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

IGNITION TIMING KART

Ignition Timing kart - technical and solutions to get the best performance from the engine of your kart
 
the choice of the ignition timing in the kart is very important both in the phase of the engine development, both in the fine-tuning on the track, where it is often overlooked in favor of the single carburetion. In general all spark-ignition engines, they are 4 or 2 strokes, the ignition has always played a role fundamental for getting the best performance from the engine.

But while in the 4 stroke engines the choice of the ignition timing is made "only" to obtain the best conversion of the energy developed by the combustion into mechanical work, and then in power to the crankshaft, in the 2 stroke engine at this purpose is added that to to obtain the right exhaust gas temperature to do work at the best the expansion chamber and to obtain therefore the maximum trapping ratio of the engine.


This second goal in the 2-stroke engine becomes predominant because if the exhaust is not working well and then the trapping ratio collapses, at that point also a proper ignition timing to obtain the maximum work mechanic, changing a little the performance, what explains because the ignition with variable timing for two-strokes are designed right to try to do work at the best the exhaust on a rpm range broader precisely by altering the exhaust gas temperatures thanks to the ignition timing.

Let's figure from a technical point of view the problems that meet in the choices of the ignition timing of the kart and hence as move to get the best result.

In kart are used two types of ignitions, at timing fixed and at variable timing usually in the categories single brand.

In both cases the approach is the same, since that the ignitions at variable timing are not reprogrammable, so the work that can be done is to shift as those to timing fixed.

HOW TO CHOOSE THE IGNITION TIMING OF THE KART

Technically speaking when a kart engine is developed, the three factors, carburetion, ignition timing and geometry of the exhaust system should be designed to have the total tuning and then at the engine speed of maximum power the carburetion should be targeted to provide the best combustion efficiency, the ignition timing to transform at the maximum the energy developed by the combustion, and with the temperatures of the exhaust gases that deriving therefrom, the expansion chamber should work optimally to generate the maximum trapping ratio.

Obtained this, the torque at low speed and the power in overspeeding of the karts come consequently in funcition of the characteristics of the engine, and, in the case of ignitions timing variable,   depending on the choices of the timing made for altering the temperature at the high speed of operation.

Obviously moving the ignition timing of the kart, change the evolution of the combustion and the temperature of the exhaust gas, then at each engine speed there are new balance, and the dyno charts inevitably change, so the first thing to do is to check if the ignition timing that is initially set for the engine is actually what creates the torque curve and the better power for your needs.

When we talk about the best dyno chart, does not mean that reaches the maximum power, but one that in the range of operation, provides averagely the torque and the power best. If you have a dynotest, fixing the jetting, you should make a series of tests with different ignition timing, and compare the dyno chart in the view of how the engine will work on the track.

This work will allow two things, the first to choose the value ignition timing of the kart that allows us to obtain the dyno chart more suitable for your use, and the second to know how to play with the timing for a specific track, compared to another (more torque in low, more high speed, more power, etc.).

At this point has been done the first part of the work, that if you have a dynotest, and you have the appropriate expertise in the choices, is the easiest part. The hard part is then how manage the ignition timing on the track, under varying atmospheric conditions. In fact, usuallly the dynotest are made on standard atmospheric conditions, but what happens to the combustion of the kart when changing the pressure, the temperature and the humidity?

As you know the weather conditions require for first an adjustment of the carburation, but also would need an adjustment of the ignition of the kart, in fact different conditions of pressure and temperature by changing the speed of combustion, the heat transfer of the engine, and consequently also if is proper the jetting, the exhaust temperatures change, and therefore the curve of torque and power does not vary simply its level in proportion to the density of air, but it changes also its trend, and behold that all the decisions made before may be biased.

How to intervene on the ignition timing of the kart track at changing weather conditions to always obtain the best engine performance and the torque curve best suited, is therefore very important, but it is also extremely difficult, in fact also if we've available the sensor of the exhaust gases temperature, and we know on which values of temperature the engine operates at better, you will never know if the temperature is high or low for fault of the carburetion, or for the ignition timing of the kart that must be changed.

Given this difficulty in practice rarely act on ignition timing, but will compensate for variations in speed of combustion and heat transfer, always acting only on the carburization, this conventional practice by a point of view of performance mitigates the problem, but often determines problems of detonation, overheating, and in any event not lets you really get the most out from your engine karts.

Apparently there would not be alternatives to this way proceeding, if not to use the experience to avoid damage, and to play on the wire with the carburetion, also because in the race there isn't the time to do tests with several ignition timing, Fortunately, however, the technology can provide a great help, and tell you with a good approximation to what happens to combustion and heat transfer when the weather conditions change and then tell you how to adjust the ignition timing accordingly.

These algorithms of calculation have been studied in the first place to the electronic control units, in order to manage both the carburation, both the ignition timing, the variation of pressure, temperature and humidity, and then you get the most from the engine.

In the kart and in the other 2-stroke engines used in other competitions, not having an electronic control unit, these algorithms are implemented in software that according to the specific engine characteristics and the weather conditions tell you beforehand how you must modify the ignition timing of the kart for the new conditions, thus is possible to do manually what would make the control unit in those conditions of pressure, temperature and air humidity.

The use of these software allows to the mechanics to have an opportunity hitherto impractical for the fine-tuning on track of engine kart, namely, to optimize both the carburetion, both the ignition timing of the kart, not being therefore more forced to work only on a single parameter to compensate the deficits of the other.

This can lead to undoubted advantages both from the point of view to find the maximum performance of the engine kart, both to reduce drastically problems of detonation and overheating. 

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 choose the best ignition timing of your kart in practice and in the race

voto 4.4/5 su 757 voti
Where to intervene and how to get always the maximum performance of the kart in practice and race