Abstract
The usage of CNG for vehicles face many dilemmas. One of the dilemmas is the poor acceleration of Natural Gas Vehicles (NGVs) compared to standard gasoline vehicles.
In this research an additional acceleration control system for improving the NGVs performance in acceleration condition. The main idea of this additional control system is similar to the accelerator pump in the carburettor which is to supply an additional amount of gas to the engine if an acceleration process occur.
The system was tested on a various testing condition, including static condition, transient condition and on the road acceleration condition. The static and transient testing was done in the laboratory, using 4 cylinders in-line, 1800 cc Toyota 7K engine, the tests shows that the additional control system can improve acceleration time around 3 14% from the original CNG system. With optimization, the additional control system can improve acceleration time of 4 cylinder in-line, 1300 cc Datsun pick-up 521 in a real road test acceleration condition around 10 - 15% of its original CNG system.