We asked the European KZ Champion to share his shifter kart secrets. He went all out for TKART readers, telling us how he does it, point by point – from kart settings to driving strategy
“There are standard distances, but a lot depends on how tall of a driver you are: you want your arms to be somewhat bent, never too tense; same for your legs, your calves shouldn’t touch against the steering rods. I want the shift lever close to the steering wheel, like an inch off; this way, on some corners I can keep both hands on the steering wheel and shift with my fingers. Foot position is important too: you want your heel anchored nicely and your foot almost vertical, just slightly tilted forward, so you won’t risk giving gas while braking.
“Sometimes, the seat position is changed to adapt to track features and conditions. Some drivers also use seat position as a set-up factor. That’s not me: once I find the position that feels right, I rarely change it. For instance, between Zuera and Genk I didn’t touch it at all. See, when you move the seat, you are shifting the kart’s center of gravity and this changes its behavior completely. It’s a very delicate element.” I drive with my heels pressed firmly into the footrest, to keep from sliding forward with my butt. A lot of drivers avoid this by padding the seat with foam”.
“As far as climbing up the gears, the goal is to be as fast as possible. It’s the only way to make time: the quicker you move up, the faster you’ll stop. I start braking and then start upshifting right after. Rev-wise, you might see the rmps go up 1,000-1,500 more than usual. Of course, it also depends if you prefer to brake more by shifting or with the actual brakes. I tend to use the brakes more. This said, for sure climbing up the gears helps, especially in tight bends that require sharp braking. You got to do it right, though: it takes a lot of coordination and a quick hand: if I’m quick at shifting, but I’m not strong enough on the brakes, I could risk an engine failure. So, shifting and braking have to go hand in hand”.
CLUTCH, AND ACCELERATOR CABLE
Moving on to the accelerator cable: it needs a lot of leeway, because otherwise vibrations and braking can accidentally open up the throttle. It’s a very important element for carburetion, especially on KZ engines.
The clutch also needs some “margin“ going in, so you can pace and regulate the start well.”
“With hard tires, you slide a lot more, with obvious consequences on carburetion and many other parameters. Of course, the more you slide, the more tires heat up; so you want to make sure you don’t end up going sideways.
As far as wear and tear goes, tires start wearing down from the inside and wear more and more quickly on the rear, because of the greater weight load and traction. The less your tires wear in the rear, the more steady you are and, in the long run, it shows. Front tires wear down less and more slowly, but if you see “crests” form on the inside, it means your front-end set-up is seriously offset.”
“If you’re a Sunday driver, keep it lean, because carburetion that’s rich in fuel hampers progressive acceleration when coming out of corners. If you’re coming out of a hairpin and want to go partial throttle, you can’t risk having problems right there. And if your carburetion is rich, this is exactly what you’ll have, issues: at low revs, your kart will start jumping. So first, set the carburetion; then do the final fine-tuning based on the track you’re on.” As Vittorio Venturi, Head of Carburetors at Vortex, puts it: “The ideal thing would be for the accelerator to work like an “on-off” button, because it’s partial throttling that causes problems: if the carburetion is too rich, there’s an explosion and you start jumping… Carburetion should be custom-set for each driver, because everyone gives gas differently.”
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