How good is the factory electric fan?

[Ravins]

I am just finishing up my m50 swap. My plan is to just use the factory electric fan. At what temp does that fan kick in, or should I just hook up a toggle switch to it?

[bdi_fc]

http://www.e30dohc.com/wiki/index.php?title=DOHC_Swap_Basics#Cooler_Thermostat_Setup

[1990m3]

it works well to keep my car cool. i use the smaller 318is radiator too and as long as I turn the fan on in 80+ heat my temp stay at half marker or lower. If I'm moving the fan does not have to be turned on, only in traffic. It is wired through my A/C switch so I use that factory switch as my toggle

[nando]

it works fine, but it's really loud and draws a lot of power.

I have a 16" flexalite S-blade 2010cfm fan. it draws less power than the stock fan, moves more air, and is WAY quieter. it's also a couple pounds lighter.

use the aux fan switch 61 31 8 361 787 (like the say in that link above) and that's pretty much all you need.

[So Live]

I rigged mine up and it works great. Im using a external thermostat witha relay which is in the rad. it clicks the fan on at a temp you can adjust. I got it at auto zone.

Where abouts does that fan switch turn the fan on (in relation to the temp gauge) Right now mine kicks in a little over half with my 75* thermostat it runs about 1/4 -1/2 and no hotter. id rather have the factory switch than my hacked together kit.

[e30_kid89]

Im running a hayden electric 14" fan as a pusher with a 318is rad. The most it'll go in hot weather is 1/2 before the fan kicks in. Ii went back thru some old threads and the best way to hook up a e/fan is just using all the factory wiring shit/relays...it still works with the rad's temp swich and you can always override by just using the a/c switch inside.

[1990m3]

e30 kid89 - you got a pic of the fan that you're running? Did you wire it through a factory style resistor?

[e30_kid89]

there is what it looks like, not sure if thats the exact 14" one like i have. wiring was so simple; all i did was cut off the harness from the stock aux fan join both the factory low and high speed switches to the E/fan's single speed power wire, hook up the ground, and plug the fan in! it works just like the stock fan would would work but better and quieter. the 14" is perfect for the m42 rad imo it covers it perfectly.

[FredK]

So with the 318is radiator is 14" the max size you can run, or can you use a 16"? Thanks man!

[e30_kid89]

yep...14" is the biggest....lucky they didnt have 16" in stock or else i would have to find that out the hard way.

[FredK]

Thanks!

[So Live]

Cool thanks for the info on the switch. looks like thats my next upgrade. i dont llike relying on the a/c button as it will actually turn the a/c on in my car.