The aim of this research is to study the brake proportional affected to vehicle stability. Braking performance and vehicle stability testing are the main of research purposes. Otherwise learning research center and new researcher in automotive engineering are the minor research objectives. The results of research discovered to the braking performance depend on driver behavior. By the minimum deceleration was appeared on the non-proportion in front axle with braking ratio 0:100. In term of vehicle stabilities yaw and pitch moment are normally occur by the driving behavior. But the sideslip is an absolutely effect to vehicle handling. With the braking ratio 100:0 there is the highest risk for controlling a vehicle cause of the wheels were locked-up condition in the rear axle. Therefore the value of the sideslip was exceeded with the criteria. Furthermore these project researches were got the learning research center and the new researcher in automotive engineering field.

Currently transport has played an important role in everyday life resulting in huge traffic jams caused by big city streets and pollution problems from global warming to global temperatures are rising. Since humans are creatures that prefer comfort in all areas which contrasts with the higher temperatures of the Earth. Currently the use of air conditioning a lot. To modify the temperature is reduced in the range 2 3 to 25 degrees Celsius makes people feel comfortable. However the use of air conditioning in the car cabin cooling efficiency can be increased to a higher level than it is by cooling the refrigerant. The aim of this research is to test and compare the performance of car air conditioning systems usually equipped with a heat exchanger. Using water from the condensation of evaporator as a medium for heat transfer. By installing the equipment at the outlet of the condenser. This causes the temperature of the refrigerant is low. The pipe lengths in the equipment from the calculation of 1 .2 meters and copper lines that increases the length of the tubes was calculated to compare with a length of 1.6 meters to test the speed of the compressor 1000 1500 2000 and. 2500 rpm and a wind speed of 20 35 and 50 kilometers per hour. The results of experiment found that the temperature refrigerant equipment decreased from an average of 1.6 degrees Celsius the pipe length of 1.2 meters and 1.6 meters of pipe temperature drops 1.8 degrees average temperature attended Eva sufficiently reduced operator. It increases energy efficiency ratio averaged 6.68% of the pipe length 1.2 m and 22.24% at a length of 1.6 meters as well as to increase the coefficient of performance of the air conditioning system. 6 .6 9 % of the pipe length of 1.2 meters and a length of 1.6 meters at 22.4% with the key factor in optimizing the cars air conditioning system. Making the refrigerant from the condenser the temperature drops to pull heat out of the cabin through evaporator higher.

Nowadays an automotive industry steadily has been growing and playing a major role on economy development for many years. The crash box is one of the most important parts for safety but it was found that the crash boxes manufactured domestically are not met international standard requirements. This is due to process and material limitation. This process for automotive safety test requires high budget and there is unclear approach for specific test. Therefore a study of crash boxes referred to energy absorption project was conducted as the alternative materials for product. Consequently this project was aimed to design and test crash boxes which made from the diversity of the alternative materials such as aluminum aluminum reinforced by foam resin reinforced by fiberglass resin reinforced by water hyacinth and resin reinforced by water hyacinth and husk. In addition it was also emphasized in studying energy absorption behavior and physical deformation of crash boxes after dynamic and static energy being applied. The experimental works were applied for these tests in partly referenced to US NCAP and ECE R29 standard for automobile collision test. Testing all types of crash boxes indicated that the aluminum reinforced by foam type was able to absorb energy at 189 MJ/m3. It is higher than resin reinforced by water hyacinth and husk at 1 MJ/m3 as 188 times. Furthermore the comparison of the energy absorption (per unit volume) between the aluminum reinforced by foam type and the steel type from the previous project equivalent 20 MJ/m3 found that it is 8.45 times of difference. While the front impact test was not successful because the size of crash boxes was not suitable for the energy volume. It was a cause for non-available calculation of energy absorption value.

Nowadays the majority of environment problem is pollution of vehicle including the noise of engine combustion. For this reason this thesis aims to compare and study the parameters which affect noise reduction on exhaust pipe. Not only reduce the noise pollution but also maintain the efficiency of the engine. These two substances must be considered. Therefore the researcher emphasized to study the parameters on 3 types of muffler with an equal volume: direct reverse and offset type of mufflers. Initiated by data collection the pressure and the velocity in muffler at the speed of engine at 1000 RPM (slow-running engine mode) and 4000 RPM (maximum running engine mode) were investigated. The data were applied into the program that called “SolidWorks” in order to study parameters. In this step the relation between the pressure and velocity of exhaust were represented. In addition the muffler models were selected to manufacture and test by the standard of The Department of Land Transport. As a result there are two major parameters of the muffler. Firstly the metamorphism of the exhaust gas flow direction pleasurably causes the lower noise at the speed of engine at 1000 RPM. Besides an increase of the flow gas distance can diminish noise at the speed of engine at 4000 RPM as well. However this muffler models were tested under the working mode of catalytic device that is standard equipment for automotive vehicles.

Nowadays an automotive industry steadily has been growing and playing a major role on economy development for many years. The crash box is one of the most important parts for safety but it was found that the crash boxes manufactured domestically are not met international standard requirements. This is due to process and material limitation. This process for automotive safety test requires high budget and there is unclear approach for specific test. Therefore a study of crash boxes referred to energy absorption project was conducted as an alternative choice of testing. Regarding to the problems as addressed above this project was aimed to design and test crash boxes which come in various structures; simple type corrugated type and honeycomb type of crash box. In addition it was also emphasized in studying energy absorption behavior and physical deformation of crash boxes after dynamic and static energy being applied. Numeric simulation and static test methodology of front collision were applied for these tests in reference to USA NCAP standard for automobile collision test. Testing all types of crash boxes indicated that the corrugated type was able to absorb energy at 2.8% and 5.9% higher than honeycomb type and rectangular type respectively. This is capable to pick up stress and strain continually and effecting to more energy absorb than another type. Additionally this corrugated structure is feasible and suitable for crash box design in automotive manufacturing.