81°C Cooler Thermostat?????

[holdenvx38]

Hey all,
im looking for a bit of info/reviews on whether it does much or anything? have done a search but came up with nothing
has anyone put one of those 81°C Cooler Thermostat on their commo?
wondering if its worth it?
link to it is:81°C Cooler Thermostat from Forced Induction Technologies - Australia's V6 Supercharged Specialists

current mods are
custom cai
splitfire dual core leads
triple platnium sparks

thanks

[Shounak]

Cooler temperature means inefficient compression, higher emissions, possibly worse economy which would lead to increased wear on your exhaust and engine.

I don't see how an 81 degree thermostat would help a basically stock motor like yours. You haven't got any modifications, you'd be on drugs if you think this will make any improvements.

If you really want a cooler engine, just take the thermostat out altogether. That way you'll keep it very cool at all times. But you'll probably be suffering from a milder version of the symptoms I listed above.

Plus, your engine is designed to operate at 90, that's the whole reason you have a thermostat. Best not to screw with it unless you start making some real power.

For you, there are much better ways to waste your money.

[Shounak]

I just read the website. What a load of rubbish.

If cooler engine = more power, as they so authoritatively stated, then why wouldn't all engines be better off without a thermostat? All it does it heat the engine up more.

It sounds like they have no idea about optimal operating temperatures. My vote is to steer clear.

[holdenvx38]

thanks mate
i got yt rockers and plenmum spacer coming, + exhasut system in the next month or so just wondering if anyone has done it, sounds cheap but just a thought as i havnt heard of it and i know fit make some alright stuff..

[VL Berlina 5speed]

If you really want a cooler engine, just take the thermostat out altogether. That way you'll keep it very cool at all times. But you'll probably be suffering from a milder version of the symptoms I listed above.

if you remove the thermostat your car will over heat when sat at lights or driving up a hill etc.
the thermostat is designed to also slow the flow of water down to allow it to cool the engine.

if you take it out you will soon find the car overheating

[Shounak]

if you remove the thermostat your car will over heat when sat at lights or driving up a hill etc.
the thermostat is designed to also slow the flow of water down to allow it to cool the engine.

if you take it out you will soon find the car overheating

Why would it overheat? The constant circulation of water around the system would keep it cooler I would imagine.

I've never tried this at all btw, I'm just talking theoretically on what I think would happen. I'd be happy to be proven wrong with empirical evidence or a good explanation.

[hail storm]

By taking the thermostat out the flow of coolant has no restrictions,hence the coolant flows through the radiator to fast and doesn't cool down.

[LowVp]

the idea of the 81 degree thermostat is to reduce the pinging in the supercharged motors as intercooling them is on the good side of 2.5k so a 10 dollar item. its just a small step in reducing pinging. i have a 81 degree thermostat in my V6 but its boosted and for the same reason

[commsirac]

By taking the thermostat out the flow of coolant has no restrictions,hence the coolant flows through the radiator to fast and doesn't cool down.

Sorry, the no.1 old mechanics tale in motoring.
If you applied the same logic at the other end it would be flowing so fast it wouldnt have time to heat up as it goes through the engine. The block would turn red hot, but the coolant would be stone cold and the temperature gauge would read low.........doesnt happen.

Taking the thermostat out can upset coolant flow, much like when you turn a tap on full bore in the sink and it goes everywhere and doesnt drain properly. The upset to coolant flow can create a drop in the actual rate of coolant ciruculating through the radiator causing an increase in temp of the coolant in the block. The actual chances of this happening is quite small, and most cars will not suffer this fete when removing the thermostat.......they'll just run too cool.

Engine's are more efficient when they are hot. But design of materials restricts them to the temps we have, ie coolant boiling point, piston,valve material etc.

[Bravotwozero]

I just read the website. What a load of rubbish.

If cooler engine = more power, as they so authoritatively stated, then why wouldn't all engines be better off without a thermostat? All it does it heat the engine up more.

It sounds like they have no idea about optimal operating temperatures. My vote is to steer clear.

They run hotter because of emissions nothing else. When I had my MAFless tune done it was recommended I run a cooler thermostat. Don't know if there would be a benefit on a stocker though.

[Fr3ak+--]

my theory would be a cooler thermostat would keep the engine that tad colder which would stop the air from heating up as much in the engine bay

in turn you get colder air into the engine

if i am wrong please tell me otherwise

just a theory

[VN_Luke]

from the link:

meaning the engine will operate cooler and produce more power, as we all know cooler engine = more power

I'm not sure if by 'operate cooler' they mean 'cooler combustion temps' or 'cooler engine bay'

in either case;

I doubt this would have a significant impact on combustion temperatures - if it does, then you might be able to run a bit more spark advance before you get detonation, but of course this will require an ecu remap...

