KZ Braking Is Different: Front Brakes, the V Line and Engine Braking

If you want to feel what it means braking into the corner, well, you have to try the KZ, because the KZ has front brakes, whereas all the other single-speed karts on earth do not have front brakes. It used to be, in the past, I drove until 2014, I mean that year I drove with front brakes, it was really cool, it was called KF2, and it was amazing because you could really brake into the corner, because you had a really light go-kart, which was like 150 minimum weight, but the, the, you know, the brakes were, were really effective, you had both fronts and rears. But you had to brake with a lever on the steering, that's how you used to do to brake with the fronts, so you had to literally, you know, press the lever, like almost like the, the clutch that you have on the KZ, but to the other end side, so you had to really press, it was on the right.

So that was the last category that has been using front brakes as a single-speed kart. Now all the single-speed karts are not using front brakes. If you ask me why, I'm not quite sure, but they told me that it was mostly due to the weight, because when you have front brakes you kind of, uh, you know, have to remove two, three kilos on the kart, because I think the total weight is like three kilos or something, they're quite heavy actually if you have to think, the disc, the, the calipers and everything. So for those, uh, who were on the edge of, of doing that category, they weren't really able to drive it, because this weight was kind of hurting them.

Why KZ is the only kart left with front brakes

And so they wanted to remove those brakes. But anyways, in KZ now you have them. So if you want to experience driving in karting with front brakes and being able to pull 1.8, 1.9 Gs in terms of longitudinal deceleration, well, the only kart you can get is a KZ, and it's going to be so much fun. But at the same time, it requires a kind of a different technique, because when you brake with a KZ, you need to be doing a bit of a V-line, in a way, because you want to take advantage of the brakes. Because the brakes are so powerful, in all the hairpins you won't be really just doing the corner like in single-speed karts, juniors, seniors, or even mini karts, where you take the corner nice and wide open on the entry. You will have to instead be more of a V-shaped in terms of a line.

Because when you want to take advantage of the front brakes you need to be kind of straight with the steering wheel, and you won't be able to be straight if you are opening up the line, that's kind of the thing, you know. Because if you're trying to trail brake using the front brakes until pretty much the apex, you gotta arrive almost in a diagonal way so that you're kind of straight all the way through. So you come nice and wide open on the, on the beginning of the corner, but then you have to really point the apex and go in a diagonal direction towards the apex, instead of like a round direction, because again you want to take advantage of the front brakes, and the front brakes require you to brake as straight as possible in order to avoid locking them up on the fronts, and that would unsettle the kart and you would lose time.

It won't happen like in Formula cars, you see in Formula 1 that when you are locking and turning at the same time, yeah, more than locking, it's just braking hard and turning at the same time, in Formula you're gonna see white smoke coming out, okay. In karting you don't quite see that, it's very rare to arrive at the point of locking the fronts, but you may get vibration on the front instead, that also is quite upsetting, but it's quite rare to get actual front tires locking up. In the wet it's quite possible, happened to me a few times in the formation lap as well, when you try to brake really hard to warm up the tires and everything, but in an average lap and a race scenario you won't really be getting to the point where you lock up the front tires in that way.

The numbers, and why the brakes aren't optional

So you will still be braking really hard and efficiently so that you can stop the kart. I mean, you have to think about it, the KZ is 175 kilos for the KZ2 category, and for the KZ1, then now it's called KZ simply without the one at the end, that's 170 kilos. So, you know, of course it's 30 kilos heavier than a junior kart, which has the minimum weight of 145 kilos, and 25 kilos heavier than a senior, okay, that is 150 kilos. So, you know, there's a lot more weight in the kart, and the only way to make it stop is by using front brakes. I mean, if you just try to use the rear brakes, even though, I mean, they're attached so you can change the brake balance, that's the thing, you can change the brake balance, and we're gonna talk about that in a minute more in detail.

