Jump to content
The mkiv Supra Owners Club

Is it worth getting a TRD thermostat over a stock one?


Scott

Recommended Posts

even better then if thats the case it will maintain 85c, i assume mine has an 88c in it as it maintains 91 c and only goes up or down 1d from that so the cooling system is doing its job perfectly, if i was on a 82c stat and it went up 10c to 92c under hard use it wouldnt sustain 92c as the cooling system wouldnt be doin its job so the temps would keep rising.

 

No- The cooling system can only extract heat relative to flow - any stat can only open to a max , if the heat isnt extracted fast enough ,the cooling temp only reaches a set amount - the oil temp rises ,and the head temp rises

If the coolant temp rises ,you would have major problems ,head and oil temps would be real high!

simply looking at coolant temp is not enough to say its fine and under control ,any rise in coolant in driving conditions is not good ,stationary is another matter as the system is undercooled and uses the fan to regulate as the engine is off load

The water system is not a stand alone cooling system but works in conjunction with oil and air ,all three are interlinked.

the opening stat temp if lower simply slows the oil warm up time and engine warm up time its the max open temp that controls the running temp by controlling flow- maximum flow is when you remove the stat altogether , but now the engine is overcooled for most of the time and very slow oil warm up along with engine warm up and unstable block and head temps

Link to comment
Share on other sites

  • Replies 60
  • Created
  • Last Reply

Top Posters In This Topic

90916-03093

 

Thanks mate :thumbs:

 

No- The cooling system can only extract heat relative to flow - any stat can only open to a max , if the heat isnt extracted fast enough ,the cooling temp only reaches a set amount - the oil temp rises ,and the head temp rises

If the coolant temp rises ,you would have major problems ,head and oil temps would be real high!

simply looking at coolant temp is not enough to say its fine and under control ,any rise in coolant in driving conditions is not good ,stationary is another matter as the system is undercooled and uses the fan to regulate as the engine is off load

The water system is not a stand alone cooling system but works in conjunction with oil and air ,all three are interlinked.

the opening stat temp if lower simply slows the oil warm up time and engine warm up time its the max open temp that controls the running temp by controlling flow- maximum flow is when you remove the stat altogether , but now the engine is overcooled for most of the time and very slow oil warm up along with engine warm up and unstable block and head temps

 

That was my thinking of it all, I couldn't see how the earlier action would mean the flow changed once everything was up to temp. I'm not fussed about it opening earlier, I don't need to worry about the temps rocketing due to tracking etc..... if the day ever comes I'll take the stat out :D

Link to comment
Share on other sites

I've always been paranoid about boiling my engine when I first fired it up after dropping all the coolant, it happened with my blue car when I first built the engine, it was a learning curve I know and wouldn't happen again but it makes me paranoid all the same. I think the They open 10 degrees earlier so anything that can aid cooling is a must for me, especially with an engine running a hot single turbo.

Link to comment
Share on other sites

No- The cooling system can only extract heat relative to flow - any stat can only open to a max , if the heat isnt extracted fast enough ,the cooling temp only reaches a set amount - the oil temp rises ,and the head temp rises

If the coolant temp rises ,you would have major problems ,head and oil temps would be real high!

simply looking at coolant temp is not enough to say its fine and under control ,any rise in coolant in driving conditions is not good ,stationary is another matter as the system is undercooled and uses the fan to regulate as the engine is off load

The water system is not a stand alone cooling system but works in conjunction with oil and air ,all three are interlinked.

the opening stat temp if lower simply slows the oil warm up time and engine warm up time its the max open temp that controls the running temp by controlling flow- maximum flow is when you remove the stat altogether , but now the engine is overcooled for most of the time and very slow oil warm up along with engine warm up and unstable block and head temps

 

the only way anything you have wrote is relevant is if the trd stat opens wider than a stock one ? if it doesnt then what ive said is correct.

Link to comment
Share on other sites

the only way anything you have wrote is relevant is if the trd stat opens wider than a stock one ? if it doesnt then what ive said is correct.

 

That's not how I read it. His point is that they don't open wider hence they make no difference to the operating temperature. The operating temperature is governed by the cooling system as a whole, not when the thermostat comes in. The only difference here is that it will take longer for everything to warm up. This is obviously an advantage when you are taking your car out to cane it as the temps will rise quickly, the stock thermostat might not react quickly enough to the rapidly rising temperatures and might overheat. With the TRD it opens 10 degrees earlier so the full cooling system, radiator etc, is already in full use giving that extra 10 degree cushion.

 

That's how I understand it anyway.

 

Oh, and that's no use to me as when I'm caning it the engine will already be up to full temperature etc :)

Link to comment
Share on other sites

Someone mentioned removing the `stat altogether earlier. this is BAD BAD BAD. Modern engines have a calculated and physically measured flow and pressure drop around the head and block, and the way the 2JZ `stat operates has a profound effect on this. Removing it altogether could actually cause nucleate boiling and / or a far less efficient cooling system. There are very good reasons why you would NOT want to run a lower than stock coolant temperature actually, and I can think of very few good reasons to run the TRD `stat.

