i noticed over heating when tracking so i installed a 3 row koyo. fit fine with my stock engine and never saw temps pass a little above 1/2 mark in 4 track days. temps this past weekend were about 90 degrees. also only noticed the higher temps when going uphill. temps fell back under 1/2 for the rest of the track. also added some water wetter for good measure. definately go for a cheaper radiator like the koyo instead of an arc. you can spend your savings on other cooling parts, oil cooler, tranny cooler, diff cooler, ps cooler or vented hood.

 

Arg, so it looks like the Nismo dropping at 160 really won't be all that effective? I imagine the temp is rising relatively quickly from 160 to 180. Just wondering if the time it takes is worth it.

 

It's B.S. huh?

You don't have a clue what you're talking about. Do yourself a favor and Google "thermostat" and "detonation" together.

The Nismo thermostat is just a small piece of the puzzle.

 

I understand the detonation and heat thing. My arguement is not with that....

please explain to me that when you will most likely be running around 190-200 degree max temps that it matters if your thermostat opens at 160 or 180.

 

I am running a Nismo Thermostat with my stock radiator and it works great for my S/C'ed Z. Temps stay pretty low but sometimes too low, my check engine light came on several times over the winter due to the temp being too low not a big deal now that the weather is getting warmer. I plan to install an aftermarket radiator soon.

 

Of course it doesn't matter! The thermostat is not a maximum temperature regulating device. The thermostat is the cooling system's minimum temperature regulator. Combined with an efficient cooling system, it will be able to keep the temperature at the desired level. However, at 190-200 degree coolant temperatures, both thermostats (OEM or NISMO) will be at full open, and if you're running too high of a maximum temperature, then your cooling system is inefficient.

 

Important to measure coolant temp vs time in say 10 second incrememnts and create a graph..............which will show you what is happening.

My custom made larger capacity radiator just decreased the slope of the curve by about 8% for $800................but in extreme conditions it lower the temperature by 4F which prevented the ecu from decreasing ignition advance in bumper to bumper traffic/

Small improvements over oem are often very expensive per degree improvement.


Once theromstat is fully open 194-196F, you are at the mercy of coolant capacity, and rad efficiency.

Adding extra oil capacity often drops coolant a few degrees.
Same with adding an external ATF cooler and removing the heat source from in rad AT heat exchanger.

Every degree improved is worth it.

 

I guess I don't see the point you are making your argument from?

And 190+ is too high of a maximum temp?

 

How does the thermostat in a car's cooling system work?
Any liquid-cooled car engine has a small device called the thermostat that sits between the engine and the radiator. The thermostat in most cars is about 2 inches (5 cm) in diameter. Its job is to block the flow of coolant to the radiator until the engine has warmed up. When the engine is cold, no coolant flows through the engine. Once the engine reaches its operating temperature (generally about 200 degrees F, 95 degrees C), the thermostat opens. By letting the engine warm up as quickly as possible, the thermostat reduces engine wear, deposits and emissions.

http://auto.howstuffworks.com/question248.htm
http://auto.howstuffworks.com/cooling-system.htm

 

Everything you post helps my arguement. You just stated that 200 degrees is generally operating temp. So again, how does a thermostat that opens at 160 vs 180 make ANY difference, when temps are generally around 200?

 

Let me explain this to you.

Under post #13, you said, "That nismo thermostat will make no difference, so save your money."

I replied by stating a fact, "The Nismo thermostat is for people that require extreme cooling to resist detonation."

In which you replied, "That is a huge line of BS." Next, after you called me a liar, you proceeded to sort of ask an odd question that also suggested how it was worthless for maximum temperatures. "please explain to me that when you will most likely be running around 190-200 degree max temps that it matters if your thermostat opens at 160 or 180." When I read this post, I realized that not only were you were trying to discredit me, but it was obvious to me that you didn't seem to understand what a thermostat even does.

