Do I need a 3rd radiator?
01-26-2017, 04:31 PM
#16
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.. we are getting our 3rd radiator kits in early next week, on the 997.1 they are price very reasonably (~$225). On the 986 and 996 they are about twice as much!
As track rats, we like to get as much cooling as possible. I agree as Iceter mentioned that your thermostat doesn't open until temps get higher hence adding a 3rd radiator shouldn't slow down the warming up process.
As track rats, we like to get as much cooling as possible. I agree as Iceter mentioned that your thermostat doesn't open until temps get higher hence adding a 3rd radiator shouldn't slow down the warming up process.
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01-26-2017, 05:53 PM
#18
Three Wheelin'
Why did Porsche start offering a 3rd radiator on the 997.1? On the 997.2, they went back to no 3rd radiator because cooling was improved, then they added the option again.
01-26-2017, 10:52 PM
#19
JAMES -
A cooler thermostat doesn't affect the high end of a car's normal operating temperature because that upper limit is dictated by the car's cooling system as a whole. A cooler thermostat will extend warm up time, which allows the car to run at a suboptimal temperature longer than it should. It also allows this to happen when the outside temperature is low and the cooler thermostat is not restricting flow as early as the stock unit would have. This is rarely a good thing.
A LTT opens the flow earlier - so will not extend the warm time - quite the opposite.
I have no idea how sensitive these engines are to engine and coolant temperature changes, but I do know that there are lots of cars that are extremely sensitive to coolant temperature being outside of a narrowly prescribed range. I would think that a DI engine would be particularly sensitive to this. I wouldn't go with a lower temperature thermostat unless I had both a ton of evidence showing that it wouldn't negatively affect my engine and a real need for that thermostat.
OP has 2005 car NOT DFI ( which already have LTT in them)....
Also Porsche did this for Emissions which had become stricter.
A cooler thermostat doesn't affect the high end of a car's normal operating temperature because that upper limit is dictated by the car's cooling system as a whole. A cooler thermostat will extend warm up time, which allows the car to run at a suboptimal temperature longer than it should. It also allows this to happen when the outside temperature is low and the cooler thermostat is not restricting flow as early as the stock unit would have. This is rarely a good thing.
A LTT opens the flow earlier - so will not extend the warm time - quite the opposite.
I have no idea how sensitive these engines are to engine and coolant temperature changes, but I do know that there are lots of cars that are extremely sensitive to coolant temperature being outside of a narrowly prescribed range. I would think that a DI engine would be particularly sensitive to this. I wouldn't go with a lower temperature thermostat unless I had both a ton of evidence showing that it wouldn't negatively affect my engine and a real need for that thermostat.
OP has 2005 car NOT DFI ( which already have LTT in them)....
Also Porsche did this for Emissions which had become stricter.
01-26-2017, 11:19 PM
#20
Not to harp on - but i just saw this linked from another article posted - it's from pelican Parts Tech article
The factory thermostat starts to open at about 187 degrees F (86 degrees C) and only fully opens at almost 210 degrees F (99 degrees C). This means that the engine needs to get very hot before it starts sending its coolant to the front radiators. For this reason, I recommend installing a low-temperature thermostat in place of the factory one. LN Engineering has developed a thermostat that starts opening at 160 degrees F (71 degrees C) and is fully open at about 180 degrees F (82 degrees C). Lower coolant temperatures translate into lower oil temperatures, and the dyno tests that LN Engineering has performed on the cars with the low-temp thermostat installed have revealed a small increase in horsepower (typically about 5 horsepower). It is my guess that Porsche designed the thermostat to open a bit later in order to help the cars run a bit hotter, which typically helps with emissions testing and the burning off of water out of the oil, which can then lead to longer oil change intervals. Installing the low-temp thermostat is a smart idea for engine longevity--it's available for about $175 from PelicanParts.com.
http://www.pelicanparts.com/techarti...eplacement.htm
The factory thermostat starts to open at about 187 degrees F (86 degrees C) and only fully opens at almost 210 degrees F (99 degrees C). This means that the engine needs to get very hot before it starts sending its coolant to the front radiators. For this reason, I recommend installing a low-temperature thermostat in place of the factory one. LN Engineering has developed a thermostat that starts opening at 160 degrees F (71 degrees C) and is fully open at about 180 degrees F (82 degrees C). Lower coolant temperatures translate into lower oil temperatures, and the dyno tests that LN Engineering has performed on the cars with the low-temp thermostat installed have revealed a small increase in horsepower (typically about 5 horsepower). It is my guess that Porsche designed the thermostat to open a bit later in order to help the cars run a bit hotter, which typically helps with emissions testing and the burning off of water out of the oil, which can then lead to longer oil change intervals. Installing the low-temp thermostat is a smart idea for engine longevity--it's available for about $175 from PelicanParts.com.
http://www.pelicanparts.com/techarti...eplacement.htm
01-27-2017, 08:54 AM
#21
Rennlist Member
It was never an option. Some configurations had a 3rd radiator. IIRC, cars with tiptronic trans or X51 performance package...but not always.