I think there's SFA chance that this would impact engine bay/intake temperatures. (I ran a cooler thermostat on my vp, and noticed no 'feelable' difference)

I reckon in this particular case, unless you remap your ECU, it's more likely that any power gains will be negated (and probably over-ridden) by the fact that your engine will never reach 'correct' operating temperature, and as such, the ECU will provide fuel/spark for an engine that's 'warming up', rather than optimal temp.

[immortality]

it is a proven fact, hotter for economy and emmisions, cooler for making power(going to cold will also cause issues however as mentioned above^^^, don't run without a thermostat). a couple of cheap worthwhile mods for a V6 is the MACE manifold insulator. helps keep the intake charge cooler and increases runner length. proven results on a dyno. many happy customers that i've heard from.

then there is the EGR gasket "support" plate mod which will also reduce intake temps at certain times. refer to the raptor blown VY project thread for more info. extremly cheap mod

edit: i run a 81 degree thermostat along with a host of other "keep it cool" intake additions to my car. after cruising, pulling in my driveway, stop car and pop bonnet the TB is still cold, i'll type that again...cold... to touch. only the elbow between TB and plenum is starting to get warm. how does my car run. read my ride thread and see for yourself.

[Shounak]

it is a proven fact, hotter for economy and emmisions, cooler for making power(going to cold will also cause issues however as mentioned above^^^, don't run without a thermostat). a couple of cheap worthwhile mods for a V6 is the MACE manifold insulator. helps keep the intake charge cooler and increases runner length. proven results on a dyno. many happy customers that i've heard from.

then there is the EGR gasket "support" plate mod which will also reduce intake temps at certain times. refer to the raptor blown VY project thread for more info. extremly cheap mod

edit: i run a 81 degree thermostat along with a host of other "keep it cool" intake additions to my car. after cruising, pulling in my driveway, stop car and pop bonnet the TB is still cold, i'll type that again...cold... to touch. only the elbow between TB and plenum is starting to get warm. how does my car run. read my ride thread and see for yourself.

Keeping the air cool and the coolant valleys in the head are two different things.

When you cool down air it has more oxygen in it and provides for a bigger bang. That's why intercoolers reduce the psi, but provide for the same amount of power.

A cooler combustion chamber will not allow efficient compression and therefore combustion. This will of course lead to worse emissions and less power.

A combustion chamber operates optimally at a specified temperature, reducing that temperature is likely to do absolutely nothing good.

I seriously don't see any benefit from this thermostat, for a stock engine. It will prevent the engine from operating at its optimal temperature, that's about it. In the combustion chamber, it's not a good thing.

[immortality]

Keeping the air cool and the coolant valleys in the head are two different things.

When you cool down air it has more oxygen in it and provides for a bigger bang. That's why intercoolers reduce the psi, but provide for the same amount of power.

A cooler combustion chamber will not allow efficient compression and therefore combustion. This will of course lead to worse emissions and less power.

A combustion chamber operates optimally at a specified temperature, reducing that temperature is likely to do absolutely nothing good.

I seriously don't see any benefit from this thermostat, for a stock engine. It will prevent the engine from operating at its optimal temperature, that's about it. In the combustion chamber, it's not a good thing.

it's a proven fact that engines make more power at certain coolent temps, proven on a dyno where they can artifically control the coolant temp. your run of the mill engine isn't designed to produce max power, it's designed for economy and emmissions. this is fact.

(static) compression is effected by stroke and displacment. changing the temperature isn't going to effect that. changing the intake charge temps alters the desity of the intake charge this does effect power. cooler air = more oxygen therefor you add more fuel and you get a bigger bang (power)

dynamic compression changes dependent on engine rpm,loading, throttle setting etc. dynamic compression changes if you put in a larger cam due to increased cam duration and overlaps. effectivly the piston is further up the bore before the cam closes the valve. this is reduced dynamic compression at lower rpm's and the reason you normally increase static compression when fitting a larger cam.

dynamic compression effects the amount of timing advance you can run before you get pre-ignition/detonation etc. it's all about time/heat/compression or pressure (and fuel quality). compression(static) is generally something you don't alter on a day to day basis, so is the time the charge is under compression (only alters with RPM) heat on the otherhand is something that you can control. the intake charge is effected the the metal of the surrounding engine parts, intake manifolds, heads, valves etc

will a 81 degree thermostat make a difference on a stock standard engine. not really, will it on a highly tuned, modified engine. yes it will

when i fitted the 81 degree thermostat i didn't notice any decrease in economy, that comes down to my right boot and seeing it's a size 15 it's fairly heavy

[commsirac]

double post

[commsirac]

from the link:



I'm not sure if by 'operate cooler' they mean 'cooler combustion temps' or 'cooler engine bay'


.

