Learning A New Track In 4 Sessions
It is not often that one has an opportunity to learn a new track. New road courses are not constructed frequently, and there are usually few within one's driving distance.
Therefore, when EMRA ran the first event on reconfigured and repaved Pocono South/East I was excited to be among the first to drive that configuration knowing that I would need to figure it out by myself.
The event was actually a Time Trial practice on Saturday and Time Trial competition on Sunday, giving me an excellent opportunity to compare my track learning abilities with those of other attendees.
This guide was compiled from my experience during that weekend. It is written in present tense, following my thoughts and reasoning throughout the event, because writing an entire article in past tense seemed silly. The advice comprising most of this guide is not track-specific; only the preparation section draws on previous knowledge of Pocono and at the end I include actual event results and notes.
Let's get to it!
Pocono repaved South and East infields and added connecting roads to allow for a "Southeast" course to be built out of South and East together (actually, there are several "Southeast" configurations possible).
While nobody has driven the configuration we are going to run, Pocono has some distinguishing features that I expect to carry over into the new courses:
- Very fast oval to infield turns. Because the oval is very wide, it is possible to line up the car with the infield portion of the course while still on the oval without losing too much speed, and carry substantial speed through the apexes of these turns. It is typical for drivers to apex these turns too late and brake too much and too early.
- Very rough oval to infield transitions. This was a feature of Pocono North last year, and judging from last minute pre-event reports it carried over into the newly repaved courses as well. Luckily for me I drove Pocono North before the last repave at respectable speed and therefore I am prepared for both properly done and horrible transitions. (Sadly, transitions turned out to be on the horrible side.)
- Oval (Nascar) turns are very fast. As with oval to infield turns, many drivers take the Nascar turns too slowly. Partially this is because their line is not quite right, usually too early and then off apex, and partially it is due to a lack of confidence. Again, I was lucky enough to run various configurations using two of the Nascar turns as well as the entire oval, and thus have an idea of what I can do.
Saturday Session 1
The goals for the first session are, in order of importance:
- Commit track layout to memory. This means, for the most part, which turns are right and which ones are left, and where the corner workers are.
- Classify each corner into "late apex/needs patience", "early apex/needs aggression" or "mid apex/carry speed". This provides a prioritized list of corners to work on in subsequent sessions.
- Do an 8/10 run through the entire course while staying on line. This validates knowledge of the track layout and provides correct ballparks for braking points.
Saturday Session 2
The goal for the second session is to run the school line consistently. This means:
- Run 8/10 to 8.5/10 pace the entire session.
- Do not miss any apexes.
- Do not be early in late apex corners.
The second session should yield a good lap at speed to compare the following sessions against.
Session 3 Preparation / "Brainstorming Session"
With a 8.5/10 run in the books, now is a good opportunity to classify corners yet again into the following three categories:
- Corners where line can be improved so as to obtain a lap time reduction either in that corner or over the following straight.
- Corners that can be taken more aggressively to obtain a lap time reduction.
- Corners where improvement is unlikely.
To illustratet the difference between first and second bullet points, the first bullet point can aim to reduce the distance traveled through the corner whereas the second bullet point can aim to drive the same line at a higher tire slip angle.
Some considerations that can be useful for improving lines are:
- On corners leading to straights, is the car flat out from the apex forward? Can a later apex be run to be flat out sooner?
- Is entire track width being used?
- Is there any coasting leading up to a corner, where time can be taken out by braking later?
- Are there corners where the car is accelerating from turn in? These call for higher apex and consequently entry speed.
Aggression typically is the realm of advanced drivers. Some considerations for more aggressive driving would be:
- In a bumpy turn, can the car still be landed at higher speed, and will driving faster with more bouncing produce a lower lap time? What is the likelihood of car damage at higher speed? Is the damage probability acceptable for the remainder of the event? How about a single flying lap?
- How hot are the tires getting so far? Can the car be slid around corners at higher speed without toasting tires in 20 minutes? How about for a single flying lap?
- How fully is the track being used in corners with little or no runoff, and how much speed increase there would keep the risk of going off acceptable?
If anything on the car is adjustable, consider whether the car's handling can be tweaked to make it more suitable for important corners. For example, if there is excessive oversteer at corner exit, can the car be made to understeer via shock or sway bar settings or tire pressure? How will a more understeering car behave on the remainder of the course?
Saturday Session 3
The goal for the third session is to improve the lines in preparation for going faster, and to validate which corners can be taken more aggressively. Primary point of attention is the feel of the car in each corners where opportunity for improvement is possible.
In the car, predictive lap time delta for each corner being worked on is extremely important. Overall lap time is, however, not. If all corners are addressed with time left in the session, a "conservative" 9/10 lap can be attempted. What that means is driving at maximum speed and with maximum aggression given a hard constraint of never overdriving the car. Which means, in turn, if you are sure you can be more aggressive and hold your line - do it, otherwise do not.
Not overdriving is important because given limited track time available, it is better to be conservative than to get used to doing the wrong things (which is what results in overdriving).
