Tested and Ready 70° and 75° Thermostat

[oceansize]

I'm in. Will send PM. I'm due a cooling system refresh so now is the perfect time.

[Anri]

To take full advantages from the 70C Sachs Fan clutch is a Must !!!

I can supply that as well. Let me know if you need that.

Regards,
Anri

[maupineda]

Sent with my choice

[Anri]

I will give a week of waiting to see if more people will join
and will ship at ones.

Thanks
Anri

[Pklauser]

Very interesting. What are the downsides for a dual-duty car? Additional wear on the street in some form from running colder?

I still have AC and my car definitely gets toasty on track despite having an all new OE cooling system. Can't remember numbers, but the gauge gets up against the red if I'm pushing in 90+ ambient temps depending on the track, though the manual says that's expected.

[Anri]

Additional wear on the street in some form from running colder?

This is not truth. No additional wear and I can prove
this scientifically but to convince single individual I have no desire
to spent time typing a long post.

I was thinking very hard if it was a good idea to share this
on public place but rather with close friends only.

I am more than happy to see more head gasket failures
coming to my shop between 5-6cyl...LOL

Regards,
Anri

[Pklauser]

This is not truth. No additional wear and I can prove
this scientifically but to convince single individual I have no desire
to spent time typing a long post.

I was thinking very hard if it was a good idea to share this
on public place but rather with close friends only.

I am more than happy to see more head gasket failures
coming to my shop between 5-6cyl...LOL

Regards,
Anri

My understanding is that you're selling this as a product, correct? It seems worthwhile to explain the efficacy of a product that allegedly improves on thousands of hours of BMW R&D. How come they didn't chose 70C? Were they wrong?

I know you run a prestigious shop, and I appreciate your contributions to the forum, but I usually approach deviations from stock like this with caution. If you can't, or won't explain why myself and others shouldn't be concerned about potential downsides, then how are we supposed to read this as more than snake oil?

[Anri]

Hi Pklasuer,

If you can't, or won't explain why myself and others shouldn't be concerned about potential downsides, then how are we supposed to read this as more than snake oil?

Without a doubt you are correct with your statement and
my apology.

I made a mistake, I should have said that its easier for
me to explain over the phone rather than typing. From
there rather you agree or disagree and take your gut choice.
I get calls periodically from E46M3 people for suggestions
and if I were to reply via typing I will be sitting on the computer
most of the day.

I suggest you to read the first 3 pages for 10min out of your time
and then call me I will sent you PM with my phone, its so much
to say about this which I did via previous replies.

My understanding is that you're selling this as a product, correct

And yes and no. I initially put this custom part together when
I rebuilt S54s as part of the entire package I do offer. But more
than happy to offer this to people.

PM sent.

Regards,
Anri

[EthanolTurbo]

I am more than happy to see more head gasket failures
coming to my shop between 5-6cyl...LOL

Regards,
Anri

This is exactly where mine failed LOL 😂

[0-60motorsports]

Anri I sent you a message on instagram. I need a 75c Tstat ASAP as temps have started to go up here in Bahrain and even at nights its like 90-110F!

In the mornings air temps are 125F around 10am onwards but road plus air temps might be around 135-140F. high humidity on most days too.

[bigjae46]

Very interesting. What are the downsides for a dual-duty car? Additional wear on the street in some form from running colder?

I still have AC and my car definitely gets toasty on track despite having an all new OE cooling system. Can't remember numbers, but the gauge gets up against the red if I'm pushing in 90+ ambient temps depending on the track, though the manual says that's expected.

The only downside is your fuel economy will drop and the O2s might not last as long because it will run richer. Might also throw codes in some cases - like on cold days.

[Anri]

Might also throw codes in some cases - like on cold days.

Jae,

I specifically underlined that the Check
engine light will NOT turn on.

I just put 900 miles on the test car and out
of those 400 miles were on a 60F morning starts.

On 55C the check engine light will turn on..
one can turn it off from the ECU menu but
its cold for daily.

I have to ask Tomba and I hope he can
share some data at 70C if the OEM map is out
of Enrichment mode?


