Racing Lines

[DC_McGregor]

I just made a couple of posts at Speedsims. I thought they might be interesting, so I'm copying them here.
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In my experience, the ai drivers are easy to beat. By anywhere from 5 to 15 seconds a lap and more, depending on the circuit and the car.

At almost all tracks, the ai cars use an "early apex" line, which isn't the fastest but is a good passing line. "Late apex" is better. However, if you use the late apex line with an ai car close behind, you'll get punted off almost every time. Adopt the same line as the ai cars in that case. I've found that the ai cars will give way if you're blocking their line into a corner.

Briefly, a "late apex" is defined as the closest point to the inside of a corner - _after_ the midpoint of that corner. You brake earlier, turn in earlier and get a straighter shot out of the corner and can begin accelerating down the following straight earlier. An "early apex" (or late braking maneuver) is defined as taking a straighter line entering the corner allowing you to brake later. You'll be closest to the inside of the corner before the midpoint of that corner and your exit speed from the corner will be slower. This is the classic line for making an inside pass. There is a danger that you may run wide on the exit and the other car can repass on the exit of the corner - on your inside.

A blocking line is somewhere between the two. It won't deter the ai cars from passing you on the inside, but it will work against human drivers.

Another technique is the "counter pass" (my name for it).

Take your usual late apex line - perhaps even a little later apex. Let the other car pass on the inside (human or ai) then duck inside for a repass. You'll have a straight shot out of the corner and easily be able to out accelerate the other car. Be advised though. If the other car doesn't run at least a bit wide, your exit line may be blocked.

You can use this technique when you've neglected to take a proper blocking line early enough to avoid being punted off. Again, human or ai. If the other car has disappeared from your mirror, it's too late to take a blocking line. He (human or ai) has already began his passing maneuver. He won't be able to see you and you will make contact.

If you have a friend who's close to you in skill, you can practice these techniques on each other and have a lot of fun in close racing. Almost like the real thing. <grin>

Robert

[jtace]

Good post mate! :)

[edit]

Copied from the SCGT forum. ;)

[MATT]

A blocking line isn't necessarily between the two... it certainly would deter a pass if you went completely to the inside to block the pass, now wouldn't it? ;)

[DC_McGregor]

Originally posted by MATT
A blocking line isn't necessarily between the two... it certainly would deter a pass if you went completely to the inside to block the pass, now wouldn't it? ;)

Actually, no it wouldn't. That line is slower yet. By staying to the extreme inside, you leave the entire road to the following car. He'll be able to maximize his corner speed while you have minimized yours. If you go to the outside on the exit of the corner, he can easily duck under and pass with his greater speed. Kind of like a counter pass. If you can hold the inside or middle on the exit, you are even slower. The other guy can drive around you on the outside like you are standing still. I tested this personally against DC_Racecar in SCGT and that's exactly what he did!

By sticking to the middle of the track, you are forcing the following car to stay behind and hope that you run wide so he can duck under. Or else try the extreme inside, giving you all the options for the counter pass.

I've also tested this against DC_Racecar in SCGT. He hasn't found a way around it yet, but he's working on it. (Assuming, of course, that I don't run wide.)

If you watch racing on television, you'll see that the blocking line is approximately in the middle of the road - perhaps just a bit towards the inside. You literally have to block both lines.

McRoadblock and his twin brother, McGrin

[MATT]

I stand corrected ;) There are some corners in which you can get away with this, though (Parabolica in GPL, anyone?) but for most corners, you would be correct.

[DC_McGregor]

Matt,

Refresh my memory. The Parabolica is at Mexico City isn't it? Or is it Monza?

Either way, you're quite correct. You stay to the inside all the way around those corners. There are exceptions to every rule. To say nothing of a bunch of ifs, ands, or buts.

Speaking of exceptions, the high speed 180 degree turn at Mexico City is where Nigel Mansel passed Gerhard Berger 'round about 1990. On the OUTSIDE. LoL

I saw that race and I was astonished! I didn't think it could be done.

