Jump to content
SAU Community

Recommended Posts

Hi,nice to meet u all down there. I've a question about the coolant.

"Heat is turbo car killer, right" And most of the people said that add 50% of coolant and 50% of water into the radiator,and that is the correct formual, right. Here is my silly opinion.

If add 60%of coolant and 40% of water into the radiator, will it be more effective for cooling down the engine?

Or 55% of coolant and 45% of water! So i wonder is anyone has that experience about that. Becasue soon i need to flush the radiator and change the coolant. Therefore, i had that idea in my mind.

Cheers mate

Steven

Link to comment
https://www.sau.com.au/forums/topic/27793-question-of-coolant/
Share on other sites

Well the last time I flushed a radiator I used 100% coolant, purely for its non corrosive nature, I dont know if it would make a huge difference to the ability of the radiator to exhange heat - in I doubt it very much.

I was under the impression that coolant served two purposes, to extend the boiling point of water and inhibit corrosion.

water is actually more effective at cooling

but it corrodes like there is no tomorrow

also the coolant acts as a layer in the system to the water doesnt boil like crazy

btw u can buy antifreeze antiboil seperate or as a 50/50 mixed solution

The higher the concentration of glycol in the system, the lower the heat transfer capability of the coolant. So if anything you would want to _reduce_ the coolant concentration to ~30%. No less than 20% howeever. But in either case, it wont have really any real effect on turbo temps on the street.

Alot of ppl get confused and think the glycol (the green shit) in coolant does the cooling in the engine. On the contrary it actually impedes it slightly (compared to straight water) but offers antifreeze/boil protection aswell as caviation/corrosion protection.

Yep, you have pretty much hit the nail on the head, Busky...

Aim for between 33% - 50% Ethylene Glycol mix, as this has a good balance of the superior heat transfer ability of water and the advantage of a broader operating temperature range with the Anti-boil properties.

It's possible with 50% concentration to get a boiling point of around 109 degrees Celcius instead of the usual 100 degrees. This is good in the extreme case of a failed cooling fan, for example, and avoiding the possibity of hot-spot damage which used to badly damage the alloy heads of early RB30's and VG30's by cavitation...

When you buy coolant, read between the lines for the properties. An excellent concentrate will have at least 1000g/litre of glycol. Anything less like nasty cheapo brand ready made and diluted coolants have concentrations as low as 30g/litre. It's pretty much green cordial!!

Thanks mates. So i think it was my silly idea. what about change the radiator perssure cap, will it be help? Our factory cap is o.9Bar, what if changed to 1.3 Bar perssure cap. How's the effect? As i knew is, after changed the higher level perssure cap, the fun will open more often , and could keep the tempture down esaier. Is that right?

Cheers

steven:D

Nope. Another wrong idea.

The reason we use pressure caps is to hold the coolant at a particular pressure. A pressurised system will have a higher boiling point, say 5C higher at 1 bar (Im not sure of the exact figures). The cap will not allow the pressure to exceed its rating by bleeding off the exess into the overflow bottle so it doesnt cause damage to the pipes/radiator etc.

However its not necessary to increase the stock cap pressure unless your coolant constantly hits >95-100C and you need that extra anti boil protection. In most cases, you've probably got a stuffed radiator or a malfunctioning thermostat in order to warrant a higher pressure cap. Unless of course, youve got a T88 hanging off the side of a 2JZ and do circut racing or something...

Most coolants on the market are glycol based, glycol is more effective than water for absorbing heat..

More glycol more heat can be extracted from your engine, but your cars cooling capacity, must be efficient enough for removing

the heat from the cooling medium, so not necessary the more coolant the cooler your car can run, glycol will retain heat if you do not have the capacity to cool it down...

But bear in mind that if a concentrate glycol coolant were used over around 65% with water, you would actually have overheating problems. You are correct though about the car's capacity to actually remove heat in the first place. Not trying to sound smart, but glycol has the ability to stabilise and transfer heat more evenly than water - nuclear thermodynamics.

Here is some links to specs on good quality coolants:

http://www.nulon.com.au/content/tech_ll.htm

http://www.castrol.com.au/products/pdf/B11...reeze%20350.pdf

hmmm, you're not supposed to mix two different types/brands of coolants. reason being that they can actually react against eachother and accelerate corrosion. Should try to at least drain the radiator and undo the drain plug on the block. otherwise, drop the bottom radiator hose and drain it all and flush the whole system with a hose while the heater is set to hot and turned on. that way, you'll get rid of all of the old coolant running inside the car for your heater.

Lets clear up some issues....

Glycol is generally more viscous than water and has a lower heat capacity and thermal conductivity than water. Therefore has a lower heat transfer properties (than water) as the glycol percent (based on a water/glycol mixture) is increased...

These are the boiling points of a Ethylene Glycol mixture with water with E.G in weight percent mixture within the water

0% 99

10% 100

20% 101

30% 102

40% 104

50% 106

60% 110

70% 115

80% 123

90% 140

100% 160

Therefore using something around 40-50% sounds right.

I hope this helps guys!

:uh-huh: yeap! :uh-huh: spot on. although those figures will vary slightly depending on the brand and concentration of the ethylene glycol content of the coolant. I couldn't find a link for Tectaloy, but the Nulon and Castrol links in my previous posts point to what i consider the main players of concentrates.

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

    • Hard to say, just pop the rocker covers off and have a look if you think it's cammed. You probably need to replace the valve cover gasket/half moons anyways.
    • From my youth: GTi-R clutch change is a massive pain. The gearboxes are fragile? But the car is super cool and I want one 😢 
    • Remember this is 1988 tech.
    • Driveline vibration is resolved. I ended up loosening all my engine mount and trans mount bolts, giving it a good shake then retightening everything and it's gone... Let's just say I was surprised that fixed it.  I've been happily driving it around again but unfortunately put zero time into my direct port/constant pressure WMI setup. I'm on vacation next week, so I'll try and finalize it then.  On a different note, I spent all week fuel/ignition mapping 2x 216L V16 engines. Turbo's were burning glycol and we swapped them out for larger units. We also had planned emissions testing on site, so I figured I'd be there the same week to use their instrumentation and massage any emissions issues out if needed. This was a first for me. Fuel management is similar in certain ways to automotive (i.e air density as load variable) but very different in others. It's all PLC based and AFR's are controlled by air and not fuel. They use a control valve between the turbo and air manifold to control pressure which in turn controls AFR's. Due to this, target AFR tables supplied by the OEM are in pressures and not mass which really through me off. They use air pressure vs fuel pressure tables. I also relied on an O2 concentration sensor the emissions team had in the exhaust. Ignition timing was also all over the place and we were losing a fair bit of power. They're now happily sitting at 16-40BTDC depending on load. We were making about 1600kw at 900rpm at 90% load. Engines were running a lot smoother as well.    
    • heh, aint no R32 ever meeting modern targa cage rules unless the driver is veeeery short OP, good luck with the sale, since its already in the land of freedom I'm sure you will find a good buyer.
×
×
  • Create New...