What water temp should an SR run at?

[cobras89]

i have an sr and i was wondering what temp the motor should run at. after a good hour of driving my car is warmed up to about 200 F is that too hot? my fans kick on just when the needle reads over 200 F and brings it down to about 180F

[Sileighty_85]

yeah thats way too hot, OEM thermo opens at 170* temp should be a little above that

[D.Adams]

i have mine runing at 180 - 185

[Csomme]

180-185 is perfect. ^

[slider2828]

Performance Thermostats open at 67, but 67-68C is the norm... Mine runs cool at 63-64C.... In traffic or at speeds....

you do the conversions... but this is a track car....

[cobras89]

alright so i am running no thermostat as of now. what thermostat should i use? nismo? or just a stock sentra se-r?

[slider2828]

Nismo or bullion... hwatever, just don't run stock

[cobras89]

alright thanks guys ill most likely order a nismo one before summer starts

[jspaeth]

Performance Thermostats open at 67, but 67-68C is the norm... Mine runs cool at 63-64C.... In traffic or at speeds....

you do the conversions... but this is a track car....

Your car runs abnormally cool, since you have it set up to withstand intense tracking.

For regular driving, temps should be around 80-85C (176-185F), which makes sense, since the SR comes equipped with a 76.5C thermostat from the factory

[bl3ujay07]

like slider88, mines ran at 65-67* C via power fc normal driving. If i do freeway driving then it gets up to around 80-85*c. Could be because i had a nismo thermostat and because i had my electric fan running after it gets up to 60*C.

[jspaeth]

like slider88, mines ran at 65-67* C via power fc normal driving. If i do freeway driving then it gets up to around 80-85*c. Could be because i had a nismo thermostat and because i had my electric fan running after it gets up to 60*C.

Nismo thermostat and low fan setting like that WILL do it. Why do you want your car to run SO cool?

Isn't there a proper coolant temperature for safe/proper operation?

FYI, when the steady-state coolant temp goes down by 20*C (i.e. 80--->60*C), that does NOT mean that the temperature of the metals in the head and block only go down by 20*C.


In all likelihood, they are going down by WAY more than that, due to how the heat transfer works.....


Honestly, I think it would probably be best to try to keep your coolant temps really close to what the OEM specs are.....

60*C is really damn cool.

[slider2828]

Yeah nothing really I can do about that cause I run a clutch fan and straight distilled water with water wetter and a 19 row oil cooler... but its track setup... I think 180 IS the magic number as Jspaeth said from what I heard from a friend who took a mechanics course.... I think the nismo opens at 67.5 or something right?

Just got a megan swirl pot and that POS leaks... damn it I hate their stuff but they had both fittings included in the kit.... DAMN ITTT......

[jspaeth]

Hahahah ohhhhh Megan

[slider2828]

Hahahah ohhhhh Megan

Seriously I mean they had both water fittings for 1/8" NPT which is all US adapaters and also the M8 for the bleeder! Both Fittings, but when I put my nismo cap on their swirl pot, that POS leaks... Either I gotta cut a rubber seal to seal it better or get another one.... :duh:

[s15specR]

Not trying to thread jack, but what temp. should a thermostat be set at for you electric fans to turn on at ?

[chituntang]

Not trying to thread jack, but what temp. should a thermostat be set at for you electric fans to turn on at ?

No. E fans should kick on and try their best to keep the water temp at around 180.

[jspaeth]

No. E fans should kick on and try their best to keep the water temp at around 180.


What do you mean by "no"?

To answer his question, this is a matter of preference. If you DO have explicit control (i.e some sort of a digital setup or setup where you have a dial or knob you can use to adjust it), just play with it so that they come on when your temps get right above your target temp.

So if you don't want to see temperatures go above 80C, set it so that the fans come on right at 79-80C.

[s15specR]

What do you mean by "no"?

To answer his question, this is a matter of preference. If you DO have explicit control (i.e some sort of a digital setup or setup where you have a dial or knob you can use to adjust it), just play with it so that they come on when your temps get right above your target temp.

So if you don't want to see temperatures go above 80C, set it so that the fans come on right at 79-80C.


I notice that the ECU turn the electric OE fan on at 90C (Through data logging my ECU), so I set my adjustable thermo at 90C as well, I guess that may be a little to high, should I drop it to 80C ?

The adj thermo has a probe in the rad, the ecu is of the intake manifold, if that makes a dif.

[jspaeth]

Yeah it may be a little different. I would adjust it for them to come on earlier.

Granted 90*C is still safe, but kinda hot....

[slider2828]

Well you have to remember, that at certain temps its already hot enough where it gets very difficult to expel after a certain point.... I'd say 80C is a good area to have fans full blast.....

[s15specR]

Great thanks, also I have the Derale Cooling Products 16759 - Derale Cooling Products Deluxe Adjustable Fan Controllers with Radiator Probes - Overview - SummitRacing.com (http://www.summitracing.com/parts/DER-16759/) and the Defi Water temp guage telling the temps, any suggestions for a better fan controller ?