In any event, the general rule is, "protect the inside line" when being closely followed by another racer. However you do it. Watching racing on TV will help the new racer a lot. Not only to see these things done, but also for the commentary. Sam Posey and David Hobbs (to name just two) are experienced racers from way back. Almost back to my time, as a matter of fact :) (Anybody remember Masten Gregory? Or Paul Freres? :D )

McG

[MATT]

It's Monza. The last corner :)

While I'm way too young to remember Masten Gregory or Paul Frere, I do at least know who the are and what they did :) I take great interest in real motorsports (i.e. NOT NASCAR :p lol. I could write everyone here a very long post about that too giving all my reasons... I've done it many times elsewhere... IGN, NFSCheats, NFBS... heheh). I always enjoy articles magazines like Road & Track run about says way back when in racing. Especially Rob Walker's old GP peices. Anyone remember Phil Hill? ;) Actually, he's another one who writes for Road & Track on occasion. He was the first American to be crowned the F1 World Champion as well (back in 1961 driving for Ferrari). Sometimes I kind of wish I was there to see some of these things. There were some great technological revolutions going on, especially at Indianapolis. Mid-engined European GP cars taking over from the American front-engined Roasters, Turbine cars, NA engines, Turbo Engines... etc. It was certainly the most innovative time in racing history with all of those different cars racing at once. Now Indy is practically a spec series ("Indy Lights with V8s" haha).

Anyway, there are a good number of examples of people passing around the outside.. but mostly very rare and special, though. It's one of the reasons why I miss Greg Moore in CART. He used to do that quite often on ovals and even on a few road-courses. Jacques Villeneuve did it a few times himself, including when he first joined F1. He pulled a few Indy Car tricks on the F1 field ;) OR how about Gil de Ferran's last lap pass on Kenny Brack at Rockingham this year (the British track, not the NASCAR track :P) around the outside. Absolutely amazing! Doing it at extremely high speeds (180+ mph) and the car wiggling its way down across Kenny's nose. Absolutely amazing. We're talking about something much more amazing that Zanardi's Corckscrew pass at Laguna Seca in 1996 ("The Pass" as it became known as.. ). Only drivers with a special talent (and a hell of a lot of guts) can pull manouvers like that.

[JeffR]

Originally posted by DC_McGregor
Briefly, a "late apex" is defined as the closest point to the inside of a corner - _after_ the midpoint of that corner....
An "early apex" (or late braking maneuver) is defined ...
A blocking line is somewhere between the two....
Another technique is the "counter pass" (my name for it).


I think you've got the terms backwards. "Apex" refers to the point where the car is turning with the smallest radius, and going the slowest. Early apex means just that, brake a bit early, apex the corner early, then push out of the corner. Late apex is braking late, turning late.

Most modern racing cars can pull more g-force cornerning than accelerating. For most road tracks, this means that there is only one best line. Banked ovals are the main exception to this rule, some cars will run well up high, and others down low. Counter passing is rare because of this.

Motorcycles are the exception. Because of the lack of downforce, and the high power to weight ratio, there are multiple lines at most road tracks for motorcycles. Almost no time penalty for late or early apexing a corner. This allows a lot of oppurtunities for counter passing.

[AccadaccA]

Originally posted by MATT
.... Only drivers with a special talent (and a hell of a lot of guts) can pull manouvers like that. What about when you drop a lit cigarette in your lap? Passes like you have described have been done on two wheels, in standard road vehicles, through peak-hour traffic. :D heh

I tend to agree with JeffR. When I read the opening post I thought that sounds kinda mixed up. Sorry if we are mistaken.

Excellent post, btw -^ -^

[MATT]

LOL Rob ^_^

The Apex is simply the center point of the corner. You start from the outside and dive towards the apex and then the car naturally goes back to the outside on the exit (especially if you're getting back on the throttle like you SHOULD). Of course, early and late apexes mean you just change your line. Early apex you turn in early, usually not a good thing, but in some circumstances it can be good (like when the road is much wider on the exit than before the turn...) But yeah, Jeff is right in that you'd have to brake earlier for an early apex than a late apex, as you would be traveling slower through the corner in most cases because it would make your exit a lot sooner and much wider than usual... not a good thing, as you usually would want to maximize your exit speed for the following straight (that is if the next thing after the corner is a straight... Otherwise you may want to change your line and sacrifice the first corner for the next corner so you can make the corner with the straight after it the one with the faster exit.... always must be thinking about where the straight is and how you can maximize your speed)

Jeff is right in pointing out the part about how most racing cars with all their downforce can pull so much G's of cornering force that altering lines isn't wise. Usually there's only one line. Bikes are very different. Plus Bikes are much thinner than cars, so to them there's much more road to use (a lot of these guys run on Grand Prix tracks as well....) Although the fact that bikes can lean so much also play a fairly large factor in cornering as well. Bikes can create a fair amount of G's themselves.

