Nismo Thermostats In Rb Motors?

[ibz]

Well just wondering is it good or bad to use a nismo thrmostat?

Nismo thermostat- 62 degrees Celsius

OEM RB thermostat- 76.5 degrees Celsius

I've been hearing from a few people that an oem thrmostat is better because the nismo thermostats were designed to be used in japan in there cold conditions, so there water temp doesnt get so high, but when it is the 62 degree nismo thermostat is useful for them...

But in australia our temperatures are hotter so our average water temp on our rb's are much higher, around 70-90 degrees i think( not 100% on that)...

In saying that, that means that nismo thermostat is constantly open, which doesnt give the water enough time to cool down, which in turn will make your car run hotter..

Which makes sense...

Has anyone else got there opinion and facts on this?

[beemae30]

I really think oem thermostat is fine. I've never had any issues with mine flogging it in 40c heat with just the factory radiator. That being said mines pretty factory just fmic, exhaust, 12psi. I'd rather spend the money on a bigger radiator to be honest.

[mad082]

the nismo thermostat is designed for motorsport where the engine temps will be higher so you need it to fun cooler. whoever said that the nismo thermostat was designed for the japanese climate more so than the OEM one is an idiot, since the OEM was designed for the japanese climate as they weren't exported to many other countries.

unless you are using your car as a track car the OEM is the best to use, especially on a day to day basis. if you use the nismo one on a road car you will most likely increase engine wear as well as increasing fuel consumption.

[ibz]

the nismo thermostat is designed for motorsport where the engine temps will be higher so you need it to fun cooler. whoever said that the nismo thermostat was designed for the japanese climate more so than the OEM one is an idiot, since the OEM was designed for the japanese climate as they weren't exported to many other countries.

unless you are using your car as a track car the OEM is the best to use, especially on a day to day basis. if you use the nismo one on a road car you will most likely increase engine wear as well as increasing fuel consumption.

Can you explain to me how the thermostat runs cooler? do you know how a thermostat works?

yes car is going to be a track/drift car... pushing 500rwhp...

If the thermostat is rated to open at 62 degrees Celsius, does this mean that the thermostat will stay open all the time as soon as your water hits normal operating temp?

[SargeRX8]

Normal operating temp for my car is 70 to 82c. These colder winter days I'm around 71 on pfc casual driving. If I used the nismo piece the thermostat will almost always be opened, unnecessarily, causing faster wear due to the water cooling down when it isn't needed to.

[pipster11]

Basically Nissan designed the motor to run at 85ish *c with all their toleranceing and ecu setup

So more r&d than any engine builder in Australia determined the ideal temp to regulate the coolant to was 85ish

Running lower than this will give you more headroom to the boiling point but you are running the motor cooler than designed

If your car is going to be tuned for it then fair enough but your probably better off running a stock thermostat and spending the money on a bigger radiator

[mad082]

the cooler thermostat opens at a lower temp. this will start to reduce the overall operating temp the engine runs at because it won't be able to get to the initial higher operating temp to start with. the other thing you need to remember with a thermostat is that it isn't just open or closed. it can fluctuate as you drive, so if it opens up fully and then the temp of the coolant flowing through it cools a bit (meaning that either the engine is cooling down, or the coolant is flowing too fast to absorb heat) it will then start to close a little bit which will slow the flow of coolant down. unlike running no thermostat, even a fully opened thermostat still provides enough restriction to allow decent heat absorption. the fact that the lower temp thermostat stays open longer means that at temps where the OEM thermostat is closing so it can cool the engine more, which would also be good for when the engine is cooling down on shutdown.

also if the rest of the cooling system isn't performing that well then the temp rating of the thermostat means less.

you also have to remember that coolant isn't the only thing that cooling the engine. there is also oil, so an oil cooler would also be a good addition.

[Cassbo]

I found that the Nismo thermostat was an upgrade over the OEM thermostat... but mainly because the rubber seal on the OEM one was perished and letting all the coolant through at all temps.

I will admit though, combined with my 42mm radiator it never gets past 70°C on the street so I probably could have used another OEM one

[ibz]

Basically Nissan designed the motor to run at 85ish *c with all their toleranceing and ecu setup

So more r&d than any engine builder in Australia determined the ideal temp to regulate the coolant to was 85ish

Running lower than this will give you more headroom to the boiling point but you are running the motor cooler than designed

If your car is going to be tuned for it then fair enough but your probably better off running a stock thermostat and spending the money on a bigger radiator

I've already got a bigger radiator... Yep leaning towards running a stock thermostat..

the cooler thermostat opens at a lower temp. this will start to reduce the overall operating temp the engine runs at because it won't be able to get to the initial higher operating temp to start with. the other thing you need to remember with a thermostat is that it isn't just open or closed. it can fluctuate as you drive, so if it opens up fully and then the temp of the coolant flowing through it cools a bit (meaning that either the engine is cooling down, or the coolant is flowing too fast to absorb heat) it will then start to close a little bit which will slow the flow of coolant down. unlike running no thermostat, even a fully opened thermostat still provides enough restriction to allow decent heat absorption. the fact that the lower temp thermostat stays open longer means that at temps where the OEM thermostat is closing so it can cool the engine more, which would also be good for when the engine is cooling down on shutdown.

also if the rest of the cooling system isn't performing that well then the temp rating of the thermostat means less.

you also have to remember that coolant isn't the only thing that cooling the engine. there is also oil, so an oil cooler would also be a good addition.

