Best aftermarket oil thermostat solution for N54?

Jeffman

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Jan 7, 2017
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This is again why I suggest focusing on adding aux radiators rather than oil stuff.
I’ve been saying this for years, starting over at Bimmmerboost. I’m not a psychologist, and I’m probably wrong here, but I suspect we all initially got brain-washed to believe that our oil temp is much more important to monitor and control than coolant temp, all because we have an oil temp gauge on our dash and not a coolant temp gauge!
 
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houtan

Lieutenant
Nov 2, 2017
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I can see a problem with 200F oil as moist isn't burned off over time?
I don't see the problem with 230-260F oil. This is oil temp measured in the oil sump remember. I mean sure, a thermostat that fully opens from 220F-230F would be better, but why 185F?
I do see a problem with coolant exceeding 212F when the DME is trying to target 176F though... This is again why I suggest focusing on adding aux radiators rather than oil stuff.

Here's a log from last weekend. Did a 20min session on a semi-wet track in 85F humid heat. I was a bit annoyed coolant got so hot (223F) considering I was barely pushing. The DME was clearly trying to target 176F, as was finally achieved at the end of the cool down lap. Oil temps on the other hand were low enough (max 270F or so) that I didn't even care to turn on the second oil cooler on my car. WI and external water spray was both turned off. AC was also on, which never helps coolant. As most of you know I run two large aux radiators, one on the side, one behind fmic.

Very cool to see the data. Do you think turning on your second oil cooler would have helped with your coolant temp? Meaning, maybe the coolant was having a hard time dealing with the heat from the rising oil temp?
 

gmagnus7

Corporal
Dec 3, 2018
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I can see a problem with 200F oil as moist isn't burned off over time?
I don't see the problem with 230-260F oil. This is oil temp measured in the oil sump remember. I mean sure, a thermostat that fully opens from 220F-230F would be better, but why 185F?
I do see a problem with coolant exceeding 212F when the DME is trying to target 176F though... This is again why I suggest focusing on adding aux radiators rather than oil stuff.
True, coolant temperature is critical and aux radiators definitely help. I think that improving airflow through the engine bay would also help the radiator do it's job - via hood vents or vented underbody panels. What doesn't help is those stupid intake scoops that block the rad opening loooool.

For the oil temp, I think anywhere between 90-110 is perfectly acceptable. That's not considered low on other platforms. For myself, I'd like to keep it under 110-115 MAX if possible. I don't like not knowing what viscosity the oil is operating at, and oil manufacturers only test/release information up to 100C so anything above that is a variable. Maybe it doesn't change much, but I don't know that.

As far as I understand it (maybe I'm wrong), the water vapor / contaminants don't simply vanish once it hits 100C. Yes that's the boiling point of water but
A) the water doesn't "boil" like it would in a pot, there's no singular pool of water anywhere in the engine bay
B) it's mixed with lots of other fluids and oil (obviosuly) and is only a tiny fraction of the overall fluid composition
C) the water and contaminants (like fuel) will evaporate over time when heated, and that starts much lower than waters boiling point. it doesn't just magically disappear out of suspension at 100C

Also I think oil wt plays a part here too. If you regularly have high oil temps, maybe it's a good idea to keep a higher wt oil. If you have a good cooling system that keeps temperatures under control, a thinner wt can likely do the job. But oil wt on this platform is a hot (and fun) topic lol, but that's a different discussion.
 
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martymil

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Sep 6, 2017
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I've been saying for years that running your oil hot is better than low, just change it more frequently especially when running e85

But the factory thermostat is really for sub zero cold climates, being in an extreme hot climate most of the year and having a slightly lower thermostat like 220f would be perfect but an adjustable one would be better to set your desired temp as I mention earlier.
 

Asbjorn

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Mar 10, 2018
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Very cool to see the data. Do you think turning on your second oil cooler would have helped with your coolant temp? Meaning, maybe the coolant was having a hard time dealing with the heat from the rising oil temp?

I believe they dont transfer much in the real world, and that the impact would be low/slow. That being said, experience does say that running mhd track mode lowers the oil temperature. This means that lower coolant temps will transfer to the oil temp and vice versa. However, previously when I was running larger oil coolers and smaller radiator the coolant temp would go much much higher (as in limp mode high) at the same type of oil temps (130C).

