planning on fitting my hks coolant temp and boost gauges this weekend.was wondering if anyone has fitted these and if so where did you fit the temp sensor for the coolant gauge?looks like you would need to drill and tap somewhere to fit it but where is best?
also for the boost gauge is it just a case of cutting a boost pipe and jopining in the t-piece for the gauge?

 

As for the coolant temp, I have no answer. I have an Autometer boost gauge and I used a stem on the UIM that was capped for my boost gauge and it works great. Just need some extra 1/8" vacuum line to reach it

 

there are lots of opinions here on where to tap into. Some feel that tapping into the front of the coolant filler neck, as close to the back of the thermostat is best. From there you will read coolant temps directly coming from the engine once it is at operating temp. Others have tapped into the radiator hose lines themselves. There is a kit, I believe HKS sells it to do this. I tapped mine into the coolant filler neck.

 

yep think i will go for the filler neck.
as for the boost gauge...uim? only thging i can think you mean is upper inlet manifold?so there is a capped stem i can un-cap and pop it on there?

 

There are several stems at the outside base of the upper inlet manifold, right where upper meets lower. Just uncap and use one.

Terry7

 

best place for the coolant temp gauge is right on the engine side of the thermostat. that's where the coolant will be the hottest.

 

Read this -

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/water-temp-sender-thermostat-housing-bad-idea-392910/

We need to squash the myth NOW that drilling/tapping the thermostat housing is a good idea. A T in the throttle body coolant hose line is -

- easier to do
- faster to do
- gives BETTER readings
- gives ACCURATE readings

There is NO downside. I have run this setup for a while now, and comparing my water temps on my HKS fan controller and PFC to my gauge, they are identical. The water in the throttle body coolant line is on the way to the thermostat housing from the back of the motor, so you're getting the hottest reading. The setup works great.

Tapping into the thermostat housing will give a good reading when the thermostat is open, but until that point you will get NO reading. That's just ghetto. And, if the thermostat is stuck closed, you'll get no reading at all. Not cool. Many times thermostats fail by slowly opening later and later, a trend you can see with the sender installed in the PROPER location.

Dale

 

i think you overlooked that i said on the ENGINE side of the thermostat.
you think mazda stuck the ect there for ***** n' giggles?

 

But, that would require removing the whole water pump housing to drill and tap. I'm just trying to get rid of the myth that drilling and tapping in that area is a good idea for a water temp sender. There's a MUCH easier, cleaner, and faster way .

Dale

 

dale do you have any pics of your location?
if not where exactly is the pipe and is it a case of cutting the pipe and joining in a t piece that the sensor can screw in to?