Data Analysis Fundamentals: Braking Performance
Watch This Course
$129 USD $64.50 USD
-OR-
Or
8 easy payments of only $8.06
Instant access. Easy checkout. No fees.
Braking Performance
06.38
| 00:00 | - Two of the most common mistakes a novice driver will make are to brake far too early and not brake hard enough. |
| 00:08 | This comes from a lack of trust in the car and the grip available, a lack of experience and also bad habits that had become ingrained while driving normal cars on the road where extreme braking is uncommon. |
| 00:20 | For these reasons, it can take a lot of practice pushing you outside your comfort zone to get the most out of the braking system. |
| 00:27 | Poor braking performance becomes glaringly obvious when analysing the variance channel with a good quality reference lap. |
| 00:34 | What we're looking for is what happens to the variance channel at the end of the longest straights where we're holding a high speed. |
| 00:42 | You'll often see the variance increase sharply here indicating that you're giving away speed and hence lap time to the reference lap. |
| 00:51 | These are the areas we want to drill down into and explore in more detail. |
| 00:55 | The first thing to note is the braking point being used by the reference driver. |
| 00:59 | It's quite likely that they're braking much later than you are and by analysing the data, you can get a good idea of how many meters later you can get on the brakes. |
| 01:08 | This is something I suggest creeping up on. |
| 01:11 | Let's say for example that the reference lap driver is braking a full 50 metres later than you at the fastest section of the racetrack. |
| 01:18 | In this case it's a good idea to start by trying to extend your own braking point by just 10 metres at a time and test it out. |
| 01:26 | Once you're comfortable with this new braking point, you can start pushing a little further, creeping up on what you know the car is capable of. |
| 01:34 | This however needs to be considered along with how hard you're braking or to put it another way, how quickly you're able to slow the car down. |
| 01:42 | It's a fine balance between your braking point and your ability to slow the car sufficiently in order to allow it to turn in and make the apex of the corner. |
| 01:52 | It's quite likely that you're braking too early but also not braking hard enough which has the effect of throwing away time while you're still only barely getting the car to a suitable turnin speed so we need to analyse your braking effort here too. |
| 02:06 | If you've got brake pressure data, then this becomes very obvious. |
| 02:09 | However this is an advanced channel which is not something you're likely to have on an entry level logging package. |
| 02:15 | We can still get a good idea of how quickly the car is slowing relative to the reference lap by analysing the speed channel. |
| 02:23 | The more aggressively the car is slowing, the more quickly the speed trace will reduce. |
| 02:29 | By overlaying your speed trace with the reference lap, you can easily see the relative gradient of these traces and if you're not slowing as quickly, then you know you've got some work to be done here. |
| 02:39 | It's quite hard to make much sense of this data when you're viewing an entire lap. |
| 02:43 | So it's much easier to zoom in on a particular braking zone so you've got better resolution. |
| 02:49 | You may also need to rescale the speed range or resize the graph you're looking at to see the detail that you need. |
| 02:56 | Another channel that will show you the result of your work on the brake pedal is the longitudinal G force channel. |
| 03:01 | From here, you can see how much negative G you're able to pull and compare this to the reference lap for an indication of your own braking force. |
| 03:10 | You can also pick up a little more detail using this channel as you can see how quickly you're able to build up your maximum braking force and how well you're able to maintain it. |
| 03:19 | Let's talk first about how quickly you can build up braking force. |
| 03:23 | This is an area where most novice drivers can easily improve and gain precious 10ths of a second. |
| 03:30 | Let's consider a braking zone where the car is travelling at 200 km/h. |
| 03:35 | This equates to approximately 56 metres of distance travelled for every second. |
| 03:39 | Let's now consider the act of transitioning from full acceleration to hard braking. |
| 03:45 | It's not uncommon for a novice driver to take as much as 3-4/10ths of a second to get off the throttle and onto the brake. |
| 03:53 | During this time, the car will have travelled an additional 17 to 22 metres which has a significant impact on your ability to make it through that corner. |
| 04:02 | The other area that we can often see potential for improvement is how quickly the maximum braking force is achieved. |
| 04:09 | This is a balancing act as braking too heavily can unsettle the car however we should be able to achieve peak negative G force within half a second of the initial braking. |
| 04:19 | Given how much distance the car is travelling per second at high speed, any delays here are really magnified. |
| 04:26 | Once we've achieved maximum deceleration, we also want to maintain it right at the point of wheel lock up until we begin reducing the braking effort to allow the car to turn in. |
| 04:36 | This sounds easy but there's actually quite a lot to it. |
| 04:39 | Particularly with a car that provides some level of downforce, the braking effort will need to be reduced as the speed drops and the effect of aerodynamic downforce reduces. |
| 04:48 | While braking, we'll also be changing down through the gears which with a conventional gearbox, requires the throttle to be blipped to match the revs using the heel and toe technique. |
| 05:00 | Since our concentration is now split, a natural result of this is that we are almost guaranteed to reduce our braking effort while we're trying to blip the throttle. |
| 05:09 | This becomes immediately obvious if we can analyse the engine RPM or throttle position along with our longitudinal G force. |
| 05:16 | You'll almost certainly see a reduction in braking G force as you blip the throttle to match RPM. |
| 05:22 | Often after the blip is complete, you'll see maximum G force is now again achieved. |
| 05:27 | Now this is a situation even professional racing drivers struggle with so don't beat yourself up trying to get a perfect and uninterrupted braking effort. |
| 05:36 | However, it's also likely that there is room for improvement here. |
| 05:40 | The other area to be mindful of with novice drivers is the situation where they've hit the brakes too early, bled off too much speed approaching the corner, then realised their mistake and got back off the brake pedal. |
| 05:51 | This doesn't need to be a complete lift off the brake pedal either and a reduction in braking effort will give the same result. |
| 05:58 | Often the driver will then reapply more braking effort again as they get closer to the turn in point and are able to better judge their speed and distance. |
| 06:07 | This sort of situation is immediately obvious in a brake pressure channel however you'll also see it in the speed channel. |
| 06:14 | We can assess braking performance by the gradient of the speed trace while the driver's on the brakes and the steeper the gradient, the faster the car's slowing down. |
| 06:23 | When the driver eases off the brakes, you'll see a flattening of the speed trace gradient. |
| 06:28 | If the driver has eased off the brakes before reapplying then this will also be apparent with the gradient flattening before dropping again sharply. |