Session 4 Preparation / "Data Session"
I prioritize traction sensing over data. The plan formulated in the brainstorming session relied on feeling the car in the second session. More than anything the driving efforts in the third session were about feeling the car as it approached the limit (on close to correct lines).
With individual corners if not the entire third session done at 9/10, it is time to look at data and verify the hypotheses made in the brainstorming session, and thus to determine whether the driver is evaluating correctly the grip level that the car has in each corner.
Data should show improvement through all corners identified as "improvable" in the brainstorming session. If track segmenting is available, the last few laps should generally have those corners being executed in less time than the best times in the second session. Without segmenting this can still be determined but with more effort.
Data can also be used to examine whether the car is consistently placed at the grip limit in all corners. For example, most corners should achieve a similar top lateral g, and braking zones should show similar forward g. Identify corners where this is not happening for improvement in the fourth session.
Go over the plan from the brainstorming session again, both in terms of line improvements and car setup improvements. Are changes resulting in decreased corner/segment/lap times (in other words, are changes working in the right direction)? Should any of the changes continue to be made?
Driving harder in the third session may expose car setup deficiencies that were not as clear in the second session. Is the car complying with what the driver is requesting at 9/10?
Saturday Session 4
The last session of the day is the time to put everything together for a 9.5/10 attempt.
Save 10/10 attempts for the competition day. The goal still is to drive as hard as possible without overdriving the car.
Session 4 Analysis
Look over the data. The best lap of session 4 should be better in every corner than any lap done in any of the earlier sessions. If this is not the case, find out why.
If you made changes to the car or lines between third and fourth sessions, carefully evaluate whether they are moving in the right direction.
Plan For Competition Day
If data analysis after the fourth session showed areas of potential improvement, prepare a plan for them for day two.
Otherwise, rest on your laurels.
Sunday - Session 1
Do everything you did in the fourth session of day 1. The goal should be to progress from warmup to 9/10 by the end of the session.
Sunday - Timed Sessions
Do the same thing you did in the first session but dial aggression to 10/10.
Congratulations on your win!
Pocono North Time Trial Review
This article was written from what I did at Pocono, and it therefore follows that what I did matched the plan outlined here quite closely.
I noticed that the car was running hot early in the second session on Sunday, and parked it until the timed sessions. In effect, the sessions I enumerated above were exactly the sessions I ran.
Turn numbers with start/finish where it was originally placed:
- Turn 1 - fairly sharp and late apex right hander. The turn itself is not a late apex turn but correct setup for turn 2, which is the third most important turn on the track, requires a late apex line out of turn 1.
- Turn 2 - absolutely late apex left hander, leading on the longest infield straight
- Turn 3 - a kink curving left with a bump on the geometrically ideal line
- Turn 4 - a slow, very long and late apex right
- Turn 5 - a late apex left leading on the second longest infield straight
- Turn 6 - 90 degree right sweeper
- Turn 7 - infield into oval
- Turn 8 - oval into infield
The importance of turns for lap time would be something like this:
- Turn 7 (leads to longest straight)
- Turn 8 (carrying huge speed from the longest straight)
- Turn 2 (leads to longest infield straight, or second longest overall)
- Turn 4 (leads to third longest straight; in lower power or higher grip cars turn 6 does not require braking, therefore for these cars turn 4 becomes even more important)
- Remaining ones
Best lap times and notes for each of the sessions:
- Day 1 session 1: 1:31.050
I identified turns 2 and 5 as late apex turns that were easy to blow and lead on straights, which therefore required patience. Turn 8 lead to the oval and was therefore the most important turn on the track; it also had the bigger bump (compared to turn 9) and therefore the most potential to damage the car. Turn 9 (leading from oval into the infield), as expected, provided ample opportunity to carry lots of speed with a correct line.
- Day 1 session 2: 1:28.857
I decided that the line through turn 1 should be a sufficiently late apex to set up for turn 2, despite an obvious cost in turn 1.
In either the second or the third session I decided that turn 4 should be trailbraked into because of the line required to set up for turn 5.
- Day 1 session 3: 1:27.208
In either the second or the third session I realized that turn 6 required very little braking or possibly none at all.
After the third session I put the front bumper on hoping to gain front end grip on the oval.
- Day 1 session 4: 1:23.117
I was able to take the oval almost flat out. Definitely felt the car wanting to overrotate on the oval. Front bumper seemed to add front end grip.
Here is a comparison between my 1:28 lap in session 2 and 1:23 lap in session 4.
- Day 2 session 1: 1:23.480.
Based on this lap time I was comfortable not running any more practice sessions on Sunday when it was announced that timed runs would be done with stopwatches at the end of the day.
- Timed session 1: 1:22.7 (unofficial, did not count)
I misshifted in one corner on each of the two timed laps. Luckily for me there was a timing issue and I was given a rerun.
- Timed session 2: 1:21.78 (official time for the event)
I made no mistakes and managed an amazing exit out of turn 7, better than on any other lap in the weekend.
1:23.117 would have been good enough for a class win. 1:21.78 is a class win with a big margin, fourth quickest out of a ~35 car field and about a second off FTD set by a car in a higher class.
Tagged: advanced, data analysis