It will only slow down the operating temp the coolant runs at because it will open earlier so the coolant may pass through the engine a few times but after that your coolant will start to warm up an get to normal operating temps which is 70+ degrees...

Yes the thermostat will fluctuate but after it reaches normal temps this will stop and thermostat will be fully open yes? This means coolant will not stay in radiator long enough for the coolant to be cooled down yes?

Whole reason for a thermostat is to open too cool engine down an close to give enough time for the coolant to cool down through the radiator and pass through the engine in a cool state...

I've got an rb26, its going to be running n1 water pump, ford thermo fans, pwr radiator, 8.5L sump, 25 row oil cooler+thermostat etc.... So i'm doing the best i can with the cooling system...

I just want to confirm if an oem thermostat is actually better to use then the nismo thermostat, if not, some facts on why its not... Coz at the moment i'm not getting why nismo thermostat is better.... Even though i've already bought a nismo thermostat, if its not good to use then i'll just go buy a brand new oem thermostat..

[mad082]

I've already got a bigger radiator... Yep leaning towards running a stock thermostat..

It will only slow down the operating temp the coolant runs at because it will open earlier so the coolant may pass through the engine a few times but after that your coolant will start to warm up an get to normal operating temps which is 70+ degrees...

Yes the thermostat will fluctuate but after it reaches normal temps this will stop and thermostat will be fully open yes? This means coolant will not stay in radiator long enough for the coolant to be cooled down yes?

Whole reason for a thermostat is to open too cool engine down an close to give enough time for the coolant to cool down through the radiator and pass through the engine in a cool state...

I've got an rb26, its going to be running n1 water pump, ford thermo fans, pwr radiator, 8.5L sump, 25 row oil cooler+thermostat etc.... So i'm doing the best i can with the cooling system...

I just want to confirm if an oem thermostat is actually better to use then the nismo thermostat, if not, some facts on why its not... Coz at the moment i'm not getting why nismo thermostat is better.... Even though i've already bought a nismo thermostat, if its not good to use then i'll just go buy a brand new oem thermostat..

firstly, if you have ever run a car with a faulty thermostat that isn't closing properly you will see that it can take a long time for the car to come up to temp (depending on the engine load). i've had a car with a thermostat not closing properly and on the highway it wouldn't go above the line above the C.

as for the colder thermostat not letting the coolant stay in the engine long enough to absorb heat, on an application where there will be high load, it is going to spend most of it's time fully open, no matter whether it's the OEM one of a lower temp one. also the temps they are rated at are generally the opening temp, but they also have a temp at which they will be fully open. so if the stock one has a fully open temp of 88 degrees and the nismo one has a fully open temp of 80 degrees, and the engine gets to 89 degrees, it doesn't matter which thermostat is in there as they will both be fully open and flowing the same amount. another point i'd like to make is that the car i had that ran cool on the highway, the thermostat would neither close fully, nor open fully (when i tested it when i pulled it out). this resulted in it running pretty hot on hot days, so in that case, more flow would've helped and putting a new thermostat in helped the situation.

also the fact that plenty of people who run the nismo thermostat have posted about how their engine runs cooler, even on track days.

oh and i'll just point out that the N1 water pump actually pumps less than the stock one, but it is designed to run at higher rpm, so the flow rate balances out. for a street car the stock pump is a better option. for a track car the N1 pump is a better option.

[ibz]

firstly, if you have ever run a car with a faulty thermostat that isn't closing properly you will see that it can take a long time for the car to come up to temp (depending on the engine load). i've had a car with a thermostat not closing properly and on the highway it wouldn't go above the line above the C.

as for the colder thermostat not letting the coolant stay in the engine long enough to absorb heat, on an application where there will be high load, it is going to spend most of it's time fully open, no matter whether it's the OEM one of a lower temp one. also the temps they are rated at are generally the opening temp, but they also have a temp at which they will be fully open. so if the stock one has a fully open temp of 88 degrees and the nismo one has a fully open temp of 80 degrees, and the engine gets to 89 degrees, it doesn't matter which thermostat is in there as they will both be fully open and flowing the same amount. another point i'd like to make is that the car i had that ran cool on the highway, the thermostat would neither close fully, nor open fully (when i tested it when i pulled it out). this resulted in it running pretty hot on hot days, so in that case, more flow would've helped and putting a new thermostat in helped the situation.

also the fact that plenty of people who run the nismo thermostat have posted about how their engine runs cooler, even on track days.

oh and i'll just point out that the N1 water pump actually pumps less than the stock one, but it is designed to run at higher rpm, so the flow rate balances out. for a street car the stock pump is a better option. for a track car the N1 pump is a better option.