But yeah, I mean, you have to use both, because if you're just using the rears, or if you're just using the fronts, the kart just won't stop, because the weight is just too much. That you want to be able to stop and it's gonna feel like it's not stopping, that's pretty much the feeling. And by the way, I feel that's one of the reasons why they've introduced the front brakes, because, I mean, when the kart is so heavy you need to rely on front brakes too, because the kart is just not gonna stop, there's too much mass that needs to, you know, be, be slowed down. And right, so it's absolutely fundamental to run front brakes in that case, I mean, you, you can't drive without. But that was just the explanation to you, of course the weight is so much higher, and with the fact that you have gears the speed is also really high, so you have this double scenario where the, the approaching speed is really high, the weight is really high, and therefore you need to arrive and be able to stop efficiently. Otherwise, it almost becomes kind of dangerous when the kart is not stopping, you know?

So we talked about probably the reasons why they introduced front brakes in a KZ. We talked about the driving feeling being different, because of course you need to point more at the apex and do sort of a diagonal line on the entry. You also have to be doing a diagonal line also on the exits in the hairpins, not in the fast corners, but in the hairpins in a KZ, because you obviously have to take advantage of the huge amount of torque and traction that you have. And so if you would make the same lines as the other single-speed karts on the exit, making them round, you simply will get so much push understeer from the super high torque, and in that case traction, where you won't be able to just do the corners very fast. So you gotta take advantage of that traction by straightening up the kart quite well on the exit.

Yeah, the reality is that you have to drive quite differently from single-speed karts. I mean, single-speed karts is all about keeping up the momentum, and, you know, making sure the RPMs are as high as possible in the middle of the corner, and making the corners as wide as possible on the entry and on the exit, like as round as possible. KZ is a bit of a different animal, in fact you need to attack the entries like crazy, stop, specifically referring to hairpins where you arrive at high speed, and then once you rotate you're gonna go on the throttle, making sure the kart is quite straight, so again you can take advantage of the power, the traction, and all the gears you have to go through.

So fundamentally, the driving is really different compared to single-speed karts. It takes a bit of time to adapt. In fast corners, it's actually very similar, almost the same as a single-speed kart, because again you don't have to take advantage of the brakes, and the torque isn't that much higher than a single-speed kart that is on high revs. As I said, in fast corners, driving KZ and driving a single-speed senior kart is pretty much the same. It's just pretty much the difference in the slow speed corners.

But let's talk numbers. In terms of numbers, what's the average peak acceleration in a KZ? Okay, now I can give you my numbers, like when I drive, for example, and I drove last year in Franciacorta for the World Championship, the CIK-FIA, which I qualified P2 and was P2 in the superheat, it's really strong all the week, unfortunately in the final, uh, I was involved in a crash in the first corner of lap one, but that's racing. But yeah, I remember, like, I pulled 1.8, 1.9 G on the braking for turn number five and turn number 13, basically the last hairpin, so that's pretty high. I remember of course when you go, and the track is not grippy and the tires are not grippy, you probably won't be getting anywhere up 1.6, 1.7 G's.

So it really depends on many factors. First of all, the track conditions. Second, the state of your tires. And third, probably most importantly, your brake system, whether the pads are new, whether, you know, they're not. Or fourth, I would say, even, I mean, the chassis grip level, because again it's not just the tires but also the chassis, if you can have a really low rear end it gives you more confidence, more support, to, you know, to brake late and hard. And finally, fifth, I would say, it's also your driving, because, you know, you need to trust the brakes, and you know, trust yourself in braking really late and hard, stamping the brakes and holding them, trailing them, so that you can accelerate as quickly as possible, as well as using the engine brake that acts as an extra little bit of the deceleration.

