N54 Cooling - Temp Control Logic and what are your temps during extended track use?

[barry@3DM]

While I understand the argument of the 7.5 race IC heat soaking at the top as there is basically no air flow on the top 1/3, does the IC not act like one large heatsink at the end of the day? I would think larger and increased total mass of the 7.5 race IC would still be a better choice vs the 7'' HD. Be curious to hear your thoughts.


While the space is small I wonder if you could duct any air from above the brace down? Almost like where the plastic in the pic below is curved up?

I see no reason to keep that rubber that blocks the radiator, that part that kind of mimics the front kidney bean grills. I hope everyone removes this when they do their IC install or at least cuts the middle part out:
View attachment 24774
Not my pic btw

Totally agree that the 7.5" would be better choice than the 7" if only 1" top and bottom were blocked. The areas blocked from air would continue to stay somewhat cool because they are so close to the surrounding metal that is being cooled by air.

In the case of some of these intercoolers like the Wagner at 11"+ tall, over half of the intercooler doesn't get any airflow. They are so close to the back of the bumper/bumper support, trying to divert air 90 degrees up or down 1" to 2" past the bumper/kidney opening just doesn't work. Now you are stuck with 5" of the cooler getting air and 6" getting nothing.

When doing dyno pulls or drag racing these HUGE intercoolers work because they have a chance to cool down between runs. The metal blocked from airflow never hits equilibrium to the hot charge air coming in. It basically can continue to act like a heat sync and will still cool the air.

When you are on a track, charge air is constant for 30 min at a time if not more. The top portion just keeps getting blasted with hot charge air until it eventually hits equilibrium and totally heat soaks that part of the intercooler. Now you have 5" of intercooler working (the airflow part), 1" maybe 2" doing a little bit (because its close to the cool part) and 5" to 6" of intercooler doing nothing. Hot mixes with cool and gives you warm intake air.

 

[MDORPHN]

Lest there be any misunderstanding, the VRSF 7.5" race intercooler is 11" tall. The 7.5" refers to its depth.

And Barry's description describes what I experience with my car on track. Hence my plan to replace my enormous intercooler with the VRSF 7" HD (race) unit.

Neil

 

[barry@3DM]

Lest there be any misunderstanding, the VRSF 7.5" race intercooler is 11" tall. The 7.5" refers to its depth.

And Barry's description describes what I experience with my car on track. Hence my plan to replace my enormous intercooler with the VRSF 7" HD (race) unit.

Neil

Did not look at specs.. shame on me. Assumed 7.5" was height.

But back to the point... any heat exchanger should have full airflow across ALL fins or else its a moot point.

 

[Torgus]

How much does/would a tubular crash bar like this help given the bumper is still in the way? I am guessing not much.

Not 7.5'' deep:

Almost seems like the bar should be another inch or so out in front...

There are no larger front openings for off the shelf front bumpers...only option would be to cut/modify.

 

[MDORPHN]

Hah, I’ve been considering same! No data, but I suspect only marginal gains with the stock bumper cover. However, it would allow much more airflow if openings were cut into the cover.

Neil

 

[aus335iguy]

This is likely the reason the f80 has water to air.

 

[barry@3DM]

How much does/would a tubular crash bar like this help given the bumper is still in the way? I am guessing not much.

View attachment 24830


Not 7.5'' deep:
View attachment 24831


Almost seems like the bar should be another inch or so out in front...
View attachment 24832

There are no larger front openings for off the shelf front bumpers...only option would be to cut/modify.

It would depend on how big the gap is between the backside of the bumper and the entrance to the fins of the intercooler. It would also depend on the ducting as well. You want the entire front surface of the heat exchanger to have good airflow.

Here is an example of airflow behind a bumper/kidney grill. This is an e46 I helped develop and we put string to show both good airflow and turbulence. Pause the video between the 15-20 second mark. Look at the very top string, it is hanging down while the car is stationary. When the car is moving that upper string is planted to the ducting. This is good! The lower two sections of string are flying all over the place from turbulence. This is bad!

I like to explain it this way... You have a bowl of hot soup you need to cool down. You can blow on it with your mouth which will cool one little spot and the rest gets some turbulence from the air swirling around the edge of the bowl. Or, you can stick it in front of a fan that has a $hit ton of air over the entire surface of the soup. The fan will win the cool down battle.

