Ideal Electric fan cut in temp

[pdtaylor18]

FC TII

Well my electric fan install went well and the controller does its job superbly, the fan actually drops the temp by almost 10 degs in about 20 secs.  With this in mind what is the best temp for the main fan to come on without fighting the thermostat.
The thermostat on the FC starts to open by about 83 deg C and fully opens at 95 deg C, with this fan dropping the temp by 10 degs it would start to close of the thermostat which i dont really want to happen.
I do have another smaller fan that was the leftover from the now defunct air con system but still works in conjunction with the water thermal sensor which I think activates at 97 deg C, this will be my backup in case of main fan failure and will still be man enough to lower the temps out of the danger area.  My fan controller will tell me if the main fan is working or not.  Its also progressive speed and will run higher speeds according to the higher temps and gradually eases off to maintain a more constant temp..... not that I noticed this happening.

So All I could do with is some expert advice on best temp for fan to kick in.

[antnicuk]

not sure about expert but i set my fans to come at 92. Works well on road or track for me.  I think the stat will be fully open before 95 degrees.

[pdtaylor18]

well I thought that but that is the workshop manual figures.
The thing I find interesting and one reason why not to trust the stock S5 gauge is that on the gauge there is so little difference between 70 and 90 degs, needle hardly moves at all.
I can see why people are so cautious of these gauges as I doubt you will see an overheat until its too late.  At least with my controller I can see digitally oil and water temps.

[Prof]

With logging on the Emanage, I was able to map the water temps during a run.  With hard running, the temperature would go to 100 degrees, but no higher now with the bigger rad.  General running temps seem to be around the mid 80\'s - so I\'ve set my fan to come on at 92 and off at 89 - you can monitor when the relay output comes on - so I was able to see that my previous settings tended to keep the fan running - which isn\'t what you want.
 
Those set points of 92 / 89 seem to be better, as you say, a good fan can bring the temps down quickly.
 
If you can monitor the fan from in the cabin, then it might be worth setting the temps and see how it performs on the road.

[pdtaylor18]

Thats just it, I can monitor the temps but I have yet to drive this on the road so all my temps are standing still temps. I think the 92 degs is what i will aim for then and go from there. Its easy to set temps on the controller and the range is from 70-100 degs C and displays temps all the time. I\'ll post some pics on my project thread tomorrow.