Engine braking is part of your braking

So if you just brake hard without engine brake, you won't be able to stop anywhere close as if you were, you know, braking with the engine brake in a quite aggressive way. So you have to use both. So that's another thing with the KZ, you can brake so late in the wet as well, also because you can take advantage of the engine brake by downshifting gears quite fast, you can, yeah, over-rev a little bit and get the kart to slow down a lot, but it's really cool. And that's one, again, fundamental difference between doing single-speed karts, is because you gotta use the gears in order to stop efficiently, whereas in a single-speed kart you always have the hands on the steering wheel, and you're not really doing anything besides just, obviously, okay, it's still hard, of course, let, don't get me wrong, but in a shifter kart you're a little bit more busy because you're always changing gears all the way through the lap.

But again, it's really fun. I mean, I just like, uh, I preferred single-speed karts back then, but now I prefer shifter karts, because to be honest it feels a bit like driving a Formula car, it reminds me of that. And I mean, yeah, the fact that you can brake so late and hard, and you can have so much torque and so much braking, it feels like a beast, yeah, it just feels more alive, and it's just so much fun. But of course it's way more tiring, I would say, even though the G's you pull in the middle of the corner roll are not that high, I mean, they're high, of course, don't get me wrong, but like single-speed karts maybe are even higher in a way. But, uh, the G's you get in the acceleration are for sure higher, a lot higher than any single-speed kart.

In terms of downshifting, you know, it's a bit of a taboo topic, because, uh, there's some teams and some, uh, engine tuners who don't want you to downshift so much, there's other ones who don't really care and they're fine with you downshifting as much as possible. Like, in terms of downshifting, I'm not talking how many gears, I'm talking how aggressive the engine braking should be. So I, to be honest, preferred being on the high end of the downshifting, uh, aggressiveness, I want to use the engine brake quite, uh, quite a lot, so that it helps me stop, and it's really cool because you can brake one meter later, or two, just by using your downshifts properly, and it feels quite fun as well, like as you feel the engine roaring in, in the back when you're doing that.

But equally, you got to be careful, because when you downshift very aggressively, first of all it's a bit, uh, more, more stressful on the engine, on the gearbox, on the crankcase and everything, but then second, it's a little bit more locking the rear tires, because every time you downshift aggressively, basically the rear tires are kind of locking, and so you may get some rear locks, which overheats a little bit the tires, I would say. And yeah, maybe it'd be good if you need to warm up the tires in the first few laps, but later on it's gonna be maybe too much locking, and again it may cost you some stability and even lap time, of course. But again, you need to get used to that.

The rule of thumb that tells you something is broken

I like to be using a lot of engine brake, but you need to be feeling that, and need to be used to that feeling, where you don't go obviously beyond, and first of all you don't seize the engine, but also you don't want to, yeah, just like rely only on the engine brake. What I normally have as a rule of thumb is that if I'm relying too much on the engine braking, there's probably something that's not well, either on the, the brakes, because maybe they're not braking really hard, maybe the pads are finished, or maybe there's a lot of air in the system that needs to be bled, or maybe just the grip level of the kart being not enough and therefore not allowing me to stop. Or sometimes it's just the grip level from the track.

Okay, in the wet, for example, you're using a lot of engine brake because there's no real grip, and pretty much one of the only ways to stop is by gluing yourself to that engine brake and taking advantage of it as much as possible, um, because it really stops the, the karts really stop, especially when you go down from second to first gear. That's when you feel the engine braking like stopping you so much. It almost feels like you don't have to brake in that final phase because the engine braking is doing braking for you. So yeah, it's really cool, you just have to get used to it, but it's very, very fun.

Back to the V line

Of course, you need to get used to the line. As I said before, the V line is key. You got to make that V-shaped line on the braking. In the fast corners, not, as I said, you have to go normal. In the medium corners, also not, you drive pretty much like a single-speed kart, opening up the entries. But in a slow speed corner you need to do it a lot, okay, you gotta V the line quite a bit. Of course, you don't want to overdo it, come on, you still want to carry quite a bit of minimum speed. But the goal really in a KZ is to win more time on the entry and on the exit by, again, like doing a stop-and-go technique, rather than a coasting where you carry the speed in the mid-corner but then you have a bad entry, because you can't brake as late because you can't brake straight, you know, if you're too open and not in a V-shaped line.

