Deceleration Efficiency Explained

So deceleration efficiency is basically: going from a top speed to the minimum speed in the shortest amount of time possible, right?

There’s nothing else about it. So you’re going from, let’s say top speed of 110 to, let’s say 50 in the shortest amount of times possible.

You have this 60 kilometers Delta from 110 to 50, and you have to try to to get that 50 as soon as possible, because you know that at 50, by the apex, you’re going to get on the gas, and that’s normally the way to go.

So you know that your your minimum speed at the apex is 50 on average. It’s nothing that you do consciously. All right, I’m just showing you in the numbers, in the theory, in the when you’re driving, you’re not thinking about, Oh, I’m arriving at 110.

No, you don’t think about any of that. You just drive, drive for the limit.

This is maximum efficiency

But the efficiency, okay? This is, let’s say, maximum efficiency, amazing efficiency.

This is not so amazing efficiency, because you still arrive, you see, go from one under 10, okay, let’s pretend from here, we still go from one under 10, but and we see, go to, what, 50, but it takes us a lot less time, a lot a lot more time.

Sorry, this is another example. Again. We go from 110 to 50. We take we go from from from point A to point B, in terms of speed, but it takes us a lot longer, even more like that.

This is worse and worse and worse, acceleration efficiency

It takes us even longer, even more like that. This is worse and worse and worse, acceleration efficiency, so you arrive here, arrive here, and it’s like that.

You arrive here. This is worse and worse and worse, deceleration efficiency, and that is everything I’m here to explain to you, because irrespective of the exit, because I believe that the exit is going to be very similar, no matter what you do, on the on the on the braking.

Of course, if you get a very good braking and you stop, you’re going to get a much better exit as well. But let’s say that we get to the minimum speed at the same time.

Well, we get to 50 as we should. So let’s give it for granted, the axis speed is going to be the same, all right, so it’s going to be for all you can agree with me that, you know, if I were to draw a very, very small line here.

You can see very well now what it means to decelerate the kart in a much more efficient way

Ah, hey, that’s so my friend, you can see very well now what it means to accelerate the kart in a much more efficient way.

And I can show this to you now right, right now, when I have a look at the data, are going to explain to you how that looks in the real world, let’s say, not just in the theory of our whiteboard, but this is really the key.

If there was Max was happening here, it would probably do something like that. It would arrive and it would break even later.

It would get from 110 to 50, and it would do it in an even shorter amount of time. Now, of course, there’s a limit of physics to that. You can’t you need to have like front brakes, you know, and have like light kart.

Of course, you need to have, the more grip you have, the layer you can break. But you know, my point is, the late related later, later you break and the more efficient is not just about your peak pressure.

It’s not just about your peak braking pressure

It’s not just about your peak breaking pressure. It’s about how much and how long.

So did you hear that how much breaks in terms of intensity and how long in terms of duration. So this is the thing.

So the deceleration efficiency, in my opinion

So the acceleration efficiency, in my opinion, well, not in my opinion, but it’s just like, it’s not really a law, but it’s like that.

Think about it. I think this, you can stamp it in your brain, right?

So the acceleration efficiency equals intensity. So how much from one to 100 times the duration. How long? Alpha? Second, one second, two seconds, three seconds, are you breaking and coming off right away? Are you breaking and holding on to the brakes?

And finally, the grip level? So is it very grippy on the track? And then there’s nothing you can do, but it’s just part of the equation.

You know, it’s, if there’s a lot of grip on the track, you can break later. You’re going to stop, you know, you’re going to have less time.

I’m going to write down duration percentage

But if you hold the brakes for the majority of time, you’re gonna stop. You’re gonna be, you’re gonna be stopping far, far short.

I could change, I can actually change this. This is quite clever. So I could change this. Um, I’m saying to myself, this is quite clever. So I’m saying duration, percentage, instead of just D, I’m going to write down duration percentage.

Why? Because I think it just meant it’s more relevant. Because it’s not just about so duration percentage, it’s not just amount, the duration, it’s also the person. It’s more the percentage.

The goal is that you are going to stay on the brakes with max intensity for the longest amount of time.

So you’re breaking for like, say, three seconds, okay. I mean, you’re stopping from 110 to 50, okay.

