The engine/belt driven fan on the AE86 is an unnecessary work load for the engine. Though power gains wouldn't be worth mentioning, removing it will do wonders for the 4AGE's throttle response.
The fan you use must be electrical and must be narrow enough to fit between the radiator and the pulley where the OEM fan was originally mounted. I found a perfect fan in a 1981 Datsun 310 (two door hatchback). I honestly have yet to see any fan which is narrower than the one from this car, and I'm doubtful I ever will...but it would be cool if someone could prove me wrong!
Directions for the Datsun 310 fan:
- The fan will have an arm running off one side diagonally away from the fan housing, you'll need to cut it off and basically make it look like the first pic on the left. If you take a close look at the bottom of the fan, you'll see it's been hacked (I did it in mechanics class, and time was more critical than quality)
- Once the arm is cut, the fan will sit in/on the little ledge which protrudes from the bottom of the AE86 radiator (engine side)
- There are two holes on top of the radiator for 10mm bolts. One of the holes from the fan housing will match up perfectly with the hole in the radiator. An extension plate will have to be measured and drilled so the second hole in the fan housing may be attached to the other hole in the radiator (far right pic)
- Once the two bolts are put in place, the fan is now installed, the ledge at the bottom of the radiator will keep the fan from moving
- Wiring: Attach the ground wire anywhere to the fan housing or anything metal attached to the chassis of the car. The positive wire can be run to the "engine" fuse inside the engine bay fuse box. This will mean that whenever the key is at the "ON" position, the fan will run. OR you can figure out some kind of switch to turn the fan on at your leisure, or when the engine gets to a certain temperature.
Here's some pics of the final finished and installed product...