Regards,
Anri

[Tomba]

I have to ask Tomba and I hope he can
share some data at 70C if the OEM map is out
of Enrichment mode?

Hi Anri I have to dig in to this, for sure the ECU checks if the normal operating temperature is reached in xx time. I would expect that parameter to be adjustable to prevent the error code from triggering or just disable it.

I suspect that lambda regulation kicks in after xx seconds of operation or once the front lambda probes exceed a certain voltage threshold. If started in -40°C environment it doesn’t take up to 70-80°C Coolant to enable lambda control. Enrichment tables are meant to add fuel during cold coolant temperatures to still target lambda 1. Currently only for short periods or really low temperatures a richer mixture is allowed. For an equal operating condition more fuel has to be injected on a cold engine as on a hot engine and the lambda value would still be equal once measured in the exhaust. From an OEM perspective you don’t want the lambda controller to adjust this, it has to be on target from the base.

In some engines the engine block and cylinderhead runs different temperatures by using double thermostats. On (current) BMW engines the (electric thermostat) temperature is controlled by load conditions (85 – 113°C). Full load will trigger to lowest to get maximum power from the engine. The highest are used in part load, ditching more heat will have less efficiency, the higher the better in terms of efficiency. New (BMW) engines have ditched the electric water pump and brought back the mechanical driven pump back. Engine developers used the mechanical driven pump for a reason, when increasing engine speed more horsepower is created (or better kiloWatts) and more heat loss. Once the pump rotates higher the massflow of medium is also higher (Q = massflow (m) * constant (Cp) * delta T(dt) ). Perfect as it is equal to power (Power = Torque * 2*Pi* engine speed in Hz).

On the test engines I have from OEM the coolant outlet temperature from the engine is controlled by the ECU. The coolant inlet temperature towards the engine needs to be controlled to ~70°C all time. I personally think that here the debate starts on the thermostats. If for some reason the radiator outlet / motor inlet temperature becomes too high the results is higher coolant temperatures than the thermostat is specified. From the M52 engine or maybe earlier BMW engines had a radiator outlet/motor inlet temperature sensor to control the auxiliary fan. Might not be present on S54 (I am not sure). It would be helpful to monitor this temperature in case the engine performs on higher temperatures than specified.

When fitting a lower opening thermostat I would suggest the complete delta of temperature is dropped and as a results prevents it from running on high temperatures. I would personally look for a root cause as I would suggest the radiator heat exchange might dropped by contamination (or blocked condenser) and or the water pump lost efficiency. There are probably more parameters to take care off.

I don’t know for people that currently experience issues if the environmental temperature has increased over time? As it is +25 years back the S54 was developed it might cause issues. Once no other options are possible to drop temperatures (increased waterpump flow, increased heat exchange from radiator, fans, etc) I would expect Anri’s thermostat to work as a (low cost) solution.

I believe on the S38 /E34 M5, different waterpump pulleys (smaller diameter to get more flow) were used in hot climate version. Also 1^st and 2^nd stage aux fan thermoswitch sensors were used to cool the engine better ways. I never seen thermostat difference.

I usually come by to a customer who is racing with a lot of S54 engines powered cars, currently even has the newest GT3/4 models as well. On none of these the thermostat opening temperature is changed, and no issues there. But our European temperatures might be relevant.

[Anri]

Hi Anri I have to dig in to this, for sure the ECU checks if the normal operating temperature is reached in xx time.

Tom,

The 900miles test car I had it till yesterday.
I should have called you yesterday and have
you log in and get the data...I will be around
the car on Weekend if you are around?

Knowing how sensitive the ECU is on S54
after 900miles I don't have check engine light
and also not even passive code.

Edit: I will have ChapterM3 car for 70C t stat
upgrade and I will have you log in collect the data
from the 80C. After like an hour I will have the 70C
installed and I will have you log in again and get the
data. Meanwhile if you can dig those maps it will
be great.

Regards,
Anri

[Anri]

Anri I need a 75c Tstat ASAP as temps have started to go up here in Bahrain and even at nights its like 90-110F!

Hi,

My suggestion is in such hot environment getting 75C is
waist of time. If its my choice I would go with 70C for sure.

I will sent you PM back.

Thanks,
Anri