I will turn off the AC and use the water spray and see what kind of temps I reach this weekend.
 
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rev210

Corporal
Feb 24, 2019
235
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335i - 08 Coupe .
I run the external improved racing one with STETT stage 2 oil cooler. Works great. Gets up to temp pretty close to stock .The thermostat design is quite niffty . I'm using the 185f one that STETT include in their kits. Which based on local temps in Perth is spot on. There are a few options for them in temp range.

Can use them for transmissions as well.

 
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houtan

Lieutenant
Nov 2, 2017
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135i N55 DCT; PS2
I run the external improved racing one with STETT stage 2 oil cooler. Works great. Gets up to temp pretty close to stock .The thermostat design is quite niffty . I'm using the 185f one that STETT include in their kits. Which based on local temps in Perth is spot on. There are a few options for them in temp range.

Can use them for transmissions as well.

How many miles do you have on the Stett?The only thing I saw missing from that kit is some sort of vibration dampening. I also heard of fitment issues once you try to put the bumpers back on. Did you have any issues?
 

rev210

Corporal
Feb 24, 2019
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335i - 08 Coupe .
Been on the car for 5yrs.
I'm running a prior design widebody kit.
My experience with oil cooler kits on a variety of platforms is that you end up doing little basic fitment mods . Oil line length is often a gotcha. In the past Ive bought the thermostat fittings and cooler etc and got my own lines done to perfect length.
 

F87Source

Sergeant
Oct 14, 2019
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if this hasn't been brought up before, improved racing is the best highest flowing aftermarket thermostat which is great because other kits may be too restrictive which is not ideal for cooling under hard driving conditions like racing.
 
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rev210

Corporal
Feb 24, 2019
235
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335i - 08 Coupe .
Improved racing design is better than earls and the others based on the thermostat placement (less pressure drop) and it allows a small amount of the oil to circulate through the cooler and pipes to ensure no air pockets and a more even temp ramp up. Even though thermostats do gradually open , the initial cracking temp I would observe in the past would see the oil temp drop again as the relatively cool oil is flushed into the motor. Doesnt happen with the improved racing one. The oil temps at full flow are very stable too.
 

gmx

Specialist
Dec 8, 2017
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In case of someone interested we also have a stock oil thermostat delete plate in stock. More info in our instagram: _gperformance.
By the way now we designing an upgraded oil thermostat for N54/N55/S55. What t do you want it to be full open?
View attachment 39142View attachment 39141

Make a housing that fits a popular make/model element. That way, people can choose rather than argue what's right
 

F87Source

Sergeant
Oct 14, 2019
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2017 Bmw M2
In case of someone interested we also have a stock oil thermostat delete plate in stock. More info in our instagram: _gperformance.
By the way now we designing an upgraded oil thermostat for N54/N55/S55. What t do you want it to be full open?
View attachment 39142View attachment 39141
Is it possible for you to make an oil filter housing delete plate to completely delete the oil filter housing? This way we can run larger can style oil filters, have the coolant and oil be further separated to help isolate temperature differences and thus have better temps, and avoid OFHG failures. This is what I mean and what TYSPEED did on his fully track build m2 racecar.

 

F87Source

Sergeant
Oct 14, 2019
332
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2017 Bmw M2
In case of someone interested we also have a stock oil thermostat delete plate in stock. More info in our instagram: _gperformance.
By the way now we designing an upgraded oil thermostat for N54/N55/S55. What t do you want it to be full open?
View attachment 39142View attachment 39141
I also forgot to ask can this plate have integrated groves or chamfers per say allowing for the use of ORB AN fittings instead of having to use a thread sealer?
 

Asbjorn

Lieutenant
Mar 10, 2018
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Is it possible for you to make an oil filter housing delete plate to completely delete the oil filter housing? This way we can run larger can style oil filters, have the coolant and oil be further separated to help isolate temperature differences and thus have better temps, and avoid OFHG failures. This is what I mean and what TYSPEED did on his fully track build m2 racecar.


