radiator cap pressure rating? [Merged 9-9]

[pilsner]

how much pressure is the rad cap in the 1g turbo talon supposed to hold?

 

[Evol]

13 psi

 

[pilsner]

thank you!

 

[98spydert]

So are these things a joke or a good idea? One came with my new car and I was wondering if I should sell to an ebayer or use it?

The boiling point of water is raised when it's presurized but (assuming good hoses) can the system take the higher pressure?

 

[Royalty]

i have a greddy one. it looks freakin awesome.

 

[12sec92Tsi]

I also use the greddy unit. Looks great and haven't had any problems with it yet.

 

[Defiant]

Stay with the factory-specification radiator cap, regardless of what name's on it.

 

[98spydert]

Stay with the factory-specification radiator cap, regardless of what name's on it.

What harm can come from the higher pressure cap?

 

[alexg1323]

for every 1psi of pressure raised the boiling point is raised 1* F But then again when are you ever running your car near the limit of the coolant boiling anyways? Unnecessary and only helps squeeze coolant places you dont want it to be if you ask me.

 

[16g-95gsx]

It's 3* for every 1psi roughly, not 1*.

 

[alexg1323]

opps your right, my bad

 

[Bohrn]

it does help keep your car cooler. BUT it will add more stress to your cooling system.

If you have a Fluidyne or other welded rad, and really good hoses etc, go for it if you need top.

I have had 2 rads let go at the crimps, one tank crack and one upper pipe crack off. And this is just with the stock cap.

 

[RitdoggyGS]

Whats the factory radiator cap pressure... between 6-8 psi??

thanks all

 

[CYCLONE]

its 0.9bar, which is right around 13 psi.

 

[Tarantula]

I wanted to know if getting a 1.3 bar radiator cap too high for our engine. Will it be a help or will it be bad for the engine?
I'm worried about blowing the water pump seal or throttle body fiav seal. It is said that a higher pressure makes the engine run cooler. Anyone with experience???

 

[JiggahMan]

I run 20psi daily on my 20g, no problems.

 

[Newlogics]

I run 20psi daily on my 20g, no problems.

He's asking about a 19psi radiator cap, not boost level.

19lb cap will put make certain types of radiator hoses bubble. It's not enough to blow a seal on the pump, but it does speed up wear a bit. When are you overheating? Why are you trying to run cooler? Have you tried cooler thermostat?

 

[DSMTalonAWD51]

umm, hes talking about radiator caps not turbos. But anyways, you should be fine with either the .9 or the 1.3 cap. With the 1.3 the higher pressure is going to circulate coolant coolant faster, so it will cool the motor better at higher speeds. The problem is that at idle the faster circulation doesnt cool it down as well and you may run a little hotter at stop lights. Also with the higher pressure you want to make sure all your hoses are in good condition and clamped on tight you dont want them coming off. I got the .9 just because it was cheaper and my car never overheats anyway, as long as you keep your coolant system in good shape theres not really a need for it but its up to u.

 

[Tarantula]

He's asking about a 19psi radiator cap, not boost level.

19lb cap will put make certain types of radiator hoses bubble. It's not enough to blow a seal on the pump, but it does speed up wear a bit. When are you overheating? Why are you trying to run cooler? Have you tried cooler thermostat?

Basically I put on a fmic and my coollant gets to 222 degrees at freeway speeds (70-80). At idle and normal driving around town, my temps are fine (210) Also If I step on it to booast, my temps rise. I have a new all metal radiator, and I have always changed and flushed my coolant every year. My cap is a Mitsubbishi .9 cap (1 yr old) and the thermostat is also 1 year old and its a Mitsubishi 180 thermostat. Even with the stock fan running high (A mod I figured out myself) all the time going up hills on the freeway or slamming the gas boosting 18psi makes coolant temps rise. It does cool off but takes a while but if I stop the car and let it idle, it will go down to 206. The FMIC block flow to the radiator and that is why I'm having difficulty keeping temps down. At night I haven't noticed a problem, just in the hot Cali day. Oh and I'm not running antifreeze. I'm running distilled water and 40 below ( a product similar to Water Wetter)
I'm going to try a 170 degree thermostat. And another fan as a pusher to see if it helps. I am worried about using a higher radiator cap (even though I already bought a 1.3 bar Raliart cap)

