High quality 160* thermostat?

[mkIIIman089]

Pretty self explanatory, I'd like to try a 160* thermostat in my 7M and I know (as I'm sure has been brought up before) that TRD makes one for JZs but I'm having trouble finding a nice, high quality 7M version.

To get these bits out of the way:
-The ECU is not an issue
-Excess cooling capacity is available
-I always go for longer drives (if a very short commute exists) to help evacuate water from the crankcase.

Of course I'm open to "why I shoudn't" aspects beyond those... just please don't bring those aspects up.

 

[figgie]

-The ECU is not an issue
-Excess cooling capacity is available
-I always go for longer drives (if a very short commute exists) to help evacuate water from the crankcase.

Of course I'm open to "why I shoudn't" aspects beyond those... just please don't bring those aspects up.

Why is it not an issue? I ( and the rest of us, and incase you missed it, this IS the technical section) need to know why "the ECU us not an issue. We ned to validate that first sentence before starting off to spout answers. Otherwise, all for not.


I hope you know that running cooler is not necessarily a good thing. In short, more heat is removed, which means less energy for work. After all the combustion process is heat, Why do you think they still run cars hot even with direct injection? Has nothing to do with motor overheating or anything, basically increasing efficencies.

 

[mkIIIman089]

I control what temp the ECU sees.

As to the heat/efficiency bit I stated in my initial post "I want to try" not "This is definitely the way to go gimme a 160* thermostat NOW" for a reason. I want to try it and see what the results are.

 

[figgie]

mkiiiman

edit: I accidently edited your post instead of replied to it... I have corrected that though you might see that I edited, for that I appologize, There is nothing wrong or incorrect in your post, it was done in error!

well in the end, it is a lie.


temprature of the coolant sensor for us is just that but for the engineers to come up with that "magical number", they had to take into account some many variables it is not funny.


metallurgy (which acounts for thermal expansion, hardness etc) of the head, iron block, pistons, rods, crank etc.
thermal conductivity of head, iron block, pistons, rods, crank etc.
keeping most of the heat IN the combustion chamber (ie higher combustion efficencies), which means that the less temprature delta between two objects, the less heat transfer (if they could run the engine at 300c they would) would take place which means the heat is used for pushing the cylinder down instead of heat losses.

and that is what I can currently think off the top of my head. They then do FEA for stress as the heat rises, what tempratures the metals are ok with, and all that good stuff.

 

[mkIIIman089]

I feel like I missed something... lie?

I never doubted those points, but the designers have other agendas to worry about like keeping emissions below a certain level increasing the efficiency by running as hot as the structure allows like you said. We all know the flaw they had in prescribing the head bolt torque spec, so who's to say they didn't also push the temp limit a tick too far for one reason or another? Perhaps localized heating was too high in certain places and helps the notorious 7M gasket issue along and running a lower temp helps to lower the hotspot.(unsubstantiated remark... just as a hypothetical situation) Perhaps a slight reduction is better than a 30F reduction... TRD chose to make a low temp thermostat for the MK4, why?

Either way, I'd just like to try.

 

[gofastgeorge]

I have run 160 thermostats in the 7M for years.
And yes, I had to deal with telling the ECU what temp it should think it is.
I did this by installing a full throttle switch that cuts the actual engine temp signal, and goes to a set resistance.
I only did this because I noticed that if I ran the 1/4 mile with a lot of engine heat,
that it ran quicker than if I had to sit in the staging lines for a long period.
The set resistor value cured that.........

Anyway, back to your original question, Most major thermostat manufactures make the 7M 52mm size theremostat in 160, but they are a bitch to find in stock anywhere.
You have to find a parts guy who will actually dig out a real book, and look it up,
then wait weeks for it to come in.

So now I just buy a high quality cheesy chevy 54mm thermostat, put it in the lathe, and cut the OD down to 52mm.
I like the EMP/Stewart ones by Robertshaw, Summit racing sells them.
I think a NAPA 42 is the same, as I have a new one sitting here in the box, that I have already turned down.

