A/C Shut Down with Sport Cooling Mode

Jeffman

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Jan 7, 2017
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A few weeks ago in hot weather (93F) my A/C kicked off. For some reason I had a hunch it was related to selecting “Sport Cooling Mode” when flashing my MHD map. So I reflashed it with stock cooling map.
Result: the A/C works fine now.

Any know why this should be the case? Apparently I’m not the only one to have experienced A/C shutting off with “Sport Cooling” selected in MHD in 90+F weather:
I also found the AC to work really poorly in daily driving when enabling MHD sport cooling, as it would run the water pump at a higher speed, even when just cuising.
 

Asbjorn

Lieutenant
Mar 10, 2018
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European, based in China
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Z4 N54 DCT
A few weeks ago in hot weather (93F) my A/C kicked off. For some reason I had a hunch it was related to selecting “Sport Cooling Mode” when flashing my MHD map. So I reflashed it with stock cooling map.
Result: the A/C works fine now.

Any know why this should be the case? Apparently I’m not the only one to have experienced A/C shutting off with “Sport Cooling” selected in MHD in 90+F weather:

oh my case is not related to your problem if think. Remember I have a radiator in front of my condenser. When car is running hot, that radiator gets warm and blows hot air at the condenser so it stops working.

On a car with a normal radiator setup, you only loose ac if coolant temps exceed 117C as the car enters power reduction mode.

At least I have never experienced the ac kicking off. I have only experienced the max cooling kicking off when ambients where too hot.
 

Jeffman

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Jan 7, 2017
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oh my case is not related to your problem if think. Remember I have a radiator in front of my condenser. When car is running hot, that radiator gets warm and blows hot air at the condenser so it stops working.

On a car with a normal radiator setup, you only loose ac if coolant temps exceed 117C as the car enters power reduction mode.

At least I have never experienced the ac kicking off. I have only experienced the max cooling kicking off when ambients where too hot.
Thanks for your comments. I’ll double check my A/C system.
 

Rcboosted2007

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Jan 28, 2018
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Throw a set of gauges on the high side port and see if it it cutting out on high pressure safety from the change in air circulation/cooling of radiator fan speed.
 
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Rob09msport

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Oct 28, 2017
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09 335i msport le mans 18 x5
Does anyone know if race mode changes anything with ac? Im wondering if the threshold where its disabled gets lowered based on the kft cooling mode. Also Ac disables at wot correct?
 

Rob09msport

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I don't think you would see anything in the cabin but I believe the compressor clutch disengages to increase performance and possibly could be too prevent excess wear on compressor
 

typedRew

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Feb 25, 2019
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We have had several 90+ days recently with lots of city and highway driving for me. I havent had an issue with sport cooling enabled and i run the AC constantly.
 

sb335xiE92

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Feb 19, 2018
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2008 BMW 335xi E92 Sport
A few weeks ago in hot weather (93F) my A/C kicked off. For some reason I had a hunch it was related to selecting “Sport Cooling Mode” when flashing my MHD map. So I reflashed it with stock cooling map.
Result: the A/C works fine now.

Any know why this should be the case? Apparently I’m not the only one to have experienced A/C shutting off with “Sport Cooling” selected in MHD in 90+F weather:
I've run "Sport Cooling" for almost three years without issue. 335xi e92 n54. I do have a CSF street radiator.
 

sb335xiE92

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Feb 19, 2018
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While running "Sport Cooling", I hear the fan running constantly. I assumed the water pump is not part of the tune?
Am I wrong?
 

Asbjorn

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Mar 10, 2018
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While running "Sport Cooling", I hear the fan running constantly. I assumed the water pump is not part of the tune?
Am I wrong?

The water pump is definitely used to reach the lower targets as well.

I don't understand why people run sport cooling in MHD. The DME already has adaptive cooling targets from stock.
 

AzNdevil

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Nov 4, 2016
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The water pump is definitely used to reach the lower targets as well.

I don't understand why people run sport cooling in MHD. The DME already has adaptive cooling targets from stock.

lower temps = things dont wear out as fast + more overhead to compensate for a shit cooling system
at the expense of highe rfuel consumption
 
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Asbjorn

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lower temps = things dont wear out as fast + more overhead to compensate for a shit cooling system
at the expense of highe rfuel consumption

All it takes is one WOT pull to force the cooling system to enter "sport" mode. Of course it will take some time for the coolant temp to drop to 90C, but in most street scenarios there should be enough headroom. Highly doubt any of us will be able to push the coolant temperature much over 100C on the street after the DME has started to adapt. Of course the oil temp will be higher as it can't react as fast, and therefore the oil temp peaks will be higher without sport mode. But I'm not aware that things wear faster running 115C oil daily as compared to say 100C with sport cooling in MHD?

Maybe Im missing something. I just replaced my water pump, so no need to be concerned about that part wearing out anymore. Maybe I should indeed just run the sport mode now.
 

AzNdevil

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All it takes is one WOT pull to force the cooling system to enter "sport" mode. Of course it will take some time for the coolant temp to drop to 90C, but in most street scenarios there should be enough headroom. Highly doubt any of us will be able to push the coolant temperature much over 100C on the street after the DME has started to adapt. Of course the oil temp will be higher as it can't react as fast, and therefore the oil temp peaks will be higher without sport mode. But I'm not aware that things wear faster running 115C oil daily as compared to say 100C with sport cooling in MHD?

