GP3 Telemetry Guide - Ride Heights - Suspension - Packers - By Charlie "NoCharlie" London - Page 1 of 3
Right, sit yourself down, brace yourself and I'll try to
go through this with you. It ain't pretty, and it may be painful, but here
goes. What we will cover here is interpreting the telemetry graphs in order
to optimise ride heights, suspension travel and packers, as these seem to
be the most common areas of concern.
Right your aim is to run your car as low as you possibly can, but without
wearing the plank out, this has the distinct advantages of:
1: Creating under car downforce, the car is effectively "sucked" onto the
track, this is important because under car downforce does not have a drag
penalty, where as increasing the wing downforce does. So more grip totally
freeeeeeeeeee.
2: The lower the car the less it can roll in corners, imagine rocking say
a bus from side to side and then a go kart, you know which is going to sway
most, o.k. Poor comparison I know, but you get the idea. So, more stability,
totally freeeeeeeeeeee.
Right we now understand why we need to be low, so now we need to understand
the telemetry in order to achieve this.
We must also remember, that the figures we are talking about are measured
in millimetres so for example if you change from a stiff spring to a softer
one. Don't expect massive changes in the telemetry, they will be small, expand
the graphs to make them more obvious. As you can see from this image some
telemetry can be difficult to read when not expanded.
So zoom the x-axis to maximum and work on different parts individually.
It also pays to get into the habit of reselecting the tyres you have just
run on then fetching your data, and graphing foreground and background laps
to make comparisons.
O.K Doc get the prescription pad ready, it's onto the graphs themselves. We'll
start with ride height, and you're going to have to go out on track, told
you it was gonna be painful, also we're going to use default settings with
only two minor changes purely for the purposes of ease of explanation and
to make it easier for you to see and understand how to read and use the graphs...but
please understand that this is NOT a car set up guide.
Right take two bravery tablets, go to Monza, enter the pits, choose a car,
evict the driver and strap yourself in. Using the default settings, which
should have equal wings of 15, we will make changes only to the wings, (as
the default is too great for a high speed track like Monza) and the two upper
gears to take account of the wing alteration, so that said, set your wings
to 8 front and 5 rear and adjust fifth gear to 52 and sixth gear to 61.
Use rookie mode with all driving aids enabled, this will remove driver
ability from the equation, and ensure that telemetry changes reflect setup
changes rather than differences in the driving of a particular lap. (For newcomers
it will also show you the importance of driving a good line, just wait and
see :-).
Now exit the pits with thirty laps of fuel, on soft dry tyres, (set rain to
zero if ness') and complete five or six of those laps. It is very important
in this exercise that you stick to the driving line as close as possible,
keeping your foot hard on the throttle, never touching the brakes for all
of the complete laps, when done, return and fetch, view, copy and graph the
laps, you should have something resembling the previous image with the x-
axis set to maximum. Now expand along the y-axis times two to give you a clearer
indication as to the distances involved (I personally find that the ride height
graph becomes too scrappy if enlarged too much).
Ok now we see that the suspension travel traces are fairly straight and regular
as opposed to the ride height traces that are somewhat bumpier, this I'm pretty
sure is a reflection of the ride height changes over bumps due to tyre deflection
that is not accounted for in the suspension graphs, so therefore the ride
height trace is a very good indicator as to how bumpy or smooth a circuit
is. A point worth remembering and later we will see how to highlight particular
bumps.
Right, so now we see that we have an approximate front ride height of about
5 or 6mm and a rear ride height of approximately 10mm or so at their lowest
points along the fastest straight but at the end, as braking commences, note
how the front dips to 2 or 3mm and the rear rises as the weight is shifted
to the front. Two things to bear in mind: Firstly, the plank is not
taken into account in the graph as it is an "add on" and ride height is measured
from the chassis itself, subsequently if your ride height traces are below
the imaginary 10mm line then you are in potential plank wearing territory.
Secondly it is possible to have a front ride height lower than 10mm because
the car has an angle of pitch, the rear always being higher than the front
with the plank situated more centrally.
Right now look at the suspension travel traces and we see that we have about
22mm or so of remaining travel left for the front suspension, and around 40
to 44mm for the rear after maximum compression due to downforce acting upon
the car, note also how the traces once again move apart as braking starts.
Remember that in the case of the suspension graph the baseline equals zero
suspension travel left and we don't need to worry about the plank in this
graph, as opposed to the ride height graph where zero is the track itself
but we have to remember that we need to allow 10mm or so for the plank.
Now we need to establish if we can lower the car, and if so by how much. Checking
the plank wear indicator we see that we have 0.1mm of wear at the front and
no wear at the rear after five laps without any adjustments, and a heavy fuel
load, so there is definitely room for improvement there as we want to shave
the plank (within limits).
Seeing that most damage will be done in the early stages, with a heavy fuel
load the plank wear indicator is a very good yardstick as to ride height settings.
Remembering that most plank wear is done over bumps rather than grounding*,
and that the car will lift as fuel load lightens we now need to make decisions.
*(You can hear when the car is grounding rather than flashing over
bumps. As a sub exercise drop the car to about 20mm and drive it, you will
hear and see what I mean immediately)
