Cool me down to take another round

[SavagePassenger]

Has anyone tested different coolants such as VP Stay Frosty or Redline Supercool? In exchange for freeze protection they have a higher heat transfer load with the low or no glycol levels. Online tests i've seen seem promising.

I haven't yet but I thought about mixing a lower amount of the bmw ht-12 coolant with one of those or Summit Racing non-glycol coolant. Maybe I'll do that first for the low temp circuit to see if it helps lower IAT at all.

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[FLtrackdays]

I haven't yet but I thought about mixing a lower amount of the bmw ht-12 coolant with one of those or Summit Racing non-glycol coolant. Maybe I'll do that first for the low temp circuit to see if it helps lower IAT at all.

It’s funny since I stopped driving off season, I don’t remember doing anything different with the coolant. But it’d be interesting to hear how it turns out for ya! Maybe things have changed. That’d be a cheap & quick way to bring IATs down if it works…

 

[Vegas17]

Working in the commercial HVAC business there's a significant de-rate in chillers when adding glycol (anti freeze) to the system. It's roughly 30% glycol = 6% derate in btuh capacity. Not perfect science but watching the Project Farm youtube video testing these coolants was surprising for comparison sake.

 

[FLtrackdays]

Working in the commercial HVAC business there's a significant de-rate in chillers when adding glycol (anti freeze) to the system. It's roughly 30% glycol = 6% derate in btuh capacity. Not perfect science but watching the Project Farm youtube video testing these coolants was surprising for comparison sake.

Sounds like VP Stay Frosty would be best for track only in a never freezing climate. Redline Supercool if doing a full flush and VP Racing additive for topping off your current coolant. Good video!

 

[kyle9]

Easiest thing to do is mix water + water wetter and then add coolant as needed to achieve the freezing point desired:

GLYCOL % BY VOLUME​	°F​	°C​
12.5​	25​	-4​
17​	20​	-7​
25​	10​	-12​
32.5​	0​	-18​
38.5​	-10​	-23​
44​	-20​	-29​
49​	-30​	-34​
52.5​	-40​	-40​

 

[TBK]

Another cooling mod to mention is upgrading to the G series M 1000w radiator fan. Our Supra one is 800w and a different blade design.

The M series 1000w fan is what they use on the Supra GT4. BMW also uses it on the M240i/M340i/M440i with the cooling package.

It's a drop-in mod and helps the whole front cooling stack (radiator, heat exchanger and trans cooler). The negative is it's $1100 or so new. You can try and find used ones off wrecked cars on ebay and get them for about half the price.

Is there any on-track benefit to having a bigger fan? I'm trying to understand what i'm missing here. Once above 60–70 km/h, the volume of air being forced through the radiator is orders of magnitude higher than what even a 1000W fan can provide.

So heat soak recovery between sessions aside, are there any mid-session cooling benefits to be had?

i found this btw, which seems to be cheaper aftermarket solution. Not sure about the quality though, but i'm trying to look into it.

https://www.1aauto.com/bmw-engine-cooling-fan-assembly-trq-rfa80243/i/1arfa00879

 

[i3igpete]

Is there any on-track benefit to having a bigger fan? I'm trying to understand what i'm missing here. Once above 60–70 km/h, the volume of air being forced through the radiator is orders of magnitude higher than what even a 1000W fan can provide.

They would be on the same order of magnitude at cruising speed. For it to be an order of magnitude of difference, the fan would be pushing air like 2 mph in freestream, and that is certainly not true.

 

[TBK]

They would be on the same order of magnitude at cruising speed. For it to be an order of magnitude of difference, the fan would be pushing air like 2 mph in freestream, and that is certainly not true.

Point still stands though. The fan isn't really adding any meaningful incremental air flow at track speeds. So i'm just trying to understand if there's another use case, or if the logic i'm using is faulty

 

[i3igpete]

The fan isn't really adding any meaningful incremental air flow at track speeds. So i'm just trying to understand if there's another use case, or if the logic i'm using is faulty

Well lucky for us, it should be trivially easy for us to test your theory. The fan connector can be reached without removing any parts, and your car already comes equipped with all sensors for you to log. Just unplug the fan for a session and report back.

 

[TBK]

Well lucky for us, it should be trivially easy for us to test your theory. The fan connector can be reached without removing any parts, and your car already comes equipped with all sensors for you to log. Just unplug the fan for a session and report back.

This isn't a bad idea, but 1) it's going to take me a couple of weeks to get to the track 2) 0W to OEM 800W fan impact won't necessarily tell us enough about the 800W to 1000W upgrade. and 3) i'd still like to understand the science/theory from those who are more knowledgeable than me.

This also raises another question....surely something like this has already been tested before. By someone. Not even necessarily with a Supra. But essentially the mid-session cooling impact of a fan upgrade

 

[Habu]

This isn't a bad idea, but 1) it's going to take me a couple of weeks to get to the track 2) 0W to OEM 800W fan impact won't necessarily tell us enough about the 800W to 1000W upgrade. and 3) i'd still like to understand the science/theory from those who are more knowledgeable than me.

This also raises another question....surely something like this has already been tested before. By someone. Not even necessarily with a Supra. But essentially the mid-session cooling impact of a fan upgrade

More CFM.

 

[razorlab]

The fan duty changes depending on many factors. One of which is coolant temp vs target coolant temp vs ground speed.

If coolant temp is not at coolant target, the fan can keep running up until around 75 mph or so.

 

[Subydude]

The design of the fan blades does come into play along with motor power. That said, as vehicle speed increases most vehicles do turn the fans off. The Supra has the highest speed I've seen in a vehicle at 75 mph for full off and most others (that I've seen) are like 50ish mph. It would reduce some back pressure, but the effect obviously drops off with speed.

Unless you have other cooling issues I don't think the 1000w fan would really come into play on track. For autox it might since speeds rarely exceed 75 and it could help there, or if the track itself had very few sections above 75 and was overly busy.

I would chalk this mod up more to decreased cool down time between rounds at a drag strip, runs at an autox, or if you were codriving the car at a track day and only had 20ish minutes between sessions.

 

[AJRMKV]

Point still stands though. The fan isn't really adding any meaningful incremental air flow at track speeds. So i'm just trying to understand if there's another use case, or if the logic i'm using is faulty

Sitting in the lane at a packed drag strip.. But even then, not incredibly useful in comparison to other cooling mods for the strip.

 

[Subydude]

Sitting in the lane at a packed drag strip.. But even then, not incredibly useful in comparison to other cooling mods for the strip.

I agree as having the hood open with a water sprayer on the front stack would greatly outweigh the fan. The fan wouldn't hurt though.

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