Experimental Investigation on Improvement in Fuel Economy At Low Speed on Engine With Throttle Body Injection

In this paper the problem of fuel economy at low speed on passenger car with throttle body injection (TBI) engine is explored.

According to the theory of turbulent flow in pipe, as the internal diameter of barrel of throttle body is decreased, the speed of air flow in smaller barrel will be increased under the same air-flow, the Reynolds Number will be also increased and the turbulence becomes stronger. Therefore the fuel atomization can be improved.

A new type of throttle body (Duplex) for TBI engine is presented.

On the other hand, the air flow at wide open throttle can be compensated by means of an auxiliary barrel for developing max. output of engine.

The result of the experiment is satisfactory. The fuel consumption is decreased about 6% when that type of throttle body is used on TBI engine.