Well.. pardon me for the long delay, it has been a difficult time for me the past month.
The following is a short or summary analysis of the data taken during the track day. It would hopefully show the capabilities of the system and data acquisition, and also hopefully enable amateur drivers starting out circuit racing to see a potential in this as a tool to gain feedback and improve their lap times.
First of all we have the GPS plot, which when overlaid on Google Maps, gives a rather impressive pictorial description.
Although positional data has an error of up to 3m, which means actual racing lines cannot really be taken literally, the overall data as a whole gives a rough idea on the lines taken.
The lap is broken down into sectors, with each sector comprising of an entry, corner and exit. Naturally, there would be 15 sectors since Sepang has 15 turns. The sectors are not 'official', but their collective times add up to the overall lap time. Sector times allow a more detailed, quantified section of a track serving as a constant to compare the performance of multiple laps against.
The sector times are what every driver is interested in reducing eventually. But how and where the times can be reduced is what this is all about.
Next important bit would be the speed of the car through the entire track.
The speed is fundamentally what all drivers try to maximise throughout the entire circuit. By laying out multiple laps over one another, the first thing we notice is consistency. Whether the driver reaching the same speeds at the same points of the circuit. Whether he is braking at the same point in the circuit as well.
This is an example at Turn 4. Firstly, we can tell the maximum speed reached just before braking. In the above example, the difference in speed between the laps was caused by the difference in exit speed for Turn 3, which is a long right hand sweeper. As a bonus, the drop in speed is caused by shifting the gears, and through that, it is possible to estimate the shift time, as well as mis-shifts or other shifting errors. In the red lap, the shift took a split moment longer than the rest, which suggests uncertainty later confirmed by early release of the throttle.
Next, we can tell the delay the driver takes in lifting his foot off the accelerator and applying the brakes. If this is done well, the speed would peak and drop sharply similar to the green lap. The blue and red laps show a noticeable lift off, as if he applied the brakes too early and later realised it. The rate at which the speeds drop are almost constant, suggesting that the brake pressure of the driver is consistent.
The next example is lateral Gs. This is the measure of the car's lateral acceleration throughout the circuit. In this analysis and convention we will be using, negative values are turns to the right, while positive values are turns to the left. You might observe that the readings when the car is supposed to be travelling in a straight line are not zero. This was due to an installation oversight which resulted in the unit being slightly tilted. so what can the lateral G plot tell us?
Besides showing the cornering capacity of the car (maximum lateral Gs the car can produce), it shows us the rate that the lateral G is building up for every turn, and whether it remains constant, increases, or falls through the turn. This gives an indication to whether the car is over steering, under steering, or a change in line has taken place.
An example of a lateral G plot for a corner (Turn 15) is shown above. For example, corner entry understeer shows as a slower buildup of lateral Gs after the initial rise.
The following is a short or summary analysis of the data taken during the track day. It would hopefully show the capabilities of the system and data acquisition, and also hopefully enable amateur drivers starting out circuit racing to see a potential in this as a tool to gain feedback and improve their lap times.
First of all we have the GPS plot, which when overlaid on Google Maps, gives a rather impressive pictorial description.
Although positional data has an error of up to 3m, which means actual racing lines cannot really be taken literally, the overall data as a whole gives a rough idea on the lines taken.
The lap is broken down into sectors, with each sector comprising of an entry, corner and exit. Naturally, there would be 15 sectors since Sepang has 15 turns. The sectors are not 'official', but their collective times add up to the overall lap time. Sector times allow a more detailed, quantified section of a track serving as a constant to compare the performance of multiple laps against.
The sector times are what every driver is interested in reducing eventually. But how and where the times can be reduced is what this is all about.
Next important bit would be the speed of the car through the entire track.
The speed is fundamentally what all drivers try to maximise throughout the entire circuit. By laying out multiple laps over one another, the first thing we notice is consistency. Whether the driver reaching the same speeds at the same points of the circuit. Whether he is braking at the same point in the circuit as well.
This is an example at Turn 4. Firstly, we can tell the maximum speed reached just before braking. In the above example, the difference in speed between the laps was caused by the difference in exit speed for Turn 3, which is a long right hand sweeper. As a bonus, the drop in speed is caused by shifting the gears, and through that, it is possible to estimate the shift time, as well as mis-shifts or other shifting errors. In the red lap, the shift took a split moment longer than the rest, which suggests uncertainty later confirmed by early release of the throttle.
Next, we can tell the delay the driver takes in lifting his foot off the accelerator and applying the brakes. If this is done well, the speed would peak and drop sharply similar to the green lap. The blue and red laps show a noticeable lift off, as if he applied the brakes too early and later realised it. The rate at which the speeds drop are almost constant, suggesting that the brake pressure of the driver is consistent.
The next example is lateral Gs. This is the measure of the car's lateral acceleration throughout the circuit. In this analysis and convention we will be using, negative values are turns to the right, while positive values are turns to the left. You might observe that the readings when the car is supposed to be travelling in a straight line are not zero. This was due to an installation oversight which resulted in the unit being slightly tilted. so what can the lateral G plot tell us?
Besides showing the cornering capacity of the car (maximum lateral Gs the car can produce), it shows us the rate that the lateral G is building up for every turn, and whether it remains constant, increases, or falls through the turn. This gives an indication to whether the car is over steering, under steering, or a change in line has taken place.
An example of a lateral G plot for a corner (Turn 15) is shown above. For example, corner entry understeer shows as a slower buildup of lateral Gs after the initial rise.