What are you guys using ?

[slider2828]

I had a friend use the unit from flexilite....

I dunno all the same in my opinion....

Flex-A-LIte Dual Electric Fan : S-Blade *NEW* (http://www.phase2motortrend.com/fl210elfan.html)

[lazysk8er2]

what happens if you have an Electric fan constantly running

[slider2828]

E Fans run at two different speeds. Hi Lo and Off if you say that is a speed... Constantly running your car will fail to warm up and your car is always at high idle because water temps tell your ecu that the car is warm. Failing to run coolant at proper temps will lead to engine efficiency issues and possibly problems down the road if oil temp vs water temp is too far apart.....

[chituntang]

What do you mean by "no"?

To answer his question, this is a matter of preference. If you DO have explicit control (i.e some sort of a digital setup or setup where you have a dial or knob you can use to adjust it), just play with it so that they come on when your temps get right above your target temp.

So if you don't want to see temperatures go above 80C, set it so that the fans come on right at 79-80C.

This is not really a matter of preference when you do not control when your engine runs at close loop.

Sure, you can run a Nismo thermostat and have the e-fans turn on at a really low temperature, but when some idiot this setup for his/her daily driven car, he/she will think it is cool to have his/her car's water temperature running at the temperature the thermostat opens because this idiot does not know jack about cars. What he/she is doing is just kept the engine running at open loop at all times.

The thermostat opens when your engine is running arounding the right temperature, not when it is overheating. Lowering your water temperature using e-fans right after your thermostat opens will only bring your engine back to open loop.

So no, you do not set your e-fans to come on when the thermostat opens.

Unless you run a EMS where you can control your car to run in close loop at a lower water temperature, it is useless, harmful, and a waste of money to run a Nismo thermostat, because running your car in open loop for a long time means you are wasting gas, and if your engine runs rich enough, you will destroy it.

[jspaeth]

When you say "open-loop" are you referring to feedback from the O2 sensor or in terms of fuel trimming against coolant temps?

[chituntang]

There are more than one way how the ecu determines the way a engine runs, not just air fuel ratio. And your fuel input is not only affected by the o2 sensor. If that is the case, the ecu will only have wiring going to the injectors and o2 sensor.

I am talking how the ecu determines when it runs in open/close loop mode, i.e. when coolant temperature reaches this temperature, among with other conditions, it will run in close loop mode. I am not talking about in this temperature, the fuel timing will increase/decrease by that amount.

[jspaeth]

Your answer was meaningless.

I asked you "what do you mean by open/closed loop" and you gave no answer.


Open loop means that it will do whatever it wants to, closed loop means it will use some "output" information (like water temp, a/f ratio, knock sensor reading, etc.) to change the inputs.

So what are you talking about then.....

[godsmack]

This is not really a matter of preference when you do not control when your engine runs at close loop.

Sure, you can run a Nismo thermostat and have the e-fans turn on at a really low temperature, but when some idiot this setup for his/her daily driven car, he/she will think it is cool to have his/her car's water temperature running at the temperature the thermostat opens because this idiot does not know jack about cars. What he/she is doing is just kept the engine running at open loop at all times.

The thermostat opens when your engine is running arounding the right temperature, not when it is overheating. Lowering your water temperature using e-fans right after your thermostat opens will only bring your engine back to open loop.

So no, you do not set your e-fans to come on when the thermostat opens.

Unless you run a EMS where you can control your car to run in close loop at a lower water temperature, it is useless, harmful, and a waste of money to run a Nismo thermostat, because running your car in open loop for a long time means you are wasting gas, and if your engine runs rich enough, you will destroy it.

so then what u r saying is that me having a nismo t-stat is a waste of money. you sir need a little more rocket science information. if you put a nismo t-stat in this means that the water transfers over at a colder temp.

keeping the temps from running up to overheating. the only things that fans are supposed to be used for are while sitting in traffic not getting any airflow through the radiator. other than that ur coolant is what keeps the the motor cool and having a nismo t-stat lets ur engine run alittle cooler and keeps ur ecu from pulling overheating codes or what ever ur saying.

and on another note the efans don't cool the motor they cool the coolant in the radiator. sure a real little bit cools the motor but it doesn't really do much at all. so if they kick on right around when the t-stat opens that means they start to cool the water that just circulated out of the motor.

[godsmack]

and if the ecu would do anything when it comes to adding or subtracting fuel at a colder temp. it would run less fuel since less fuel means hotter burn.

[jspaeth]

and if the ecu would do anything when it comes to adding or subtracting fuel at a colder temp. it would run less fuel since less fuel means hotter burn.


What you said in you FIRST post was correct, but this ^ is actually wrong.

The ECU runs richer at colder temps because the fuel does not atomize as well.....hence, it requires more TOTAL fuel per injection to get the desired amount of vaporized fuel.

[godsmack]

What you said in you FIRST post was correct, but this ^ is actually wrong.

The ECU runs richer at colder temps because the fuel does not atomize as well.....hence, it requires more TOTAL fuel per injection to get the desired amount of vaporized fuel.

oops got caught up in brain fart.

