In my system;
I use a thermostatic clutch, and a 195*F hi-flo stat; which sets the minimum coolant temp to 195. The T-clutch cuts in at 205*F and the coolant never gets any higher.
The T-clutch will cut out as soon as the rad sees adequate ram-air flow, and when it does, it will leave off sucking power.
Once warmed up, the coolant temp never fluctuates more than a couple of degrees.
Some guys on FABO believe 205 is way hotter than it needs to be and that I could make more power running cooler. They might be right.
But the thing is this; my car went 93 in the Eighth, with 3.55s, set up this way, still hazing 325/50-15 BFG DRs ,they say,thru the traps. Don't bother to ask if I care about more power, cuz I don't. Don't care about more traction either. My car is a streeter.
Forget about power loss. As soon as the car hits 30/35 mph, on a properly set-up system, and a properly tuned street engine, ram air should be sufficient to cool the rad.
At that point, a T-clutched fan should be idling, driven by the wind.
I installed a HD T-clutch from an early 2000s Ford pick-up.
The thing is this; That 7-blade fan, together with the HD clutch, is H-e-a-v-y. I would not install it on a regular 1/2 inch shaft water-pump. I chose a Milodon hi-flo pump for it's bigger shaft (assuming a bigger bearing) and for it's anti-cavitation plate. My pump was installed in 2000 so you decide.....