 

[barry@3DM]

I was thinking... all this intercooler discussion should be combined with the cooling thread, lol

N54 Cooling - Temp Control Logic and what are your temps during extended track use?

(Edit) I am trying to refocus this thread to DME temp control logic only. For those who are newcomers to this thread you may want to skip straight to post #51 and pickup there. Thanks! (/Edit) (Edit 3/18/19) This discussion has now morphed into all things cooling related to the N54 for track...

bmw.spoolstreet.com

 

[Asbjorn]

Here's another data point for the collection. This time from Zhejiang Circuit

Conditions today
22C/72F indicated in cluster on track;
21C/70F indicated by weather app;

Average speed on fastest lap was 100kph, and the track is basically one very long WOT section followed by one long zig-zag section with very limited WOT and time to cool down. More info here.

Car setup
DSC = off;
MHD stock cooling;
AC = off, heater/blower = on, low;
Semi-dry oil sump system = on;
DCT oil cooler = on;
Roof = down;

Mods on car relevant to this test
No changes since last time

Results

I did one log during the first practice session. First few laps were with safety car. Then I did four laps with gradually increasing speed. There was alot of traffic though.

datazap.me | Asbjoern | Zhejiang Time Attack Temp logging

datazap.me

Peak coolant: 106.5C / 224F
Peak engine oil: 136C / 277F
Peak iat: 77.5C / 172F (100F over ambient, fyi @MDORPHN )

Conclusion

Coolant still peaks too high, but average was better on this circuit. Peak IAT was very high here.

I have ordered a 40-50% larger radiator to replace my current additional radiator. Also need the HD version of my 7in FMIC, but that is just power related... not important hahaha

I should have the new radiator installed and ready for testing in a good one months time.

 

[gmx]

Agreed, it should. What'd you end up doing on the E46 to resolve turbulence in the lower portion. I mean, isn't that a result of the car ingesting air and it not able to pass through the top section of the core where it ends up bouncing around and causing turbulence on the bottom section of kidney grille?

Also, shout when you're guy in England can program these ABS Controllers/Modules for something like semis/R comp or slightly stickier compound like Cup2s.

 

[Jeffman]

As you increase power you’ll increase heat, hence cooling need. Right now you suggest you need more cooling which is why you need a larger radiator. Shouldn’t you limit your power and just get the larger radiator and be happy?

 

[Asbjorn]

As you increase power you’ll increase heat, hence cooling need. Right now you suggest you need more cooling which is why you need a larger radiator. Shouldn’t you limit your power and just get the larger radiator and be happy?

My car has simiar power as an M4... so I am not ready to give up yet.

I will get the larger radiator first. Test. Share. Evaluate. Then take the next step. We all drive differently on track. I only do time attack, so I might be fine alternating between hot and cool laps, or at least resort to this method when the weather is hotter. If my demand changes as I become more experienced, I may indeed just have to lower the power. Others may want to run continuous hot laps with even more power, so they can use my data as a wake up call. It is a challenge that must be taken seriously.

Don't get me wrong, as the car is now, I could do continuous hot laps in 20C or below ambient. It is not like I get limp mode or system protection / AC reduction at all. It is just not a good idea according to some, incl Barry obviously.

 

[barry@3DM]

Here's another data point for the collection. This time from Zhejiang Circuit

View attachment 25062

Conditions today
22C/72F indicated in cluster on track;
21C/70F indicated by weather app;

Average speed on fastest lap was 100kph, and the track is basically one very long WOT section followed by one long zig-zag section with very limited WOT and time to cool down. More info here.

Car setup
DSC = off;
MHD stock cooling;
AC = off, heater/blower = on, low;
Semi-dry oil sump system = on;
DCT oil cooler = on;
Roof = down;

Mods on car relevant to this test
No changes since last time

Results

I did one log during the first practice session. First few laps were with safety car. Then I did four laps with gradually increasing speed. There was alot of traffic though.

datazap.me | Asbjoern | Zhejiang Time Attack Temp logging

datazap.me

Peak coolant: 106.5C / 224F
Peak engine oil: 136C / 277F
Peak iat: 77.5C / 172F (100F over ambient, fyi @MDORPHN )

Conclusion

Coolant still peaks too high, but average was better on this circuit. Peak IAT was very high here.

I have ordered a 40-50% larger radiator to replace my current additional radiator. Also need the HD version of my 7in FMIC, but that is just power related... not important hahaha

I should have the new radiator installed and ready for testing in a good one months time.


