where does everyone put their water temp sensors for gauge installs? i put mine in the back of the thermostat housing in the small port that has the bolt in it. my temp readings on the gauge gets so hot so quick, it goes up to 220 degrees if im not moving for a moment while dash temp and logger temp still say its at 180. when im cruising it stays at 180 so i doubt the sensor is bad. the 1g thermostat housing is full of water so i wonder if its not seeing steady water temps from moving so much. any other locations to put it?

Not sure but just for ref, the bolt seen here?

yes correct

what is the sensor on top of the water neck?

That's basically where I have mine. The one on top is to cut out the AC compressor in an overheat situation IIRC.

^ Correcto.

If you think about it, that is a good location for the temp sender. I ran mine there, and it seems to be a good indicator of what is going on temp wise, as it'll fluctuate more than say in the radiator. This, in thoery, should clue you in sooner to anything wonky on the cooling system (sticking thermostat, low fluid level, etc.).

Personally I don't know where else you'd want to run the temp sender.

The sensor where the bolt faces the rear of the car. It causes both fans to turn on. The one on my vr-4 is broken, it's shorted to ground all the time. This cuases both fans to run all the time. I just unplugged the connector to it.

Top one is for the AC system.

Engine temp sensor is on the lower psrt of the radiator passanger side, next to the hose.

You're probably getting two different readings because the sensors are on different sides of the thermostat. When you're sitting, the temp will rise because coolant isn't flowing as much at idle. Then you'll start moving, the thermostat opens and coolant flows, bringing colder coolant to your secondary sensor. That's probably why you're getting two different readings at idle, and similar readings while on the move.