Rob Wilson - driver coach?

[mike]

Yes, you'd have to go on the power MUCH later - but then at that point the traction is big enough and you don't really have to wait before going full throttle

doesn't this point contradicts the point you make about trail braking? wouldn't it be better to be progressive on the throttle? and full throttle at full lock doesnt give you good acceleration. If the car has most of the turning done at the apex it leave less turning and more power down as you exit the corner even with a slightly lower speed it can make up the time at the exit. the reason is that apex speed assuming pure lateral requires the square of velocity of force while throttle application is almost linear. if car 1 corners 150km/h while car 2 corners at 135km/h with 10% difference in velocity car 2 will be able to put down 19% more torque and hence acceleration at the exit. the point is that the car is better to have a progressive throttle from the apex of the corner.

I don't follow. Why would you need to brake earlier?

if the extend the phase of trail braking *too much trail braking* you would need to brake earlier like as in you turn as you brake from the very start of braking. by reducing the phase of trail braking (overlap) you yield later braking and in the apex you should have no braking and maximum yaw

Rob Wilson wants drivers to speed up transition not killing transition

I'm not sure I understand what you're saying here - are you saying that this driving style suits it when the car is tail happy?

what is true is that tail happy cars are faster because engine power are around 540kw while brakes can hit 2000kw, it requires less traction in the rear to keep it from spinning up too much than the front,this balance also giving better turning ability *ie same total downforce same mass, cars are judged on how well it can turn* afterall there is no such a thing as understeer, it is just oversteer and the more oversteer you have the better the car is. if you put on more rear wings and less front to give driver the confidence to push that is called building the car to suit the driver.

Yes we are agreed on that, definitely. But the question is not whether or not you're at the limit of both. It's how much you compromise in each for the other. Try driving a circuit in all straight lines, just driving apex to apex - where you will get a hell of a yaw moment - but you won't get anywhere racy fast. There has to be a balance somewhere.

in any corner there is a yaw amount that you would need to do. the slower you go the faster you can do it but since the traction circle is smaller at lower speeds thats is not always the case. the limit is where the shortest time that maximum slip angle can be applied, like the response of the car. if you go too fast the car will have this input lag from the moment you put on the steering wheel lock. The limit it the fastest velocity you can go with least or no input lag. If there is no input lag then they can always go for a faster steering setup. im not really sure but i think this is a really interesting topic

[raymondu999]

wouldn't it be better to be progressive on the throttle?

The point I was making is, as you hold, let's say, 75% throttle to maximise the apex speed, and hit the entry, apex and exit kerbs perfectly. Now there is a point before you hit the exit kerb (very near it) where you will have to decrease lock, so that you can go straight. As you turn out of the corner you increase the throttle, but that's all you have to manage - the transition. ie not worry about being traction limited, but rather just "turning" the traction.

If the car has most of the turning done at the apex it leave less turning and more power down as you exit the corner

Agreed 100%.

even with a slightly lower speed it can make up the time at the exit.

In some cases, this is true. But would you agree that this is not true of ALL cases?

the reason is that apex speed assuming pure lateral requires the square of velocity of force while throttle application is almost linear. if car 1 corners 150km/h while car 2 corners at 135km/h with 10% difference in velocity car 2 will be able to put down 19% more torque and hence acceleration at the exit.

the point is that the car is better to have a progressive throttle from the apex of the corner.

Agreed. The example I gave of purely devoting the grip to lateral is indeed an extreme case just to make a point. But the thing is, how much lateral do you give away, to have a "squarer" exit? Rob Wilson seems to advocate doing all the turning near the apex, and just having the tyres all squared up in the same direction on exit. See my Maldonado example in the opening post.

by reducing the phase of trail braking (overlap) you yield later braking

Trail braking would mean you brake later, as you brake up to the apex instead of until you turn. Sometimes even for a hairpin you start turning before you brake. See Lewis Hamilton's pole lap as he's braking for Turn 4 (that's the end of the final straight, before they go into the cornering sector)

what is true is that tail happy cars are faster because engine power are around 600kw while brakes can hit 2000kw, it requires less traction in the rear to keep it from spinning up too much than the front,this balance also giving better turning ability *ie same total downforce same mass, cars are judged on how well it can turn* afterall there is no such a thing as understeer, it is just oversteer and the more oversteer you have the better the car is. if you put on more rear wings and less front to give driver the confidence to push that is called building the car to suit the driver.

I'm not sure that's always true. For slower corners you'd definitely want a strong front end. But if you have no rear stability in a fast corner, it would also kill the laptime.

in any corner there is a yaw amount that you would need to do.