 

[Newlogics]

Basically I put on a fmic and my coollant gets to 222 degrees at freeway speeds (70-80). At idle and normal driving around town, my temps are fine (210) Also If I step on it to booast, my temps rise. I have a new all metal radiator, and I have always changed and flushed my coolant every year. My cap is a Mitsubbishi .9 cap (1 yr old) and the thermostat is also 1 year old and its a Mitsubishi 180 thermostat. Even with the stock fan running high (A mod I figured out myself) all the time going up hills on the freeway or slamming the gas boosting 18psi makes coolant temps rise. It does cool off but takes a while but if I stop the car and let it idle, it will go down to 206. The FMIC block flow to the radiator and that is why I'm having difficulty keeping temps down. At night I haven't noticed a problem, just in the hot Cali day. Oh and I'm not running antifreeze. I'm running distilled water and 40 below ( a product similar to Water Wetter)
I'm going to try a 170 degree thermostat. And another fan as a pusher to see if it helps. I am worried about using a higher radiator cap (even though I already bought a 1.3 bar Raliart cap)

Keep in mind that coolant is also a lubricant. Water pump will not last much on pure water. Also, water has lower boiling point, and based on personal experience, when it gets very hot and water boils, it cool much worse then water/coolant mixture.

 

[DSMTalonAWD51]

1. dont go lower than a 180 thermostat, besides thats not going to cool you down more its just going to open up sooner.
2. if you have a 50/50mix try 60water/40coolant it may bring temps down a few degrees
3. buy some sheet metal and create ducting from your front mount to the radiator. it seriously works wonders. it will reduce air turbulance and force more air directly through your radiator.

 

[92awddsm]

With the 1.3 the higher pressure is going to circulate coolant coolant faster, so it will cool the motor better at higher speeds. The problem is that at idle the faster circulation doesnt cool it down as well and you may run a little hotter at stop lights.

Are you sure you understand what the higher pressure cap really does? It doesnt speed up coolant circulation, that is determined by the water pump volume and rpm. The higher pressure cap does just what it says. It raises the pressure in the cooling system. This excess pressure effectivly raises the boiling point of the water and in turn keeps the coolant from becoming vapor which is what causes the overheating and boiling over.

 

[Tarantula]

1. dont go lower than a 180 thermostat, besides thats not going to cool you down more its just going to open up sooner.
2. if you have a 50/50mix try 60water/40coolant it may bring temps down a few degrees
3. buy some sheet metal and create ducting from your front mount to the radiator. it seriously works wonders. it will reduce air turbulance and force more air directly through your radiator.

1) I figured that if it opens sooner than it will flow into the radiator sooner. Where there will be a fan steadily flowing air through to cool it down. Even with the 180, my temps (Even before the fmic when I had no problems) never went lower than 195-199. The thermostat starts to open at around 180 and by the time its fully open you would have reasched 10 degrees hotter. I figured by 170, I would have a fully open thermostat at 180-185.
2) I have 80/20 mix. It has brought temps down a few degrees but it still manages to get to 222, just takes longer. Like I said it only gets there if I drive at 70-80 steadily for at least 10-15 minutes or climbing small hills or racing the engine to higher RPM through shifts. (18 psi)

3) When I installed my FMIC, I made a shroud out of sheetmetal and its joined to the original ducting that was originally there. I just made it so the FMIC can go snugly up against it.

 

[radbradyah]

anyone know of a link to pics or an example of making a duct to push air to the radiator for those with a fmic?

 

[Tarantula]

anyone know of a link to pics or an example of making a duct to push air to the radiator for those with a fmic?

This LINK Helped ME when I was fabricating my ducting. Its not all that clear but it gave me the idea. You can see how I did mine. I since then removed the lower part of the plastic ducting. I used those pipe insolators to have the FMIC snugly up against it to seal it off. It helped a little when I did it.