Jump to content
SAU Community

Recommended Posts

i discovered my thermostat was a factory nissan one and it opened MUCH further than the aftermarket one i bought. it would open about 15-20% more. it opened at similar temps, but it made the car run a bit cooler as it could flow that little bit more water.

cubes: what you said about the thermostat opening too far and not letting the water spend enough time in the radiator to cool enough sort of makes sense, but it works both ways. the less it opens the more time that water spends in the motor, so the hotter it gets. the hotter it gets, the hotter then engine is, and the longer it would take to cool the water down. that is why when you run the car without a thermostat it will run cold. by your theory it should run hotter without the thermostat.

  • Replies 44
  • Created
  • Last Reply

Top Posters In This Topic

mad082,

Can you grab the part number off the genuine thermostat? Maybe the RB20 and Rb25 thermostats are slightly different.

The new genuine rb20 thermostat I tested really didn't open much at all. I'd say in total it opened 15mm off its seat.

The 2 aftermarkets opened all the way which appeared to be approx 20-25mm off its seat.

The aftermarket opened sooner, opened at a greater speed and also closed quicker; essentially it was more responsive than the genuine.

The genuine was sluggish in its movements and didn't open as much.

As I mentioned above on the road the aftermarket had the car running cooler on cruise and showed temperature fluctuations when u gave it beans. The genuine holds a solid 83-85ish degree's, essentially temperature warms up quicker and holds consistent. Much nicer than a swaying temp guage + it held the motor within the apparent fuel efficent 85degree temp range.

The r32 did get too warm like the VL with the aftermarket thermostat when hitting the big arsed willunga hill.

In the VL Willunga hill requires approx 1/2-3/4 throttle to hold 110km/h; the hill takes a couple of minutes to reach the top of. So its a fairly big hill. :(

With regards to running a car without a thermostat which makes it run cold... This is 'generally' true under light load BUT give it full throttle for any length of time and they overheat. I've experienced this back in the old carby days with 308's and mild 250 2v precross flows.

yes I did try no thermostat in the VL.. It ran stupidly cold on cruise and overheated up willunga hill to the point where i Had to back off and turn around; slap a genuine thermostat in it and it was as good as gold.

No thermostat was a bad thing.

Which brings me back to maybe there isn't enough suction or vac on the water pumps side to provide reasonable flow; maybe the theory regarding water flow speed through the radiator is barking up the wrong tree and all along it has more so to do with providing a vac on the water pump so that it pumps water instead of spinning it around and around.

Some one with a little more fluid dynamics knowledge would be able to look at the water pump design and know for sure.

Not that it is really applicable but remember.... The greater the temperature differential the greater the effiency of heat transfer/removal.

without a thermostat the water flows to fast through the radiator to remove heat once the coolant is saturated.

another function of the thermostat, which not many people know is that it causes a restriction in such a manner that the pressure in the block and at the cylinder head is increased above the radiator pressure. this is critical in preventing localised boiling and steam packets in this area.

lowering the thermostat opening temp is going to reduce thermal efficiency reducing power and economy, this is why cars now are usually rated at well over 100degC opening temp.

i don't suggest going higher then standard in the RB engines as temperature of the engine is also related to the metalurgy of the head as alloy heads are sensitive and can go soft it overheated beyond standard temp.

with regards to the nissan vs aftermarket, genuine nissan are same price if not cheaper then aftermarket, so why mess around with the cheap flimsy chinese crap, that has crap temp regulation and are prone to jambing open or closed.

So its a little bit of everything then. :(

Comparing the aftermarket thermostats to the genuines the genuine looks and feels a hell of a lot more solid. Down this way aftermarkets are ~$25 each compared to the genuine nissan @ $49.

If you mention import, they might wack an extra $10 on :(

Just buy for RB30 R31, $39 retail, last time I ordered (not to say price has gone up)

Aftermarkets are like $40 here for RB30, can't get over it, every other cars is the usual $15, which is still overpriced for the quality they are.

Sent you a PM as well.

Hey Cubes, yeah it's been a while, was away in Europe for 5 weeks. Ran into your missus just before I went.

Well I this thread activity has suddenly exploded.

I ended up going to Unley Nissan today & got a genuine thermostat for $53 & FYI Cubes, the part number is 21200-42L06

It makes more sense for the thermostat to vary gradually with warm up instead of acting like a switch, I'd say that this kind of action in itself would mean that it regulates temperature better than the aftermarket ones. Going by what RB30-POWER also elaborates with the no thermostat situation, perhaps the aftermarket thermostats open up too much to keep sufficient pressure in the block for the pump.

Biggest thing that made me decide to go with the stock temperature thermostat was that my car fails to get to full operating temperature even when I'm driving it hard in this cool weather. Couple that with the fact I don't even have a front mount to cool the intake charge more, & I see little need for a low temp unless I was about to rebuild my engine for a serious power upgrade.

