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ITALFRENO, THE BRAND NEW BRAKING SYSTEM BY EMME RACING

TKART Staff

19 June 2021

The company that designs and manufactures the EKS chassis is based in northern Italy, near Verona. Its owner, Giampaolo Masotto, has certainly not exhausted his inventiveness and, in recent years, has launched a braking system on the market that is different from any of the types up to that moment on the market for karting. It is called Italfreno and from 2020 it is also available for the MINI class. Let's find out about it.

The principle of operation is as simple as it is effective. Inside the pump there is a shaft (whose diameter can be varied if necessary), which is directly connected to the brake pedal by means of a rod. The pumping element is mounted on the shaft, a sort of ring whose function is pushing the oil into the system circuit and directing it to the caliper. Once the brake is pressed, the flow of the oil is immediate, given the absence of play and friction present in the pumps with leverage. The intensity of the braking effect is directly related to the size of the shaft you decide to mount. In fact, the volume of oil that the flange pushes is obtained from the difference between the total volume of the internal chamber of the brake master cylinder and its volume. With the same flange, therefore, if the diameter of the rod is increased, the volume of oil to be moved is reduced and the pressure generated by the system increases. In other words, by applying the same force to the brake pedal, a rod with a larger diameter allows for greater braking power.

In the above interactive animation you can see the operation of the Italfreno pump. In the first part of the animation it is possible to see how an internal shaft with a smaller diameter exerts an X force. In the second part of the animation, however, it is shown how, as the diameter of the stem increases, the pressure generated in the system with the same force exerted on the pedal.

GENESIS

The Italfreno plant was launched on an experimental basis at the end of 2017, but its most recent approval is from 2020, for the MINI class. The operating principle is something never seen before in the karting scene and is inspired by the system adopted by some cars of a lower class than F1. The EKS technicians decided to introduce a new type of brake pump, bringing a solution that allows minimising the friction losses during the braking phase, which inevitably occur in models with the classic linkage integrated with the brake pump. Furthermore, thanks to this configuration of the pedal-brake pump unit, drivers have perfect braking modularity, without this being modified by the intervention of levers.

The first version of the Italfreno system made its debut in the 2017 KZ World Championship in Germany, in which it contributed to the achievement of third place for the Croc Promotion team, with driver Ben Hanley.

The pump and caliper, still on an experimental basis, had a rougher style and more angular shapes than those that were actually approved.

THE BRAKE PUMP

The system’s pump designed by Emme Racing is made from a solid aluminium piece and CNC machined. Inside, there are two holes in the upper part. One, positioned in the rear area, is close to the inlet of the oil present in the tank, while the one placed approximately halfway along the length of the pump is for safety and serves for the recirculation of the oil when the brake is released to return to the neutral position. The shaft is made of ergal, an aluminium alloy that has a resistance similar to that of C40 steel; as previously mentioned, the flange (pumping element) that pushes the oil into the circuit, the return spring in neutral position and the oil seal rubber are mounted on the shaft. The pumping element also performs the function of regulating the idle stroke of the shaft: based on its position on the shaft (more or less distant from the pump cover, so to speak), thanks to some thicknesses that can be used in a variable position, it allows a greater or lesser stroke of the brake pedal, so that the brake has a "safety" threshold in case the driver is used to resting his foot on the pedal even when this is not required. The rubber pump plays a fundamental role for the correct functioning of the system: when the brake is activated, the rubber tends to expand under the pressure it receives from the oil: once the brake is released, the rubber tends to detach from the [1] perforated disc on which it rests and allows the oil to pass beyond the grommet, in the area of the brake pump connected to the tank, which is filled up again. There is a cap to close the pump, which can be removed with a special key, in which the shaft is free to slide with a concentricity constraint, and inside which an anti-dust seal is mounted.

The Italfreno master cylinder kit. In addition to the [1] pump body and [2] to the pumping assembly, we can see the [3] bracket for attachment to the chassis and the [4] optional shafts of different diameters.

The ergal shaft is the central point of the system designed by Emme Racing. Its operation is inspired by that of the formula classes.

The rubber pad and the different position of the wedges allow you to adjust the free movement of the shaft and therefore of the brake pedal.

Above, the displacement pump setup positioned on the shaft to offer a reduced idle stroke. Below, vice versa, the setup that allows giving a greater stroke.

In the video, the activities required to reverse the thicknesses on the shaft that allow you to affect the responsiveness of the braking system to pedal pressure. Below, the elements that make up the rod/pumping assembly.

The cap that closes the pump has a rubber anti-dust seal inside.

HOW TO MOUNT IT

The oil tank is vertical and there are two ways of mounting it: it can be positioned directly on the brake pump, or it can be placed in a different point via a connection pipe. This second type of assembly is preferred in the MINI classes, so that drivers do not have the fuel tank disturbing them under their legs. The master cylinder connects to the brake with a classic adjustable rod. On the other hand, the Italfreno pump is not fastened to the chassis with the two classic bolts that would force it into a fixed position. This is because the return rod and the shaft must always remain on the same straight line because there are no joints between them. This is why the Emme Racing technicians had to design a specific attachment to fasten the pump to the chassis which provides a joint that allows two degrees of play, i.e. vertical and horizontal rotations, so that at any time the pump and the shaft are perfectly aligned with the rod that connects them to the pedal: if this were not the case, there would be a risk of system seizure. There is a single pump for the MINI and single-speed classes, while in the case of the shifter class, two perfectly identical pumps are used, on which the classic braking distributor is mounted.

The kit that is supplied for mounting the external oil tank with respect to the brake pump.