Talk:Racing line

Diagram
On my browser, the SVG diagram has lost the arrow indicating direction of approach to the corner. (Safari 2.0.4 on Mac OS 10.4.8) St3f 21:56, 21 December 2006 (UTC)
 * Mine too. It's like the SVG has jumped back in time 7 months, that's bizarre.  I've posted the question to Wikipedia:Village pump (technical)#SVG problem.  --Interiot 22:53, 21 December 2006 (UTC)

The lines do not ease in and out of the straight
I tried to comment this on the image page itself, but I think perhaps that's wrong, so I'll say it here. Consider the light blue line especially. It is an absurd way to come out of the corner. The problem is a straight line was used where instead a gradual curve should have been used. As it is, a kink will result after you should have accelerated. But, instead, a gradual change of direction should have been done from the tangent which was inappropriately extended into the line shown, to a line parallel to the outside edge of the roadway on the exit straight. The same problem exists with the dark blue line, too, in reverse.--SportWagon (talk) 15:35, 12 August 2008 (UTC)
 * Oh yes. And the entire article is entirely rubbish anyway.  The discussion of "late" and "early" apexes has its statements backwards.  A late apex (clipping-point) allows earlier acceleration.  That would be clear from the diagram if the diagram didn't erroneously have straight lines.  More exaggeration in the diagram might help, too.  Actually, the problem in the diagram arose when you tried to base it around the symmetric entry/exit with a central apex.  A late apex will require having the exit line meet the edge of the roadway further to the right than the symmetric or early apex lines will.  I might start editing soon, if no-one interested appears soon.  I feel currently lacking in references, however.  And am not really familiar with tools to produce improved diagrams.  All-in-all, I'd be in favour of removing the example.  (Appears to be original work, after all).--SportWagon (talk) 18:01, 12 August 2008 (UTC)
 * "late" and "early" were subsequently fixed (switched).--SportWagon (talk) 18:27, 25 August 2008 (UTC)

Apex entry and exit
Previously, the assertions made in this section were backwards. I fixed that. I find the example difficult-to-follow and unconvincing in its conclusion. It's not clear whether the hairpin is in the same direction as the 90degree corner, or in the opposite direction. If they are both in the same direction, everything probably makes sense except that such a configuration (ending in a long straight) would require a "figure 8" at that point (the final straight would cross the first straight in that case, e.g. via a bridge). If, as seems more likely, the turns are in opposite directions, the advantage of retaining incoming speed versus a desire to "widen" the following hairpin make it even less obvious that a correct solution would use an early apex for the 90degree corner. All-in-all, I'd support removing the example. It does appear to be, after all, original work. An example from a reliable source would be better.--SportWagon (talk) 14:10, 14 August 2008 (UTC)

Geometric vs. Racing Apex
I've made no edits here as I'm not an authority. However I've done some open-wheel racing in my time, and my experience is that the sooner you get on the accelerator, the greater your exit speed from the corner, and that's what wins you the straightaway that often follows: giving your engine that revving head-start at the curve. This is very different from the theoretical apex of a curve. I can't argue that the green line labelled as "Ideal" hits the mathematical apex, but, were I in a car or on a bike, I would choose the "late" line. It still isn't ideal, but it's closer. The reality in racing is the tighter curve in the beginning is offset by being the one that straightens out the corner first and allows you to pile on the revs sooner. I have no sources to quote, but that's my experience. And what's the deal with beginning and ending on the extreme outside edge on the straightaways? Who drives like that? I guess the bottom line is that I agree that the diagram is a bit crap as a racing illustration. -Cap&#39;n Crust (talk)
 * All of what you say is true for a turn that leads into a straightaway, but not all of them do. For example, if a long straightway leads into a turn which is followed immediately by an even sharper turn that you need to brake heavily for, then getting back to the gas sooner is not going to be as important as taking a line that allows you to keep some of your speed from the straightaway for a little longer. Recury (talk) 18:20, 25 June 2009 (UTC)
 * Biggest problem with the illustration is that it uses straight lines for entrance/exit where it should use an arc gently merging to/from parallel to the roadway edge. If your vehicle has very poor acceleration, it may be more important to maximize mid-corner speed rather than start your poor acceleration sooner from a slower starting speed.--SportWagon (talk) 16:15, 6 July 2009 (UTC)

Source of late/early apex terminology confusion

 * The apex is often but not always, the geometric center of the turn. Hitting the apex allows the vehicle to take the straightest line and maintain the highest speed through that specific corner. It is also the tightest part of a corner.