When TYSPEED talks about separating temps I believe he is referring to the removal of the oil to water heat exchanger (and associated booster pump) on the n55 m2.

Btw which improved racing thermostat did you refer to exactly? There are alot to choose from on their website.

Also here's a log from the last laps today. This time with WI and external spray turned on together with 2nd oil cooler. AC was off with heater on max. 25C/80F ambient. Lots of traffic on track but last lap was fast.

peak iat 50C / 122F
peak water 103C / 217F
peak dct 102C (because that's when the thermostat started the oil pump and activated the cooler in the middle of the log, I believe it turns off again at 85C/185F)
peak oil 128C / 262F

 

F87Source

Sergeant
Oct 14, 2019
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When TYSPEED talks about separating temps I believe he is referring to the removal of the oil to water heat exchanger (and associated booster pump) on the n55 m2.

Btw which improved racing thermostat did you refer to exactly? There are alot to choose from on their website.

Also here's a log from the last laps today. This time with WI and external spray turned on together with 2nd oil cooler. AC was off with heater on max. 25C/80F ambient. Lots of traffic on track but last lap was fast.

peak iat 50C / 122F
peak water 103C / 217F
peak dct 102C (because that's when the thermostat started the oil pump and activated the cooler in the middle of the log, I believe it turns off again at 85C/185F)
peak oil 128C / 262F

Yes the heat exchanger and the OFH because coolant and oil flows so close to one another that the thin walls of the housing allows a significant amount of heat to be transferred, so it would be a benefit to also have those separated even further with a housing delete plate. Also it will allow you to run larger more effective can style filters that offers better filtration.

Here is the improved racing thermostat I was talking about: http://www.improvedracing.com/oil-thermostats/high-flow-engine-oil-cooler-thermostat-p-212.html
This is by far the best oil thermostat on the market, nothing else comes remotely close. I learnt about these guys a few years ago while digging through the corvette forum.


Wow your IAT's are still quite hot, how much boost and power is your car making?

Water temps are good, I don't know anything about the dct, and oil temperatures are really hot almost starting limp at 132ºC. How big is your oil cooler, and if you are running two how ate you still having oil temperature issues? Especially since ambient temperatures were not that high.
 

syn909

Specialist
Jun 27, 2018
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I bought one of these hoping it would lower the opening temperature have yet to test it though:

See also:
 

F87Source

Sergeant
Oct 14, 2019
332
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2017 Bmw M2
I bought one of these hoping it would lower the opening temperature have yet to test it though:

See also:
Those after market thermostats will lower triggering temperatures but the con is that flow is not improved due to the stock housing. (FTP is a pretty solid company so no real worries from them)

So despite having a lower opening temperature eventually the cooling loop will heat up to the same temperature as before, it will just take longer because the loop opened sooner.

The benefit of having a higher flowing thermostat is that you can circulate oil quicker and that will be able to lead to better cooling performance overall.
 

syn909

Specialist
Jun 27, 2018
64
22
0
Ride
'07 335i
Those after market thermostats will lower triggering temperatures but the con is that flow is not improved due to the stock housing. (FTP is a pretty solid company so no real worries from them)

So despite having a lower opening temperature eventually the cooling loop will heat up to the same temperature as before, it will just take longer because the loop opened sooner.

The benefit of having a higher flowing thermostat is that you can circulate oil quicker and that will be able to lead to better cooling performance overall.

Yes I realize that the heat soak is real I guess down the line when I install this external oil cooler I will upgrade to an external 10an thermostat and delete the oem thermostat housing
 
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rev210

Corporal
Feb 24, 2019
235
138
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335i - 08 Coupe .
Btw which improved racing thermostat did you refer to exactly? There are alot to choose from on their website.

185f is the one I am using , works great.
If you opt for aftermarket transmission coolers like I have for the 6AT then same deal, they have a thermostat for that too.
 

F87Source

Sergeant
Oct 14, 2019
332
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185f is the one I am using , works great.
If you opt for aftermarket transmission coolers like I have for the 6AT then same deal, they have a thermostat for that too.
Does your car warm up properly with a 185ºF thermostat? Because it starts to crack open lower than that. I guess a more specific question is what temperature does your oil stay at during normal daily driving?