Cooler engine bay can help, but if you use a lower temp thermostat, then more heat is released into the engine bay via the radiator, which could actually have the effect of actually making the intake air hotter if you dont have a cold air intake.
The design principles of a heat engine call for its combustion temps to be as high above the surrounding temps as possible.....that means making the temp on the inlet and exhaust as cool as possible and/or operating the engine in as cold an environment as possible.
For what its worth the instantenous fuel reading on my vx tells me it uses less fuel when the temp gets to full operating temp 90C, ~7/15 on the gauge, compared to much higher use when at 1/3 readings. What is happening, cant be sure.......whether the computer feeds a richer mix because of the coolant sensor or that more petrol is fed because its not operating as efficiently .......cant be sure.

[chargedvx6]

Keeping the air cool and the coolant valleys in the head are two different things.

When you cool down air it has more oxygen in it and provides for a bigger bang. That's why intercoolers reduce the psi, but provide for the same amount of power.

A cooler combustion chamber will not allow efficient compression and therefore combustion. This will of course lead to worse emissions and less power.

A combustion chamber operates optimally at a specified temperature, reducing that temperature is likely to do absolutely nothing good.

I seriously don't see any benefit from this thermostat, for a stock engine. It will prevent the engine from operating at its optimal temperature, that's about it. In the combustion chamber, it's not a good thing.

The whole point of trying to reduce temps in an engine is to reduce detonation or pre ignition or pinging, whatever you want to call it.


Also cooler air doesn't have more O2 in it. It will have a denser structure which means in the same space eg. comp chamber, there will be a greater volume of air.

Shounak you have some good points but I think they are extreme examples. A cooler thermo is a 1% mod and wouldn't really alter all the parameters you are talking of. Things that will alter those parameters are cooler plugs, a cam, different boost levels on FI etc.......

The thermo would only really be useful at the drags if you let the car cool cown between runs then b4 the next run start up and go and run straight away b4 heat soak sets in again.

[andyman]

it will do nothing, remember this, a 81 thermostat WILL OPEN at 81 degrees, a 91 thermostat WILL OPEN at 91 degrees, the thermo fans turn on at 100degrees or there abouts,

all a thermostat is basically a restricter, it allows an engine to heat up quicker and maintain temperatures while there, it will not keep a car cooler - it will just open sooner, the radiator keeps the car cool,

in short, the engine will still get to 100degrees at the lights, heavy traffic, towing etc, on the open road it will be a little lower, there is really no need for it unless your in burnout comps etc, which you would just use a punched out thermostat anyway but thats another story....

[daron]

holdenvx do it it makes a huge difernece in the way it runs
go to your local repco or natrad only 19 bux i payed and 2 bux for gaskit
38 bux is steep in my opinion
ive read all the crap in this thead and most wouldnt know cause they dont have it but the onnes who do have itwill tell you go do it
its easy to do takes under 30 mins
good time to flush system too

[IMCRZY]

I have one in my car and it did not make no difference performance wise... The gauge reads 77 - 82 degrees when on highway and probably uses a little more fuel than what it used to...

They make a high flow 91 degree thermo that would be a better option and what im going back to...

But its not worth the hassle....

[vxcalais_01]

Firstly, you would be better off getting the Tridon Hi Flow Thermostat in the 91 degree. The Tridon Hi Flow has the same ability as the 81 degree thermo and works in Harmony with fans sensors etc.

If you wanna go the colder one so you can put it on a bragging list, don't get the FIT one, look how much they charge, just get a Dayco/Stant/Trident etc for $17-$19.

[vxcalais_01]

ARE Cooling (Aluminium Radiators & Engineering P/L)

This site has the best explanation you could get on Thermos.

[Shounak]

The whole point of trying to reduce temps in an engine is to reduce detonation or pre ignition or pinging, whatever you want to call it.


Also cooler air doesn't have more O2 in it. It will have a denser structure which means in the same space eg. comp chamber, there will be a greater volume of air.

Shounak you have some good points but I think they are extreme examples. A cooler thermo is a 1% mod and wouldn't really alter all the parameters you are talking of. Things that will alter those parameters are cooler plugs, a cam, different boost levels on FI etc.......

The thermo would only really be useful at the drags if you let the car cool cown between runs then b4 the next run start up and go and run straight away b4 heat soak sets in again.

Agreed.

Also good explanation above about the thermo's. The link's awesome.

So pretty much conclusion is that the FIT thermo is a waste of money, much cheaper alternatives exist, but are pretty much useless on a stock engine unless you partake in burnout comps or drags?

[vxcalais_01]

Why would you pay $50 for a FIT Thermo ? Does it make it faster, and its not as if FIT make em either. Dayco, Stant etc are the way to go, or standard temp hi flow is what i am looking at getting. Repco or Bursons just order them in. Even call Tridon for the Part No. and order that in.