Well, I know that every corner has it’s unique shape and every driver has it’s unique style. The goal of this topic is to clarify some technical and “scolastic” notions, to give a good starting point to build an own driving style.
I state that I have read every words of @Terence_Dove book on Kindle, it’s incredibly enlightening, but I still have some doubts:
Why coasting is absolutely not recommended but it’s accepted trail braking?
I really can’t understand this point. Let’s make an example: if I trail brake, I will arrive to the apex with a little brakes on. In my mind, until I take my foot off the brake, the weight of the kart (and of the driver) is on the front and so I’m asking to the kart to both turn and brake; the result is that the kart is not ready to turn well, because to turn well all the load must be on the outside tyres, not on the front. Furthermore, I’m killing my engine (talking about no shifter Iame X30) because RPM are slowing down quickly while I’m on brakes.
On the other hand, let’s make an example of coasting: I do an hard and short brake to have a first important slowdown, then I do coasting to have the right load on outside tyres and meanwhile the RPM don’t come down as far as if I were with my foot on the brake. In this way I’m going to the apex with the right load to turn well and with the right RPM to return on throttle without killing the engine.
So the question is, what I’m missing?
Trying to put in a place what I read in the book, I can’t understand the right moment to return on throttle (always talking about no shifter engine): should I accelerate while I have the maximum load on outside tyres? I tried this but with a very little throttle input the inside tyre go down too heavily, so I get the goal to keep RPM high but the tyre bumps and I lose time. Should I accelerate as soon as the inside tyre go down? It helps a smooth drive but it’s too late, beacuse at this point the RPM are too low and I lose time again. Here the question is: what can I do to go on throttle in a smooth way, without sliding, in order to keep the moment when my RPM are good to accelerate but without make the inside tyre bump? And how this point is linked to the speed I carry from the very first part of the corner with the braking?
These first 2 questions are pretty about hairpins or similar medium-slow corners. I have a third and last question that really frustrate me:
In fast corners, what the hell I have to do to have high speed without sliding the rear? If I partialize too much, I’m smooth but I lose time; if I try to have more throttle and to be veeeery gentle on steering wheel, I go wide on exit; if I try to have more throttle and to turn well to the apex, giving a little more steering wheel, I slide and I lose time.
I’m really going mad about this point.
Just to give an idea of my level, in the national club championship (Italy) I’m 7-8 tenths slower than the champion in a 42.0 laptime. I’m not a top driver but I’m not a crap
Thanks to everyone will help me and sorry for bad english.
Any time you’re coasting, you are not loading the kart up. The kart must keep the inside rear wheel unloaded to help it rotate smoothly and not bind up on exit. When you coast, the inside rear wheel drops down, as no load or force is going through the frame. Braking puts load forward and out to help the kart tip up on its nose, and throttle flexes the frame to start leaning on the outside tire. It’s true that with trail-braking, you maybe sacrifice a small bit traction that could be used for slowing down, and instead use it to help rotate as well, but if you are good at blending your inputs together, that sacrifice is very small, and the advantages of braking deeper and later will outweigh what you lose.
But let’s take trail-braking out of it. Even when you are straight-line braking, you shouldn’t really be coasting either. Braking means we are slowing down (obviously) and we want to spend as little time slowing down as possible. Any time we are not accelerating, we are losing time. So if we need to get down to 30mph to make a corner, we need to get down to that 30mph as quickly and efficiently as possible so we can start accelerating sooner. If we are coasting, we are not getting down to that apex speed as quickly as possible, delaying when we can start accelerating, and extending our braking zones. It doesn’t matter if you coast or brake hard; if you have to get down to 30mph to make the corner, your RPM will be the same at apex either way. Braking vs. coasting has no effect on what your minimum apex RPM is. If you are finding that when you brake hard you are getting too low RPM at apex, then you are braking for too long. There is a maximum apex speed and RPM for a given corner, and it is always the same, regardless of how you get there.
Drivers who are good at trail-braking have good feel for where the limit is on all their inputs (steering, braking, throttle), so they can blend them correctly without going over or under the traction limit.