But then again, maybe modern race cars like F1 and CART cars simply make out TOO MUCH power to make a good passing show. Passing in CART races was awesome back when they had around 700 hp (well, the big difference was on short ovals when they ran big wings). Now they have around 900 hp and run small wings to slow down the cornering speeds and the passing isn't quite as great (Handford Mk II rear wing isn't helping either! It just creates a bunch of turbulence which makes it tough to run close behind another car). CART can and does put on some great passing shows on road courses, although nowhere near as spectacular as bikes. Maybe those steel brakes help.... it gets tough with those F1 carbon fiber brakes. The braking distance is so short that it makes it really tough for a driver to even think about trying to make an attempted pass. Plus the fact that F1 cars have a fairly large difference in performance from team to team. It might not be all cornering forces which prevent passing. They can and do change their lines a bit, but not quite as much as bikes.

[DC_McGregor]

Matt and JeffR,

Technically, both of your definitions of "apex" are correct - so far as the dictionary is concerned. However, the definition that I use is the one used by racers in the real world. I'll repeat it here:

The apex of a corner is the point where the car is nearest to the inside of the road.

Hence, a "late apex" corner is where the car is nearest to the inside after the midpoint of the corner. The term, "early apex" doesn't actually exist. It's actually called a "late braking maneuver", "passing maneuver", "inside line" and probably a few more.

I did a brief Google search ...

http://www.google.com/search?hl=en&q=late%2Bapex

... and found this link:

http://www.turnfast.com/tech_driving/driving_cornering.lasso

It is an excellent text and graphic depiction of cornering techniques. It also properly defines late apex. Log onto that site and bookmark it!!! Under the Reference Point section, he says, "Next, is the apex point. This is the target point that the inside tire of the car should touch as it reaches the maximum inside point of the driving line."

I'd read the whole article. From the brief sections I've read so far, it's better than anything I've done.

Here's a couple more from the same Google search:

http://www.geocities.com/tocawtc/brazilia.htm
http://www.perfectlaps.com/support/glossary.shtml

And there are a ton more.

Robert

[DC_McGregor]

I think some clarification is needed at this point.

The purpose of a late apex is to get as straight a shot as possible out of a corner so that you can begin accelerating sooner and have a higher speed down the ensuing straight. The sooner you begin accelerating, the higher the speed you'll reach at the end of that straight.

If the next section of road is another corner rather than a straight, your line through the first corner should optimize your entry and exit of the 2nd, assuming the 2nd corner leads to a straight. Use a late apex for the exit of the 2nd and adjust the line through the 1st corner to achieve that. If it's a 3 corner sequence, it's more complicated yet.

A good example of this in PU is the right/left sequence at Cote d'Azur leading to the "straight" (with 3 tunnels) going into the town of Cote d'Azur proper. It's a difficult sequence. You take the 1st corner a bit slower and on the right side of the road to maximize your exit speed from the 2nd - using a late apex, of course. You will gain a lot on any racer that doesn't do it. This corner is examined in Racing Lines 101 (and associated replays), which can be found at:

http://online.totalnfs.net/dc/

Again, I recommend reading it. Agree with it or not, it has good content.

There are many other types of corners and sequences that may also require different techniques. The most difficult is the decreasing radius corner. I still have trouble with those.

To be sure, modern F1 cornering speeds have become so fast that there is essentially only one line through a corner. When you couple those speeds with the loss of downforce caused by following another car too closely, passing has become a lot more difficult, but not impossible. The basic principles outlined in Racing Lines 101 and the links in the previous message still apply.

When Nigel Mansell went to CART after winning the Formula 1 championship, he said, "... these guys pass ANYWHERE!" :D

Robert

[MATT]

You'd late brake the inside line when attempting to pass, sure... but I never heard anyone refer to it as the late braking line... but whatever :)

I think you clarified what you mean quite well :) Thanks.