Well its going to be a drift car so theres going to be alot of load...

I thought that the fully open temp for nismo was 62 degrees... so what your teling me is that they fully open at 80 degrees, is that correct or an assumption?

thats good coz my cars going to be used for track...

[beemae30]

62 degrees is cracking temperature. As cracking temp is lower full open temp is lower.

[mad082]

the fully open figures were just an example. i'm not sure on the exact fully open temps. from what i gather the general running temp, is about 6 degrees higher than the opening temp. after doing a bit more research the lower temp is also designed to, in colder climates, be low enough that the ecu will trigger cold temp enrichment to take advantage of the colder intake temp and improved effectiveness of the intercooler. so there is some plausibility to it being designed for japans colder climate, but i think it was a bit of an after thought/side effect. they probably just fine tuned the temp for that but would've made a lower temp thermostat regardless, since they don't only have cold temps in japan, and their temps aren't that much lower than the southern states here, but their summers aren't as hot as ours.

[ibz]

ok... no worries... thanks for the input guys...

[CrimsonLey]

the fully open figures were just an example. i'm not sure on the exact fully open temps. from what i gather the general running temp, is about 6 degrees higher than the opening temp. after doing a bit more research the lower temp is also designed to, in colder climates, be low enough that the ecu will trigger cold temp enrichment to take advantage of the colder intake temp and improved effectiveness of the intercooler. so there is some plausibility to it being designed for japans colder climate, but i think it was a bit of an after thought/side effect. they probably just fine tuned the temp for that but would've made a lower temp thermostat regardless, since they don't only have cold temps in japan, and their temps aren't that much lower than the southern states here, but their summers aren't as hot as ours.

Hugh, what do you mean by 'ecu will trigger cold temp enrichment?' I'm curious as a live in west Japan.

I'm running a stock 32-R but I'm going to do some cooling upgrades as I plan on tracking the vehicle. I live in Japan and as of now the GTR is more of a street car than a dedicated track monster.

I want to buy a nismo t-stat but it sounds like this might not be the time for me to purchase one.

[89CAL]

The ECU runs a 'cold start' map where it will inject more fuel and slightly reduce timing. This is designed to warm the car up quicker

If you start your car when its at ambient temperature then you should notice it smells more fuely out the exhaust and revs slightly higher. This means its in the cold start map. Having an AFR gauge shows this in greater detail

The Nismo thermostat is designed for motor sport as said, because the car will always be under load and revving then it needs some help cooling the engine. Its a bit like the Nismo water pump. Not really an upgrade unless its going to going near the rev limiter frequently. Both items should not be needed in a street car.

Most of what I said has already been said previously. If everything is working efficiently in your cooling system and your getting temps in the 80's then there is no problems at all. I run a fully standard cooling system and it has never had an issue. Even when I've been out at the drags, temps have never been high enough to cause concern

[mad082]

yeah callan is spot on. when the engine is cold it uses more fuel. when the engine is cold fuel doesn't vapourise as much, and it is actually the fuel vapour that burns, not the liquid fuel. a side effect is that this actually reduces the engines power output by a small amount and keeps the compustion temps down, which is good when the engine block is still cold (you don't want it heating up too quickly). if you have a mower/trim that has a choke on it that is a seperate lever, pull the air filter off and have a look at what happens when you turn the choke on. lots of them will simply slide a restrictor over the inlet to the carby. that is a mechanical way of doing it. engines with an ecu can simply make the injectors inject more fuel.

as for the cooling system, there are generally only 2 causes for overheating (with the odd exception). 1 is the thermostat, the other is the radiator. if the thermostat isn't up to scratch then sometimes they won't open and close properly. not closing properly is generally easy to tell because the engine will take ages to warm up. not opening properly is harder to tell because you generally don't know it until the car overheats. but usually, if it isn't closing properly it probably won't open properly either.

for the radiator, if it is a bit blocked then it may still be fine for everyday use, but it may get a bit hot on very hot days if you get stuck in traffic and are sitting still, or when giving the car a hard time. a quick and easy way to diagnose a blocked radiator is to take the car for a short drive (just to get the engine a little warm) and then pull over, turn the engine off and pop the bonnet. run your hand over the fins of the radiator and feel for cold spots. if you find a section of the radiator that is much colder than the areas around it then there is a good chance there is a blockage in that section of the radiator. to fix it you either need to have it professionally cleaned, or to buy a new radiator. those radiator flush products you can buy won't do a thing.

[CrimsonLey]

Profound..<br /><br />Honestly, I real reason I visit SAU is because it saves me money. <br /><br />Sent from my SC-03D<br /><br />