Water temp at track?

[bleunetizen]

Hi guys

Just wondering what kind of water temp everyone else are seeing when they do a few hot laps at a race track.

I was checking out obd logs and found that my water temp was shooting up to 115 degC at a long straight and around 105~110 degC on average.

This was only with 3 hot laps on a 3.4km long track. Oil temp was still below 120deg I believe. Air temp was around 20deg I think, so it wasnt a hot day either.

[finlandm5f10]

Did you use sportplus mode?

[bleunetizen]

Yes sport plus the entire time.

https://www.ecstuning.com/b-assemble...11537586885kt/

Just saw this one, seems like stock themostat is opening at 105deg opposed to the 90deg aftermarket one?

[M5Rick]

Originally Posted by bleunetizen

Yes sport plus the entire time.

https://www.ecstuning.com/b-assemble...11537586885kt/

Just saw this one, seems like stock themostat is opening at 105deg opposed to the 90deg aftermarket one?

That cooler running thermostat is interesting though I'm sure there are good reasons why Munich chose the 105 one, any engine technicians want to chime in on that..

[bleunetizen]

http://www.bmwlogicseven.com/?cat=151

Another interesting read there.

[bleunetizen]

Checked a few things today, during idle once the car is warmed up, the water temp stays at 105c in economy mode.

When I change the mode to sport plus, the fan kicks in and temperature drops to below 95c. Did not stay long enough to see how low it would get but it was obvious that the temperature is dropping so the car has some sort of water temp control.

I read from several posts saying that the ecu controls the thermostat electronically, but the stock thermostat do not seem to have any electronics in them except a temperature probe - according to what I can see from ECS Tunings website.

I wonder how the car controls the thermostat - surely the stock thermostat is not a 105c one if the car can drop the temperature to below 95c. Yet I am seeing 110c+ after a very short drive which is worrying. I wonder if it is considered safe in BMW"s books.

[M5Rick]

Originally Posted by bleunetizen

Checked a few things today, during idle once the car is warmed up, the water temp stays at 105c in economy mode.

When I change the mode to sport plus, the fan kicks in and temperature drops to below 95c. Did not stay long enough to see how low it would get but it was obvious that the temperature is dropping so the car has some sort of water temp control.

I read from several posts saying that the ecu controls the thermostat electronically, but the stock thermostat do not seem to have any electronics in them except a temperature probe - according to what I can see from ECS Tunings website.

I wonder how the car controls the thermostat - surely the stock thermostat is not a 105c one if the car can drop the temperature to below 95c. Yet I am seeing 110c+ after a very short drive which is worrying. I wonder if it is considered safe in BMW"s books.

I deduce then that the ECS 90 stat claims that it will keep the temp at 90 whatever the engine mode though with just a temp probe in it that's ECU controlled it would then have to have a spring blocker in it to allow more coolant through than stock.

[SapphireM5]

It controls it electronically with a probe that heats up to melt the wax inside the thermostat housing which causes the thermostat to open and allow coolant to flow back to the radiator. Under normal / economy mode the wax melts on its own around 105* and the oil temps are kept hotter for better fuel economy - all controlled by the ECU. In sport plus mode the ECU tells the heating element in the thermostat housing to melt the wax to open the thermostat sooner and to open the oil cooler at a lower temp. It does this believing since the car is in sport or sport plus the car is getting pushed harder than economy mode and prepares for this.

[KMORGSM5]

Originally Posted by bleunetizen

Hi guys

Just wondering what kind of water temp everyone else are seeing when they do a few hot laps at a race track.

I was checking out obd logs and found that my water temp was shooting up to 115 degC at a long straight and around 105~110 degC on average.

This was only with 3 hot laps on a 3.4km long track. Oil temp was still below 120deg I believe. Air temp was around 20deg I think, so it wasnt a hot day either.

Are you saying your water/coolant temps are getting to 239 degrees Fahrenheit?!?!

They should NEVER surpass boiling point, 100deg Celsius-212 deg Fahrenheit

[SapphireM5]

Originally Posted by KMORGSM5

Are you saying your water/coolant temps are getting to 239 degrees Fahrenheit?!?!

