Improving the ability of F1 cars to overtake ontrack

[Ciro Pabón]

Ogami, I think that Conceptual is asking for two parallel racing lines. I posted something about how this could be accomplished, but I've not produced anything you can test.

This the problem to solve:

- Draw two parallel racing lines that do not intersect (allowing for the width of the cars). Both racing lines can be traveled in the same time.

Or this more interesting variation:

- Draw two parallel racing lines that do not intersect. The outer curve can be traveled in less time than the inner curve.

You can use changes in the radius of the curve and in the sideslope to achieve that.

We talked once about designing something like Brooklands, whose curves have a parabollic sideslope (the outer racing line has larger banking).

Brooklands parabollic banking. Flynfrog pointed out that the ride height varies and thus it's not a solution


Of course I'm not proposing a banking as extreme as this. The banking has to be slight to avoid safety issues.

Perhaps, maybe, it's possible to design a curve with enough length and slight "differential banking". Let me show some numbers:

The problem here is that, with a slight increase in grip provided through banking, you need a long curve if you wish for the overtaker to catch the overtaken before the exit of the curve, where the overtaken can block.

For example, I take the Renault curve, which is the longest curve at Catalunya track (the one in red thick lines, lower left:



Length of the curve: 198 m
Radius: 111 m
Deflection (the angle between entrance and exit straights): 102 degrees
Maximum speed: 195 kmh (from FIA site)

The centripetal acceleration is 2.7 Gs, or, what is the same, the lateral friction coefficient is 2.7

The time it takes to travel through the curve is 3.7 seconds.

Now, if you increase the lateral grip to 2.85 Gs (by increasing banking 15%) you can get an increase in speed to 200 kmh.

This means that by increasing grip 15% you gain only 5 km/h. In the 3.7 seconds it takes to move through the curve you gain only 5 meters.

Let's say, for the purpose of this post, that an advantage of 15 meters would do the trick and allow you to overtake.

To gain 15 meters through the curve you need to go at 210 kmh while the overtaken goes at the same 195 kmh we assumed initially as the "regular speed" for the curve.

This means that, at the Renault curve in Catalunya, the overtaker has to produce 3.2 Gs laterally, while the overtaken uses only 2.7 Gs. This will give you a difference in time to travel the curve of a mere 0.3 seconds. The difference in grip is 3.2 - 2.7 = 0.5 Gs.

Conclussion: you need 0.5 Gs of advantage in grip if you want to overtake at Renault.

Now, if the Renault curve were longer, what would happened? I'll add the length of the transition that exists after the circular part of Renault (the curve with the thick orange lines in the previous image). It measures 193 meters more, for a total length of 393 m.

Now the overtaken uses 7.2 seconds to travel the curve. I'll spare you the numbers, but the overtaker now only needs a grip of 2.9 Gs!

As the overtaken car is using a grip of 2.7, you need a banking differential of only 20%. This is how it would look in real life a first drawing showing a section of the curve:



Sorry for the lengthy explanation and the simplifications, but I've been thinking on this for a while and I've had the help of the forum.

I know I performed some "magic tricks" here (who can find the worst? ), but if someone reads this I hope he'll get the idea: in principle, it seems possible to produce a racing line that is faster and allows you to catch and overtake a car along the curve. You can do it only by geometry.

[Ogami musashi]

About road relevance, ok i'm maybe biased being an aerodynamics enthusiast (well, viscous fluids would be the better description) but i do think aerodynamics are road relevant.

This is two sided and i'm sure that's why very few if not any constructor never produced this but actually a car high downforce would be far safer in whatever weather you want.

I would also help increasing braking, accelerating forces while requiring less powerful engines, smaller brakes etc..

The only reason i see why it is not implemented it is because it is a dynamic force it increases with the square of speed and it would temps people to go faster in turns.


About the aero in F1, few months ago i would have agreed with you about ground effects. The problem with ground effects is that they tend to make the cars understeer and reduce their transient rates (the rate at which they change direction) and if there's something that really help F1 overtaking is their ability to change direction.

Actually it is known that future ExDP01 champ cars have downforce performance not so far from f1, but they are heavier and their ground effects make that they don't move so fast, so overtaking in narrow places is quite a no go, while on F1 this is not a problem at all.

Also on a more technical side, wings have the great capacity of shaping the wake after them reducing drag, which is not possible with ground effects.


on the overtaking subject, let's not mix things: the kind of thing Ciro talk about is a nascar/irl like overtaking move.

But most of the traditional overtaking on closed circuit is not done by having more grip that the other but by simply stealing the line.

The same misconception reigns when braking, people think you out brake people by brake better, no..you brake deeper at simply place yourself so that the overtaken car can't regain its position (if not you experience a "switch back").

However, in F1 and in some series you can see some kind of parallel overtaking but i'm not quite sure it involves having better acceleration.
We would have to study all that moves correctly.

All in one the problem is more that now, you loose to much grip. Until cars don't run on aeros or big large soft tyres, you'll always experience some grip loss, but the nature being extraordinary, when you overtake someone it is that you are faster so have more grip, so the goal is that losing you grip, you end up with enough grip to make an overtaking move which more a geometrical move than a dynamic one i think.