Agreed. You have to get the same amount of rotation in the corner, no matter in which phase you do it in.

the slower you go the faster you can do it

I assume you mean the faster you can perform the rotation? Just looking at the rotation alone (ie not looking at the speed carried through)

but since the traction circle is smaller at lower speeds thats is not always the case.

Agreed.

the limit is where the shortest time that maximum slip angle can be applied, like the response of the car. if you go too fast the car will have this input lag from the moment you put on the steering wheel lock. The limit it the fastest velocity you can go with least or no input lag. If there is no input lag then they can always go for a faster steering setup. im not really sure but i think this is a really interesting topic

I don't think I understand what you're saying here, sorry. Could you rephrase?

[mike]

The point I was making is, as you hold, let's say, 75% throttle to maximise the apex speed, and hit the entry, apex and exit kerbs perfectly. Now there is a point before you hit the exit kerb (very near it) where you will have to decrease lock, so that you can go straight. As you turn out of the corner you increase the throttle, but that's all you have to manage - the transition. ie not worry about being traction limited, but rather just "turning" the traction.

well almost all cases you are dealing with traction limited situation out of a corner, im not sure what you are trying to say, but 75% throttle at the apex means that it is a high speed corner as you move in a traction circle longitudinal increases while the lateral decrease, lateral slip is decreased by the driver as longitudinal is limited and a higher limit is required to put down as much throttle as possible.

In some cases, this is true. But would you agree that this is not true of ALL cases?

well not all if there is less power at the same grip level *ie high speed tracks* but if you can go around with less wings on the car than i guess that is the faster way

how much lateral do you give away, to have a "squarer" exit? .

do you mean when exiting a corner without steering lock, the driver is therefore not using the lateral grip available in the tyres? as in by having less transition from full lock to full throttle the car has lateral grip that was not used? yes you do have a point but traction circle is alot bigger at higher speeds the order of priority in grip is braking steering and powering out so at the biggest traction circle you brake and the middle part you steer and the last part you power out and if you do that in order you should have very little lock at the exit?

Trail braking would mean you brake later, as you brake up to the apex instead of until you turn. Sometimes even for a hairpin you start turning before you brake. See Lewis Hamilton's pole lap as he's braking for Turn 4 (that's the end of the final straight, before they go into the cornering sector)

I think that is braking in a diagonal it is still braking in a straight line but it is pointed towards the corner. looking at the exit of the 2 cars lewis's car almost got the the start of the exit kerb while pastor is later meaning lewis is going at a shallower angle, i cant get a video with speed for lewis so its hard to compare further. we also have to factor in the speed of the cars . at a shallower angle and wider exit means that he has to turn more for the next corner. The problem with trail braking is that when you do too much of it the inside tyre loses grip so you braking force is limited to the inside tyre and since both brake do the same thing you would need to reduce the braking force thus brake earlier.

I'm not sure that's always true. For slower corners you'd definitely want a strong front end. But if you have no rear stability in a fast corner, it would also kill the laptime.

you can always chose to steer less in high speed corners and it will do the same thing has having a less strong front end. that is assuming both cars have the same downforce

I assume you mean the faster you can perform the rotation? Just looking at the rotation alone (ie not looking at the speed carried through)

yes

I don't think I understand what you're saying here, sorry. Could you rephrase?

when you apply steering it takes time for the car to react the higher the speed the slower it reacts, the limit is when you apply full lock and the car still ran wide or the car can not react quickly enough to get all the rotation done in time

[raymondu999]

Rig. Gotcha. So why rotate at the apex? Why not go for a more "traditional" late apex?

[raymondu999]

Any more takers to the thread?

Generally, should you:
a) reduce a car's reliance on its weakness
or
b) work with the car's strengths?

Eg. car with MASSIVE grip, but little power - should you then get the power on earlier so you go quicker down the straight? Or maximise the speed carried, because you don't have much power to accelerate?

[mike]

Rig. Gotcha. So why rotate at the apex? Why not go for a more "traditional" late apex?

rotate at the apex because the rate of yaw is the greatest and if you can actually go for a late apex having all your turning done before the apex I would say that is when the driver is not going fast enough.

my lecturer on vehicle handling in uni said that over 30km/h the car is always turning with slip angles, and one way that engineers used to measure oversteer was to drive the car around the track on the racing line at above 30km/h and map the steering angle for one lap and go for a fast lap, if say the lateral steering angle was 12, anywhere where the driver had to use more than 12 degrees compared to the mapped steering angle the car is understeering and if he was not using 12 degrees he wasnt going fast enough. that is the reason why i said the more oversteer the car has the better it is given the same downforce. some may ask "If that is the case why do cars still have rear wings??" you only have to look at how early some of theses drivers are opening DRS/stalling rear wings to know that the wings are not doing much in the traction zones.