Maybe Im missing something. I just replaced my water pump, so no need to be concerned about that part wearing out anymore. Maybe I should indeed just run the sport mode now.

to be fair if you are just driving normally on the street with stock turbos it shouldnt be that much of a difference
with upgraded turbos we need all the cooling we can get...i can easily get my coolant to be 105-110C even in sports cooling mode after a few pulls during the summer

oil temps is the another concern... i cant even get 3 minutes of pulls on the street with upgraded turbos + stock radiator and stock oil cooler on normal mode without reaching 130 C+ oil temps ....i can barely get 5 minutes with sports cooling

i bought my car used, dont know the history of my waterpump but it ran in sports mode for 4 years before it died randomly so im not that concerned

i did consider to drop the thermostat opening temps as well but i cant really justify if it will do much
 
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Asbjorn

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Mar 10, 2018
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to be fair if you are just driving normally on the street with stock turbos it shouldnt be that much of a difference
with upgraded turbos we need all the cooling we can get...i can easily get my coolant to be 105-110C even in sports cooling mode after a few pulls during the summer

oil temps is the another concern... i cant even get 3 minutes of pulls on the street with upgraded turbos + stock radiator and stock oil cooler on normal mode without reaching 130 C+ oil temps ....i can barely get 5 minutes with sports cooling

i bought my car used, dont know the history of my waterpump but it ran in sports mode for 4 years before it died randomly so im not that concerned

i did consider to drop the thermostat opening temps as well but i cant really justify if it will do much

Great data! It all makes sense now.

Im really surprised you can hit 110C coolant on the street. High oil temps sure, but high coolant surprises me. At least where I live it is really hard to imagine using WOT for more than a few seconds at a time on the street.

I recommend installing a large aux radiator if you are blessed with roads like that. It is proven to work.
 

sb335xiE92

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Feb 19, 2018
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The water pump is definitely used to reach the lower targets as well.

I don't understand why people run sport cooling in MHD. The DME already has adaptive cooling targets from stock.

" I don't understand why people run sport cooling in MHD. The DME already has adaptive cooling targets from stock. "

I run Sport Cooling in MHD, a BMS oil thermostat delete and a CSF street radiator all in the effort to reduce operating temperature. With MHD, my oil temperature stays around 200-215. in 95F ambient.
 
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Asbjorn

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Mar 10, 2018
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" I don't understand why people run sport cooling in MHD. The DME already has adaptive cooling targets from stock. "

I run Sport Cooling in MHD, a BMS oil thermostat delete and a CSF street radiator all in the effort to reduce operating temperature. With MHD, my oil temperature stays around 200-215. in 95F ambient.

Pretty sure that even stock cooling targets lower the setpoints when approaching 95F ambient, giving you the same lowered oil temps. I actually raised these setpoints in my map, because I live in a hot climate, and didn't want the lowered coolant and oil temps in daily driving. I don't really need the headroom on the street, and on the track it will enter sport mode adaptively during the warm up lap before I really push anyhow. Again that was before I replaced the coolant pump. Now I guess it doesn't matter.

Btw even with the stock oil thermostat, the oil temperature will be lower when the dme enters that mode, but it takes time to decrease. I ran the same thermostat insert for a year or so and went back to stock. There are really no benefits to having it, only downsides (oil runs too cold in winther).

From a cooling point of view, the CSF radiator is also not an upgrade and just a waste of money in my experience. But I have said this a hundred times and it will still sell like crazy. If you want any meaningful increase in cooling capacity, what you need is a large auxillary radiator. The reason for this is that the gains you get from increasing radiator thickness are minimal (I tested all the way up to 8cm thickness), and the stock unit is already very thick. What you need is more frontal area instead. My build has proven this. The 1M and S55 both confirm this direction. Even F1 cars run angled coolers to increase frontal area rather than thickness. There's an engineering explained video about that.
 

AzNdevil

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Nov 4, 2016
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Great data! It all makes sense now.

Im really surprised you can hit 110C coolant on the street. High oil temps sure, but high coolant surprises me. At least where I live it is really hard to imagine using WOT for more than a few seconds at a time on the street.

I recommend installing a large aux radiator if you are blessed with roads like that. It is proven to work.

in case you havent noticed... im from hong kong so our climate is pretty much similar for the hot and humid part
highways in china are a lot longer and wider as well... we don't have that here so im sure if you put your foot down you can do the same ;)
some of my friends have blown up their engines while driving from hong kong to guangdong international circuit (4 hourish drive for us)

anyways i rarely drive fast these days except for datalogging so i can barely get by...

speaking of china...these picture came up to my mind
1390253100.jpg


20140803_PN_NAPKIN_02.jpg


Btw even with the stock oil thermostat, the oil temperature will be lower when the dme enters that mode, but it takes time to decrease. I ran the same thermostat insert for a year or so and went back to stock. There are really no benefits to having it, only downsides (oil runs too cold in winther).

From a cooling point of view, the CSF radiator is also not an upgrade and just a waste of money in my experience. But I have said this a hundred times and it will still sell like crazy. If you want any meaningful increase in cooling capacity, what you need is a large auxillary radiator. The reason for this is that the gains you get from increasing radiator thickness are minimal (I tested all the way up to 8cm thickness), and the stock unit is already very thick. What you need is more frontal area instead. My build has proven this. The 1M and S55 both confirm this direction. Even F1 cars run angled coolers to increase frontal area rather than thickness. There's an engineering explained video about that.

its the same case with the oil thermostat bypass imo, its another workaround to buy some headroom before our cars' weak cooling system give up

the csf radiator does get rid of the plastic hose outlets so its sort of worth it...the added thickness does somewhat add to coolant capacity so its another way to get headroom (more coolant takes longer to heat up but longer to shred heat)

when you add headroom to all the components in the system, it does give you some more time before your car overheats...
but its still not enough for a ~30 minute time attack session on full blast (even with stock turbos)

angled coolers (v mount) do work but its not easy to get the angles right without analysis, lots of rx7 switched over to using kits from japan to accomplish this but it doesnt make too much of a difference from what i can see

without data, proper ducting like what you have done on your car has the best chance of working
 
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