[Conceptual]

Ciro,

I appreciate the education on this, but that isnt what I was suggesting. I just think that if the series was opened a bit, you would possibly have some exotic variance in the field.

I believe that different designs of car would have different specific lines through a corner. Maybe this car is set up to drive into the corner like a spike, and that car is setup to just swoop through it. It is very apparent in GT4, although I know it isnt an exact sim, it is very good at showing the difference of car character. Both cars can put down comparable times on the same track, it is just about the driver knowing how to squeeze it out without dying.

Chris

[Tom]

One of the best overtakes I've ever seen was Mika and Shumacher, Spa 2000 I think, where the Mclaren driver ducked right of a helpless Minardi and Michael swooped left. Mika came out parallel with the Ferrari and took the racing line into the corner.
Basically there were two racing lines seperated by an island. Had the Minardi not been there the odds are Schumi would have occupied that space and been able to block Mika, so why not put an island on top of the fastest line on a straight (or into a corner?), a piece of grass in the middle of the racetrack and an equal distance around either side.

[bar555]

Tom wrote :
One of the best overtakes I've ever seen was Mika and Shumacher, Spa 2000 I think, where the Mclaren driver ducked right of a helpless Minardi and Michael swooped left. Mika came out parallel with the Ferrari and took the racing line into the corner.
Basically there were two racing lines seperated by an island. Had the Minardi not been there the odds are Schumi would have occupied that space and been able to block Mika, so why not put an island on top of the fastest line on a straight (or into a corner?), a piece of grass in the middle of the racetrack and an equal distance around either side.

It was not Minardi , it was BAR 002 Honda and was driven by Zonta ( Renault's 2007 Test Driver

[Tom]

You're quite right, here it is http://youtube.com/watch?v=LyROseZgtVg

[Ogami musashi]

This is the kind of overtake that i think you could hardly see elsewhere than in F1: fast reactions, short braking zone, aggressive guys, and backmark car totally without resources.

[Conceptual]

This is the kind of overtake that i think you could hardly see elsewhere than in F1: fast reactions, short braking zone, aggressive guys, and backmark car totally without resources.

At least the backmark knew to NOT MOVE and let the leaders go by. It could have been very messy had the BAR moved at all left or right!

Chris

[modbaraban]

I quickly scanned through those ideas on improving track geometry. Quite interesting, though it doesn't sounds credible that any tracks would be rebuilt just for that.'

But did you consider the mechanical grip of the rubbered line while talking about grip and track geometry? It's hard to count on the field to get split so that each dozen of cars would go rubbering one of the parralel lines before the race

[Ogami musashi]

This is the kind of overtake that i think you could hardly see elsewhere than in F1: fast reactions, short braking zone, aggressive guys, and backmark car totally without resources.

At least the backmark knew to NOT MOVE and let the leaders go by. It could have been very messy had the BAR moved at all left or right!

Chris

Yes! But of course i talked about the absence of ressources of the car, typical to non spec series were large differences in pace are seen.

[Ciro Pabón]

I had a heart and I know that without a heart you cannot race.

Video: René Arnoux-Giles Villeneuve http://video.google.com/videoplay?docid ... pr=goog-sl

When was the last time someone blocked the brakes on purpose to overtake?


Of course I appreciate the type of curves. In the video you can notice the width of the track and the long sweeping curves with relatively high banking.

I don't like aerodynamics today because they have deprived us of this kind of curves and overtakes. The level of grip is so high that they are dangerous for drivers: too much lateral acceleration.

I've submitted the ideas posted to the owners of a new track in Russia, modbaraban. Who knows. I'm not sure if the track will be built.

[Ogami musashi]

When was the last time someone blocked the brakes on purpose to overtake?

Last year's brazil GP, nico rosberg did the same manoeuver in the very first corner (two times narrower) on heidfeld or kubica...that was very cool indeed.

And since i have bad memory i'm sure it has been done another time.

Anyway, okay this is a bit special and one can not like the offroad excursions but the alonso on heidfeld or massa vs kubica battle and overtaking (hey that was a fightback!) were also very cool to me.

Of course I appreciate the type of curves. In the video you can notice the width of the track and the long sweeping curves with relatively high banking.

I don't like aerodynamics today because they have deprived us of this kind of curves and overtakes. The level of grip is so high that they are dangerous for drivers: too much lateral acceleration.

Well i don't think this is true, eau rouge is taken at 320km/h (okay this year 310km/h thanks to V8's) and make a 4,5G lateral, that's sustainable (it makes a 5G vertical tough!) and magny cours , sliverstone or indianapolis still have some of those bends.

I think this is more that now because of grip levels you can make a track with more severe turns but that does not prevent for having great curves.

The width of the track however...yes that's right.

I think F1 cars are nimble enough (that's an euphemism) to handle overtakings in narrow corners, all necessary is to clean up the aero a bit, and make the tyres more predictable.