And then you also lose on the exit, because you won't be able to go on the gas with the kart straight, and yeah, that's just going to not allow you to get on the gas early and aggressively, because again, if you go on the gas and you're still doing a, let's say, single-speed line, super open on the exit, then you're like being pushed out wide onto the curb, or maybe you have to release the throttle. Yeah, it's just a mess, you know, it doesn't really work doing those, those lines on the exit of the corners as a single-speed kart.

But okay, you don't want to overdo the V line, make no mistake, of course there's a limit to everything. In fact, when you overdo it, you still lose a bit of time compared to the optimal line, so the goal is to do something in between, you know, you don't want to make it too extreme, but you don't want to again do a single-speed line, you gotta find the sweet spot. Of course, every corner, every track requires kind of a different approach, that's the great thing about racing, you know, it's more an art than a science, and you can't have universal rules for every single corner. But, uh, but yeah, it's really important if you're moving up to KZ.

What about DD2 and the other shifters?

So shifters, there's even the Rotax DD2, I mean, I've never tried that, but for sure it does front brakes too, it, um, it's for sure more powerful than a senior, you have two gears only, uh, it's not bad, of course it's, it's, it's fun, I've never tried it but I've heard it's fun, it's almost in between a single-speed and a shifter KZ. Of course, I don't think you have to V the corners as much, I think you have to drive very smooth and open up the entries and exits, pretty much like a, um, like a single-speed, that, that's what I would think about. But the cool thing is that you have front brakes, so you can brake really deep into corners, so it must be, must be a really cool experience to drive that too.

And then also, if you're driving like Rotax or X30, there's shifters there too. And if you're moving out from a single-speed, like an X30 junior, or like X30 senior, or like a Rotax senior, you know, the common question is like, okay, well, how do I get used to it, Alessio, what should, should I do? Well, the reality is that, as anything, you just have to go out and experience it yourself. For sure you should focus on, uh, on doing that V-shaped style line on the brakes, that's what you have to get used to. You can't just drive the same way in the slow corners. In the fast corner, yes. In the medium corners, yes. In the slow corners, not.

Moving up: how to actually learn it

So I would suggest you to have a look at an onboard video, if you have, from somebody on YouTube, if you, if you watch also some race videos, that's fine, from, from YouTube, you can have an idea where the lines are. And I would suggest you to, yeah, yeah, obviously record your onboard videos, your telemetry sessions, upload them here on PURPL. Make sure you connect directly on MyChron so you can get all the insights. I think it's gonna be really quite insightful and you will have an idea. Okay, am I braking late? Okay, how late am I braking? Hard, okay, specifically how hard, you know? How many G's am I pulling? So yeah, your goal is to pull more and more G's so you can brake later and later, and hold the brakes, and use the engine brakes properly, and just get used to it, honestly.

As I said, I think everybody learns by practice, and they may take their experience like that. So I think the, the theoretical side is kind of important, the theory, but, uh, the practice is where, where you actually learn, you won't be learning by just reading books, you have to go out there and, uh, and doing it. So I encourage you to go out there and smash it, push yourself as much as possible, downshift quite aggressively, you want to get to the point where you lock up the tires really well, make sure there's no air in your braking system, as well as the pads being in a good state and the tires being in good state.

And, of course, I think you will have a ton of fun, and hopefully you'll become one of the greatest shifter KZ drivers in the world and the history of karting. And maybe one day we'll drive together, I love it. I just drive KZ as much as I can, even though it hasn't been much in the last year, I've been really busy with Babyrace, Senndit and PURPL, so I didn't have really the time, but I can't wait to be back. And probably I will do the race in Vegas Supernats this year, so if that's the case, I'll see you there, or you can have a look on YouTube how it goes. But anyways, I hope to meet you one day and drive against you, send me a message on Instagram if you want to get in touch, and remember, keep sending it. Ciao.