This is definetly a bit more tricky to "tune"
Since my car does NOT come with the harness for the upgraded E-fans from the dealership, I had various options. I could of done like Dave-O and gotten a variable controller (expensive) you can use a push type thermostat or tap into the temp sensor from the ECU, or opt for a standard push in type thermostat.
I opted for the push in type. for one simple reason. (I can control where the fans kick in the radiator instead of at the engine).
After my research with the fan clutch temperatures I decided that I wanted the fans to kick on around 188-191 degrees Internal engine temperate. It'll allow the engine to run optimally close to the performance of the Fan Clutch (OEM).
So I ran the car with the fans off until the engine temperate reached 205. I allowed the radiator to heat soak. This allows you to get a more consistent temperature reading because now the entire cooling system is at an even level.
I then turned off the engine and allowed the car to cool down to around 190. at this point I programmed the fan control switch to kick on at 190 (at the center of radiator)
I have made a photoshop diagram of how the temperature works across the radiator:
Orange = Engine to Radiator Inlet (Passenger side)
Green = Radiator to Engine Outlet (Driver side)
Red = Hot
Blue = Cool
The top of the radiator tends to stay hot because first and foremost heat likes to travel UP!
The optimal location is at the center, because it will allow the radiator to actually work more than the fans. Remember the cooler the fluid the more abuse you can give the car before the engines temperature will come to the point where you need to be less aggressive.
But the cooler the liquid the more your fan has to work. Everything in this world has a . So the best thing to do is allow the radiator to stay 50/50. It'll allow for lots of aggressive driving also it'll allow you to give your fans plenty of life. I engage the fans when the temperature hits 188 internal ENGINE temp. which is 180 radiator center temp. The exit for the radiator is at 167-170. The entrance for the radiator is around 195-197. Doing so I can cool the water in the center from 188 to 168, this relay/sensor that Hayden sells will only cut off at 20 degrees from whereever it clicks on. So if you click it on at 200 it will turn off at 180.
While driving on the highway the fans are constantly off as the radiator drops nicely. and during heavy traffic the fans click on and off every few minutes.
So how I have it internal engine temperatures:
188-190 fans are ON.
181-182 fans are off.
This keeps the temperatures right between where the fan clutch kept the temperatures.
After some aggressive driving I have brought the engine temperatures up to 195. Pulled over checked the radiator exit temperature and the radiator exit is at 180ish. So the fans do a great job.
This fan panel does the following benefits:
First and foremost, I have taken the fans OFF the fins/tubes. and onto a panel. I created tabs at the bottom of the panel so that it does not dangle or keep all of the weight at the screws, it rests on the clips that PWR made, and bolts onto the ports PWR welded internally. For vibration I installed a high heat foam around the panel. additionally I gave the panel a 1/2 inch spacing between the radiator fins and fans (this helps act as a fan shroud) You have to remember OEM fans are mounted a bit far from the radiator core to act as a Fan Clutch fan shroud. Aftermarket fans tend to mount directly on core thus limiting the area of cooling.
Clearence is very tight on the drivers side. I have about 1/2 inch of space from the a/c compressor and the motor for the 16 inch fan. Yet it is safe, and I can still change belts with ease.
All the wires were soldered together and heatshrinked then wire loomed and zip-tied neatly around the E-fan housings all the way to the electrical destinations.
I'll post pics of the end results tomorrow (need day light).
Why stainless steel and not aluminum?
I don't have the equipment to weld aluminum.
You will need 14 gauge or stiffer aluminum so it is not flimsy and supports the weight of the 2 fans.
Panel does NOTHING for cooling. So stainless steel works just fine.
Yes, FUEL IMPROVEMENT!
I drive more than 150 miles per day between city and highway. I see a weekly bill of around 150-200.00 dollars of gas.
I see a significant difference at the pump. Over 80 dollars savings per week.
Horsepower gain myth:
So far it's just a myth I have not dyno tested the product.
But to the defense of the myth and food for thought,
With the Fan clutch I could NOT and I did try a before and after within 10 minutes of each other and temperatures being relative (within 1-3 degrees engine temperature)
I could not spin my tires in from a complete stop.
With the fan clutch the car tends to lag until the fan clutch disengages at 2600RPM.
Current wheel setup is 275-35-20(rear)
with the e-fans the tires would not grab.
highway the accelleration is obvious.
People who are sceptical, I would like for you to try this out with your hands.
Grab the fan clutch housing and blade (out of the car of course) and try to spin it and have the fan blade spin LESS than your hand. Hard huh?
this is because it takes a lot of enery to spin the fan clutch assembly and further more it takes a lot of energy away from your hand.
now try to spin the pulley where the fan clutch assembly by itself, a lot easier huh?
Though to an engine it may be "not much"... In power, every little bit helps.
Crusing on the streets, say I let go of the throttle at 45mph the RPM would hold for about 5-8 seconds before it comes to idle yet the car continues to cruise under its inertia. With the E-fans the moment I back off the throttle the RPMS come down to 1,200-1000 RPM near instantly. All the while not aiding with engine braking. I thought this was a placebo effect. I removed the plate which contains the fans and tested the fan clutch and what do you know.... It's a fact, the fan clutch acts as a engine brake.
Remember at the end of the day (to every action there is an equal and opposite reaction)
that being said as the Clutch engages it tends to "slow down" the amount of speed it's missing thus increasing the speed of the fan blade itself.
this concludes my assesment of the setup and tests.
I am very pleased with the end results. Both financially at the pump and with the way it helps the engine perform.