Mechanical Fan Delete

#1

Just wondering if anyone has had any negative experiences from removing the mechanical fan and not installing an electric fan in its place?

Thanks.

#2

The only time it is a problem is if the car isn’t moving. I wired up the stock aux. fan to a switch for those times I’m waiting around in pit lane. The high speed mode keeps my water temps just fine even on those 100F days at the desert tracks.

#3

is this with removing the a/c condenser and mounting the aux fan to the radiator?
thanks
bruce

traqrat wrote:

#4

I’ve seen prople have a problem when their new electric fan was only wired with a switch and they forgot to keep watching the water temp.

I did this at the end of the '05 season but included the automatic temp probe, not that I ever forget anything…

Carter :S

#5

leggwork wrote:

[quote]is this with removing the a/c condenser and mounting the aux fan to the radiator?
thanks
bruce

traqrat wrote:

Yes. Condenser removed so that the aux fan blows directly onto the radiator.

#6

Can anyone weigh in on the procedure? Do you just remove the blade and leave the hub/balancer? Do you remove the fan shroud that surrounds the mechanical fan and put the electric fan on the engine side? Not sure I saw anything in the rules that would prohibit a temperature probe actuated relay, but seems like that would be the best way to go.

Thanks,
ED

#7

edavidson wrote:

[quote]Can anyone weigh in on the procedure? Do you just remove the blade and leave the hub/balancer? Do you remove the fan shroud that surrounds the mechanical fan and put the electric fan on the engine side? Not sure I saw anything in the rules that would prohibit a temperature probe actuated relay, but seems like that would be the best way to go.

Thanks,
ED[/quote]

You remove the fan along with the fan clutch. You can also remove the fan shroud. For the electric fan, you yank out the A/C condenser and aux fan since they are attached to each other. Then remove the fan from the condenser and remount the fan in front of the radiator. You can either wire up a manual switch in the cockpit or tap into the temperature switch on the radiator and use that to drive a relay that actuates the fan.

#8

Just wondering where I can tap into the wiring so that the fan still works with the thermostat, and can run off of a switch. (The Aux Fan isn’t working right now, so I can’t tell if the A/C switch will normally run the fan, even without the compressor wired in and functioning.)

Wiring diagram

Euro condenser-less aux fan brackets

Post edited by: sharkd, at: 2006/01/15 17:53

#9

Thanks for the info. My condenser has already been removed and I have the original fan - uninstalled. All the rest of the AC stuff (compressor, evaporator, etc.) has also been removed.

Do you know if I plug into the original connector for the fan, will it pick up the siginal from the temp sensor? Also, would I have to push in the A/C switch to activate the circuit?

Thanks,
Ed

#10

edavidson wrote:

[quote]Can anyone weigh in on the procedure? Do you just remove the blade and leave the hub/balancer? Do you remove the fan shroud that surrounds the mechanical fan and put the electric fan on the engine side? Not sure I saw anything in the rules that would prohibit a temperature probe actuated relay, but seems like that would be the best way to go.

Thanks,
ED[/quote]

Ed:

The temp probe is part of installing a fan and we want to encourage the drivers to use one, for reliability-sake.

I mounted my aftermarket fan on the front of the rad, due to space issues. I used the push-through mounting squeeze tabs that came in the kit. Yes, I know they aren’t as good as real brackets but a friend used these for years on his JS E30 M3 and they did fine.

Carter

#11

Thanks for the clarification Carter. I just helped my son install an aftermarket fan on his 240sx and we used a fan relay kit and an adjustable temp probe. Sounds like I will need to do the same on the e30. I don’t feel comfortable with the manual switch - I would likely forget to turn it on, I also like to let it run after the ignition is turned off if the engine is still hot.

Ed

#12

FYI to all. Interesting article on race car cooling

http://stockcarracing.com/techarticles/general/scrp_0509_cooling/

Ed

#13

I am in the process of building a Spec E30 and just wanted to confirm what I think I am reading about the aux fan. I plan to remove the condensor and remount the stock fan to the radiator and leave everything plugged in as stock. My understanding is that the fan will come on when the temp probe on the radiator senses the correct temp that would normally turn on the fan in the first place. Is that correct?

#14

Scott - you are correct, but I believe you need to have the temp sliders moved to the right and the ac switch on to get the higher speed. Most have removed the stock engine fan.

There was a post in early october on this subject with more detail on various options.
http://spece30.com/component/option,com_mamboboard/Itemid,/func,view/catid,16/id,6466/#6466

Ed

#15

I run totally fanless. It’s never been an issue for me except on the street with a M20. The M42 has no overheating issues at all.

#16

not sure if we’re allowed to remove the electrical fan - unless it is considered to be a part of the a/c system. The rules just say you can remove the mechanical fan and add an electrical one, but don’t say you can remove the electrical one. People are replacing the electrical one so perhaps this is a point to clarify.
cheers,
bruce

robweenerpi wrote:

#17

Bruce, IIRC, the auxiliary fan was only standard on cars that were equipped with an A/C and the european M3s (whether or not they had A/C.

#18

I’ve always thought the interpretation was that the elec. fan was part of the A/C system, which is allowed to be removed, so it was a non-issue.

In the brief history of SpecE30, has there ever been a challenge for rules compliance between competitors, and if so, was it based on a significant competitive advantage or more along the lines of missing trunk light bulbs? I hope not the latter, as the ability to get along with a spirit of friendly competition is part of what makes this series great.

Perhaps the first guy to argue the point of a missing trunk light may find himself suddenly short on trackside assistance in the future. Just a possibility.

#19

Spec E30 sees the aux fan as part of the A/C system.

Carter

#20

For those that have gone to electric fan cooling and cycle the fan via thermoswitch, what are you using for the thermoswitch? The standard thermoswitch on a 325i/is low temp stage activates at 91F as I recall. Is that okay or would a lower temp thermoswitch be better. And if a lower temp switch is better what can I use (and where to get it)?