Okay.
I did get good grades in thermodynamics in college, but I’m still a little lost here.
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- Thread starter TiGeo
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I did get good grades in thermodynamics in college, but I’m still a little lost here.
What is in these? What are they made of...
They are primarily a surfactant and lower the surface tension of water. Most also include corrosion inhibitors and other things that help when plain water is used as a coolant. But a formulated coolant already has these ingredients, therefore they do little to nothing in a glycol coolant mixture. They are generally used when it’s required that plain water be used such as at a race track.
DI water and a higher psi radiator cap may work better..
That isn't surprising, the active ingredients need a carrier and that would be water.
If I were running plain water in a cooling system (which I'd never do), I would want some corrosion protection that most of these products undoubtedly provide. Lowering the surface tension of the water improves heat transfer and has other benefits such as lowering the potential for cavitation. But as I mentioned a commercial antifreeze already does this. The additive is a benefit with plain water.
agreed
if i were strictly just racing though i would do complete drain of antifreeze and run straight DI water with higher psi rad cap.
in OP driver is using a daily driver and there is no gain in that case.
sincerely,
john
I know several folks that have recommended these products from their on-track experience and have told me that running one these products, even with a normal 50:50 antifreeze water mix, still has some benefit on-track w/r to cooling. I see no downsides to try this out but yes, the ideal for track is straight water with a water wetter product. I will be doing several track days in warmer weather in the coming months so will be interested to see if I note any difference in coolant or oil temps.
I’m sure there would be no harm in using the product. But this is where I get lost, how can you see a coolant temperature difference if it’s controlled by the thermostat? Unless of course you have no thermostat or it’s out of control. But then the temperature would be greatly affected by ambient conditions, both temperature and airflow.
As far as oil temperature goes that would be second-order and I’m not sure how any direct correlation could be made.
Measuring heat transfer in a system like this is not easy and is likely impossible without far better controls and better measurements. I just don’t see how anyone could do it outside a laboratory.
On track, you are pushing the car hard/to the limit and you can see the coolant temps rise beyond "normal", sometimes enough to move the dummy gauge (which is about 230 F - the gauge stays put within a range of temps) - in this case the thermostat should be fully open. I can watch the actual temps using a scan tool which is much more helpful (man...wish I could program the car's gauge to read the correct PID). On my car, both the oil and DSG fluid are cooled by heat exchangers with the cooling system which can add significant heat/reduce engine cooling capacity under those conditions - the higest I've seen sustained oil temps is 272 F over a chunk of a 24 min session; ambient was in the low 80s F. Many drivers have noted that once these cars' oil temps get above ~270 F, coolant temps can start to creep up which of course is bad and at some point you have to back off and will be down on power. The MK7 VWs run hot on track, it's a well-known issue. The idea here is anything you can do to aid the cooling system may be helpful. Ideally, the answer is better venting to promote air flow through the front stack (condensor/intercooler/radiator) but to do that, you need to install hood vents which have been shown to reduce both coolant and oil temps. Many have tried larger radiators which seem to be hit/miss. External oil coolers are also popular. However, what some of these larger heat exchangers inadvertantly do is reduce air flow through the stack actually compounding the issue. Same with v. larger intercoolers. Some have divorced both the oil and DSG from the cooling circuit and installed separate heat exchangers. It's a balancing act. For me, I have an upgraded aftermarket intercooler that is more moderate in size vs. other brands and will leave it at that - it's a daily driven car, not a dedicated track car.
I understand the desire for proper testing but at some point, you just try things and watch the numbers. I track cooling and oil temps consistently and am curious if I see any difference in either oil or coolant temps (at similar ambients) with this product - my gut says I won't see anything that would stick out/outside of normal variation. I had this installed when I was at the track back in Feb but it was cool out (50s) and I didn't have any oil temp or coolant temp issues.
Yes on a track where the system is out of control you might see a difference depending on the airflow. I’m sorry I didn’t know this was a track situation, I was only thinking of a street vehicle where the system wasn’t oversaturated with heat.
On a street vehicle where the cooling system is within bounds then the thermostat will determine the operating temperature.
On a street vehicle where the cooling system is within bounds then the thermostat will determine the operating temperature.
Agreed. This is purely a track-interest to me and will do zero on the street. It was a cheap test! I paid about $15 I think at Advance for a bottle.
@kschachn, can you explain how the aforementioned reagents affect the specific heat value of the antifreeze/water solution
that is likely some 20% less than plain water by adding more of the same in order to try and make it more effective at cooling than plain water when the volume is fixed?
i don't see it, let me know what I'm missing.... and thanks for your help.
that is likely some 20% less than plain water by adding more of the same in order to try and make it more effective at cooling than plain water when the volume is fixed?
i don't see it, let me know what I'm missing.... and thanks for your help.
No that’s above my pay grade. Specific heat is an intrinsic value, so any small amount of something else isn’t going to change much. Water already has a very high specific heat value.
But then again, proper coolant operation is more than just specific heat. A lot more. You can make up for lower specific heat with proper design. Air conditioning systems do it all the time as refrigerants change.
I've been in a situation on a hot day (maybe 90ºF), stuck in bumper to bumper freeway traffic, and the fan wouldn't turn on. But I suppose that's your airflow situation.
Saw the temp needle keep on going and going. There were periods where I could go maybe 15-25 MPH and the needle always moved back to normal quickly. But when stuck I heard that in such a case the best thing to do is turn on the heater and just live with it, and it did bring down the temps a bit even without airflow.
Sometimes folks will do just this on-track...blast the heat.
I had a friend with an old beater (Buick something) with no A/C that when it got really hot the engine would want to overheat at stoplights. He had to turn on the heater to keep it within limits, so here we sat motionless on the very hottest of days waiting for the light to turn green, all the while with the heater on full blast.
"so any small amount of something else isn’t going to change much. Water already has a very high specific heat value."
thanks, yes much higher than a antifreeze and water mixture and adding a small bit of that bottle additive is not likely going to change anything much as you said. and even though there are differences in the vapor point of different coolants for ex Ethylene glycol and propylene glycol that have higher vapor points and therefore can absorb heat at higher temperatures without boiling it is not enough as even with its lower vapor point, water still carries more heat per unit.
i agree with you that redesigning systems can make a change but in this case we are talking about everything being fixed except for the addition of a 1/2 liter of mostly water and some minute reagents.
...my experience from running heater to cool hot engine only yields about a 10 degree drop in temperature in stationary traffic on a hot summer day ymmv, enough to possibly keep a boil over from happening so this is handy to keep in a handy shirt pocket!
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