M20 Electric fan Installation

[robgoesvroom]

Greetings!

I wanted to get some insight and help from the E30 community regarding electric fans. I am going to be replacing my mechanical clutch fan with a 16” Puller SPAL from bimmerworld (Model 30100400).

I am retaining the stock A/C system including the auxiliary fan that connects to the side of the radiator. The car is a 1990 model with aluminum Mishimoto radiator and is a multipurpose California car (autox, track day car, daily driver). The car is run at Willowsprings and Buttonwillow if that helps any.

The main reason for this post is regarding how to hook up the electric fan. I have searched the main E30 forums (r3v and e30tech) as well as spece30 forums and the majority of people either wire up their electric fan directly to a switch in the cabin or use the thermoswitch/bung on the passenger side of the radiator. As I am planning on keeping the air conditioning I would like to keep the auxillary fan operational. I plan on using an “adjustable temperature control switch” similar to the one below available from JEGS. It uses a probe type sensor that is inserted between the radiator coolant tubes and allows for fan activation between 160-240 *F




I am also planning on purchasing the SPAL installation harness kit with relay from bimmerworld and modifying the OEM shroud to accommodate the fan.

Will this combination work successfully? Any positive input would be appreciated.

Parts to be used:
16" SPAL puller - Bimmerworld
Adjustable temp control switch - JEGS
SPAL rubber fan surround gasket - Bimmerworld
Billet water pump shaft nut - Bimmerworld
SPAL Installation harness w/ Relay – Bimmerworld

Thanks

[robsgotit]

its really straight foward
mount the fan
mount and run the thermo switch to key on power
make sure polarity is right (pulling air not pushing)
let it warm up to temp
adjust the thermo switch

drive hard

[AndrewBird]

I recommend hooking it up to constant power, not switched, that way when the engine is still hot after you shut it off, the fans will stay on until it is cool again. Pretty much every car that has electric fans stock is hooked up this way.

And as far as the thermo switch in the radiator goes, you can just hook it up parallel to the AC fan without any issues. Al it will do is turn on both fans instead of just the one.

[jlevie]

The fan you have picked is only rated at at 1300cfm, which is not even close to being equivalent to the engine driven fan & clutch. A 16" fan rated for at least 1800CFM would be the minimum that I'd use. The fan I'd choose would be a 30102120 (16" rated for 2360CFM). That is almost, but not quite, as effective as the OE set up. That fan will fit behind an OE radiator, but it will have to be mounted off center to the left.

The biggest problem will be mounting the fan. The through the radiator "zip ties" should never be considered as they can (and will) eat through the radiator fins and cause a leak. The fan mounts must be made so that the load of the fan is carried by the top and bottom flanges of the radiator.

If you are keeping the AC and want the fan to be automatic, you need a second bung in the radiator for an 82-83C thermo switch or you need for the thermo switch to be in the top radiator hose next to the radiator.

Since this car appears to primarily be a street car that sees some track time, my advice is that you retain the engine driven fan and make sure it's clutch is good. Switch to an electric fan only when you've turned the car into a pure race/track car (and deleted the A/C). And in that case use a +2300CFM pusher and shroud in front of the radiator.