High speed temperature trigger for 993 oil cooler fan

[jb 911]

I recently replaced two of my ballast resistors to successfully restore the two-speed operation to both my oil cooler and ac condenser fans. I used bruce7's nice DIY on rennlist to do it:

http://forums.rennlist.com/rennforum...resistors.html

Forgive the newbie question, but I am just trying to understand the system a little better and how it works. I have a couple of questions.

1. What temperature does the high speed oil cooler fan kick on in a 993? Anybody? It seems to be a mystery. Basically, I'm curious to know what range of temperature cooling you 'miss out' on if your low speed fan fails to start at it's prescribed temp. The low speed 'on' temp is stated as 230F.

The high speed start is listed as unknown on a variety of places including Pcar
964/993 Oil Cooler Fan Operation & Troubleshooting

A search (I admit I am not the best) did not provide an answer. It seems someone with the Bluetooth dongle and the iphone ap or anybody that has software to see the oil temperature while running could easily determine this temperature just by waiting and listening for the high speed fan to kick in.

2. Another thing I am curious about is does anyone know why Porsche decided to raise the 'on' temperature setting for fan operation on the 993 vs 964? 964 operation is stated as 212 for low speed on to 239 for high speed on. VS 230-x for 993? What effect does allowing the engine to run 10-20 degrees hotter have?

Thanks in advance.