Race Driving Fundamentals: Practical Discussion
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Practical Discussion
06.56
| 00:00 | - Right we've just gone through and learned about ABS vs conventional brake systems, we've also learned about factory road car ABS vs a professional level race grade ABS system and just talking to Andrew here, get a little bit more insight around this. |
| 00:16 | Now I think it's important to understand that even when we're talking about road cars, and a lot of the people taking this course will be using a modified road car on the racetrack, not all factory ABS systems are created equal so for our purposes here, two of our own development cars are Toyota 86s and I've personally found that the ABS system in the 86 actually works really well on track so can you add anything around that? - Yeah it's a great system in the 86s in how well it does work. |
| 00:46 | It's obviously a more modern ABS so it is something when you're racing the series 86s, you do, you use quite a bit of the ABS because it does work so well. |
| 00:58 | You may not be getting the absolute 10th, last bit of time out of it using the ABS but it actually brings in consistencies. |
| 01:06 | So that consistency of knowing your brake marker every time does outweigh maybe that half a 10th difference over a lap of ABS vs no ABS. |
| 01:16 | - As we talked about in the module though, you can't go and apply what has been proven to work well in the 86 for every car with factory ABS and that's what we talk about in the module that sometimes if you've got an ABS system it can be basically calibrated to be overbearing. |
| 01:32 | Trying to be just off that ABS limit can be beneficial and I know you've got an example that you wanted to talk about here with Porsche, can you let us know about that? - Yeah sure so obviously some of the older Porsches, 996 cup car, for example a car like that you actually want to stay out of the ABS. |
| 01:48 | So you're coming to a braking zone, you still want to hit the pedal nice and hard initially but you're trying to brake as hard as you can without using that ABS because it's just not as good as modern systems now and it seems to just lengthen your braking time, it just doesn't seem to hold the weight forward as well, it's just not a nice feeling compared to more modern ABS systems. |
| 02:10 | - Right so 997 onwards, Porsche got on top of that? - Yeah they did, they seemed to get on top of it and they obviously for 997, without getting too much into detail about separate cars but something like a 997, that's more race focused ABS and that's where it becomes all tunable and that's another whole topic as well. |
| 02:26 | - So this really comes down to the OE aims with their ABS system is really around, obviously they want the car to stop but it's not necessarily about stopping the car in the absolute shortest distance, it's really primarily around allowing the driver to still steer around and obstacle which pre ABS, a novice driver, all 4 wheels locked up, you can do anything on the steering wheel, it's not going to go around that thing that you're about to hit so that's the thing that's important to keep in mind. |
| 02:53 | So the other thing I think for a novice who hasn't spent a lot of time on track, particularly with ABS on a road car. |
| 03:00 | Unless something goes wrong you're not actually experiencing how the ABS works and that pedal feedback, obviously it varies between different cars but that can be quite disconcerting so what should a driver be doing to experience what that's like? - There's plenty of ways you can experience it, just come into a corner, making sure you're nice and hard on that pedal and it is a bit of a horrible feeling, the pedal does vibrate back at you, it sort of feels like it's trying to push you away from the brake pedal and it doesn't quite feel right and if you're doing it quite late on a corner, you go to turn in, it actually pushes the car forward, it doesn't want to turn as nicely as if you're coming out of that brake pedal a little bit. |
| 03:38 | So yeah that's probably the best way to understand the feeling of it, you're better to test it in a straight line, make sure there's no one around you or behind you and give that pedal a nice hard press and understand how it does feel. |
| 03:50 | - So again there's no generalisation we can apply to every car here but what we really need to do is test our own car on the racetrack and find out if we're getting better results with our without the ABS cutting in rather than just saying we must stay away from ABS. |
| 04:06 | And we use the pedal feedback to sort of give us that insight into where the ABS is just starting to cut in? - Yeah and just to go back to your point about testing it and how and where, what I would do is I would do maybe 3 or 4 laps when you're confident with your car of using the ABS nice and hard on that brake pedal to understand and feel that and get some consistent laps in and then maybe do another couple of laps later without using that ABS and see what your lap times look like and if you're good on data you'll be able to understand as well how that G is looking under brakes and understanding how that feels. |
| 04:38 | - Now just to talk a little bit about a brake booster as well, getting off our topic of ABS here, just talking about the brake booster and the assistance that that gives and we've talked in the module that this can give a little bit of inconsistency in the pedal feel, particularly with brake modulation in a proper racecar we do away with that, we're going completely mechanical with a pedal box and this is something I do notice in our 86. |
| 05:04 | From lap to lap, and it will depend I guess on the manifold pressure or vacuum that's available but we do get a little bit of inconsistency which can be a little bit disconcerting when you get on the pedal and you don't get exactly the same feel or results that you got the lap before. |
| 05:17 | A lot of people want to just disable their brake booster in a factory car. |
| 05:22 | Can you talk to us about whether or not that's a good idea. |
| 05:27 | - I don't think it's the greatest idea disabling that, it's something that you're better to just get used to that feeling. |
| 05:34 | Maybe have a think about how you're pressing your brake pedal, maybe you are too hard on that initial hit and you're actually giving yourself a bit of a lock out out of that booster working to its optimum and what you can also get as well is ABS lock out. |
| 05:46 | Where if you are way too quick on that pedal, way too hard, it just doesn't compress the front of the car and it pulls the ABS on before there's any compression so you get a bit of a lock out so it's just understanding and getting that feeling to make sure that you are nice and hard on the pedal at the right point and you're better to build the consistencies through that but one thing I would suggest you don't do is keep the booster and disable ABS. |
| 06:08 | There's a couple of cars that I've driven set up like that and it creates another whole level of inconsistencies and makes it so much easier to lock tyres. |
| 06:17 | - Now I know that a lot of people think that that is the key, just disable, pull the fuse on the ABS system and from my own experience, we haven't done this with our Toyota 86 but it is a really good example, the brake bias is also controlled by the ABS unit so when that's not active, the brake bias is all over the place and essentially I've driven that car with the ABS not functioning, essentially just about touch the pedal and you're going to end up locking one of the tyres so yeah it's undrivable and it's definitely not like reverting to a non ABS system. |
| 06:49 | Alright so I think that covers that topic, let's move on with the rest of the course. |
