Quote:
Originally Posted by RedDevil
My advice would be to choose the blocking in such a way that the 12V battery benefits from the air stream through the remaining unblocked parts.
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If the engine bay temps are high enough to damage the battery, the airflow from the front of the car is too little to improve anything, even on highway, leave alone city traffic.
The best way to pump air through the battery box, if the car has a closed box: use the engine intake. Drill a hole about 1 inch through battery box and another in the air filter box, and fit a pipe (either plastic, or a wire-reinforced hose between them.)
A 1.6-liter engine draws thousands of liters of air per minute even at slow rpm, enough to bring quickly the inside of the battery box at outside temperatures.
Quote:
Originally Posted by TimV
I also found out that i could hold my upper grill block longer.
Previously I removed it when it is 20 degrees celcius.
Now it stays on until 23 degrees if i do stop and go. And 27 degrees when i do lots of highway  |
The upper grill block may stay there all the time, if the air is properly ducted through radiator core.
The logic of ducting is like this:
1. Most of the drag at the front of the car is due to the airflow
through engine bay, not the shape of the car's front;
2. The airflow through radiator is mostly due to pressure differential at the front and rear sides of the radiator.
So, if the intake grill is left open at the highest pressure point on the car's nose and the exit of the air from the engine bay is at the lowest pressure point, the grill opening may be very small and still achieve good cooling.
Drag improvement is not due to smaller opening, but due to leaving more air to flow
over the nose of the car.