Our projects are programming the ECU system of the engine, purchasing, mounting and calibrating the sensors for the ECU and manufacturing the connecting cable harness. Further projects are running the engine tests on testbench and in test car.
For EVO 1 and EVO 2 engines, we used Bosch MS4 ECU and sensors, we designed unique cable harness and a wireless telemetry system, so we can storage and read 15 different parameters of the engine.
In case of EVO 3, due to cost efficiency and simplicity, we used a KTM ECU, so we built a supplementary cable harness. Beside them, we help to other departments, such as electro-pneumatic shifting mechanism, electro – hydraulic clutch or actuation if the intake pipe. During these projects, we often use microcontrollers, so we can develop our C language programming knowledge.
We have to use electronics for the testbench. Our team members can get to know the controlling of electronic machines, with the help of an inverter. For controlling we use CompactDAQ system and a LabVIEW software on PC thanks to NI Hungaria Kft.
During tests on testbench it is very important to measure and log different data from the engine. We used CompactDAQ system for this as well.
Team members on the cooling – lubrication department has the objective to design the oil and water circuit of the engine. We have to ensure the optimal temperature and lubrication of the parts of the engine and design the parts as light as possible. For engine operating it is indispensable to deliver the necessary measure of oil and water into the engine, as well the sumping and circulating.
In cooperation with other departments, designing, placing and manufacturing the parts of the lubrication system is parts of our job. The single parts (such as oil pump) has to operate perfectly as a part of the whole system. We have to ensure the connecting pipes and holes between the different parts. We use Creo 3.0 for designing and in case of some parts, we use CFD simulation as well.
At the moment we use a stock aluminium water pump with custom rotor to survive the loads. Oil pump is custom designed, trochoid type, and has a flow rate of 120 l/1000 pump rotation / hour. The oil tank has 800 ml capacity, with built-in dropping and carter gas blow-off. In case of EVO 3 engine, we have chosen a dry-sump lubrication system, sumping on both sides to prevent failures in case of side accelerations.
The basis of EVO 3 cylinder head is a stock KTM cylinder head. It has SOHC valve drive, four valves and low mass, so it is a very promising basis due to its mass, cost and competitiveness. To become more competitive we managed to make several development.
First of all, we managed to develop the valve drive, so a unique, custom adjustable camshaft with custom cam profiles was born. For this, we a custom adjusting machine was designed for the most accurate and easiest adjusting. This custom adjustable camshaft is for testing only. So our project is now to design a custom camshaft with custom cam profiles.
To further develop the valve drive, we designed a sliding rocker arm instead of stock roller rocker arm. We have to reach as much mass reduction as possible on the cylinder head casting to become more competitive. There is a project to reduce the mass of the cylinder head casting. Beside that it is important to reduce the mechanical losses, so we have projects for coating the parts as well.
We use Creo 3.0 for modelling, AVL Excite Timing Drive for valve timing and other FEM software.
This department is the most exciting and complicated department of our team. Our tasks are treating, checking the engine parts and assembly the engines. Members of this department has to be clear with the smallest parts of the engine, so they have to take part in the design process as well.
The largest project on this department is running our engines on testbench. For engine running we have schedules. First we run our engines without load, just for mechanical purposes and then there are tests with load.
Beside engine assembly we have projects with engine mounting into the car, and car repairing. Our team have purchased an older Formula Student car, so with the help of this car, the testes could begin. At our university there is a stationer rolling testbench, so we can measure the force, what the engine drives onto the ground.
In the near future we will be able to test our engine on our testbench, which is also individual in Formula Student. We optimized it for our single cylinder engine.
It is very important to give feedback and results to the construction department, so we can repair failures during the design process.
The soul of the crank mechanism is the crankshaft. The crankshaft of EVO 3 engine is completely custom designed, so called fully-web design. The flywheel was left and we tried to integrate the swinging mass into the crankshaft. The goal was to reach a more compact, easier and lighter mass. As the result of this integration, we moved the load nearer to the bearings, the shaft end could be shorter and load comes from the flywheel to the shaft end was abolished.
The crank mechanism further contains the transmitter disc on the crankshaft, the sprocket of the control, the gear of the starter and the gear for driving the clutch. We use stock piston and conrod, but we are continuously working on a custom conrod. The main goal is to reduce the mass with a completely custom geometry. At the moment we are working on integrating the transmitter disc into the webs, so this part is going to leave the crankshaft and be the part of the crankshaft webs.
We use Creo for modelling and there are several software used for simulation, including FEM software to define the stress and tension. We use AVL Excite Designer to define torsional stresses and angle of rotation between the ends of the crankshaft. AVL Excite Power Unit is for defining deformation of crankpin and master pins.
What is crankcase? The crankcase is a part, what includes all other parts of the engine, this is the body of the engine. This means, that this department has to cooperate with other departments the most. What can be influenced? The placing of the engine parts, which has an effect on weight distribution and center of gravity. These are really important factors in case of a race car.
For first look, the crankcase is not complicated, until we see the design process. This part should have really low mass and must bear 10-30 KN of loads on little surfaces. Because of this effect an enormous mechanical stress can be stand in the crankcase. At the moment, the EVO 4 crankcase is under design, which is very different to the EVO 3.
For modelling we use Creo Parametric software, and FEM software are also indispensable to define the weak points of part. In race sport it is really important to be as light as possible, while you have the same strength.
We are working with topology optimization (Tosca, Abaqus Atom), which is completely new designing process. We can mill the lightest geometry from an existing model.
Integrated transmission is used in EVO 3, thanks to this, the placing of the parts has more advantage. We have gained weight due to this concept. The basis of the transmission is a stock transmission. The stock part has 6 gears, but we left the fifth and sixth gear, because four gear is completely enough for Formula Student usage. We have further weight reduction here. Because of leaving higher gears, we had the possibility to design a custom gear shaft, which is made of aluminium with milling. For shifting we use mechanical actuation with cable.
One of our current project is the development of actuation for EVO 4. There were several possibilities, such as stepper motor or pneumatic solution. We develop an anti-hopping clutch, which has an advantage, that during braking, you don’t have to look after the blocking of rear tires. We continue our work on the gear shaft to reduce more weight. We re-design the gear shafts as well.
We use Creo 3.0 and FEM software for our work.
The air intake system has projects with the air intake system, with the exhaust system, and with the fuel injection system. We work with oscillating tube injection, but we have plans for turbocharging as well. We have to follow the rules of Formula Student, related to them, we must attach a 19 mm diameter restrictor (in case of etanol), or a 20 mm diameter restrictor ( in case of gasoline) into the air intake system. We have to look after the optimal pipe length and the flowing losses, such as surface roughness and bending radius. These small things influence the performance of the engine.
AVL Boost 1D simulation software is used for optimal pipe length and airbox volume. This is the same process in case of exhaust system. Here the gas flowing also has a big effect on the performance, although the exhaust gas has already left the cylinder, with the help of the pressure waves, the performance can be further increased. Due to the limited parameters of the car, it is a huge challenge to find the ideal place of the air and exhaust system.
We use 3D fluid dynamics simulation to choose the most suitable airbox geometry, and if it is needed, we make further refinements on it.
We use Creo Parametric 3.0 for designing and for modelling all parts.
The fuel injection system is from the fuel tank to the injector. We choose fuel pump, pressure limiter and fuel filter for the suitable injector.
All of the parts is made with the most modern technology, from the 3D design to the laminating of the air intake pipe.