Our discussion has primarily revolved around a text-book style Dry Line. But is there really only 1 best line around a race track? The short answer is no. That would be too easy, wouldn’t it?

Remember, The Line is the fastest way around a racetrack. Things such as car size, weight, power and setup, track conditions, and hazards on the track can all yield different optimal lines for different cars. As we have already discussed, driving in the rain or in a race are two examples where the best line differs from the classic Dry Line.

Rain, Oil, Immobile Cars, and Other Nasties
The most obvious case in which there is more than one optimal line is when something is on the regular line. If a car dumps all of its oil right at the apex, or even decides to inconveniently park itself at the apex temporarily or for the rest of the session, you probably want to avoid the apex. In this case of oil, hitting the apex and a regular speed will make you spin, and then you would be the one blocking the track. This is undesirable. You can either slow way down so that you are at the limit of traction when you hit the oil, or simply go around it. Oil is very slippery, and chances are that a line that bypasses it completely will yield a faster time overall.

As discussed in The Line, Part 9: The Rain Line, the best Line in the rain is often different from the best Line in the dry. There are 2 reasons for this, but both relate to traction. The first reason is that going off-Line can provide higher grip, often enough to make up for going off-Line in the first place. The second reason is that you lose about 50% of your cornering grip, but only about 30% of your braking and acceleration grip in the wet. This means you want to treat your car as though it were a muscle car, because that is what it has become. It is now a car that you tip-toe through the corners, and keep it accelerating in a straight line as much as possible.

Which brings us conveniently to our next section: Power.

Power
One of the biggest determinations of Line is power. Cars with excess power want to get finished turning faster, get straight, and get on the power. They can sacrifice corner speed to get pointed straight sooner. This requires a different line than in my Miata, and is one of the reasons why driving an underpowered car is so much more difficult: your line through a corner matters much more, since you can’t cover you mistakes with power.

Turn 10 at NHIS is a good example of where power changes the line. There is a short straight in between Turns 10 and 11. It is short enough that I don’t have much time to accelerate in my Miata. So, I used up all of the available track at Turn 10’s track out to maximize my speed through Turn 10. I then swing my car wide to the right to set myself up for Turn 11. I’m actually not going in a straight line until I hit the braking zone for Turn 11. I find that I can maintain a higher speed for longer using this method.

A high power, poor turning muscle car, however, would take a drastically different line. Such cars cannot turn nearly as well as they can go in a straight line, so they would take the exact opposite approach to this section from a Miata. In a muscle car, I would compromise Turn 10, taking it slower and using very little track out room, align my car straight with Turn 11, and step on the gas.

Two cars. Two completely different lines. Exact same section of track. The only difference is how much each car relies on power.

Weight
Weight affects the nimbleness of a car, which can have a slight but nonetheless noticeable impact on the best Line. With a light car, like a Miata, Elise, or open-wheeled racecar, the car can transition its weight for left to right much more quickly, simply because there is less weight to be shifted. The tires are not loaded as strongly, and thus not upset as much, when you “toss” the car from side to side. This is why lighter cars are often coined “tossable.” That is a bit of an oversimplification, as car setup also plays a large role in how “tossable” a car is. But, for all intents and purposes, the rule that lighter cars transition better than heavier cars shall hold.

Transitions plays a large role in tight, switchback-like corners. The transition between Turn 9 and Turn 10 at NHIS is, once again, a good example of where different cars take different lines. Turn 9 is compromised, such that you apex right at the turn-in point for Turn 10. This is important, so ponder that for a second: you finish a left-hand turn right when you begin a right-hand turn. Thus, your car must go from having all of its weight shifted onto the right wheels (Turn 9, left-hander) to being shifted onto the left wheels (Turn 10, right-hander). The lighter, and more “tossable” your car, the quicker you can make this transition. You can therefore spend more time cornering and less time transitioning.

What does this mean? It means that you can spend less time going in a straight line as you transition from Turn 9 to Turn 10. This allows more flexibility in the exact line that you can take.

Another example is through the chicane at Turn 2 at NHIS . I got a ride in a 1960s Mustang Cobra, and the driver took a much less aggressive line than anyone else I’ve seen through there. He compromised the right much less than anyone else I have seen, and early apexed the left-hand turn. Intuitively, this did not make any sense, but he said the car felt better poised with this approach. He said it was just too heavy and cumbersome to do that much turning and transitioning in that tight of a space.

Bumps
Ideally, every racetrack would be as smooth as glass. Unfortunately, idealism has no place on racetracks. Exiting Big Bend at Limerock is so bumpy that my sunglasses shake and I can’t see anything until track-out. Even at “smooth as glass” NHIS, there is a sharp bump leaving the NASCAR oval in Turn 3, and reentering it in Turn 10.

Some cars handle bumps better than other cars. My Miata tends to bottom out in the rear, and I need to take this into consideration in Turns 3 and 10 at NHIS (I usually wind up just going for it and letting the suspension sort itself out, but I am still aware of my car’s interaction with the bump). If a stretch of track is bumpy enough to unsettle a car’s suspension, it may actually be quicker to drive off-line around the bump, depending on where the bump is and what precedes and follows it.

A good example of where such a decision comes into play is with rumble strips. Many corners have rumble strips at the edge of the pavement to conveniently warn you that you are about to fly into the wall. Most gracious of them, indeed. While bumpy, these rumble strips are still pavement, and can provide that extra bit of room needed to pull off a much faster line. A good example is the Chicane at Watkins Glen just after the Back Straight. There are huge, glorious rumble strips flanking the chicane. I hop right up on them in my Miata, straightening out the chicane considerably and letting me take it much faster. Guys in more tightly sprung cars often don’t like the rumble strips, though. They feel it unsettles the car too much (though my buddies in their Spec Miatas don’t seem to mind).

Car Specific Quirks
Beyond the broader categories listed above, some cars may have specific quirks or setups that favor a modification of the standard line. American Le Mans cars are very camber sensitive, and are able to corner much harder with even slight increases in track camber. At Big Bend at Limerock (Turn 1), this led them to take a different line than street-class cars. Most cars double-apex this turn and track all the way out before beginning the second part of the turn. But, the track is ever so slightly less cambered way out there, so the ALM cars would track out a full car width inside where I normally would be.

Given the myriad of cars and car setups one can have, such car-specific situations are bound to surface from time to time. But, before you go changing your line because of your car’s specific setup, make sure you get the basics down pat and try the other advice above. Most cars will fall somewhere within the broader categories we have talked about. Before you start changing your line based upon your car’s specific setup, make sure you have explored the typical Lines. You want to make sure that you have eliminated your own driving errors before you “adapt” the Line to your car.

Preference
Sometimes there are multiple approaches to a single corner, neither of which is faster. Turn 1 at NHIS is an example of this phenomenon. There is a Wide and Tight line. Some people say one is faster, some people say the other is faster. People have said they have timed both and that they are the same.

Such a broad lack of consensus is telling: both approaches are close enough timewise that other factors matter more than time. Do you like how the Tight line sets you up for the chicane better? Is it easier to transition to braking from the Wide line? Will someone cut you off and beat you to the apex if you take the Wide line? Do you just “like” one of the lines better, for no particular reason? I tend to favor the Wide line here. I like getting my turning done sooner, so that I can brake in a straight line and setup better for Turn 2. But, I’m beginning to experiment more with the Tight line, and it may yet win. We’ll just have to see…