There isn’t a hard and fast rule about when you should be going to throttle with reference to when the inside rear wheel is loading or unloading. In general, for almost all corners, you want to be starting to roll into throttle before you get to the apex, and driving the kart on-throttle through the apex. This will keep the inside rear wheel unloaded for longer, as we are putting that throttle force through the frame.
One thing I always tell my drivers is to make a note every time you go through a corner. So if you go into a hairpin and you get on throttle at a certain point, but the kart slides immediately, that should be your note to change your approach next lap. So next lap you can try to get on throttle later, when the kart is more settled in the corner. If that means you exit too slowly, you make a note. So next time you come around you need to get on throttle early, but do it more smoothly and roll into throttle progressively to keep from upsetting the kart. It’s just a process of elimination until you find that right point where it is easy to apply throttle without upsetting the kart. And by knowing that you should be on throttle before apex for almost every corner, that really narrows your window of throttle application.
This goes along with the point about really good drivers being able to feel the limit of the tire and not go over it. A faster corner will require a faster steering input, because the kart does not mechanically jack weight like it does in a slow corner, because you aren’t turning the wheel enough to twist the frame. So you need to input your steering angle more quickly to rotate the kart, but the key is not using so much wheel that you slide. It’s a very fine balance. Your throttle application also has to be very quick so you are driving on throttle before the apex and maintaining a constant and predictable load through the corner. Throttle too late, and you’ll upset the kart with that added input mid-corner. Throttle too soon and you’ll be carrying too much apex speed and have to lift off on exit.
Some more videos that might help:
Track guide for my home track, obviously not familiar to you but I go over how I approach a variety of different corners (fast and slow) and break it down step by step.
And then this is just some laps of driving at my home track where you can see my feet and steering wheel so that gives you an idea on the inputs I’m making and how all those are blending together.
With coasting I’m not entirely against it - though some very fast people are against it. Sometimes a kart can produce enough drag from the front wheels during a tight corner that you decelerate without applying any brake which keeps the kart nicely loaded… Sometimes is a very important word in the above sentence though
I think if I was at a track with you I would try to help you establish from all of the points you make which way you would most like to drive these corners. That means pick a way which you feel is the most correct and stick with it - then we would endeavor to make it work.
So that might mean using some coasting time during mid corner, and even finding an amount of rear sliding in the fast sections that feels good. The purpose will be to keep focussing on that method until it is refined and maximised.
To elaborate further, I agree with Terence here that on a rare occasion, coasting might be a valid technique for some corners where braking might offer just a slight bit too much deceleration, or upset the kart, so coasting becomes the only way to make certain corners work.
Just to clarify a bit more, I prefer to stay away from any coasting at all as a fundamental of your skillset. I’m against it 9 times out of 10, but on the odd corner it may be a valid way to get through the corner. So in other words, I wouldn’t use coasting as your default or go-to technique for deceleration, and we should prioritize minimizing braking zones by applying brake 9 times out 10.
But still, I would rather my drivers be applying some throttle or brake at any given time, even if that input is 5-10%. It’s my opinion and school of thought that you should always be accelerating, or getting the kart slowed down as quickly as possible so that you can get back to accelerating.
That’s the first important point I was missing: I was convinced that while coasting, the kart was very loaded on the outside tyres thanks to the driver weight, but it’s not like this.
Your braking lesson is very interesting. In both straight and trail braking there is a yellow zone between brake and throttle, so I assume it’s not coasting but it’s only the time lapse between the two pedals, because is not good to overlap them, is that true? Then, I’d like to know if I understand well what is trail braking: I find this interesting video of a Iame Series driver with pedal cam. It seems to me that he use trail braking for almost all turns, specially the slowest ones, it’s correct? We can say that this is trail braking or is something different?
So I assume that your advice is to improve little by little my own driving style, whatever it is, instead of trying to change it? As an experienced coach as you are, you can tell me that you know drivers who are equally fast in laptimes who have totally opposite driving styles? There are lot of ways to go fast?
