TRD 1.3 Radiator Cap - Toyota Nation Forum : Toyota Car and Truck Forums

JetspeedCamry · 12-18-2004, 03:28 AM

I'm running a TRD 1.3 Radiator Cap. Just wanting to know the affect of changing from the standard 0.7. Is it good for the motor? My other one was had it, the seals where gone so this one was available at the time.

Regards

88 LE · 12-18-2004, 08:20 AM

You'll have more pressure in the cooling system. If you over pressurize the system, theres a possibility for leaks, blown hoses, and seals.

0.7 bar = 10.29 psi

1.3 bar = 19.11 psi

Porkch0p220 · 12-18-2004, 10:17 AM

is that a good thing? or a bad one to add more pressure?

Gen3cruiser · 12-18-2004, 11:33 AM

standard .7?

I'ts either .9 or 1.1 onb the 5sfe

Hajoca · 12-18-2004, 02:55 PM

Higher perssure of the cooling system before it vents from boil over. Just like a pressure cooker, water boils at 100 degrees C at 1 atmosphere (101.32kpa) .

1 bar = 100kpa

at a pressure of 1.3 bar, water will not boil until it is about 130 degrees. (actual boil is the bubbling of water, changing from liquid to steam)

Now you have a Ethylene glycol and water mix, so check the concentration ratio chart and you can get the boil temperature. Usually is is given that a 15psi system pressure is used.

EG% Freeze Boil (celcius)
40% -24 126
50% -37 129
60% -52 132
70% -64 136

So the 19psi system will take more heat to boil the coolant, and the larger the temperature difference of the radiator and surrounding air, the faster heat is tranfered.

This also stresses the cooling system mechanically as it demands the seals/ hoses/connections etc. to hold that all in.

JetspeedCamry · 12-18-2004, 06:25 PM

Like a science lesson! Great thanku for your help.
My original cap when I got the car was 0.7 bar. I don't know if that is standard or not. (My manual says it, but Ill check it later). I bought this 1.3 bar one because it was just there at the time. So far, I only have one leak from, what I think is, my water pump. That was there before however. Everything else seems to be ok.
By increasing the amount of heat it takes to boil the coolant, does this mean that the engine runs better/cooler? Or is that a bad thing.
TRD made this cap, so I was under the impression that it was better than a standard cap.

terrastrife · 12-19-2004, 11:24 AM

Quote:

Originally Posted by Gen3cruiser

standard .7?

I'ts either .9 or 1.1 onb the 5sfe

he doesnt have a 5sfe -_- the trd cap would be more performance orientated, so like... for engine that would probbaly have ebtter hoses n stuff

JetspeedCamry · 08-02-2005, 04:08 AM

Will this cause any problems that I should be worried about? Anyone reckon I should put a normal pressure one in? Would the pressure difference btw this and my original cause and difference or wat not?

Thanks

(Thread Revival :P)

terrastrife · 08-02-2005, 08:37 AM

wouldnt the 1.3 give you better cooling? as long as none of the hoses fuck up...

JetspeedCamry · 08-02-2005, 09:14 AM

No idea! Tis why im asking. I need a proper explanation on what the pressure difference does.
Alot of my hoses a good condition atm, ive replace alot, the only one being the bottom one and heater hoses that i havnt.

terrastrife · 08-02-2005, 09:34 AM

raises the coolant boiling point, so itll overflow at a later time.

Super Kaioken · 08-02-2005, 01:05 PM

gen 5 stock is 1.1 bar.......i've read a couple threads about this cap.....
someone said it won't be much use because the water doesn't usually boil? or something to that degree.

5Sfte · 08-02-2005, 08:36 PM

I have been using the 1.3 bar cap on my setup even longer than I have had the turbo and it has presented no problems. Even when my thermostat was stuck and I overheated, it still boiled over as normal and did not blow any hoses or seals. But do make sure your hoses are in good condition anyway. Because like Hajoca said:

This also stresses the cooling system mechanically as it demands the seals/ hoses/connections etc. to hold that all in.

This means that higher stress will expose weaknesses in the cooling system.

SmokingTires · 08-02-2005, 08:59 PM

Seriously.... What benifit does increasing the pressure of the coolant give you? (directed mainly at 88LE since he is one of the few with real tech knowledge)

What benifit does it have that bypassing your thermostat wouldn't help? Even more so, what would it help on any engine that isn't fully built? Unless your overheating majorly, you don't need the increased coolant flow. Which could be more safely done by bypassiong the thermostat, and just keeping coolant constantly flowing?

5Sfte · 08-02-2005, 09:18 PM

Quote:

Originally Posted by SmokingTiresV6

Seriously.... What benifit does increasing the pressure of the coolant give you? (directed mainly at 88LE since he is one of the few with real tech knowledge)

What benifit does it have that bypassing your thermostat wouldn't help? Even more so, what would it help on any engine that isn't fully built? Unless your overheating majorly, you don't need the increased coolant flow. Which could be more safely done by bypassiong the thermostat, and just keeping coolant constantly flowing?

I can only answer this one from my point of view and benefits for my setup. Obviously increased coolant flow equals better heat transfer. This aids me specifically because of the increased heat of the turbocharger. You can as you say remover the thermostat, but I like to keep the thermostat there to warm up the engine on cold starts personally.