Verified with other motoring types, normal usage is to say the "apex" of the driving line ("clipping-point" as you have used) is the point at which that line comes closest, usually touches, and sometimes even runs over, the inside edge of the roadway in the corner. That apex will not be the tightest/slowed part of the driving line; it is not in any sense the apex of the line (trajectory, path) of the vehicle--in fact the clipping-point apex tends to occur opposite to anything a mathematician would call the apex of the line; late apex (clipping point) causes the tightest, minimum speed part of the line to occur earlier, and vice-versa. It's not obvious to me what is meant by saying "It is also the tightest part of a corner".--SportWagon (talk) 14:23, 14 August 2008 (UTC)
 * I agree, "tightest" here is confusing at best. Recury (talk) 17:18, 14 August 2008 (UTC)

I'll remove the entire statement when I've convinced myself I can't find a reasonable replacement. On other fronts, I think I've finally determined the relationship to a mathematical apex. An apex is usually a highest vertex, e.g. on pyramid or cone. Or, in two dimensions, one vertex of a triangle is the apex, if you define a "base", and typically the base is considered to be the longest side, that is, the apex is usually considered the vertex of a triangle opposite its longest side. For any corner, you can draw a straight line directly from entry to exit. The inside edge of the roadway should project beyond that. If you pick any point on that curve (i.e. curved roadway edge), you can construct a triangle whose apex will be that point. "The apex" of that corner could be chosen as the triangle with the greatest height, or perhaps the one with the most symmetry. But obviously triangles giving "early" and "late" apexes (apices?) can be chosen instead. Still, this choice of point is only tangentially (somewhat literally) related to the actual line the car will take around the curve.--SportWagon (talk) 20:46, 18 August 2008 (UTC)
 * It must be something like that. My confusion the other day came from trying to think of the apex as the highest part of the arc of the racing line, which it's not. Recury (talk) 16:05, 19 August 2008 (UTC)
 * Yup. Those of us who like to predict sources of confusion seem to think of that.--SportWagon (talk) 16:52, 19 August 2008 (UTC)

Better definition
An imaginary line around a circuit that provides the quickest lap time. first good one I googled up

The discussion is focused on apexes, but in fact there are lots of other situations to consider, kerbs, grip, corner sequences, weather and so on.

So in a wet weather race, the racing line may well be on the outside of the corner which provides more grip. Similarly, on a straight the racing line may be on one side or other of the track, typically the outer line, where the inner line gets dirty.

It is relevant where there are rules like in F1 where it is understood that the lead driver cannot swerve around, but is only allowed to make one blocking move, but can then move again to adopt the racing line for a corner.

Other points that could be usefully made are that the racing line gets cleaned by the tyres, so will normally generate more grip.

I haven't added this as I haven't come across any good sources that discuss this. Probably needs a book by someone like Martin Brundle or or may be on somewhere like www.itv-f1.com. 92.232.129.103 (talk) 08:44, 20 August 2008 (UTC)
 * "imaginary" sounds wrong. I guess they mean it's not actually painted on the track, but "imaginary" wrongly suggests it won't have a tangible location.  We also need to avoid confusion between the line for a single corner, and the line for an entire track. "around" also sounds wrong when used with "line".  It sounds like the line is on the outside of the circuit. Changing "imaginary line" to "route or course" might avoid using the word in its own definition.  Of course, then we lose the citation.--SportWagon (talk) 21:46, 20 August 2008 (UTC)

This looks nice old Racing line article had following (waffly, hand-waving) citation
 * http://www.driversdomainuk.com/motorsport/racing_line.php
 * http://www.miata.net/sport/Physics/05-Cornering.html


 * That last source touches on the point I am getting at: the racing line is not a line through a corner, it is the optimal path around the track. The subtle difference being that while the major influence is the geometry of the corner, the ultimate lap relies on a complete optimisation of all factors. 92.232.129.103 (talk) 07:50, 21 August 2008 (UTC)


 * The term is ambiguous. Detailed analysis such as  attempts is facilitated by the assumption that the Racing Line through a corner can be analyzed in isolation, yet, to their credit that same source, as you say, touches on the bigger picture.  As NPOV digesters, I think the ambiguity should be mentioned, although I think it will still remain NPOV to emphasize that, in real life, not only is it inadequate to consider a single corner in isolation, but that other real-life factors may influence the "Racing Line" at different times.  Another factor which doesn't seem to be mentioned at all is the type of vehicle.  125cc motorcycles use a very different line from superbikes, in some corners.--SportWagon (talk) 14:03, 22 August 2008 (UTC)


 * Personal thoughts to verify. A non-racing-line around a single corner will simply pick a side and stay on it; usually the legal side of the road for the jurisdiction.  Determining racing-line for a total course begins with finding fast lines (call it "racing-line") through individual corners, and later applying refinements.  (True, with experience, certain combinations will be taken without first breaking-down and refining).  But, in any case, the fundamental thing references must prove is that the small amount of extra distance you take by "using all the road" in a corner (as opposed to staying on the inside of the track as much as possible) is outweighed by the higher speed you can maintain.  That that is true for vehicles above a certain speed may be obvious to most people, but the proof of it is probably not obvious.  (As far as I can tell, the principle is true even for slow vehicles, since the action of turning actually slows all vehicles down).  In any case, I think the article should at least mention the concept of racing-line around a single corner, in contrast, as I say to non-racing-line.--SportWagon (talk) 00:09, 25 August 2008 (UTC)