View attachment 25063

Nice pics, looks like fun!!

I'm going to suggest getting a data acquisition system. This will help you make decisions when changing up components. You have your secondary radiator in front of the main radiator correct? You are greatly reducing the cooling capability of the main radiator by blowing hot air across it from the secondary radiator in front. Also, you are slowing the air going through the main radiator which doesn't help.

Lets rewind and go back in time... lets say you had data on both the inlet and outlet of the main radiator, you would have a benchmark. Next you put a secondary radiator in front. While you are installing that radiator you stick a temp sensor on the inlet and outlet of that plus a temp sensor between radiators to see what the air temp is coming out of the secondary radiator and into the main radiator. Now, during the next test session you could see what EACH radiator was doing. What if the main radiator is now cooling less? What if the secondary radiator is barely doing anything?

My point is that trying new things is awesome. But what is the cost of each of those new things and the labor to install them? (btw... That is a rhetorical question, none of my business what they are) Having data to make decisions is essentially priceless and the cost of the data system can WAY MORE than pay for itself over trying new parts out of theory. Just a suggestion.

Not to mention the other aspects of a system like track maps, warning lights, comparing to other drivers, list goes on.

 

[barry@3DM]

All, I asked that some cooling discussions from another thread be added to this thread. Please feel free to discuss intercooler discussions in this thread as well. I think this thread is now essentially all things cooling for the N54 for track use. Water cooling, IAT cooling, Oil cooling, etc...

 

[Asbjorn]

Nice pics, looks like fun!!

I'm going to suggest getting a data acquisition system. This will help you make decisions when changing up components. You have your secondary radiator in front of the main radiator correct? You are greatly reducing the cooling capability of the main radiator by blowing hot air across it from the secondary radiator in front. Also, you are slowing the air going through the main radiator which doesn't help.

Lets rewind and go back in time... lets say you had data on both the inlet and outlet of the main radiator, you would have a benchmark. Next you put a secondary radiator in front. While you are installing that radiator you stick a temp sensor on the inlet and outlet of that plus a temp sensor between radiators to see what the air temp is coming out of the secondary radiator and into the main radiator. Now, during the next test session you could see what EACH radiator was doing. What if the main radiator is now cooling less? What if the secondary radiator is barely doing anything?

My point is that trying new things is awesome. But what is the cost of each of those new things and the labor to install them? (btw... That is a rhetorical question, none of my business what they are) Having data to make decisions is essentially priceless and the cost of the data system can WAY MORE than pay for itself over trying new parts out of theory. Just a suggestion.

Not to mention the other aspects of a system like track maps, warning lights, comparing to other drivers, list goes on.

This is a great suggestion indeed.

I just want to add that the AC still works, which means the condensor unit does not get too hot air from the additional radiator in front. But I can definitely hear the fan working harder than before in stop and go traffic, so it is hotter out there than before (ie If I turn off the AC the fan stops). Now I should also add that in front of all this I also have the DCT cooler. Come to think of it, since I have no transmission temp problems, maybe I should get a smaller dct cooler and move it away. It is huge and sits right in the prime location behind the kidneys.

Anyway I know what your response to this is: Get data acquisition.

 

[MDORPHN]

BTW, I verified yesterday that the temp readings I posted earlier in this thread were with MHD coolant set at max track mode.

Neil

 

[barry@3DM]

Agreed, it should. What'd you end up doing on the E46 to resolve turbulence in the lower portion. I mean, isn't that a result of the car ingesting air and it not able to pass through the top section of the core where it ends up bouncing around and causing turbulence on the bottom section of kidney grille?

Also, shout when you're guy in England can program these ABS Controllers/Modules for something like semis/R comp or slightly stickier compound like Cup2s.

Hood vents were installed to help air flow through radiator. (This was a full blown racecar. I personally would not do this to a street car but that is just me.) Have not done more video yet, as the vents were a winter project. If there was ducting that started at the bottom of the kidney grill and curved down that would help remove the dead space causing turbulence. So the string thing was an exercise to show that. Any air opening should have ducting right up to the heat exchanger to help with air flow.

 

[doublespaces]

Hood vents are definitely something I'll be getting with my carbon hood.

 

[NoQuarter]

F'n losers in this thread. Be like me....

 

[MDORPHN]

I already have two small vents, but something like this would hit the sweet spot for me:

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Neil