New to data logging?
Don't worry, you will soon realise that it is not as complicated as you may have thought. Many people stay away from data systems because they believe they are complicated and too expensive, but data systems can be as simple or as complicated as you want them to be and the best way to go about introducing a data system to your car is to start simple and then build on your own knowledge and progress.
The DL1 SPORT data logger or DL1 CLUB is the ideal starting point for your data system, you can get some very good and useful data from simply installing the DL1 in your car/motorcycle, connecting the power supply, fixing the GPS antenna in a suitable place, press the red button and go drive.
The DL1 is a lightweight unit and can be secured using dual lock tape. All it needs is to be mounted reasonably flat and square. The orientation is not important any face of the DL1 can face forward.
The GPS antenna needs to have a clear view of the sky for best performance, on top of the roof or roll hoop is the best location for cars and back of the fairing for motorcycles.
Now we need to analyse the data we gathered on the track, for a basic guide on how to do this visit our data logging basics page. The latest Analysis software can be downloaded from our website. Install the software on a PC, download the data and open the file up in the Analysis software.
Using the default layout in the Analysis software is the best way to start, then all you need to do is insert the start/finish lap marker (or start of run/end of run marker for open circuits) on the track map and let the software set up your sectors. This enables you to see lap times and sector times. The graphs below the track map and timing window will then show the braking points (longitudinal G), grip (lateral G), speed and where you are loosing/gaining time (timeslip rate). Select two (or more) of your laps or sectors and you can compare them like for like to improve your time.
It is best for those new to data logging to spend a bit of time using these basic variables to improve lap times. Adding more information can lead to things appearing to be complicated and confusing so keep it simple in the beginning and when you are comfortable with the level of information it is time to start thinking about what to add next.
Having a live update of your time on the track can prove invaluable in a qualifying situation. Adding a display to your data logging system gives you the opportunity to not only know your laptime while out on the track but also your sector times and whether they are better or worse than the previous best. The Race Technology DASH2, and DASH4PRO also have a very useful function called predictive lap timing, this gives you a prediction of your current lap time based on the sectors you have completed and the previous best times for each sector not completed, using this information you can make decisions on whether to push or whether to slow down and conserve the tires. Additionally a dash display can give you information on your engine health, rpm and shift lights to name a few.
Sensors, which ones to choose and what do they tell me
The following sensors/channels are normally considered to be the next step in expanding your data system most of these can be added at a comparatively low cost and some are even free!
In most cases this is already available from the ECU, which means all you need is to connect a wire from the ECU tacho output to the DL1. Sometimes you may need to wire a feed directly from an injector or if you are running a carburetted engine to connect to the ignition system. In general RPM is easy to get and gives you a wealth of information. Are you using the rpm range properly? are your gearbox ratios appropriate? Having the RPM connected also means you can display the RPM and use shiftlights.
This is sensor found on most modern cars and therefore often just require an extra set of wires to connect directly to the DL1. Never the less a throttle position sensor is a very cheap item so adding it to a system is a very good idea. Having a record of how the throttle is applied when exiting a corner can help you maximise the traction available and helps developing a consistent throttle application
Steering angle is a bit more involved to fit, it requires a special sensor normally a string potentiometer. This is attached to the steering column and produces a trace of how the steering wheel is used. Viewing this trace can help you identify turn in points and any oversteer or understeer moments. For those that want to get even more involved with the data logging system a neutral steering path can be calculated and overlaid on the actual steering trace highlighting very quickly any understeer or oversteer tendencies in the car, this can be very helpful when it comes to set up as its often difficult for an amateur driver to sense whether under/oversteer behaviour is caused by the car or the driver.
There are two ways of measuring the application of the brakes, measuring the actual hydraulic pressure in the brake line or measuring the movement of the brake pedal. Measuring the line pressure of the front and the rear brakes independently is what professional race teams do and they use this not only to see the application of the brakes but also to tune the front/rear brake balance. Brake pressure sensors are quite expensive so if you are not interested in the brake balance a brake pedal position sensor is a cheap alternative to viewing the application of the brakes.
The ECU interface
Using an ECU interface is an easy way to a wealth of information. It is often possible to get a wealth of information by simply fitting one cable between the ECU of the vehicle and the data logger/display. Not only does this give you access to all the health monitoring systems of the engine but often also gives you the throttle position and wheelspeeds as well. The available channels depends on the manufacturer of the ECU and what sensors are fitted to it.
Tips and tricks
Here are some top tips to focus on in order to improve your lap times
- Compare speeds and times on multiple laps. Consistency is one of the key things you need to achieve in order to go faster. Comparing many laps will help you identify areas which you need to focus on improving
- Compare cornering forces on multiple laps. Make sure you are consistently using the maximum available grip in each corner.
- Look to see how much later driver could have braked using longitudinal acceleration, comparing braking points from yourself and another driver can often reveal "lost" time on the circuit.
- Time slip rate on track map (red = bad, blue = good) Timeslip can be viewed in many different ways, a quick way to illustrate where time is being gained/lost is to colour the trackmap with timeslip rate, this helps you identify areas where you can improve.
- Simulation to show what is possible with perfect driving. The simulation tool allows you to see what is possible if the driving is absolutely perfect, this can be used to set a goal for improving laptimes. Be aware though that the simulation is only as good as the input parameters so be careful.
- Simulation to show how much lap times would improve for a particular car change. Experiment with the simulation parameters to identify which area of the car will improve performance the most.
- Play back video as a function of distance for looking at line differences. Using video in the data Analysis can prove to be an invaluable tool to review different lines and the effects they have on laptimes.
- Use internet maps to find braking point "reminders". The internet map option can be useful to find landmarks close to braking point, this will enable a quicker track familiarisation and inspire more confidence in using the brakes.
- Use histograms to check RPM usage. A histogram can quickly reveal whether the engines powerband is being used properly, you find that a gear ratio change will help keeping the revs up and maximise the engine output.
- Use performance table (acceleration times) to check that the car is running 100% and to maximise start performance. The Performance Calculation tables provide a simple and easy check to make sure your vehicle is performing as it should. It also provides a very useful tool to measure race start performance. Being able to start consistently well is very important to achieve the maximum from a race.
For a guide on how to get started analysing your data, please visit our data logging basics page.