[Ogami musashi]

There's an interview of Sebastien bourdais in the french version of F1-live.com

where he gives an interesting fact:

The F1 cars have lots of downforce, low tyre grip and then the cars are harder to drive but bourdais finds it is much more fun like that since every error is paid a lot, so considering next year the downforce will be decreased by 50% isn't here an interesting debate?

http://fr.f1-live.com/f1/fr/infos/actua ... 2312.shtml

[checkered]

Well, as "Le Seb" has

experience of both F1 and ChampCars, I thought it'd be beneficial to also add an engineer's view from a person that shares that perspective. Toyota Racing Development's (TRD USA) Pete Spence's (VP & Tech. Director) musings over IRL/ChampCar's future are more or less directly applicable to F1 as well, at least when it comes to overtaking I think. Having worked with Cosworth and Senna at McLaren in F1 he came over to work in Cossie's CART program and has since acquired experience of IRL and NASCAR as well. The whole G. Kirby article is class, as usual ("There's a lot of junk out there today. If you want it straight, read Kirby." -- Paul Newman), I'm just quoting the directly applicable parts here.

We learned in the CART series that the horsepower and drag and downforce all need to stay in balance. Downforce changes the character of the racing. Early on when I was in the CART series, I thought the way forward was to take downforce away because that would bring skill back into it and then we would see more interesting racing. But the thing we learned is, that's not the case.

It was really interesting racing back when it was Michael versus Al Jr. In those days they had gobs of horsepower and thousands of pounds of downforce and were diving down the inside each other going into turn one at Milwaukee. They could outbrake each other and they had the confidence to go down the inside.

Take away the downforce and you take away the driver's confidence and you get a procession. Keeping the power, grip and downforce in balance is the key because inevitably, the performance goes up, the grip goes up, and the downforce goes up. So you have to either start adding drag, or take away engine capacity, and of course you're always under pressure not to change too much because it's expensive.

...


The challenge is to continue the balance relative to the human being. So many of the open-wheel performance parameters have advanced so much relative to the capabilities of a human being, I think the challenge there is to maintain a level of technology which makes the vehicles interesting to the fans while inhibiting the development such that the balance of the performance of the vehicle versus the driver's ability to control it and the driver's confidence all stays in balance so that people can still pull out to pass or use their skill to go faster than the next guy. At the end of the day, we're here to see a race between human beings.

I'm not sure if I'm willing to accept all that he says (he mentions the human/driver element as the "weakest link", to which I have at least philosophical objections), but this comes from a person who has been intimately involved with all kinds of top of the line open wheel racing series for a long time. I find it interesting that more and more people seem to be giving serious thought to this issue at this point of time. Not before long, it will also mean solutions emerging, some of which may or may not be complementary to each other.

[Conceptual]

Well, as "Le Seb" has

experience of both F1 and ChampCars, I thought it'd be beneficial to also add an engineer's view from a person that shares that perspective. Toyota Racing Development's (TRD USA) Pete Spence's (VP & Tech. Director) musings over IRL/ChampCar's future are more or less directly applicable to F1 as well, at least when it comes to overtaking I think. Having worked with Cosworth and Senna at McLaren in F1 he came over to work in Cossie's CART program and has since acquired experience of IRL and NASCAR as well. The whole G. Kirby article is class, as usual ("There's a lot of junk out there today. If you want it straight, read Kirby." -- Paul Newman), I'm just quoting the directly applicable parts here.

We learned in the CART series that the horsepower and drag and downforce all need to stay in balance. Downforce changes the character of the racing. Early on when I was in the CART series, I thought the way forward was to take downforce away because that would bring skill back into it and then we would see more interesting racing. But the thing we learned is, that's not the case.

It was really interesting racing back when it was Michael versus Al Jr. In those days they had gobs of horsepower and thousands of pounds of downforce and were diving down the inside each other going into turn one at Milwaukee. They could outbrake each other and they had the confidence to go down the inside.

Take away the downforce and you take away the driver's confidence and you get a procession. Keeping the power, grip and downforce in balance is the key because inevitably, the performance goes up, the grip goes up, and the downforce goes up. So you have to either start adding drag, or take away engine capacity, and of course you're always under pressure not to change too much because it's expensive.

...


The challenge is to continue the balance relative to the human being. So many of the open-wheel performance parameters have advanced so much relative to the capabilities of a human being, I think the challenge there is to maintain a level of technology which makes the vehicles interesting to the fans while inhibiting the development such that the balance of the performance of the vehicle versus the driver's ability to control it and the driver's confidence all stays in balance so that people can still pull out to pass or use their skill to go faster than the next guy. At the end of the day, we're here to see a race between human beings.

I'm not sure if I'm willing to accept all that he says (he mentions the human/driver element as the "weakest link", to which I have at least philosophical objections), but this comes from a person who has been intimately involved with all kinds of top of the line open wheel racing series for a long time. I find it interesting that more and more people seem to be giving serious thought to this issue at this point of time. Not before long, it will also mean solutions emerging, some of which may or may not be complementary to each other.

This makes using Hybrids and KERS systems seem like the obvious next step then. If the technology is human centered, and needs to be kept balanced, then the only logical assumption is to retire overly-mature technology and introduce new tech that is still within its human controllable infantcy.

Chris