The array of gauges on a racing...
The array of gauges on a racing machine can appear confusing, but each has a vital roll in commincating engine performance - or the lack of it.
The tachometer (photo above)...
The tachometer (photo above) is hooked directly to the ignition box. Here, Gosselin points to the tach lead.
A common oil-temperature ...
A common oil-temperature gauge
The oil pressuresending...
The oil pressuresending unit is mounted on the top of the oil filter relocation-mounting bracket.
The oil-pressure gauge (above)...
The oil-pressure gauge (above) is connected to a simple fitting on the backside of the block (picture below), next to the distributor.
A common water-temperature...
A common water-temperature gauge.
The water temperaturesending...
The water temperaturesending unit is mounted in the thermostat housing.
A fuel pressure gauge.
Here, you can see how the...
Here, you can see how the fuel- pressure gauge is connected to the engine. A fitting with tubing, which runs to the gauge, is mounted on the backside of the fuel rail.
Shift light.
A voltmeter.
The voltmeter can be connected...
The voltmeter can be connected on the output terminal of the alternator as well as shown in this photo on the battery side of the starter solenoid.
The gauges on the dash in a race car may be considered the most important tool a driver has while going around the track. The tachometer, oil pressure, oil temperature, water temperature, fuel pressure, and voltmeter gauges tell the driver whats going on inside the engine and when to perform tasks like shifting or heading into the pits.
Stock Car Racing took a drive over to DGM Racing in Lake Hamilton, Florida, to chat with Mario Gosselin, a Hooters ProCup driver and mechanic, about the importance of each of these gauges.
Tachometer
The tachometer monitors the speed of the engine in revolutions per minute (rpm). Its important for the driver to know the rpm at which the engine has the most power. When that power starts to drop, the driver should shift to a higher gear. Staying informed also prevents running the engine past its redline.
Oil-Temperature Gauge
The oil-temperature gauge displays the temperature of the oil inside the engine. When the temperature reaches 265-270 degrees F, the oil will start to burn and will no longer cool and lubricate properly. By monitoring the oils temperature, the driver can detect signs of problems with the components in the bottom-end of the engine. When there is a problem with bearings or the crankshaft, the oil temperature will rise due to increased friction. This sets off an alarm for the driver.
Also, an oil-temperature gauge can help set up the cars aerodynamics. This is done by closing off the airholes in the cars grille to the smallest possible size without allowing the oil temperature to rise. The smaller the holes in the grille, the less drag there is on the car.
Water-Temperature Gauge
Similar to the oil temperature gauge, the water temperature gauge keeps the driver informed of how hot the engine is running. When the water gets above 225-230 degrees F, this is a sign that the water pump is not working correctly or that a hose or the radiator is clogged and engine failure is possible.
Fuel-Pressure Gauge
The fuel-pressure gauge keeps the driver up-to-date on any fuel problems. If there is reduced fuel pressure, less fuel will reach the engine and will limit the performance. Normally, the pressure will remain constant (about 8 pounds) unless there is a clogged line or a bad fuel pump.
Oil-Pressure Gauge
This gauge will not only let the driver know the amount of oil pressure inside the engine, but it also can reveal potentially fatal engine problems. Under normal operating conditions, the oil pressure is between 50-70 pounds. If the pressure drops, the oil pump may not be working properly. Also, if a bearing or lifter is going bad, an excess amount of oil can flow through them, resulting in lower oil pressure. This can be read as a warning to the driver.
Shift Light
The shift light is designed to tell the driver when to shift gears without having to look at the tachometer. The light can be set to turn on at any given rpm, which keeps the engine in its powerband and prevents the driver from running the engine past its redline. This light is normally used in drag racing and road racing. According to Gosselin, it is seldom seen in a stock car.
Voltmeter
The voltmeter simply monitors the alternator, ensuring it is functioning properly and letting the driver know the battery has enough power.