[chituntang]

Your answer was meaningless.

I asked you "what do you mean by open/closed loop" and you gave no answer.


Open loop means that it will do whatever it wants to, closed loop means it will use some "output" information (like water temp, a/f ratio, knock sensor reading, etc.) to change the inputs.

So what are you talking about then.....

Oh, shit. I don't mean to say open/close loop. And I doubt any S-chassis ecu has fail safe mode, so I am completely wrong on this part. What I really want to say is if the engine is not running in the right temperature (not just overheat, but underheat too. i.e. Engine oil needs to reach a certain temperature before it actually works like it supposes to), over time, it will do you damage, and you will use more gas money. Now, I have been told to run my SR at around 180F by experts and I trust them and that's what I did.

so then what u r saying is that me having a nismo t-stat is a waste of money. you sir need a little more rocket science information. if you put a nismo t-stat in this means that the water transfers over at a colder temp.

keeping the temps from running up to overheating. the only things that fans are supposed to be used for are while sitting in traffic not getting any airflow through the radiator.

What the hell are you talking about?

1. Nismo t-stat brings cooler coolant into the engine when it first opens, then it will heat up by the engine, then goes back to the radiator to be cooled again. Overtime, the coolant going back to the engine will be higher than 62C.
2. So why the f**k you need a fan in the first place? A fan's function is to create airflow, not blocking it. Remember that 240sx comes with clutch fan in stock form? If fans are designed to block airflow to heat up the coolant, there would never be car runs off of clutch fan.

Engine uses t-stat to warm up, as it blocks (more like decrease the rate) coolant from going into the engine. And e-fan is used when the coolant reaches the target temperature and there is no/not enough airflow going through the radiator to cool it off. Now when your car is running, assuming you have the right ducting for your radiator, if your car runs around 45 mph, the airflow created will be good enough to cool the coolant in the radiator (less heat from your engine anyways because it is not working as hard). At speed like 65mph, the e-fan will create less airflow than the airflow form the car moving.


other than that ur coolant is what keeps the the motor cool and having a nismo t-stat lets ur engine run alittle cooler and keeps ur ecu from pulling overheating codes or what ever ur saying.

Coolant is not what cools the engine (well I know it does). It is a heat transfer agent. The radiator is what cools the heat from the engine. Do you know the basic of water cooling? If coolant is that great, we will not need radiator to cool the coolant.

and on another note the efans don't cool the motor they cool the coolant in the radiator. sure a real little bit cools the motor but it doesn't really do much at all. so if they kick on right around when the t-stat opens that means they start to cool the water that just circulated out of the motor.

And you will over cool your motor forever.

Nismo t-stat opens in a lower temperature, but it does not flow more coolant. So it brings cooler coolant into the engine earlier, not cooling the coolant harder.

Think about this: You start your engine, it starts heating up. Now coolant temperature reaches 62C, the Nismo t-stat opens and let the coolant pass by.

Now I start my engine, it starts heating up. Now coolant temperature reaches 76.5C, the OEM t-stat opens and let the coolant pass by.

In which case the engine is prevented from overheating? Both.
Which engine will more likely to overheat, yours or mine? Neither.



I need to put this in big letter:


Nismo t-stat opens earlier to let coolant goes into the engine. It itself does not cool the coolant in anyway. So if your car is actually overheating, the Nismo t-stat will not magically cools the coolant to cool the engine. So there is no way a Nismo t-stat prevents your engine from overheating.

I can go for the "Nismo t-stat is built better so it will have a smaller chance to fail." Or you can school me on how your Nismo t-stat magically cools your coolant. There are aftermarket t-stats that allow more coolant to pass by, but the Nismo unit applied for our cars does not.

[jspaeth]

Now, I have been told to run my SR at around 180F by experts and I trust them and that's what I did.

Agreed with 180F

At speed like 65mph, the e-fan will create less airflow than the airflow form the car moving.

Agreed again

Nismo t-stat opens earlier to let coolant goes into the engine. It itself does not cool the coolant in anyway. So if your car is actually overheating, the Nismo t-stat will not magically cools the coolant to cool the engine. So there is no way a Nismo t-stat prevents your engine from overheating.

This arguement is correct IF AND ONLY IF both thermostats provide the same resistance (or lack of resistance) to flow when fully open, and that both thermostats reach the "fully open" state somewhere before the overheating temperature.

I belive this to be the case.

I can go for the "Nismo t-stat is built better so it will have a smaller chance to fail." Or you can school me on how your Nismo t-stat magically cools your coolant. There are aftermarket t-stats that allow more coolant to pass by, but the Nismo unit applied for our cars does not.

Very well said^


Also, for a while, I was running an OEM thermostat, and I thought it was okay, but it was taking FOREVER to warm up, and my max temps were around 78C.

I then put in a brand new OEM thermostat, and the car warms up WAY faster, and my cruising temps are now 84C or so.

....I believe the old one was somehow just worn or failed in such a way that it was always open or too open too early.