KAJIAN SIMULASI PENGARUH TEKANAN BALIK GAS BUANG TERHADAP KINERJA MESIN SEPEDA MOTOR EMPAT LANGKAH 135CC

Abstract

It is generally known that exhaust system or commonly called muffler is a vital/main part of a
motor cycle. Therefore in the automotive sector/field, this product is progressing rapidly and
increasing the customer. Exhaust functions are to increase to speed, to beautify the shape and to
acquire the good sound hearing. But infect, many people disregard to improve/increase engine
performance by utilizing the exhaust gas itself. Related to exhaust gas issue and focus on back
pressure that occurs during disposal process, some exhaust products with different size of header
diameter are taken and analyzed to determine the amount of back pressure generated. The
analysis using ANSYS R15.0 program and the direct test using DYNOJET Model 250.The
simulation result show the amount of back pressure that occurs in the header exhaust for each type
of exhaust. The first type of exhaust (muffler type 1) the largest/the most back pressure is 3172.04
Pa, for the second type of exhaust (muffler type 2) the pressure is 2775.66 Pa, the third type of
exhaust (muffler type 3) produce 1138.39 Pa back pressure and the fourth type of exhaust (muffler
type 4) produce the smallest back pressure is 562.64Pa.The result of the four stroke 135cc motor
cycle for each type of muffler using the Dynojet show that the muffler type 1 on the 7340 rpm max
torque 0.89 kg.m (8.73 N.m) on round of 8150 rpm generating a max power 9.26 PS (6811 watt).
For muffler type 2 on around 7160 rpm produce max torque 1.05 kg.m (10.3 N.m) and max power
10.57 PS (7774.21 watt). For muffler type 3 at the around 7250 rpm produce max torque 1.13
kg.m (11.08 N.m) and max power 11.50 PS (8458.22 watt). And for muffler type 4 at around 7240
rpm produce max torque 0.95 kg.m (9.31 N.m) and at the around 8520 rpm obtained the max
power is 10.26 PS (7546.21 watt). Torque and the biggest power generated by the muffler type 3
while torque and smallest power generated by the muffler type 1.