How much is TOO much?
 

Results from a recent 370z driving experience:

--------------------------------------------
Location: Joliet, IL
Venue: Autobahn Country Club - Full track
Lap Time: 2:52.65
--------------------------------------------

Vehicle Statistics

• Oil temp = 250 F
• Oil pressure @ wot = 80psi
• Coolant Temp = 219 F
• Average Engine RPM = 5297
• Average Throttle position = 59%
• Trans temp = you wish
• Diff temp = in ur dreams

Also of note, that oil temp of "nearly limp mode" is with a 25-row Z1 oil cooler.

GPS Statistics

• Max Speed = 113.3 mph
• Avg Speed = 75.9 mph
• Min Speed = 44.7 mpg (at "patience")
• Track Elevation Change = 40 ft.
• Distance = 3.56 Mi
• Lap Time = 2:52.65

--------------------------------------------



--------------------------------------------

In regards to the thread title... at what point does coolant no longer "cool"
I was under the impression that coolant boiling point was just a "skooch" higher than the boiling point of water.

You would benefit from a triple pass radiator and a larger oil cooler. Radiator would help the most.

Also of note, this car is my daily-driver in Chicago. So it gets snow tires in the winter. Also not sure if there's a way not to over-cool the motor for winter usage.

I realize lots of this can be solved with another car, but let's move past that for now...

If you have a themostatic sandwich plate, the oil flow into the cooler will be reduced below 180F. Additionally, you can fashion a block-off plate to mount on the cooler to reduce airflow in winter.

I've driven mine in the winter (sparingly) here in NW Ohio when it was below freezing outside with a 34 row oil cooler with a block off plate along with a CSF non-triple pass radiator. While it took 10-15 min for the oil to get to 180, it did get there.

Radiator and oil cooler as these guys said. As for driving in winter, the only real thing I ever noticed was I just had to let my car warm up a little longer than normal on real cold days.

As for coolant Vs water, pure water will have a boiling point of 212F, Pure ethylene glycol's boiling point is 387F. A 50/50 mix is normally around 230F.

Good info, thank you kindly. :tup:

From a engineering standpoint I would think the boiling points would actually be some what higher as it's a pressurized system.

Higher pressure = Higher boiling point.

Pressure and Boiling Points of Water

You are correct on the pressure, most Z systems run about 15lbs and that will bump up the boiling point by a decent amount. Closer to 250-270ish.

The coolant will continue to work until it boils. Steam is still capable of removing heat but the density is much lower so it doesn't absorb as much as liquid water.

FWIW, the boiling point of water/antifreeze goes up about three degrees F per psig. Straight water is about 2 degF/psig. But those are just a rule-of-thumb numbers.

At work. We heat water up to 1,100F @ 2,000psi. And It doesn't boil. :D

I going to assume you're making power for someone.
How many megawatts are you guys putting out?
Whose turbines are you spinning?
The mothers of all feed pumps on those boilers, huh? Nice.
I'd like to see your setup.

104

250 isn't nearly 280 (limp mode)
I think your fine with your oil cooler.
Switching to water and water wetter coolant for the track season it the only think I would say you might consider.
The 2011s don't have the same pressurized coolant system as the 2012+ models. Not sure what pressure each version works at.

How humid was it during the day? That will really kill your cooling performance.

I plan on rigging a water spray system to my kit.

Was a 75 Degree day, and relatively not-humid.

I also got a spongy pedal after the 4th run, so i packed it up after nearly-boiling the Motul i'm running.
Didn't want to flush a brake system that was still 300F.