They should NEVER surpass boiling point, 100deg Celsius-212 deg Fahrenheit

That's not true in a pressurized system. Yes they get hotter than boiling point. Open up your secret menu on a drive and monitor your coolant temps you will be surprised.

[SapphireM5]

Originally Posted by bleunetizen

Hi guys

Just wondering what kind of water temp everyone else are seeing when they do a few hot laps at a race track.

I was checking out obd logs and found that my water temp was shooting up to 115 degC at a long straight and around 105~110 degC on average.

This was only with 3 hot laps on a 3.4km long track. Oil temp was still below 120deg I believe. Air temp was around 20deg I think, so it wasnt a hot day either.

OP your temps are fine. Enjoy the car!!

[finlandm5f10]

”Economy” mode 98-103 water temp
Sport plus 84-90 water temp

Oilcooler open economy 102°c and sportplus 90°C

[brad850csi]

This seems to indicate BMW are ok with up to 120c water temp.

https://f10.m5post.com/forums/attach...8&d=1360771557

[SapphireM5]

Stole this from the F30 Forum credit to Highland Pete who originally posted this. Our engines uses the same parameters as the N55 for cooling oil and coolant temps. Just too lazy to type it out:

BMW Data for typical N55 Engine Cooling

The engine control unit regulates the following temperature ranges:
• 108°C/226°F = Economy mode
• 104°C/219°F = Normal mode
• 95°C/203°F = High mode
• 90°C/194°F = High mode and control with characteristic map thermostat


System Protection
If the coolant or the engine oil overheat during operation, certain vehicle functions are influenced to the effect that more energy is available to the engine cooling system.

These measures are divided over two operating modes:

• Component protection
- Coolant temperature between 117°C/242°F and 124°C/255°F
- Engine oil temperature between 150°C/300°F and 157°C/314°F
- Result: The output of the air conditioning system
(up to 100%) and of the engine is reduced

• Emergency
- Coolant temperature between 125°C/257°F and 129°C/264°F
- Engine oil temperature between 158°C/316°F and 163°C/325°F
- Result: The power output of the engine is reduced
(up to 90%)

As you can see, 234F for engine coolant is still below any protection thresholds.

HighlandPete

[M5Rick]

So it would be wise to switch engine to sport or sport + mode if we are caught in a forever traffic jam.

[bleunetizen]

Interesting information, thanks guys. Who would've thought 115deg coolant was considered 'normal'.

I wonder if that other link i posted earlier about the thermostat is true though - suggesting the reason why bmw's are more prone to leak so much from all the gaskets compared to other cars is to do with the thermostat and allowing car to stay hot for fuel efficiency?

[KMORGSM5]

My coolant has never gone above 194deg Fahrenheit, my oil is consistent 226-230 deg Fahrenheit. Even when I have run it hard back to back runs.

[brad850csi]

Originally Posted by KMORGSM5

My coolant has never gone above 194deg Fahrenheit, my oil is consistent 226-230 deg Fahrenheit. Even when I have run it hard back to back runs.

When you say runs are you referring to 400m or actual race tracks?

[KMORGSM5]

Originally Posted by brad850csi

When you say runs are you referring to 400m or actual race tracks?

Most runs I've done in about an hour is 10 40-150mph in 90 deg heat and about 90% humidity. I do understand there is a big difference in running it around a race track for miles and miles at a time.

[brad850csi]

Originally Posted by KMORGSM5

Most runs I've done in about an hour is 10 40-150mph in 90 deg heat and about 90% humidity. I do understand there is a big difference in running it around a race track for miles and miles at a time.

Ahh cool, so half mile rolling races? I so wish we had those here! We have a few 400m tracks and a few race tracks but no high speed events.

That is about 3 minutes of wide open throttle in an hour so it isn't too much, but on the other hand, Chad was doing ~6 minutes worth of hard driving or so and seeing the water get up pretty high. Here is the track fwiw. Like most tracks you're only on the throttle for about 50-60% of the time.

[finlandm5f10]

I have in istagram video 260kmh-325km and water temps allway under 95°c and oiltemp 100°c-106°c and outside temperature about 15°c
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