Yes, yellow in that video would indicate the transition from braking to throttle, so releasing the brake as you start to turn-in and apply throttle. Again, there are instances where maybe you want some pedal overlap to help settle the kart and ease the transition from brake to throttle, but as a baseline fundamental technique, it’s a good idea to stay away from overlap of the two pedals. For trail-braking, as you release the brake you should be applying throttle in equal measure as to not overwhelm the tire but to keep the load through the kart consistent as you transition to acceleration.
Personally I see trail-braking as important for low-speed corners where you have a hard braking zone and you need to get into the corner and get the kart loaded up and pointed on it’s nose. So yes, I would say in almost all slow corners I am trail-braking somewhat. More or less depending on the corner.
It’s harder to trail-brake (and less necessary) for fast corners because the braking zone should be short, and you want all those inputs to happen quicker. You want to turn in quicker, brake quickly and get back to full throttle as soon as possible. Doesn’t leave much room for trailing the brakes.
And as always, the best drivers are using a combination of all these techniques depending on the corner.
It’s clear, so I think the job for every track is to try both braking styles for slow corners and see what is faster. But I think, tell me if I’m wrong, that the big laptimes differences is made by the throttle application on the exit, so I have to understand the best braking that helps me to have the faster exit instead of understanding which braking is faster in the first half of the corner.
Yes, you got it. With modern karting it’s hard to see, but if you watch very closely you’ll see them doing lots of different things. There are differences in braking, how they move in the kart (very subtle but it’s there), steering inputs, lines etc etc.
If there is a style of driving you like, that you enjoy most, I think you should identify it and focus on making that work. You will find you need to make compromises and refinements but you will be creating something unique. Then it becomes a lot of fun to test your way against everyone else.
This is a personal thing, but I believe even if the style you love is ‘wrong’ but you work really hard to make it work then you’ll learn so much more than you would otherwise and become extremely proficient. It’s like the story of how Honda committed to making their 4 stroke bikes compete with 2 strokes of the same capacity. The technology they invented was incredible and helped them become dominant eventually, even though the 4 stroke that revs double didn’t make the grade.
While I agree with most everything above about coasting, I would like to point out that the transition from braking to opening the throttle is a big part to the secret sauce of a fast laptime. My point is that when you load the kart up with brakes, throttle, and or steering input, you are reducing its ability to grip laterally through a corner which helps with achieving proper rotation but not with forward momentum. Following this logic, your lateral grip level is at its highest while coasting with no steering input which can be advantageous for a brief moment before corner apex to maintain maximum apex speed without sliding laterally. This can allow more grip at corner apex and acceleration off the corner. Of course floating the throttle on a two stroke engine keeping the revs up while doing so makes this a challenge. Just my two cents worth.
I think he means additional steering input. The kart is “carving” the turn and the IR is unloaded without input from brake or throttle. In this situation, the tires are using all of their friction circle for lateral acceleration. Practically, I think a small amount of steering needs to be continuously added to keep the IR unloaded for any length of time, as the kart will decelerate due to drag and will lose lateral acceleration. Not sure, if this is good or not but obviously, as everyone points out, coasting has to be used judicially.
It would be interesting to see on track brake and throttle traces.
I am not a fast guy, but I am a physical guy. I guess you use the same brake point for straight threshold braking and trail-braking. For a given corner, the speed limit of the apex is almost the same no matter how you approch it. TJ mentioned it also. You mentioned the engine is in low rpm when using trailing braking. It is not normal. You can push the braking point closer to the corner so that you will pass the corner with the same speed as in threshold braking.
I mean relative to coasting. The inside rear wheel will unload on turn-in, and as you unwind the steering it will start to come down. If you are on-throttle as you unwind steering, it will keep the inside rear wheel unloaded longer than if you were to just coast. The wheel comes down regardless, but if you keep the kart loaded up, it will let it stay unloaded a bit longer.
We want the kart to maintain peak load as long as we can through the corner, and that’s achieved by balancing steering inputs, brake inputs, and throttle inputs.