Gauges are an essential part of your vehicle's safety when performance upgrades are installed. Not only do they look nice, but they help monitor every essential part of your engine to make sure it is running safely and at it's fullest potential.
My first gauge install was the boost gauge by autometer. Installation was rather simple, and the gauge even looks stock. I mounted mine on the pillar so I can readily see it when necessary. The boost gauge is supplied with a vacuum line that you simply feed out to the engine compartment and connect it to the spare nipple on the passenger side of the intake manifold. A small piece of silicon hose is needed to connect the supplied vacuum line to the nipple.
I later installed a water temperature gauge along with an air fuel gauge, both by autometer. I made a custom panel out of a plastic clip board I found at Walmart. I mounted the two gauges next to each other where the radio used to be mounted. The radio was moved down in the space where the tape player used to be.
Water Temp Gauge
The water temperature gauge was installed due to the lack of accuracy of the stock gauge. This gauge reads engine temperatures from 150 to 250 degrees F. My factory gauge reads halfway between hot and cold before my autometer gauge even registers 100 degrees F. The exact temperature of my coolant is very important to me since car doesn't run properly until it is warmed up to approximately 180 degrees F.
After installing my water temperature gauge, I began to notice how hot my engine was running during warm summer days. I also noticed that my fans wouldn't even kick on until my temperature exceeded 225 degrees F. At times my temperature would even rise to 240+ degrees while I was sitting in traffic. What surprised me the most was the fact that my stock temperature gauge never moved. It stayed in the same spot whether my temperature was 100 degrees or 250 degrees F. To keep my temperature under control I installed what is known as the "fan mod". This simply involves hooking up a switch which grounds a fan wire which can be found sticking out the side of the ECU. My wire was black with a green stripe with a connecter on the end. By grounding this wire while the car is on runs the fans on medium speed. The wire can also be grounded approximately two minutes before the car is shut off. If the wire is ungrounded 15 seconds after the car is shut off, then the fan will run for ten minutes then shut off. This helps cool the engine compartment after the car is shut off.
While using the fan mod, my temperatures while driving the car rarely exceed 180 degrees F. Even while stuck in traffic on a hot day, the engine temperatures remain cool. This is one of the most important modifications I've made to my car and I highly recommend it to anyone who owns an FD.
The water temp gauge requires that you either drill a hole in the thermostat housing or use the "pretapped from the factory" hole. The pretapped hole requires a little grinding to get the sender to fit next to the cap as shown in the picture below.
Because of how crucial it is that the rotary engine does not run lean, I felt it was necessary to continually monitor how much fuel the engine was getting under wide open throttle. The air fuel meter simply measures the voltage of the oxygen sensor in 50 millivolt increments. The oxygen sensor reads unburned oxygen particles in the exhaust gasses. When the particles are read, the voltage increases or decreases depending on how rich or lean the air fuel ratio is. The rotary engine should not see less than .85 volts on the oxygen sensor. Any less than this would create a lean state and could destroy the engine.
The air/fuel gauge connects directly to the oxygen sensor wire and uses the oxygen sensor for its readings. I tapped into this wire (black) at the ECU.