01-28-2017, 09:46 AM
#22
RL Community Team
Rennlist Member
Rennlist Member
Not to harp on - but i just saw this linked from another article posted - it's from pelican Parts Tech article
The factory thermostat starts to open at about 187 degrees F (86 degrees C) and only fully opens at almost 210 degrees F (99 degrees C). This means that the engine needs to get very hot before it starts sending its coolant to the front radiators. For this reason, I recommend installing a low-temperature thermostat in place of the factory one. LN Engineering has developed a thermostat that starts opening at 160 degrees F (71 degrees C) and is fully open at about 180 degrees F (82 degrees C). Lower coolant temperatures translate into lower oil temperatures, and the dyno tests that LN Engineering has performed on the cars with the low-temp thermostat installed have revealed a small increase in horsepower (typically about 5 horsepower). It is my guess that Porsche designed the thermostat to open a bit later in order to help the cars run a bit hotter, which typically helps with emissions testing and the burning off of water out of the oil, which can then lead to longer oil change intervals. Installing the low-temp thermostat is a smart idea for engine longevity--it's available for about $175 from PelicanParts.com.
http://www.pelicanparts.com/techarti...eplacement.htm
The factory thermostat starts to open at about 187 degrees F (86 degrees C) and only fully opens at almost 210 degrees F (99 degrees C). This means that the engine needs to get very hot before it starts sending its coolant to the front radiators. For this reason, I recommend installing a low-temperature thermostat in place of the factory one. LN Engineering has developed a thermostat that starts opening at 160 degrees F (71 degrees C) and is fully open at about 180 degrees F (82 degrees C). Lower coolant temperatures translate into lower oil temperatures, and the dyno tests that LN Engineering has performed on the cars with the low-temp thermostat installed have revealed a small increase in horsepower (typically about 5 horsepower). It is my guess that Porsche designed the thermostat to open a bit later in order to help the cars run a bit hotter, which typically helps with emissions testing and the burning off of water out of the oil, which can then lead to longer oil change intervals. Installing the low-temp thermostat is a smart idea for engine longevity--it's available for about $175 from PelicanParts.com.
http://www.pelicanparts.com/techarti...eplacement.htm
01-28-2017, 03:09 PM
#24
Drifting
Saying this warms the engine quicker defies logic.
01-28-2017, 03:50 PM
#25
Rennlist Member
Deep in South Texas where I live, common temps in the summer are 90-99 degrees. My C4S (997.2) with the standard 2 radiator set up, has no problem with climbing temps while idling, since the oil and water temps are already high. I have tracked that car in San Marcos Texas but it was a mild day for Texas - mid to high 80s. Tracking the car had no effect on the temps at all.
01-28-2017, 06:06 PM
#27
Rennlist Member
The third radiator was developed for pdk cars to remove the extra heat generated by the trans. Not needed for street use on non-pdk cars.
01-28-2017, 06:52 PM
#28
Rennlist Member
01-29-2017, 05:05 PM
#29
Rennlist Member
.. we are getting our 3rd radiator kits in early next week, on the 997.1 they are price very reasonably (~$225). On the 986 and 996 they are about twice as much!
As track rats, we like to get as much cooling as possible. I agree as Iceter mentioned that your thermostat doesn't open until temps get higher hence adding a 3rd radiator shouldn't slow down the warming up process.
As track rats, we like to get as much cooling as possible. I agree as Iceter mentioned that your thermostat doesn't open until temps get higher hence adding a 3rd radiator shouldn't slow down the warming up process.
01-29-2017, 06:28 PM
#30
3rd radiator is a must for any 997 car. Low temp thermostat is more harmful than useful as it offsets proper operational temperature of a block. Other must do mod is a 996 x51 oil pan to prevent oil starvation - google it up, there are no more such original pans left but there are substitutes with same rubber baffles that fit snugly inside of the block.
LTT only opens earlier - it does not stop the car getting to proper operational temperature - think about at.
It starts the water circulating earlier - that is all.