cooling system temp

rossint · Postby **rossint** » Wed Mar 30, 2011 3:19 pm

No, it's an OEM Mazda one. It is possible that my gauge reads about 10deg out which would give an 80-90deg range between moving and stationary temps. I'll have to do some tests to see. I did notice the car ran cooler when I removed the AC condensor from in front of the radiator which leads me to believe the thermostat is not just open or closed as more airflow through the radiator = lower temps.

zossy1 · Postby **zossy1** » Wed Mar 30, 2011 3:21 pm

rossint wrote:No, it's an OEM Mazda one. It is possible that my gauge reads about 10deg out which would give an 80-90deg range between moving and stationary temps. I'll have to do some tests to see. I did notice the car ran cooler when I removed the AC condensor from in front of the radiator which leads me to believe the thermostat is not just open or closed as more airflow through the radiator = lower temps.

The thermo isn't drilled? Is your heater core routing as per OEM?

manga_blue · Postby **manga_blue** » Wed Mar 30, 2011 5:42 pm

Just checked Mazda's tech data. OEM thermostat for both NA6 and NA8 is two stage wax. Opening temp for the sub is 83.5 - 86.5 and for the main 86.5 - 89.5.

There's always modest flow through the heater core, even when the thermostat is shut. There's also a trickle through a hole drilled in the thermostat plate to assist thermostat operation by getting some warm water flow over it.

rossint · Postby **rossint** » Wed Mar 30, 2011 6:15 pm

zossy1 wrote:
rossint wrote:No, it's an OEM Mazda one. It is possible that my gauge reads about 10deg out which would give an 80-90deg range between moving and stationary temps. I'll have to do some tests to see. I did notice the car ran cooler when I removed the AC condensor from in front of the radiator which leads me to believe the thermostat is not just open or closed as more airflow through the radiator = lower temps.

The thermo isn't drilled? Is your heater core routing as per OEM?

Standard off the shelf thermo and the heater has not been modded at all, although I've been thinking about bypassing it as I never use it.

zossy1 · Postby **zossy1** » Wed Mar 30, 2011 6:56 pm

manga_blue wrote:Just checked Mazda's tech data. OEM thermostat for both NA6 and NA8 is two stage wax. Opening temp for the sub is 83.5 - 86.5 and for the main 86.5 - 89.5.

There's always modest flow through the heater core, even when the thermostat is shut. There's also a trickle through a hole drilled in the thermostat plate to assist thermostat operation by getting some warm water flow over it.

Certainly seems like Ross's car is running cool, if his gauge is accurate. Or the gauge may be out as he says.

manga_blue · Postby **manga_blue** » Wed Mar 30, 2011 7:08 pm

rossint wrote: I've been thinking about bypassing it as I never use it.

You can bypass the heater but FFS don't stop the flow. That's an integral part of the cooling for the back of the head.

rossint · Postby **rossint** » Wed Mar 30, 2011 7:22 pm

zossy1 wrote:Certainly seems like Ross's car is running cool, if his gauge is accurate. Or the gauge may be out as he says.

I might check the temp of the radiator hose against what the gauge says at some point, should give some idea of how accurate the gauge is. To be honest I never really pay much attention to the actual numbers and more what the gauge is doing relative to what the cars doing.
I haven't looked into bypassing the heater yet, won't be doing anything until I've done a bit of reading.

zossy1 · Postby **zossy1** » Wed Mar 30, 2011 8:27 pm

"Racer reroute" for the heater core, "coolant reroute" for the engine

Google these or search m.net or mt.net and you will be apples

Steampunk · Postby **Steampunk** » Wed Mar 30, 2011 9:23 pm

on tuning runs around sept-oct, at night, I'm getting 86-87 deg C from standard sensor at the back of the engine. BeGI re-route, auto NA radiator, standard everything else.

Postby **Okibi** » Thu Mar 31, 2011 5:12 am

I also have an aftermarket temperature sensor just after the thermostat.

From memory the thermostat opens about 180"F 82"C.

When sitting at the lights on really hot days the temp can rise to 210"F 99"C which is when the thermo fans kick in and the temperature starts to drop.

I remember Inf3ctor had temperature gauges with peak hold and he was seeing some pretty high temperatures with the stock radiator on his NB (dríven hard).

Guran · Postby **Guran** » Thu Mar 31, 2011 12:52 pm

What are you guys using to measure the coolant temperature? If it's a thermocouple, are you applying cold junction compensation? It's a common mistake with thermocouples and can account for inaccuracy in the readings.

mitch_f1 · Postby **mitch_f1** » Thu Mar 31, 2011 1:27 pm

I have a new VDO mechanical water temperature gauge in the radiator top hose, and on the road it generally hovers around 70*C, and on the track it doesn't go over 80*C. Both with constant flow. If I am stopped for 5mins or more then it will jump up to 90*C or so, and the fans will come on.