Link to comment
Share on other sites

Someone mentioned removing the `stat altogether earlier. this is BAD BAD BAD. Modern engines have a calculated and physically measured flow and pressure drop around the head and block, and the way the 2JZ `stat operates has a profound effect on this. Removing it altogether could actually cause nucleate boiling and / or a far less efficient cooling system. There are very good reasons why you would NOT want to run a lower than stock coolant temperature actually, and I can think of very few good reasons to run the TRD `stat.

 

I was joking Chris ;)

Link to comment
Share on other sites

That's not how I read it. His point is that they don't open wider hence they make no difference to the operating temperature. The operating temperature is governed by the cooling system as a whole, not when the thermostat comes in. The only difference here is that it will take longer for everything to warm up. This is obviously an advantage when you are taking your car out to cane it as the temps will rise quickly, the stock thermostat might not react quickly enough to the rapidly rising temperatures and might overheat. With the TRD it opens 10 degrees earlier so the full cooling system, radiator etc, is already in full use giving that extra 10 degree cushion.

 

That's how I understand it anyway.

 

Oh, and that's no use to me as when I'm caning it the engine will already be up to full temperature etc :)

 

but they will make a difference to the operating temperature as its the stat that controls the temp by when it opens and closes, the operating temperature isnt controlled by how far the stat opens, but by what temp it opens at. the radiator and cooling system is only relevant to try and control the temp above stat temp as the rad doesnt see any water until stat opens.

 

some of the post your refering to is actaully incorrect as lined out above.

Edited by scoooby slayer (see edit history)
Link to comment
Share on other sites

Someone mentioned removing the `stat altogether earlier. this is BAD BAD BAD. Modern engines have a calculated and physically measured flow and pressure drop around the head and block, and the way the 2JZ `stat operates has a profound effect on this. Removing it altogether could actually cause nucleate boiling and / or a far less efficient cooling system. There are very good reasons why you would NOT want to run a lower than stock coolant temperature actually, and I can think of very few good reasons to run the TRD `stat.

 

agreed

Link to comment
Share on other sites

but they will make a difference to the operating temperature as its the stat that controls the temp by when it opens and closes, the operating temperature isnt controlled by how far the stat opens, but by what temp it opens at. the radiator and cooling system is only relevant to try and control the temp above stat temp as the rad doesnt see any water until stat opens.

 

So you're saying that running a TRD stat would see constant 74 degree temps?

Link to comment
Share on other sites

So you're saying that running a TRD stat would see constant 74 degree temps?

 

if its a 74d stat then yes it will as the stat opens and lets water flow from the engine to the radiator to be cooled, ive had a drilled stat in a skyline and temps would only go above 75c in traffic never on the move as the radiator was holding temps at 75c. it wont in traffic as thats dependant on the fan cut in switch temp.

Link to comment
Share on other sites

if its a 74d stat then yes it will as the stat opens and lets water flow from the engine to the radiator to be cooled, ive had a drilled stat in a skyline and temps would only go above 75c in traffic never on the move as the radiator was holding temps at 75c. it wont in traffic as thats dependant on the fan cut in switch temp.

 

There has to be a bottom level though, there has to be a point where the stat is fully open all of the time and the system is running at it's coolest. You couldn't stick in a 20 degree stat and see 20 degree temps for example.

Link to comment
Share on other sites

I have a trd stat, my car sits around 87-91 when fully up to temp, 87 is when my fans turn off, 91 is when they turn on.

 

That was kind of my thinking. The stock system will run around 90 degrees. It won't really matter how much of a lower thermostat you have in there as it will only come into play at the level it opens at until the level it sits at normally.

Link to comment
Share on other sites

I have a trd stat, my car sits around 87-91 when fully up to temp, 87 is when my fans turn off, 91 is when they turn on.

 

is that in traffic though jamie ? if your cruising along with a 74c temp stat then temps should be around 74c.

 

all this thread makes no sense to me, im a mechanic by trade ive run an engine with no stat and it wouldnt even get hot enough to get the heater warm enough to demist properly on a mk2 escort 1600 crossflow, the stat is what regulates the temperature, same as when they stick shut will overheat as no water gets through the radiator, its the stat that regulates when the water goes from just flowing around the engine to flowing through the radiator for cooling.

Link to comment
Share on other sites

is that in traffic though jamie ? if your cruising along with a 74c temp stat then temps should be around 74c.

 

Mine are never that low, i dont study the temps as its not on my main screen, i have to flick though to see it, i have a light that comes on when my fans kick in, its never on when im on the motorway but the fans kick in and out when im driving about on b roads.

Link to comment
Share on other sites

The stat has an opening temp - this is the temp at which the rapid engine temp climb (stat closed) is started to be slowed down - then the stat controls this slowed rise upto its full open temp

the full open temp is what you see on the temp guage as normal

so if you now floor the car and maintain a very high constant speed - the water pump runs faster and stat stays full open - the water temps stay normal BUT the oil temps rise - excess heat is going to oil as the water system is maxxed out -no more flow is available -stat open and pump high speed

Along with oil temp rising the cylinder head temp rises and the cylinder wall temp rises - these all inpact the detonation point of the engine and the exhaust valve temps

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.