I was confused, because now you were trying to change the topic to talk about a temperature range that was well above the OEM or Nismo's operating range. Nothing would be different, because both thermostats would be fully open. Therefore, I agreed that a "low-temp" thermostat does nothing different than a regular thermostat as an engine approaches its maximum temperature. I also tried to explain that with an efficient (upgraded) cooling system, temperatures of 190-200 degrees should never even be reached. Mostly, to bring the topic back to the purpose of the Nismo low-temp thermostat.

You seemed even more confused in your next reply, "I guess I don't see the point you are making your argument from?" I wasn't sure if this was a question or a statement. So, I replied by gathering generic information about cooling systems and thermostats from Howstuffworks.com for you. So that hopefully you will now understand how a thermostat does work and I can properly educate you what the VQ35DE Nismo thermostat is for.

Your next reply was the most frustrating, because you obviously didn't comprehend the description of a thermostat. So you asked, "So again, how does a thermostat that opens at 160 vs 180 make ANY difference, when temps are generally around 200?"

My jaw dropped from the stupidity when I read this post, so I'm going to take a guess that one or more of these things are true:
You are a complete idiot or an in-bred hillbilly.
You are twelve.
English is not your first language.
You didn't make it past the third grade.
You have A.D.D. and are not reading my posts.
You enjoy asking the same retarded question over and over.

So my reply is: I properly answered this question in post #26

99% of people who correctly use the Nismo thermostat to reduce detonation will have upgraded cooling systems. Also, when a vehicle is turned on, it's temperature does not start at 200 degrees. Therefore, as the engine's temperature approaches 160 degrees, unless it's July and you are in a traffic jam in Death Valley, the engine temperature will be maintained around or slightly above 160 degrees.

 

You are a damn fool. Once the stat opens, it is open, it allows flow. The temps still can increase beyond the point that it opens. Your arguement of reducing detonation really only applies at max temps. Who gives a flying F^CK if the stat opens at 160 or 180? It makes no difference because again, your max temps are higher than either and are what will have any impact on detonation. Beyond that, you would REALLY have to be running on the edge to have a slight variaton in your coolant temp have any impact on detonation.

 

LOL - I disagree with you.

Why do you insist on saying that the temperature will increase beyond the temperature that the thermostat regulates? The thermostat's job is to keep the engine at a constant temperature.

Also, please explain how "your arguement of reducing detonation really only applies at max temps."

 

The thermostats job is not to keep you engine at a constant temperature, just a minimum temp. Have you ever watched you coolant temps with an aftermatket gauge, not the stock one?


If you are tracking your car temps will rise past what the thermo is set to be fully open. Only of your setup is extremely efficient (rad, oil cooler, ducting), enough to keep temps below 180*f would the Nismo thermo be worth it.

 

IMO, you should never be running so close to the edge to have to worry about 10-20 degrees making any impact on detonation. I was arguing that the temps that either stat opens will not have any impact on detonation like you seem to be implying. if temps are going to impact any potential detonation, they will be well into the 200's; much higher than 160 or 180.

And no, the thermostat's job is not to keep the engine at a constant temp. Like Lance states, it will merely be the minimum temp once the car is warmed up.

 

actually that's not what a thermostat's job is at all

the car has no internal climate control system, which is basically what you are describing. Things like oil viscosity, build tolerances, rpm, airflow, etc etc all determine what temps the coolant in the engine gets to. The thermostats job is simply to open at a prescribed temperature such that coolant is allowed to flow

What guys fail to realize is that the stock Z's thermostat already opens quite low relative to many other cars on the market. Having used the NISMO t stat, I can say its only real use, beyond having another mod to put in your signature or to brag to friends about, is for those doing heavy duty, long session track days in very high heat. Other than that, it really offers no benefit whatsoever.

 

what, no reply to the other's comments? Finally gave up??

 

The coolant temperature is just a surrogate for the cylinder head temperature anyway..............that is the important factor with aluminum heads.

Measured by sensor at the flow output of both heads.