Technical and Solutions to get the most out of your kart in practice and race

JETTING KART

Jetting kart - Technical and Solutions to obtain the best performance from the engine of your kart
 
Carburetion karting is one of the stages of development more important in practice and race. Indeed all major categories karts use 2-stroke engines that as is known they have performance greatly influenced by the jetting.

As jetting the kart, what is the carburetion best for its own engine, which carburettor calibration is more suitable when there is hot, when there is cold, on a track, for a pilot, etc. are all questions that always you will come across on the karting tracks all over the world.


Let's figure from a technical point of view the problems that we meet in the jetting of the kart and therefore as move to get the best result.

In karts are used two types of carburetors, those in diaphragm used in KF categories and in certain brand (X30, Super Rok, Easy Kart, Kart Champion, BMB, etc.), And those with float used in KZ1, KZ2, MINI 60, 60 and single-brand BABY Vortex Rok, Rotax, etc.

Carburetors diaphragm are easier to manage, but also less accurate, while those with float have many elements of calibration and therefore have a more difficult to manage, but allow to better meet the needs of the engine.

In fact all part by the needs of the engine, according to its characteristics, the engine speed, throttle opening, will need of appropriate amount of the mixture to obtain the best in any situation and this must be able to do the carburetor.

HOW JETTING THE KART

To jetting the kart is necessary firstly to have method. Basically there are two phases:
  • the first to find the jetting more suitable at the engine that we use
  • the second to know how adjust the jetting to atmospheric conditions,, to the needs that every track demand and to driving style of the driver.
Neither of the two phases is easy, but as the saying goes, those who well begun is half done, then we should spend some days of testing in the first phase and from there start to the second phase.

The first important thing to do in the test is avoid to broke the engine, then you have to start in safety, with a jetting rich and from there begin to lean, and already here began the first problems, how to lean, at full throttle, at idle, in the passage, by acting on such elements, etc. are all questions to which we must respond.

It then proceeds by trial evaluating from time to time the result. Obviously the lap time and the feelings of the driver are the first elements to which you can refer, but from a technical point of view you can help yourself to understand how far you are with jetting of the kart, analyzing spark plug and piston. This also of course it requires knowledge and experience, moreover with the current gasoline these readings are increasingly difficult.

Another help to evaluate the carburetion of the kart, you can have from data acquisition, applying sensors to see the level of detonation, and the temperature of the exhaust gas, while the use of the oxygen sensor unfortunately in the 2-stroke engine is not very reliable and is likely to provide guidance incorrect.

The analysis of the data detected by the knock sensor allows monitor reliability, while that of temperature of the exhaust gas, the performance. In this case too specific experience is required because there are no values standards for detonation and temperatures to be taken as a reference, but each engine based on the characteristics, the chamber combustion, the advance ignition, etc. works best on appropriate values.

However, the analysis on the lap of these values regardless of the levels can help you understand the behavior of the carburetion of the kart in the different conditions of engine operation.

To summarize what we have seen so far, both the old methods (ear, spark plug, piston), both the results of the sensors (detonation, exhaust gas temperature) with adequate knowledge and experience can tell us where we are and in what direction we should go, but what unfortunately they can not do is tell us how to change the jetting to achieve the goal and then have the carburetion that doesn't detonate, which doesn't damage the piston, which makes beautiful the spark plug, and that makes us have to exhaust temperatures that make the engine go fast.

To act on jetting is therefore important to know the carburetor and know each adjustment element that effect produces on carburation in the different operating conditions. Seen the carburetor now existed for more than a century (end '800) you can find a multitude of publications that provide a simplified explanation of the function of each element of carburetor.

This can certainly give an idea of the different functions, but here we are talking of races, competitions, to get the most from your kart, so you need to go further, learn the entity of the effects of each element, such as the different combinations of the calibration elements do meet the carburetor in acceleration, the passage, at full load, etc.

It's clear that to go further, in addition to knowledge, we must do so much, but so much, specific experience of each model carburetor. In fact, as long as we talk about carburetors diaphragm with only two screws to adjust or at most a few diaphragm or spring from try, this may be easy, but when we look at eg carburettors used in karting in 60 MINI (Dellorto PHBG18) or in KZ (Dellorto VHSH30), the calibration elements become 10 and 12 with respectively 26 and 115 needles, 12 and 38 atomizers, 4 and 7 throttles, and so on for the other elements, and this, playing a bit with numbers leads to well 14976 calibrations possible for PHBG18 and even 764750 for VHSH30 ... it seems incredible, but it's true ... on the contrary in the calculation we have even neglected the floats, the heights of the float and half notches ... do some of you!

It 'easy to see how to front of these numbers, as well as having the appropriate knowledge, to accumulate experiences test after test, and essential to have a technological help to get to the choices Optimal quickly and confidently, in fact without help, even a life of tests not It would be enough to ensure that you have found the best setting.

Fortunately, in recent years the technology so far confined to other important stage racing has arrived to the much reviled carburettors used in karting and so have been developed specific software to allow you to obtain the maximum the carburetor potential, helping significantly mechanical choose among the infinite possible combinations of jetting to obtain the maximum performance of the engine kart in all operating conditions.

Obviously when it talks about to software technical we need to see what can the software, and especially how it does, because if you really want to get some help for the jetting of kart from a software, the software needs to be able to keep count of as many things as possible and in the best way possible.

The software for the jetting must in fact be able to help in both phases we said above, that to search the optimal calibration for its own engine, helping the mechanic to skim the many possible combinations and choose the setting that not only allows you to get to the carburetion that best meets the ear, the spark plug, the piston, data sensors, but it is also the best for performance and reliability of the engine, for good joy of driver and team!

In addition, the software should help significantly in the other phase, which is even more important, because it is the one that leads to the end result, namely the management of jetting kart in each w.e rac,e depending on weather conditions, the characteristics of the track, and the driving style of the driver. here it must help the mechanic to be faster and more precise in the choices, because as you know sometimes it's the detail that makes the difference.

In conclusion, it appears evident from what has been written that to come the best jetting of kart, serving different components, First the method of working, in the second place a software professional who joins the knowledge and experience to speed up, simplify and optimize the choices of calibration to be done, and finally, a good eye and some sensor to have always under control the behavior of the engine. without one of these components will always be limited in the potential and they will continue to hanker after jetting in the box without knowing exactly what you are doing and thus not accumulating ever the right experience.

Continuing the reading you can start thinking of putting a important step for the growth technique of your team and of your job.
 

Solution to have the best jetting of your kart in practice and race

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Where to intervene and how to get always the maximum performance of the kart in practice and race