- The real advantage of the reference lap is that it allows you to use another function
that most logging systems that include a driver display will offer.
The lap gain/loss or time delta function.
This is a metric which shows you how well or how poorly you're doing in real time
compared to the reference lap time.
This can be displayed numerically as a variance in lap time, graphically as a bar
graph or alternatively it can be displayed using coloured LEDs to represent your
relative time.
Typically, green LED is showing that you're doing better than the reference and red
showing that you're lagging behind.
There are numerous advantages to having this information right from the driver's seat.
In particular, you can analyse a particular section of track in real time, trying various
lines and seeing the effect instantly on the dash or logger.
This allows you to speed up your development because you can learn while on track rather than
waiting until you're back in the pits and then trawling through a session worth of data to
try and find useful patterns.
If you're using a reference lap that's been set by a professional driver, then you may also
be able to find obvious areas where the car can maintain more speed than you're using.
Let's say for example there's a high speed corner on the track and that you feel the car
can't get through without lifting off the throttle or braking.
If on the other hand the reference lap shows that it's possible to stay flat or at the very
maintain more cornering speed than you're using, you'll see your lap time loss increment
quickly.
Any time you're seeing the loss increment quickly like this is an indication that this
is a part of the track that offers a large potential for improvement so you should
focus your efforts here first.
It's important to understand how to interpret this data though as it can be
misleading if you don't know what you're looking at.
For example, it's important to understand that one part of the track will influence
the next.
Let's say you brake way too late into a particular corner and you see this results in a lap time
gain since you're now carrying more speed than your reference lap.
The problem here is that if you brake too late, it's going to impact your ability to get the
car turned and to hit the apex which in turn will compromise your ability to get back on
the power at the corner exit.
This typicallly looks like a brief lap time gain followed by a loss on the corner exit that
increments the entire way down the next straight.
This highlights a scenario where in many cases it's faster to sacrifice a little corner entry
speed in favour of optimising the corner exit.
Particularly on a slow corner that leads onto a long straight.
Another way of using the gain/loss function is during a qualifying lap where you may be
trying to set a representative lap time without putting excessive wear on your tyres.
In this case, you can monitor the gain/loss during your flying lap and make the decision
on whether it's worth continuing to push on
that lap or if perhaps you're better to abort that lap, set the car up again and go again
on the next lap.
It's important to mention here that sharing your attention between driving the car at maximum
effort and watching the data on the dash can be dangerous.
For this reason, it's good practice to be a little sensible about where you choose
to look at the data.
The sensible option would be on the exit of corners that lead onto a straight where you're
going to be a little less busy on the steering wheel.
Since the gain/loss is a cumulative number, it's not necessary to watch it all the time and
a glance at it a few times per lap is sufficient.
This is where coloured LEDs can actually be a real asset.
It's normally enough to be able to take notice of the LED colour out of your peripheral vision
which means you can monitor the gain/loss a little more thoroughly throughout your lap.
With this sort of system, the magnitude of your gain/loss can be displayed by the number of
coloured LEDs visible or the specific colours used.
While watching the gain/loss channel in real time on track can be extremely useful,
we also have the ability to look at the same variance or time delta function inside the
analysis software.
This is a cumulative channel of the gain/loss that we can display which shows us the time
difference or delta between two laps which is what we'll look at in the next module.
That was just one of the modules taken out of our data analysis fundamentals course.