[raymondu999]

rotate at the apex because the rate of yaw is the greatest and if you can actually go for a late apex having all your turning done before the apex I would say that is when the driver is not going fast enough.

But the whole point of a late apex is that the entry is slower on purpose, to allow an earlier power-out...

[beelsebob]

rotate at the apex because the rate of yaw is the greatest and if you can actually go for a late apex having all your turning done before the apex I would say that is when the driver is not going fast enough.

But the whole point of a late apex is that the entry is slower on purpose, to allow an earlier power-out...

It's not really the entry that's slower – you can come charging in hotter because you're aiming to go beyond the normal apex. It's the apex speed that's lower, and the distance traveled higher, but it allows for more time for traction to build speed, and a faster entry.

[raymondu999]

Wouldn't the entry technically be the moment you start turning in? ie yes you enter the end of the straight hotter, but you're not quite "entering" the corner yet.

[mike]

" I remember watching him from overhead in the McLaren at La Rascasse at Monaco in 2006. Compared with his team-mate, Juan Pablo Montoya, Kimi was approximately two metres later with his mid-corner rotation, which is to say that in the initial phase of the corner Kimi had perhaps five degrees of steering lock where Juan had at least 15 degrees. Juan was on the power earlier – but the early power application led to oversteer bobbles on exit. Kimi was travelling faster in the early stage, had a lower minimum speed while he rotated car the car, but a much straighter, flatter exit that he “guided” with easy accuracy."

that kinda explains it

edit video
watch from 0:56
[youtube]http://www.youtube.com/watch?v=awCuP_umhVA[/youtube]

[raymondu999]

Apologies, but I'm not going to put much weighting on that. I don't trust Peter Windsor for such observations, sorry. No disrespect intended to yourself.

[gato azul]

o.k. finally I had the time to watch the TFL episode in the opening post.

just some observations from the debate so far. I think, it could help if we establish what we mean with "apex".
Maybe it´s just me (being thick), but I feel, that while we all roughly agree on what it is, we use it for different
parts of the corner.

RM999 said, fast at the apex equals fast onto the next straight, or that was how I understood it.
In my mind, apex speed and exit speed are not nesseccary linked in that way. For this I wanted to ask, what you
mean with the term "apex" or "apex speed".

Do you mean, the slowest part of the corner, the speed at the point closest to the inner boundary of the track (inner kerb/curb)
or the point with the largest curvature (smallest radius) of the line taken?
If it is the middle definition, point closest to the inner boundary of the track (which is "my" way looking at it), you could be
"very fast" chosing an early "apex" but then suffering a load of US later on, because you have a load of "turning" (yaw/rotation)
left to do, at the exit, most likely being "late on throttle" and slow out of the turn, all while your "apex speed" may be "high".

I think mike made some good points about yaw (rate) and attitude (direction of heading) of the car at the apex.

I think, Rob W is very "concerned" about slip angle induced drag, and he tries to say (IMHO) that you should try to minimize slip angles while trying to accelerate at the same time, because it will cost you "speed/time". For this he advocates an "straight(er)" exit. He is not the only one, who advocates this approach.
I think Ross Bently (Speed Secrets) put it that way. "As less you turn the steering wheel, as faster you will go".
There are other sayings along the same line like, 80% of your time comes in the first 20% of the corner, or you should get 80% rotationj during the first 20% of the corner.
All this means a straighter line at the exit ~better power down.

I think (but could be wrong), that this "slip angle induced drag thinking" is also behind the "don´t drive diagonal" to the straight advice (cross over at the last possible moment).
In a nutshell he says, that driving with tyres which have a slip angle is "slow(er)", if we see forward motion/acceleration as the goal, then driving tyres with no (less) slip angle.
Slip angle induced drag beeing the technial reason/explaination for this. - which is sound, if we compare the same car/tyre IMHO.
Now, as you have to get to the optimal line/turn in point for the next corner at one point. He says, do the crossing as late as you can, because you will lose speed for a lesser time - if this makes any sense.
In more simple words, crossing the track will cost you speed one way or the other, there is nothing you can do about it.
Now, if you cross early, or for a long time (driving diagonal), you carry this slower speed for the rest of the straight/for longer along the staright. (costing you more time)
If you cross, at the last moment, and then brake anyway, you have traveled a lesser distance with less speed - losing less time.
Let´s assume (simplyfied example) crossing the straight cost you 2km/h in slip angle drag (running the tyres at an angle), and we have a 1000 m straight.
If you cross early you will travel 800m (numbers just made up for illustration purpose), at 2 km/h less speed then the same car, which don`t cross (less tyre drag). The other car crossing late after 800m, also losing 2 km/h, but only needs to travel for 200m at the slower speed, before both start braking for the corner.
It´s a bit more complicated then this, if you put "real numbers" to it, but I think, that is the concept behind it - could be wrong after all

[raymondu999]

Yes let's define the apex for the point of discussion. I think generally, or more conventionally, the apex is the term used for the kerb at the center of the inside of the corner, and "late/early" apices are when the cars hit said corner "center" later than usual, or earlier than usual.

