I understand that. But since the e-fan shuts off every time the temp drops below 210, I don't see it helping the fan.

It seems like in warmer weather, it will run very close to 210. When it drops to 209, the fan shuts off, until it warms back up. I'd expect it to stay at 210 +/- a few. Its all well above either thermostat, so they would both stay open the whole time.

When the weather is cold enough that no fan at all is needed, then your 190 vs 180 thermostat would make a real difference. Same thing if you're going fast enough down the highway that no fan is needed - then the thermostat affects engine operating temp.

But I don't see how a 180 thermostat helps the fan keep up. Any time cooling is limited by the fan, the thermostats are performing the same (both open).

 

the only thing the 180tstat does is get a jump start on cooling.

 

Thunder is correct. The fan I dont think shuts off at 209 Im sure it takes it down 10 degrees or so before it shuts off. Your temp constantly goes up or down. You cant tell by looking at the stock gauge since its not detailed. If you had a digital one you would see the increase/decrease in temp.

 

I took the clutch fan off this Sunday and I'm noticing a difference in get up and go. I acutally didn't think it would do much but I've been pleasantly surprised. I'm still a little nervous about idling though. The aux fan did come on once when sitting in the driveway. I would like to put in a electric fan. Has anyone used one of the Hayden controllers? Can't remember and I don't have time to search at the moment. Otherwise I would recommend this to anyone but keep your eye on the temp gauge in town.

 

Yeah, it is surprising. You probably already have a stock efan, since you have an 01. Unless you don't, there's really no need to add an aftermarket efan.

 

Looks like I'm adding another project to the list.
I can't wait to try this out!

 

I heard my name?

I didn't think mine had an efan, but it does. But it's kinda disabled since the radiator is shoved into it from a meeting with a stop sign (I would imagine the fuse is blown...I tried turning it with ym hand one day, and it didn't budge, was stuck in the rad fins). But I have the SCT + 180 Tstat in mine running 91 on the 93 tune, and needle stays straight up or less. One day when I have some extra $$$ I'll do the Taurus or HHR fan swap and ditch the mechanical fan. I get 12.5 or so MPG raw without taking in effect of tire size (+10%) and with 4.10 gears. I rarely go on the highway, turns 2500 RPM to go 75, but I did the gear swap for stop-and-go city driving. IF I could keep my foot out of it, I could get 13.5 with ease. Average tank is ~250 miles on 20 gallons. The gears picked me up about 25 miles a tank.

The SCT picked me up from 12.4 (empty tank) to 11.8 (full tank) in the 1/8 mile. So overall a 8/10th gain in the 1/8 mile probably after factoring out fuel weight. I haven't gone back since I put the gears in, I could probably run 11.5's or better and be one of the faster trucks in street (bracket racing).

I still have the hardland sharp rockers on my desk that I need to put on.

 

Sorry to jack this thread but I'm about to fit some 4.10's to my 4.7.

I'm interested to hear that your gas mileage has improved (if I've understood correctly!). I've worked out that the motor will only be turning 300rpm more at 70mph but will be under less load. It will also be running closer to its peak torque/efficiency revs.

I'm looking forward to the results even more now!

 

Gas mileage is a little hard to track right now, because I'm driving pretty inconsistently on city/highways. Plus it's (almost) winter. It should be a slight improvement come summer though.

 

2003 3.9 v6 - Had my clutch fan off all summer long with no probs at all. Not needed.