Very useful thread guys I wish more threads on here were just as informative, cheers

ronin, i reckon 70 is too low. ideally for the 32 you want the temps to stabilise arond 75-85 both water and oil when just cruising around. though it is winter, and you do drive like my little niece on her tricycle so that may explain it.

ronin, i reckon 70 is too low. ideally for the 32 you want the temps to stabilise arond 75-85 both water and oil when just cruising around. though it is winter, and you do drive like my little niece on her tricycle so that may explain it.

fine mr baron. 8000rpm in second everywhere it is.

i do recall looking at the PFC controller that said 74.

btw, even on a tricycle i will dominate around the track!!

  • 2 weeks later...

i run a sard lower temp thermostat in my 34gtt (amongst also an oil cooler and thicker radiator).

do some dyno runs on your car and see what results u get at different operating temperatures;

i found 80's were fine but once in 90's i was losing noticable power.

car now runs 70's - 80's in most conditions thus when i want/use the power (and the engine gets hotter)...

i don't loose that power as a result :)

Umm, dont you have to go to nissan to get it?Why dont you just ask them.

They're usually reluctant to order stuff unless you give a part number, or your VIN, so they can be sure it's the correct part. Since I want a part from a later model car, I'd like to order with part-number in hand. :sorcerer:

GTT34: I do 98% of my driving in cruise-along mode, when I want every last drop of economy I can get. On the highway it's usually around 68deg. water temp (on the PowerFC). If I'm in thrash-mode, it's either for 1 or two corners (so temp won't have time to rise) or I'm doing a track day, so temps will never get below 100deg.C anyway. (i.e. thermostat wide-open all the time)

U know it makes sense!

Hardman I think I'd be removing the thermostat you have and making sure its working properly , ie sealing shut when its cool . I wouldn't think a coolant temp anywhere in the 70's and up should make any real difference to steady state fuel consumption . No engine would need enrichment by that stage so the only other factors I can think of would be possibly a little oil drag depending on viscosity and closed loop ECU settings . If anything cool air charge temps should allow ignition timing optomised around best mean torque rather than detonation protection I think .

Cheers A .

Disco,

The PowerFC provides fuel enrichment for anything below 80degree's. As the Powerfc base maps closely reflect that of the std ecu's maps I wouldn't be suprised if the std ecu's values also provided fuel enrichment below 80degree's.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • You just need to remove the compressor housing, not the entire turbo. I would not be drilling and tapping anything with the housing still on anyways. 
    • So, I put my boat on a boat. First of all, I'm going to come out and say it. Why is Tasmania not considered a holy goal, an apex that all road-legal modified cars go to, to experience? This place is an absolute wonderland of titanic proportions. If people are already getting club runs for once in a lifetime 30 person cruises to Tassy then I've never seemed to see it. It is like someone replaced the entire place with an idyllic wonderland for cars, and all of the people living there with paid actors who are kind, humble, and friendly. Dear god. After doing a lap of almost all of the place I've found that it's a great way to find out all of the little things that the car isn't doing quite right and a great way to figure it all out. All in all, I drove for 4 hours a day for a week and nothing broke. I didn't even need to open the engine bay. This is by all means a great success, but it has left me with a list of things to potentially address. I also now have a 3D printed wheel fitment tool which annoyingly hasn't got any threads in it to actually assemble it. I might be able to tape it together to check the sizing I actually want to use, but it'll likely involving pulling the shocks out to properly measure travel at least at the front, and probably raise the car while I'm at it, at least in the rear. I scraped on quite a few things and I'm not sure how else to go about it. I was taking anything with a bump at what felt like 89 degree angles. And address those 10 other tasks. And wash the car. God damn it is dirty. And somehow, the weather was perfect the entire time - And because I was on the top of Mt Wellington it turns out it was very much about to freeze up there. I did something I typically never do and took some photos up there in what must have been -10 and the foggy felt like suspended ice, rather than mere fog. If you own a car in Australia, you owe it to yourself to do it.
    • Damn that was hilarious, and a bit embarrassing for skylines in general 😂 vintage car life ey. That R33 really stomped. Pretty entertaining stuff
    • Hi, I have a r32 gtr transmission. Does any of you guys have an idea how much power it will hold with the billet center plate and stock gearset? At what power level and use did yours brake with or without billet plate? Thanks, Oystein Lovik
    • Saw this replica police car based on a Mitsubishi Starion XX parked next to a 'police box' (it's literally a box) in Hirohata, Himeji City in Hyogo prefecture the other day. It's owned by Morii-san who is a local Mitsubishi Starion enthusiast. According to a local radio station blog post, he always wanted to make a police car himself based on ones he saw in his favourite Manga comics.  As it's illegal to modify a car to look like a police car and drive on the road, Morii-san tried many times to get permission from Aboshi police station headquarters nearby. They refused initially by after they got tired of that they granted him permission. However, the car can only be displayed on private property and obviously can't be registered as long as the police livery is present. The car was completed at a cost of 1.5 million yen (US$ 10,000) in addition to the car cost. A location was chosen outside Hirohata Police box where the car can easily been seen from the street. Morii-san has two other Starion road cars, both widebody GSR-VRs.
×
×
  • Create New...