same time!
Why? To balance the car! We are making SMOOTH, minute changes to the inputs such that a gradual transition occurs - while we still have steering angle applied - again OVERLAP.
What occurs outside the car is a transition, not a "change-over" from one mode to another.

Then our foot slides off of the brake as we reduce its pressure and increase pressure on the throttle (there's that transition thing again.)
When we get to the apex and can open the wheel, that pressure increase can occur at a higher rate up to our usual WOT at or before the exit (assuming a simple turn scenario) because we are straightening the car and reducing the lateral fources.

The process flow looks something like this (usually):
Brakes;
Brakes & Steering;
Brakes & Steering & Gas;
Steering & Gas;
Gas

When you can master this flow (think Tai Chi type flow) and apply it to keeping the car at the limit throughout the entire turn, you can do the 11/10s dance!

Once you get it (that it can be done), you got it. It's like the first time you actually DO stay in the throttle on a downhill turn to keep the rear-end planted. Once you get past the distrust (read fear) and discover that it actually does work, you have "the knowing" and can work from there.

I hope this makes sense and is helpful. I'm in a rush, so I am far from being as eloquent as our friend Peter.

Cheers,
Chuck

 

OK, so Peter types faster than I do.
LOL

 

That's not the only thing, Chuck! <very, very big grin>

-Peter