Would it be worth getting this thermostat with my greddy tt w/fmic and built motor ???

 

Although Im sure its a good piece .That Thermostat is the most over priced part Ive seen . What is it $120 for a thermostat....geeeeez...Unless it has some type of housing or something [ never seen it ]

 

I have it on and so far my temp gauge is normal.

It helps keep my engine cooler.


Tasso-

 

It does come with the housing and gaskets. It is still overpriced. The housing is identical to the stock housing, same casting numbers. The thermostat is held in with 2 phillips screws, so it would be so much easier/cheaper just to sell the thermostat by itself. I guess Nismo needs more money. With all of that being said, I have one installed and I don't notice any change. I do not have a temp gauge, besides the stock one, so who knows. I got a pretty good deal on a new secondhand one. It was a pain to install, because I had to remove my supercharger to get to it. Otherwise it is a quite simple install.

 

We covered the function of the thermostat in Keepin' the VQ Cool - Spring 2005 Issue of Sport Z Magazine.

The thermostat (t-stat) serves two basic functions;

1) Provides a fast engine warm-up (reducing wear & emissions).
2) Keeps the engine from being overcooled. (at optimum temp)

Granted a "colder" t-stat will indeed cause the engine to run cooler - on cold days. Anytime the coolant temperature exceeds the t-stat's full open temperature it has no temp control function.

With the stock t-stat, whenever the engine's coolant temp is above approximately 194'F (350Z/G35MT) the coolant temp is "controlled" by the cooling system's (including the radiator/fans) total heat capacity. The NISMO thermostat simply lowers the control point where the t-stat is out of the picture. The easiest way to increase the heat capacity of your VQ's cooling system is to inrease the radiator's size.

 

Well the stock t-stat and Nismo t stat are identical sans a different spring. If you buy the stock t-stat it also comes with the entire housing etc. It costs $9. Nismo same thing different spring....$120. Currently I am running with no t stat at all. For some reason stock t-stats aren't up to the task. I have had two fail in as many months.

 

With that said, can you please reccommend an excellent radiator that is a drop in, no modification and will fit with the greddy tt fmic ?
Thanks, Dave

 

Dirty Dave,

According to my research at the time Blitz, Koyo, Power Enterprise and Stillen all produce a high capacity radiator for the manual transmission 350Z. As for recommendations, sorry but I have no personal experience with any of these radiators. I have heard that the Koyo may require some modifications due to it being thicker than the stock radiator's tanks/core.


Miaplaya,

Two thermostat's failed? Wow, that's very unusual. Do you know why? Have you noticed any overheating while running without a t-stat?

Many engines that run without a t-stat can overheat due to overcirculation. That's where the coolant flows through the systemso fast that it doesn't have time to absorb engine heat and transfer it to the great outdoors while in the radiator.

By the way, the pellets in the little (rust colored) can expand with heat, compress the spring, and open the t-stat. The stock VQ35DE thermostats only open 0.399 in (8.6mm) so the coolant's flow rate is restricted somewhat in order to prevent overcirculation.

 

I haven't been able to determine what caused it honestly. The car never ran hot when the t-stats were working. Always at 195 F per my return pipes temp sensor. Oil temp around 225-235. Not sure what it was. Maybe I use REALLY crappy water. Maybe it was the Redline Watter Wetter. I really don't know. As for the no thermostat way no overheating at all yet. Actually its been running COOLER then before. Water outlet temps are around 180-185. Highest spike was to 195-200 under EXTREME flogging yesterday to test exactly that. Its only been two days but the ambient temps out here were in the 90s and I full boosted the car SEVERAL times back to back to back. Nothing. Water only got to around 200 fans kicked on...cooled to 180 and stayed until next round of torture. The spike to 200 is not however abnormal as my car did that even with the t-stat and actually went higher. I though exactly what you are describing prior to doing this and ran it past several people who know infinitely more then me about motors. I got an even 50/50 split on the results. The theory I heard that sounded the most like what would happen came from protocav (who helped me do this). Although the water is moving faster it is still going through a basic heat exchanger (radiator). Lets say before t-stat removal it remove (all exmaples here) 5 units of hit per cycle of (example again) 1 qt of water during its path through the radiator. Now without the t-stat its only removing lets say 3 units of heat per cycle. You would think this would be a problem. HOWEVER because the water is flowing faster then befire the next quart of water is going through the core faster as well and also removing its 3 units of heat. Therefore in a given cycle of engine operation the same quart of water will only remove 3 instead of 5 units of heat but will go through the radiator more times then it did before. Thus balancing or even reducing the temps between t-stat and no t-stat. Again this is all conjecture and theory but in practice it does seem to work. If it any point it doesn't I am no worse off then before. I have a spare t-stat to put in and I would have had to do so anyways. I will drive the car some more this week and see if things change although over the last two days it has been fine (actually better then before). Now I just need to bump my idle up a few hundrerd RPMs as somehow disconnecting my batter to remove the turbo charge pipe has somehow thrown off my idle and the car is stalling occasionally when coming down from load. Granted my idle is set at 750 instead of 900 like other Turbonetics cars due to me being the first 04 with the kit and the higher idle was not done till later flashes.

 

Well I was having some problems overheating since I put in the built motor. I chalked it up to more boost, more heat, etc. Well guess what, my thermostat was stuck shut(could only open it in a vice). Car cools and runs fine now. I'm running without one until I get the Koyo radiator and Nismo thermostat. I've even toyed with they idea of not running one because it's always hot here in florida. What do you guys think of no thermostat?
Alan

 

Thats exactly what I'm dong. I had two thermostats fail on me so I'm running with none. Its SOCAL which is just like SoFlo...its always hot you dont need one.

 

I'm actually going to hold off for awhile to get the Koyo radiator. I did some aggressive driving on the way to work(gotta love living right off the interstate) and temps were very cool. I don't plan on road racing so a radiator might not even be needed. I plan on running a fan switch very soon. Does anyone have any pointers for the Z/G. I tested the fan relay with a DMM and it does throw a ground for it's trigger so It should be very easy. Any help would be appreciated.
Alan

 

Its funny I noticed with my Thermostat working my outlet water temp from the block to the radiator was usually between 195-200. With the thermostat removed my outlet temp is between 180-195. And under EXTREME heat as in 105+ with AC on max and full boosting my car it never gets above 203-204 at its hotest. As for a fan switch you may want to check out the HKS fan controller. I have this in my plans myself...It allows you to control you fans and set temp levels for fan activation independent of the ECU...link: http://www.hksusa.com/products/?id=1697&rsku=

 

I pretty much just want it for the staging lanes so that controller is a bit of overkill. Nice piece though. If you get one please do a complete write-up.

 

Well the beauty of the controller is that it can also run an intercooler spray at a predetermined time, push of a button, or temp...

 

Its funny I noticed with my Thermostat working my outlet water temp from the block to the radiator was usually between 195-200. With the thermostat removed my outlet temp is between 180-195. And under EXTREME heat as in 105+ with AC on max and full boosting my car it never gets above 203-204 at its hotest

If a radiator and engine is filled with the right amount of coolant the heat rejection by the radiator / coolant fans will be greater when it flows through the system at a higher rate than a lower rate..The thermo restricts flow and less heat rejection..A cooler engine is a happy engine...IMHO

 

Agreed however I had heard the opposite also that because of the drop in restriction of coolant flow it might move through the radiator TOO fast causing less heat to be removed from the coolant therefore making the car run hot. Although in practice this doesnt appear to be the case.

 

The heat transfer is limited by the air flow over the radiator. An engine coolant properly filled will dissipate less heat when the flow is reduced and just the opposite when it's sped up..