 

[mkIIIman089]

Yea, the online one I was able to find through a bit of online searching, since I don't have a lathe was one by... Motorad? Claiming "fail-safe", was definitely pricey but I have no idea if its any good LOL.

Edit: on that NAPA #42, did a google search and came up with a bunch of Miata stuff, all claiming that it is a 52mm out of the box. Edit again: Napa site confirms

 

[figgie]

So now I just buy a high quality cheesy chevy 54mm thermostat, put it in the lathe, and cut the OD down to 52mm.
I like the EMP/Stewart ones by Robertshaw, Summit racing sells them.
I think a NAPA 42 is the same, as I have a new one sitting here in the box, that I have already turned down.

Now why would that be cheezy? GM (just like ford) has so many parts that it is not even comparable to the import market. A bit of machining to make it work, that is ok!

 

[mkIIIman089]

Napa THM 42 is a Stant 13366. On the NAPA premium stats they even go as far as to say they are "Superstat" type LOL.

gofastgeorge, you drilling a small hole to at least get them 1/2 way to a jiggle valve? I probably will, just curious.

 

[IJ.]

Have ran lower temp T Stats in the past and from my experience about all they do is increase warmup time, if you do long hard pulls the cooling system will reach it's natural equilibrium (my car with the 500rwhp 7M was around the 91c mark on a 77c T-stat) dependant on the ambient temp as it can only reject xxx BTU's based on many variables.

At a steady state cruise your operating temp will be lower as the engine is producing less heat so will sit on the t-stat's opening point and this may give you xx seconds extra before you get to the vehicle's running temp but once the t-stat is open it can't open further and if you don't have enough cooling system overhead it WILL overheat.

 

[mkIIIman089]

I anticipate having plenty of cooling overhead. Right now it's running ~50C water temp (15F ambient) so a 160* thermostat is an improvement on that. LOL

 

[IJ.]

I anticipate having plenty of cooling overhead. Right now it's running ~50C water temp (15F ambient) so a 160* thermostat is an improvement on that. LOL

What have you done to increase overhead?

Small frontal area of these cars seems to be the limiting factor.

 

[mkIIIman089]

Welp, PWR, a new sensor for the pair of electrics to kick in earlier than factory. Of course in addition to a new fan clutch to ensure its working properly, as well as no condenser... whatever little that may be worth.

 

[IJ.]

Welp, PWR, a new sensor for the pair of electrics to kick in earlier than factory. Of course in addition to a new fan clutch to ensure its working properly, as well as no condenser... whatever little that may be worth.

What sort of power does the engine make?

 

[mkIIIman089]

Not much, and not dyno'd but approximating with mods and health... ~350.

 

[IJ.]

Should have a nice comfortable overhead then

 

[NashMan]

i just run a high flow thermostate

170
or 180 i think

works great for me

 

[mkIIIman089]

Should have a nice comfortable overhead then

Tolja!

 

[wiseco7mgt]

Didn't want to comment on this thread earlier for fear of my own stupidity, but I've used a high flow thermostat 77 degrees for 3 years now in the summer( no i'm not copying Ian, lol) and switch to the factory rated temp for winter.
It makes a noticeable difference in under bonnet temps and on hot days 40 degrees +
it gives me peace of mind.
My wideband tells me the afr's are all normal and the fuel economy is better if anything so is this common practice for hotter climates?

 

[Drake69]

Uhhhh... wow.

I run a 160deg. in mine. Got it from the local Car Quest store, who also distributes for our local Bap Geon's. Walked in, said I needed a 160deg. thermo, they hooked me up in 5 seconds flat. Even had the gasket to put on it, without fail. Didn't realize performance thermostats were so hard to find.

Even Pep Boys has 'em, although I don't trust them as much. They sold me a radiator hose that was about 1 1/2 in. too long for my 7m. Had to cut that much off to get it to fit right.