im not sure now that i look at it that u have to have them. I think they are just new ones to replace old ones like the thermostat sensor to control when it goes on and off.

 

if you wire it up to turn on whenever the ignition is on then the fan sensor becomes useless.

I mean you could wire it up to the original sensor also, the kit probably has a relay or something. I never really looked into the kit.

 

it doesnt give you hp, it just makes it so that when your fan comes on it doesnt rob your hp.

 

Seems to be a disconnect here. You don't install a retro electric fan to replace the electric fan. On my B5 I have a clutch fan and an aux. electric fan. The retro kit is meant to replace the clutch fan thereby reducing load on the crank via the drive belt. The aux. fan remains and the new primary electric fan requires that it be wired to a sensor to prevent it from running when it is not required. I would buy a kit with sensor rather then wiring it to the aux. fan sensor because that circuit is tied into the A/C. Also a second control circuit provides some redundancy. There must be a gain but how much I don't know. We 2.8 guys must be content with multiple small gains if a S/C is too salty.

 

i wouldn't buy the kit. I would wire it up to work continuously after starting.

 

I will be installing a EFK in a Few weeks, iam just waiting for my order parts that i order to come in. But you should buy one of this kits, Right now http://www.supremepower.com/ has there complete EFK for only 139.95 witch isnt that bad but the only problem is that they are backordered for 4-6 weeks

 

I did the fan upgrade on my 2.8 and noticed a small diff. maybe 5 hp. I bought the fan and then a temp sensening relay to run it. Its all pretty self explainitory. nice thing is that you can get completly rid of that pully that the fan is mounted on. same belt and everything.