Things to Do

 * 1) Find a drawing tool suitable for producing an improved version of the diagram, or find a better pre-prepared diagram, with suitable copyright provisions.  The straight line segments, starting "early apex" and ending "late apex", in the current diagram are incorrect.--SportWagon (talk) 18:38, 25 August 2008 (UTC)
 * 2) Decide on structure for article, so as to imply necessary source materials for reference, and then see if they can be found.  would be good for a "what would one do with a single corner, then refine that into a total circuit" approach.  Alternatively, we've got to decide whether there's really enough citable (web-citable?) material to base a NPOV digested article on.  We seem to have ideas, but not a lot of citable references.--SportWagon (talk) 18:38, 25 August 2008 (UTC)
 * 3) For me the article is unnecessary theoretical - seldom the racing line follows the "theoretical" ideal line as derived - AFAIK, nowadays - by simulations. Weather, grip laid on the track, local road roughness, tire condition, puddles, even sun position are often much more important. And if we'll be going theoretical - the road is a 2-dimention surface and the curbing might (end up being) variable across the width of the turn (like at most ovals). A sim driver will never consider most of these - but it's the common chatter in track racing briefs, and that's why every "resurfacing" of this and that section brings so much buzz.  — Preceding unsigned comment added by Kerguelen Rogue Avon (talk • contribs) 08:27, 24 September 2022 (UTC)

Dubious sources of information.
This apparent game documentation occasionally has definitions, at least some of which don't make much sense. It may have been a source of some of the original articles. The glossary does give reasonably good definitions of some colloquial terms. --SportWagon (talk) 15:46, 27 August 2008 (UTC)
 * apex http://www.fordracing.com/glossary/definition/index.asp?glossaryid=41
 * late apex http://www.fordracing.com/glossary/definition/index.asp?glossaryid=77
 * early apex http://www.fordracing.com/glossary/definition/index.asp?glossaryid=156

In general... http://www.fordracing.com/glossary/

I'm not sure if it's the videogame or actual Ford real-life racing.--SportWagon (talk) 15:53, 27 August 2008 (UTC)


 * OTOH we could extract something from
 * line http://www.fordracing.com/glossary/definition/index.asp?glossaryid=97 --SportWagon (talk) 17:26, 27 August 2008 (UTC)

Multiple issues tag removed
I removed the tag consisting of

multiple issues| cleanup|reason=Very poor writing, weird punctuation by non-English speaker|date=January 2015 manual|date=January 2015 original research|date=January 2015

after I fixed up some of the grammar etc. issues. I'm not saying it is now a gem of brilliant writing, but I think it is clearer and properly expressed. Mostly, anyway. I ignored the longer paragraphs in the section I renamed Techniques and Tactics because my head hurt a bit by then. So issue (1) is basically fixed. Issue (2) I think was a stretch anyway. (3) probably needs some looking into, so much of this article is essentially general knowledge (to race fans), but still I'm sure there are books out there that cover this topic that could be referenced.

By the way, why is the title "racing line" and not just "apex (racing)"? Because it never really goes into the whole of the composition of a racing line, with diagrams showing how the track and type of vehicle affect apex choice over the whole of a course. Huw Powell (talk) 02:05, 7 March 2015 (UTC)

Chicane & Double apex sections
I'm unclear how these two sections and the accompanying images relate to the subject. They describe features on a track, but not how those features are to be driven. Any reason to keep? Barte (talk) 16:18, 7 July 2017 (UTC)


 * Well the Apex (disambiguation) page links to Apex (racing) and "Apex" in racing may also refer to "double apex". I agree the sections as they are now are a bit out of place but I think "double apex" should be covered in some way. -- intgr [talk] 12:55, 8 July 2017 (UTC)


 * If "double apex" can be shown to have some connection to "Racing line", I agree. As it stands though, the entire section is just this sentence: A double apex is a section of a race track where one turn is quickly followed by another in the same direction. That could be true (there's no reference), but until there's a discussion about the optimum path through this feature, the section seems irrelevant. Barte (talk) 13:36, 8 July 2017 (UTC)

A Commons file used on this page or its Wikidata item has been nominated for speedy deletion
The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for speedy deletion: You can see the reason for deletion at the file description page linked above. —Community Tech bot (talk) 18:23, 14 April 2023 (UTC)
 * Racing Line showing earlier and later apex.jpg