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This paper discussed the shift strategy of Yanshan University econopower racing car in the 2007. The writer made the power train and the manual shift device on the base of the assembly of the engine and the transmission provided by the organizer of the Honda -China Econopower Racing competition. The writer also set down some shift strategies combining the mechanical performance of the racing car and does much experiment on car racing with different gear on the road which is almost the same with the real competition road, at last the writer reached a conclusion that how to drive the racing car with proper gear. The conclusion will guide the writer to do well in the improvement of the mechanical structure and the strategy of driving the racing car.

This paper has two purposes: the first is to study the air flow behavior in the MPI type engine manifold by means of flow visualization; the second purpose is the verification of the air flow characteristics described in SAE paper No.950066 (1)using the results of that paper. The tuft grid method was adopted for air visualization. The MPI type engine manifold used in this study (common chamber) has dimensions of 332 × 79 × 74mm. The amount of the tuft is 630 points. Two directions(yz and xz planes, respectively) of the tuft were instantaneously photographed at every 20 degrees of crank angle and the composed direction was calculated. The experimental conditions are 1) steady air flow, 2) transient flow, 3) the inlet pipe position and 4) ram pipe locations.

The objective of this experimental study is to clarify the air flow rate characteristics of an MPI gasoline engine intake-manifold at transient conditions. A new high-response air flow meter was investigated and developed for the study which can simultaneously measure the air flow rate of all four cylinders. The influence of transient conditions to air flow rate distribution to each cylinder were researched and verified with regard to the geometry of the ram pipe length and location, and intake air pipe location for the air distributor. The transient conditions were examined by varying the following: initial throttle opening, throttle operating opening, throttle operating period, and engine speed and crank angle at starting to open the throttle valve. A comparison was also made with a “Siamese” type manifold.

In order to study air flow distribution to individual cylinders of an SI engine at transient conditions, a new small-sized high-response air flow meter was investigated and developed to measure instantaneous air flow rates. The experiments were performed with changes in initial throttle opening, throttle movement angle and period, and crank-angle at the opening of the throttle valve and related engine speeds. Air flow rates for individual cylinders of a four cylinder engine were measured during acceleration. The relative rising rate was used for estimation of air distribution values, namely, the ratio of the initial amount of increased air flow rate of to the air flow rate for each cylinder. Air flow begins to increase from the second induction stroke from throttle opening. The variations of crank-angle at throttle opening influences the rate of increase. The effect of transient conditions on air flow rate distribution was researched.