Chris Cox

Long time lurker, first post.

Does anyone know what temperature the stock 996 GT3 thermostat opens at?
I am looking for one that opens at a lower temperature than stock. I noticed that there are two part numbers for the thermostat on the porsche parts list.
996-106-125-53 and 996-106-125-72 but there is no mention of what temp
they open at. There is also one for the cup car 996-106-125-92. Will the cup one fit the GT3 road car?

Anyone have any idea?

Thanks

911SLOW

Chris welcome to RL.

thermostat 996 106 125 53 is a successor part to 996 106 125 52 and only suitable for 996gt3 mk1.

996GT3mk2 uses now 996 106 125 72 which replaced part 996 106 125 70
(same part is used in 997GT3 / 996turbo/996GT2)

Cup cars have 3-4 different thermostat part numbers, I think that all of them would fit but have no idea on the different temp they open up or if that's true at all.
In addition I believe that oem GT3 thermostats already start to open at lower temps than the rest of the 996 / 997.1 series.

Cup cars have a different flow in the cooling system and different radiators that affect running temps.


I suggest that you leave the factory thermostat alone and save your money for something else.

John

TurboCup87

Welcome to Rennlist, Chris. There is a wealth of information here. Much of it is right up there!^^^^^

Chris Cox

Thanks for the info but I am going to research this a little bit more. I like how much harder the car pulls when it is 180 degrees vs 200. I suspect the stock thermostat opens at 195. At that temp the motor gets a little soft. I suspect the ecu pulls timing out of the motor as it gets hotter because the knock sensor
begins to detect detonation as the cyclinder heads get hotter.

Do you have the part numbers for the cup thermostats.

IMGT3

my information says that the factory (STOCK NON-GT3) thermostat begins to open at 186.8F and is fully open at 210F. I believe this is true... i can confirm tomorrow AM. Chuck 167F is the starting point for GT3

http://www.imgt3performance.com/stor...ord=thermostat

911SLOW

I did some research:

The OEM GT3 thermostat is rated at 75°C which for you is 167°F.

996 2003 to 2005 cup car thermostats were rated at 75°C as well.

Chris Cox

That is great information!! Very interesting to see in print what I was speculating. Does the above linked part fit my 04 GT3?

Chris Cox

Thanks much for the research.

IMGT3

Thank slow911...he beat me to the draw! Chuck

FFaust

Oh good, another mod I need.

911SLOW

It's the time zone difference..

You don't need anything. Your thermostat is fine!

Burger

FYI- a thermostat that opens at a lower temperature will not keep your car from warming up to 200.

IMGT3

LN Engineering is a highly regarded maker of porsche precision aftermarket parts. Here is the theory of why a thermostat that opens at a lower temperature is beneficial... remember the GT3 does operate @ 167 degrees, 19.2 degrees lower than the stock M96. Chuck

The principle behind lowering coolant temperatures (regardless of application) is that a cooler engine will have higher volumetric efficiency. Lower temperatures will also allow for more timing without detonation. Since the M96 and M97 ECU’s are capable of changing timing based off of fuel quality and temperature, the lowering of the thermostat operation range can result in higher horsepower and better fuel economy as well.

Special features of this unit include:
· A calibrated German-made 160°F thermostat pre-installed in a new OE Wahler thermostat housing and gasket
· Calibrated to open a full 20-25°F degrees earlier than factory units and fully open by 180-185°F to maximize cooling potential
· Lower coolant temps correlate to a lower oil temperature due to Porsche’s uses of laminar flow type oil to water heat exchangers

Although cooling fans are triggered by the ECU at higher coolant temperatures, while at operating speeds, there is sufficient airflow through the radiators to negate the fact that the cooling fans are not exercised as often. Models featuring the center 3rd radiator have even greater cooling capacity that can now be better utilized. The cooling potential is limited only by airflow across the radiators and unfortunately, in low speed operation, such as in traffic, the low temperature thermostat will be limited by the DME trigger of the cooling fans at temperatures well over 200°F.

In low speed operation or when ambient air temperatures are excessive, additional 'mods' to trigger the cooling fans to come on earlier help to maximize the potential of the LN Engineering 160°F low temperature thermostat. This can be accomplished by hard wiring the fans, as typically done on 964s and 993s previously or by using an aftermarket fan controller like that made by Dakota Digital.

Cold weather testing has shown warm up times are not affected nor is cabin heat affected even at 34°F below zero (with wind chill)! Cold start and warm up enrichment provided by the ECU also is not affected by the use of the LN Engineering low temperature thermostat. The low temperature thermostat remains closed below the threshold of normal coolant temperatures allowed by the DME, so it does not abnormally affect operation or result in a CEL. The 160°F Low Temperature thermostat allows the DME to operate within its normal parameters specified Porsche, and gains in performance and reliability are measured in changes to ignition curves and fuel trims.

IMGT3

Chris, the GT3 has a different cooling system from the M96/97 and the LN product is not compatible. Good news is that Porsche has already given you a thermostat that begins to open at 167 degrees.

Chuck

henny

Hello from Germany,


has anyone of you installed the thermostat 996-106-125-92 before? Is this really a 75 degree / 167 ° F thermostat.

I only get 83 degrees / 181.4 ° F thermostats from my Porsche dealer


Thanks