Whether
a trackday enthusiast, hillclimber, circuit racer or kart racer you will have
heard about, seen, or perhaps used various forms of datalogging. The aim being
to analyse your car and your driving to ascertain aspects that can be improved
upon.
From simply recording lap times to checking how many revs you're using at
various points on the circuit, datalogging is an invaluable tool. Moving deeper,
you may analyse your utilisation of grip, how different braking points affect
corner entry/exit speeds and perhaps begin to delve into perfecting a chassis
setup through the data analysis.
But where to start? Complex datalogging systems can cost from £1,500 to over
£10,000, recording everything from miles per hour to the frequency of
suspension oscillations - far more than the average clubman driver requires and,
in most cases, can afford.
Dataloggers use accelerometers to measure g-forces; from this they can
calculate speed, distance and consequently track-maps. However, accelerometers
have a tendency to wander over large distances and have trouble accurately
mapping open-ended circuits (e.g. a hillclimb or rally stage). Hence,
accelerometer-only dataloggers typically utilise a trackside beacon or a trigger
to reset the accelerometers after each pass to give the necessary degree of
accuracy.
Global Positioning Satellite (GPS) data can pinpoint your exact position to
an amazing degree of accuracy and requires only a receiver to access this data.
For our latest motorsport expedition to Barbados we were lucky enough to trial
Race Technology's new DL90 GPS datalogger. Race Technology are well known for
their popular range of G-Performance meters - the DL90 unit is their latest
creation. The unit has the usual high accuracy accelerometers for measuring
g-forces and in addition utilises a GPS receiver to cross-reference the
accelerometer data thus increasing the accuracy further. A new concept on the
datalogging market and one that is bound to create quite a buzz.
Supplied in a professional looking metal attaché case, you find the logger,
the receiver, the RPM pick-up, analogue/digital input connector, DC power
supply, cigarette adaptor power supply, instructions and software all nicely
packaged together.
Setting up the unit simply required plugging in the power supply to the
cigarette adaptor, placing the logger onto a flat surface, sticking down the GPS
receiver and away you go. The unit was instantly ready to record data for
g-forces, speed, distance, track maps and route maps. It really is that simple.
No beacons necessary, no triggers needed, no wiring to do - plug-and-play.
The unit is incredibly compact, about the size of two stacked cassettes, and
feels very robust. Carbon-faced with three coloured LEDs to indicate status and
two buttons - one for on/off, one for start/stop. Simplicity itself. The unit
has the capacity for analogue and digital inputs (e.g. steering potentiometer,
temperatures, pressures, etc.) as well as the usual speed and RPM pick-ups. The
supplied RPM pick-up is taken from a spark-plug lead and is configurable within
the software. Inputting your diff ratio, gear ratios and wheel size allows the
software to calculate selected gears.
The software is well laid out, with a comprehensive online help manual to
guide you through. Getting your first track-map on screen and plotting data onto
it is accomplished within seconds. With real-time playback and a configurable
dashboard displaying the recorded data beside the moving map you can relive and
examine each run in detail. Moving deeper into the software, you can select an
individual corner, or a user-defined sector, and plot the data - allowing you to
see how you are utilising the available grip at all points through the corner
and potential areas for improvement.
As a test, we took the unit out onto some of the rally stages while recce'ing
pace notes. After driving through a stage noting down the corners, we then
cross-referenced these with the data collected from the DL90 allowing us to
confirm the notes giving us further confidence in the accuracy of them.
When used in anger on stage it enabled us to see exactly where time was being
gained on each repeated run. Delving into the g-force readings it was possible
to see which corners we could push harder on and how well we were utilising the
friction circle. Through examining the RPM histogram we determined how
appropriate the gearing was. All very accessible and intuitive to use - and this
was just scratching the surface.
The most impressive aspect to me was the accuracy of the plotted maps. Having
found previous dataloggers struggling with open-ended stages, the DL90 plotted
perfect maps. In fact, identical to the OS map - and this was on stages that
covered large gradient changes that easily confused the previous
accelerometer-only loggers.
With 4Mb of memory the DL90 is able to log all these channels for 87 minutes.
As the unit requires no beacons to operate, it is possible to go out on track
and log data even at an event with timing/beacon restrictions.
It's
difficult to get across all the features of the immensely powerful little unit
from Race Technology in such a brief article. In short, the DL90 gives you
accurate trackmaps and laptimes, on circuit and stage alike, without needing to
wire any sensors into your car. All the data needed to analyse your car and your
own performance is recorded; accessible to seasoned competitor and enthusiast
alike - analysis of speed, distance, RPM, gear, wheelspin, BHP and more. All for
£500.