Author Topic: Understeer.com BMW fan mod (fan clutch delete) (Read 7557 times)

Cobra Jet · « **on:** April 28, 2008, 08:43:14 PM »

When I had my prior E36 M3, I did this "delete" and it worked great. I've read multiple threads on here where folks seem to delete the clutch driven fan and then install an electric fan in place of the clutch driven fan.

Upon reading those threads, my memory was jarred and I remembered this E36 fan mod from the understeer.com site. I was wondering IF this same mod can be safely done with the M42's as well?? The part #'s being used in the understeer article I believe are 92-99 specific. HOWEVER, if someone can make a similar parts list for an M42, I'm wondering if we could do the same fan clutch delete WITHOUT adding another electric fan as described in the understeer tech article...

GOOD READ: http://www.understeer.com/fanclutchmod.shtml

Post your opinions... Like I said, it DID work when I did this mod on the 95 M3 and I'm just wondering by doing this same mod to the M42 if the parts used would efficiently cool down the M42 as it does the E36's (M3 & non-M3).

dude8383 · « **Reply #1 on:** April 28, 2008, 10:47:44 PM »

I have done this...gotta find the P/N for the fan switch.

I'll check tomorrow

bmwman91 · « **Reply #2 on:** April 28, 2008, 11:14:33 PM »

What were the benefits of this? I ran my car without a fan for a while a few years ago and didn't notice anything. I have heard that engine response improves, but I didn't notice.

dude8383 · « **Reply #3 on:** April 29, 2008, 06:47:06 AM »

Quote from: bmwman91;48135

What were the benefits of this? I ran my car without a fan for a while a few years ago and didn't notice anything. I have heard that engine response improves, but I didn't notice.

honestly for me it was just added work space

i didn't really notice much change either.

kowalski · « **Reply #4 on:** April 29, 2008, 12:22:54 PM »

yeah, i think it looks 10x better, and its a lot easier to work on. As well, whether I feel it or not, I know there is some sort of small gains, and a bunch of small gains added together = large gains!

nomad · « **Reply #5 on:** April 29, 2008, 02:37:35 PM »

Not sure if the size of the aux fan is large enough to be as effective as a true puller fan. I also read that it's heavier.

Along the same lines, what fluids are you running? BMW antifreeze with distilled water?
I'll be switching to that shortly to flush and refill the green stuff I put in for the rebuild.

I've heard good things about distilled water and redline waterwetter for hot climates.
I'm considering 75* thermostat and best coolant option, and a junkyard electric fan.

Cobra Jet · « **Reply #6 on:** February 25, 2009, 08:34:35 AM »

Quote from: bmwman91;48135

What were the benefits of this? I ran my car without a fan for a while a few years ago and didn't notice anything. I have heard that engine response improves, but I didn't notice.

If I am reading you correctly - you completely removed the factory clutch fan and never installed an additional electric fan and had no overheating/cooling issues at all?

I hope you don't mind me asking - what was the average outside ambient air temps in your region - and - do you still run your M42 w/ no fan at all? Do you have your Aux fan setup to do the cooling IF the engine temps start to rise?

thx for any clarification!

JP 91iS · « **Reply #7 on:** February 25, 2009, 11:22:56 AM »

Fan switch PN: 61-31-8-361-787

I'm converting over with this delete as soon as I put my timing chain project back together.

ScreamerBeemer · « **Reply #8 on:** March 24, 2009, 03:35:21 PM »

Out of curiosity I pulled off my fan and fan clutch. I notice a snappier throttle response. I never put in an electrical fan or a lower temp switch. That was a year ago. My daily driving I'm moving at highway speeds, if I try to drive under 30mph for too long it will overheat. I'll put a fan in there eventually.

3seriesNut · « **Reply #9 on:** March 24, 2009, 04:51:14 PM »

on a fan that pushes couldnt you reverse the polarity by simply reversing the power and ground? im gonna be doing the fan and power steering delete soon.

Cobra Jet · « **Reply #10 on:** May 23, 2009, 10:26:06 PM »

bmwman91 - can you please clarify your above response (I had asked previously, maybe you never saw my above questions to your reply)

DesktopDave · « **Reply #11 on:** May 24, 2009, 07:43:03 AM »

I was thinking along the same lines...new fan switch, water wetter or purple ice to improve heat dissipation. I might also increase the distilled water ratio to 75:25.

On my e34 m20 I only installed the clutch fan during the summer. It has a huge radiator comparatively, but it never overheated. I did note a snappier throttle.

I'll be trying to reverse a spare secondary that I have and mount that on the radiator back side for a push-pull setup.

gearheadE30 · « **Reply #12 on:** May 24, 2009, 10:04:31 PM »

I did something similar with mine, with the volvo fan mod. I think response might be a little better up in the rev range, but the main reason I did it is because my fan clutch was shot...

Isamemon · « **Reply #13 on:** May 30, 2009, 11:59:44 PM »

I did the volvo fan mod too and am very very happy with it. with a dlete of p/s and a/c I now have tons of easy acess . today I put in a cooler thermostat (87c) and it took me maybe 15 minutes ( plus bleeding etc)

the other reason I went this route was to get stuff out of in front of the readiator that might restrict air flow
thats why I like pullers over pushers