WOW, this is the perfect cooling combination! My engine temp is down drasticly compared to stock. The car is always running on low temperatures and very cool. Engine bay temp has also dropped big time! I would stongly suggest this combo, well worth it for hardcore driving! Pics coming soon.

 

I have had the NISMO thermostat sitting in my room for a couple of months now...

I think I'll follow you with the radiator, thanks for the review.

BTW did you do the install yourself? How hard is it? Anything to look out for? Thermostat manual is in Japanese, lol.

 

Lol i had that same problem tried free translations but that didn't work either haha, i had somebody install the radiator for me so they also installed the thermostat, but they took pictures of the install, as soon as i get them i will post! They said it wasn't that bad, only cost 75 bucks to install radiator and thermostat!

 

can someone plz tell me what a thermostat is?

 

The nismo thermostat controls the temperature of the engine, the nismo thermostat is able to set much lower temps than oem, takes longer for the engine to heat up. Basically like i said it contols the temperature of the engine, great mod if you guy an aftermarket radiator. Car cools down alot quicker from high reving or F/I cars.

 

been debating on switching out thermostats and radiator for some time now...you are edging me in the right direciton.

 

what water temps were your seeing before the Radiator/Thermostat swap?

i'm currently seeing 190F cruising, upto 220 when on the gas boosting and as high as 210 idling in the traffic...

 

Is it desirable to run the engine cooler, I know that engines have an operating temperature range that they should run at to prevent more wear on the engine parts, I understand thats how the mating clearances are designed.

 

+1

 

Did they have fitment issues with the stock fans with the koyo radiator?

 

It was a pretty tite fitting, but should go in easly! I had no problems with it!

 

not sure you would see much improvement in stop and go city driving and especially idling with a thermostat. Fans still come on at same temperature I believe

 

not really, not only is an engine desinged to operate within a range of temperatures(alaska down to UAE), but there is good amount of tolerances as well. Thermostat main benefits is when you track the car and the car constantly sees temperatures above normal. Bigger radiator has benefits with forced induction where temperatures again tend to be much higher. Obviously on a stock car that is daily driven all this is completely beside the point....

Still... the european 350z has a bigger radiator stock (higher temperature generally = bad performance, more wear, etc... I don't believe there is such thing as an engine running too cold)

 

I didnt mean the cooling effect of the radiator. I meant the engine temperature, it may be alaska or hawaii, engine operates or reaches a steady state and stays within a small temperature range. If you see most cars engines reach a steady temperature after a few minutes of driving regardless of how cold/hot it is outside or how hard or fast you are driving. The thermostat regulates how fast its supposed to cool or heat the engine.

The reason for engine to maintain this is pistons rings can seal, proper lubrication viscosity, bearings clearances for proper lubrication etc. The engine is designed to operate at a particular temperature, at other temperatures expansion/contraction between mating parts increases clearances which is undesirable. Since VQ is aluminum engine, the effects are more pronounced because of high CTE of aluminum, rate of expansion/contraction.

Running too cold leads to inefficient combustion, higher viscosity of the oils leading to wear on the bearings/sliding parts etc.

 

Generally, engines run best in the 170-180 range. Thermostats increased to 195 or more to lower emissions. That being said, too cold is also bad as the bore size is too small for the piston dia. Most Max performance engines will run in the 170-180 range. You will need a larger radaitor if you are running lower tempatures in ther coolant as the differential between ambient air and the coolant is what exchanges heat. As the differential becomes smaller, you will require more surface area to exchange the same amount of heat.

 

What I meant is that I don't think the engine will run cooler with a thermostat and bigger radiator(it will run cooler in the sense that it will not overheat). Understanding how a thermostat and radiator operate to keep temperature within certain parameters is key. I don't see how a thermostat or a bigger radiator would affect operating temperature during normal operation. They would on another hand prevent it from overheating during strenous use.