And on a side note about Nigel; he was freaked at my hometown track at first (The Michigan Int'l Speedway). Why? Because of the wind noise! traveling at 230+ mph with your head out in the air can create quite a racket for the driver. CART engines are by no means quiet, yet drivers say they have trouble hearing the engines over the wind! Sounds like fun, huh? Nigel also complained that he couldn't see straight at first either because the wind was bobbing his head so much. Drivers may make driving look easy (especially on high-banked ovals like Michigan) but it isn't by any means easy (especially if your car starts to oversteer!... or "go loose" as them NASCAB fans call it :p It's not easy to control oversteer on banking. When Bobby Rahal retired from being a CART driver in 1998, he said the only thing he'd miss about being a driver is a loose car on an oval.. heheh).

I'm good at digressing :)

[JeffR]

>...late apexing...

Your'e correct, I sit corrected.

However, my understanding is that late apexing is not early braking, as much as just staying on the brakes longer and along a straighter path to slow down more, then turning quicker and accelerating to set up the late apex.

A true late braking pass usually involves a double apex, one going into to corner to pass by on inside, and again for corner exit.

[DC_McGregor]

First, braking will be at or near maximum for both lines.

In order to hit a late apex point, you have to turn in earlier and thus have to brake earlier. The late braking (or early apex) line leaves the braking until a bit later, maintaining a higher speed a bit longer, while still on the straight. It's this extra speed maintained until the later braking point that enables the pass.

Typically, the late braker will be at the utmost limit of his braking ability. And then some. <g> It's the "and then some" that frequently causes him to run wide. As I've mentioned before, the late braker has a poorer exit line from the corner, resulting in a slower exit speed.

I've saved a graphic from one of the above sites to illustrate (LateApex.jpg). You'll see that the car turns in a bit earlier and "squares" the corner off more to gain a higher exit speed from the corner. Since he's turning more sharply, he has sacraficed a bit of cornering speed to gain that exit speed. Let's see, 0.1 second at 50 mph equals half as many feet as 0.1 second at 100 mph. That's an oversimplification, but it illustrates the point.

If you look at the jpg in reverse (right to left), you'll see an approximate late braking or early apex line. The racer leaves his cornering until very late. The cornering speed will be about the same, but the acceleration point will be much later. Hence, the next straight will be that much shorter. Hence, a lower terminal velocity at the end of that straight.

Last, I have to stress that while the late apex is _generally_ the best line, it isn't always so. You have to adopt the appropriate technique for each circumstance.

Does this clear everything up? If not, ask another question. If so, ask another question anyway! :D

Robert

[Mickcals]

Doesnt matter what track your on, if you use the current racing line to your advantage you can create your own, that is quicker, faster, more strageric and suited to your style of driving.

Just a tip, take or leave it.

[blackice111288]

i usually use the IN-OUT-IN line.

[chris]

Depends on the car for me.

4wd cars usually don't like being rushed into corners, you ease off a bit, and then wait for the corner exit to spring the 4wd surprise on unlucky competition.

[lewi]

Well, lines also depend on camber and other factors. But the most important principal is to be on the brakes for the least amount of time, and then get back on the throttle asap. The more time off the throttle and the more time on the brakes costs you mega time, if you add up every corner of the track.

In a 250cc superkart around Mallala (South Australian circuit), the lap time is usually around the 1:06 ish mark. The on board data on a fast lap showed that the driver was off the throttle for around 13-14 seconds. So thats 13-14 seconds of not going forward, if you can start accelerating earlier, maybe 10-20 ish meters per corner earlier (provided the car/vehicle is behaving well) then you will gain anywhere between .050 s to .100 s (very rough figures) per corner which amounts to quite a bit if you gain that in every corner.

Also, the following attachment (please forgive me for the quality factor) basicly sums up the line of (specificly)a hairpin and sums up the cornering values (of F1). Notice next season when they do overhead shots of cars going through hairpins, they all follow this principal. (eg, corners such as Adelaide hairpin [Magney Cours hairpin] and on the hairpins at Bahrain).

Cheers

Lewi