And so the percentage of that, if you’re breaking and coming off the gas, sorry, if you’re breaking it, coming off the brakes or the way, and just rolling the speed, your percentage will be low. So your your the acceleration efficiency will be low.

If you’re braking hard and holding the brakes for long, because you’re breaking late, you know, and you have to stop. So your your percentage will be high, and your acceleration efficiency will be high, and the grip level, of course, if you have new tires, you’re going to be able to break a bit later than if you have used tires, and if you have a lot of grip on the track.

This is both track and tires. Track and tires, okay, th and TR, so track and tires, and also the setup, etc.

Let’s now have a look how that translates in the data

Let’s now have a look how that translates in the data, as I promised.

All right, let’s go for it. Look, we are at Franciacorta.

The two best ways for me to understand the acceleration efficiency is using the RPMs and the GPS longitudinal so the longitudinal acceleration, to me, that’s that’s always the my favorite, my favorite way, because that really shows you the how much work are you doing to stop the kart.

And if I have to watch a slow lap for sure, it would be a lot less deceleration. With the fast lap, it would be more deceleration.

So the goal was basically what I was referring to here. Remember, we were mentioning here that we want to go from one under 10 to 50 let’s now imagine the same scenario.

Let’s now imagine the same scenario in the data. Okay, we may not have one under 10. Let’s clear everything up and let’s go here. How much do we have? 106 How much do we have here? 58 so we go, let’s try to write it down so we go from one under six to 58 and again, our goal is so we know that the in this case, the grip level allows us to 58 if there is more grip, we’re going to do 60 if there is less grip, we’re going to do 56 It depends, of course, On the grip.

In the longitudinal G, you see, the sharper it is, the more deceleration you have

And that in the data, in the RPMs, you would have seen much less aggressive braking and in the longitudinal G. So in the longitudinal G, you see, the sharper it is, the more down it goes. It means the more acceleration you have.

So it gets to a peak of almost like 1g I will show you one 1g if you drive like the red does, you’re gonna be ending doing something like that. You start to hit the brakes here, and it’s gonna be like a very, very little like G’s.

And it’s gonna be like this. It’s gonna be like that. It’s just like, Okay. And then it’s just coming off the brakes and he’s just releasing them and just rolling into the corner.

That’s what a beginner makes. Almost half of the G’s off of the acceleration. So he’s not going to be breaking hard anywhere close to what the green is down here, right?

The goal is really to take this deceleration as steep as possible

The goal is really to take this deceleration as steep as possible. You know, steep means, like, it goes down the most.

You probably do if you want you to do it at school. It’s like, this is very steep. This is not steep. This is very steep. This is not steep.

The goal is that you get a steep acceleration and a steep and it translates in the longitudinal exact as well. So the peak at launch, doing is 0.82 across the lap. That is the peak, the maximum peak. I guess we get to zero, 86 so that’s the maximum peak. I think that was a very good peak.

The only thing I didn’t really like is that it did not hold the peak here

The only thing I didn’t really like is that it did not hold the peak here. Let me clear this up. Yeah, this is what I didn’t really like.

It should have, it should have held the peak a little bit longer here, instead of kind of coming off, but that’s, you know, when you’re locking up, you’re kind of like playing. Sometimes you have to just get out a bit of the of the lockup.

But I guess that’s what happened to him. I mean, that was a very quick lap, but it could have been even better. You know, there’s always room for improvement for everybody.

But it was a very sharp peak. This is what I like. It went very, very sharply down like that. It’s and also in the RPMs, you can see that you went Pam, very sharply.

And that’s what you want at the end of the day, it’s to go really bang, like that. From, as I said, that’s the optimal way, if you do something like this. And you just, like, hold, and then you come off that, and you start to break really early, and your efficiency is like that. It’s terrible.

You really have to make sure that your deceleration efficiency is maximum

So you really, really, really, really, have to make sure that your deceleration efficiency is maximum, of course, until the edge of the tires limit, the chassis limit, the track grip limit.

But your limit, the driver’s limit, is, in your mind, the only limit is the one you set yourself.

So try to drive to the limit of the deceleration of your kart, of the grip on the track, and by by doing that, you will be braking very steeply, very aggressively.

The tires are going to heat up more, and you’re going to develop way more confidence on the brakes in general.