Low temp thermostats.... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Steve Tinker · 07-10-2009, 09:12 PM

Has anyone fitted a Raby Flat6 low temperature thermostat?
I've just ordered one and will replace my 8 year old original thermostat when I change the coolant.
Any thoughts on how your engine now operates (quicker warm up) or any apparent differences to the original 'stat.....

jmatta · 07-11-2009, 07:48 AM

I recenty replaced mine with the LN part on my '02 S. Haven't drivin it enough to give feedback, but I trust what Charles and Jake state (plus the turbos and GT3s all came with low temp stats)...certainly appears to run cooler from the gauge.

I needed a coolant flush anyway; replaced with Porsche OEM coolant....car has 16k miles.

chitowndad · 07-11-2009, 10:35 AM

I once did this on my 87 Camaro. I went from a 220 thermostat to a 180 thermostat and it cardoned up the heads/valves really bad. What temp is stock on the Boxstrer and what temp are you wanting to go to?

-Steve

jmatta · 07-11-2009, 04:56 PM

According to Charles and the LN website, the stock t-stat starts to open at 186* and doesn't fully open until 210 or so. This creates some real hot pockets within the engine itself. The low temp t-stat starts to open around 166* and is fully open by 184*, IIRC. Lower coolant temp equates to lower oil temp, which in the long run, could save your engine.

Steve Tinker · 07-11-2009, 09:46 PM

I live in the sub tropics - something like Florida I suspect - where it rarely drops below 5 deg C on a winter night while summer temps are around the mid to high 30 deg C. Considering the M96 engine runs hot out of the box, I will try the low temp thermostat and report any change (if any) to the daily running characteristics.
But I am looking more to the long term reliability more than anything - new coolant & thermostat coupled with 5000 mile oil & filter changes (5W40 Shell Ultra synthetic) hopefully will do the trick.....
I've a lot of money tied up in my Boxster S (they cost about 2 to 2.5 times more here than the US) so I'm hoping the Raby/LN Engineering boys know their stuff.

blue2000s · 07-12-2009, 05:14 AM

Engines are designed with specific running tolerances in mind. These tolerances are dependent on certain material temperatures. If the temperatures are different, clearances and pressures in the nominal running state are not the same as what the designers had in mind. This will influence things like friction, oil consumption, combustion efficiency, fuel consumption, and oil pressure.

This is why a thermostat that works for one engine, like the GT3, may not be the best answer for another.

I don't know if lowering the water operating temp in the M96 is beneficial or not, but I do know that it's not what Porsche considered optimal when designing the engine.