The last two articles covered strategy and etiquette for passing drivers and those being passed. This article talks about how drivers make mistakes in applying those principles.
At a recent Buttonwillow event, I was driving an E36 M3 when a stock car approached down the front straight. I was not sure he could catch me before the corner so I kept my foot in it as long as possible. I considered my options: My nearest competitor was far enough behind that keeping the stock car between us would not benefit me, and fighting the stock car for the next corner would only hurt me. As we approached the braking zone, I believed he was too far behind to successfully pass. I also believed that my BMW would be able to carry more speed through the corner.
There is a specific point where a driver must choose between attempting the pass or tucking in and running single file. As we passed that point, he drove to the inside, so I responded by braking to facilitate the pass. It would have been an uneventful pass except that he went all the way to the inside line to brake. As such he was forced to over-slow the car to negotiate the turn. At my turn-in point, I saw that we were side-by-side with three or four car widths between us. I could carry 5 to 15 mph more through the corner, but I was concerned that he wouldn’t slow enough and slide into me mid-corner. We ended up going through the corner side-by-side and I maintained the lead at corner exit. Our positions did not change, but we both lost a substantial amount of speed exiting the corner. It was at this moment that I realized he had not read my previous articles!
I don’t begrudge the driver for attempting the pass. I might have done the same. However, the choice to take the tightest line created a dangerous situation and negated the likelihood of a successful pass. I see many drivers taking tight lines or early apexes while attempting to pass in the braking zone. I believe that drivers do this because they are afraid that the other car might turn down on them. Or perhaps they are being overly considerate and giving the other driver lots of room. Unfortunately, they create the very situation they are trying to avoid. Passing on the tightest inside line takes a high-probability pass and turns it into a low-probability pass. It also increases the likelihood of the two cars colliding.
The best that a passing driver can do is to line up close as possible side-by-side. Ideally, the two cars will graze mirrors. At most, there should be no more than half a car width between them. Positioning in this way has a few benefits: the passing car fills the other’s mirror, reducing the likelihood of that driver turning down on the passing car. It also allows the passing car to maintain the highest available speed to complete the pass, and if the driver being passed should happen to turn down on the passing car, it minimizes the speed differential and the force of impact if the two cars collide.
Another potential pitfall is when faster traffic is passing two cars battling for position. In this case, the trailing car can benefit by following an out-of-class car making a pass. It happens like this: two cars are running nose-to-tail racing for position; a faster out-of-class car puts his nose in between the two cars; the trailing car is forced to either back-off or run two-wide through the next corner. When the out-of-class car attempts to pass the leading car, the trailing car drafts behind the passing car. The leading car now has to figure out how to position himself for the next corner, facilitate a pass for the out-of-class car and also prevent the trailing car from passing.
If the leading car holds the outside line to allow the out-of-class car to pass on the inside, then he is giving up the inside line to the trailing car as well. If he takes the inside line and forces the pass on the outside, then he risks having to over-slow and go two-wide through the next corner. Both options have their own pros and cons. Planning the best strategy depends on what happens through the next series of corners. This is where experience and practice become critical. I will discuss how to prepare for these situations in the next article.
A mechanical engineer and driving coach, Joshua Allan has worked in the design offices of Ferrari’s Formula 1 team and has been a vehicle development driver for Maserati in Italy. He is a five-time Performance Touring National Champion in a Mazda MX-5 with Robert Davis Racing. Send questions for future articles to firstname.lastname@example.org.