Rob however seems to describe it more as the inflection point - the local "minima" as it were, ie if you were taking a "late apex line" you would be rotating the car before you hit the corner "center."

About diagonaling the car later, I don't think it's that simple. Firstly there's downforce to contend with, and given that downforce squares with speed I'm willing to bet that the tyre scrub drag also increases with this, as the friction forces get greater. Towards the end of the straight this is at its peak, and also, because you're moving across the track width (which is, let's assume, equal through its length) through a smaller length, you need a lot more steering to actually do that.

I've also heard the having less steering point. But then do you have points where you put in a whole lot of steering, or do you "average" it all out? A Jenson button line would have, at the end of the day, a similar amount of "accumulated" lock - as Lewis Hamilton style line.

[mike]

About diagonaling the car later, I don't think it's that simple. Firstly there's downforce to contend with, and given that downforce squares with speed I'm willing to bet that the tyre scrub drag also increases with this, as the friction forces get greater. Towards the end of the straight this is at its peak, and also, because you're moving across the track width (which is, let's assume, equal through its length) through a smaller length, you need a lot more steering to actually do that.

it is true that tyre scrub is larger at higher speeds, but i think his point was that if you move at the start you scrub off 5km/h for the entire straight, but if you only do it in the end you scrub off 20km/h for the final 50 meters into the corner. its like in drag racing the car that has the better acceleration at low speed wins and most of the time the car that loses has a higher terminal speed.

what is confusing for me is that he advertise doing more turning in the slowest part of the corner but when it comes to straights he says you should steer later. one important point is that at a higher speed the change of yaw rate is larger (greater forces) but at a lower speed the maximum yaw rate is larger. say a corner requires 90 degrees of total yaw and it takes 10 seconds to complete the corner at the middle of the corner the car might me doing 15 degrees per second while in the entry it might only do 3 degrees per second, if you where to add 10% to any part of it you would want to do it at the middle of the corner because rate is higher. if you do it at the entry, you get a late apex, but if you do it in the middle you can carry more speed at the entry.

as to the question of maximizing the strength or deal with the weakness, I will say maximizing the strength. I could be wrong, but compare 2006 and 2005 cars V8 vs V10, 2006 cars brakes later carry more speed into and out of corners (strength), while 2005 cars want to put the power down as early as possible.

[gato azul]

About diagonaling the car later, I don't think it's that simple. Firstly there's downforce to contend with, and given that downforce squares with speed I'm willing to bet that the tyre scrub drag also increases with this, as the friction forces get greater.

well as far as the slipangle induced drag goes, it´s a function of lateral force produced by the tyre and the slip angle at which
the tyre runs:

Fdrag=Flat×sin(slipangle)

therefore a tyre which is able to produce the same lateral force, at a lower slipangle (higher cornering stiffness) will produce less induced drag.
(the realtionship is similar to a wing with an higher Col can be run at a lower AoA producing the same downforce/lift
at less drag)

on top you would have the "normal" rolling resistance of the tyre, which depends on speed/velocity as well, but this would affect both cars in a similar fashion.

To make a "final" viadict, you would need to take all "real data" into consideration, I don´t think you can say anything with 100% certainity (it´s always better) in the context of race car driving and engineering (setup). The track/tyre/car is evolving all the time during a race. You could have cross winds to take into consideration and tactical considerations (maybe you can`t cross late/early) because there is a car next to you etc. etc.

So, I doubt any advice be it driving or engineering, will be a "catch all/ always&forever" type of advice.
I think, the guy (R.W.) just want´s to make people (drivers) aware of some aspects/facts, so that they can take them into consideartion at the appropriate time. Like an extra tool in your toolbox, there will be time to use it to your advantage, and at others times, you are maybe better off, to use a different tool.

If he is more often right then wrong, then overall there can/will be a benefit for a driver, even if he uses this "new tool" very stubborn (always).
That will largely depend on the type of cars ( F1 is not Formula Ford), tyres and tracks used, so there is a chance, that,seeing he seems to "coach" mainly F1 drivers, his methods could be more often benefical then not.
If this is the case, it´s a net improvement for some drivers, even if it is not "perfect" all the time.
A bit like a good trading strategy, you do lose money at times, but if you win more then you use in the long run, it´s a benefit.
I would see his work/coaching along the same lines. But surely it´s not the "only" way to go about it.