flex fan noise

[just4bob50]

I recently switched to a 18" flex fan from a black magic electric fan because the motor went bad. It didnt do the best job at keeping the car cool anyhow. the flex fan keeps the car way cooler than the electric fan did and thats great but it is really loud. is there anyway to quiet the fan down or is there a really good dual electric fan set up that throws plenty of air. I live in Pa. and summer temps can hit 100 deg.

 

[jmd2914]

this doesnt help you with your question, but i always heard that electric fans were better than flex fans

 

[HISSIN50]

The best thing I have found is the stock set-up with a metal fan blade and HD clutch. It does better than the SN95 fan on high, in 110*F heat.

Not what you were looking for, but it is what I could provide. Good luck.

 

[935point0]

The fan noise is awful. I'm replacing my flex with electric. It should be here today!

 

[srothfuss]

The largest CFM electric fan available today is the Mark Viii ('93-'96) fan. To support the fan though, you'll need a 130A alternator.

The other posibility is what Hissin is suggesting. A metal blade fan w/ a clutch.

 

[just4bob50]

The largest CFM electric fan available today is the Mark Viii ('93-'96) fan. To support the fan though, you'll need a 130A alternator.

The other posibility is what Hissin is suggesting. A metal blade fan w/ a clutch.

I actually rounded up all the peices for that exact upgrade, but with the new radiator, and 7" under/over crank pulley the fan was no where close to being able to fit. Well I dont have the fan noise any more because the under/ over crank pulley actually slows the fan speed enough that you dont hear it under normal driving, buy the time you can start to hear it at about 4000 rpms my exaust drowns out the sound.

 

[srothfuss]

If you still had the Mark Viii, I would have told you that you can trim down the thickness with a dremel or cutoff wheel. As long as the fan blades are .5" away from the radiator fins, it should be fine...

 

[Rick 91GT]

Bob, unfortunatly that is the nature of a flex fan...noise

 

[89white50]

my felx fan with also very loud. I dont mind it, but some people aske me if i have a supercharger on it. Later this summer ill do a 3g upgrade and a mark 8 fan if i have time. probably just wait till i swap motors. But yes mine is loud and keeps the engine very cool, and no there is nothing you can do about it.

 

[just4bob50]

If you still had the Mark Viii, I would have told you that you can trim down the thickness with a dremel or cutoff wheel. As long as the fan blades are .5" away from the radiator fins, it should be fine...

The fan I had was trimmed down as far as it could go. What was the biggest problem was that the crank pulley was 7" and made contact with the fan motor.

 

[HISSIN50]

I didnt read all this again (I know I Know) but if one needs a decent fan with clearance, a couple of SPALs would work. It also seems to me that a Viper fan has a thinner profile. Rick might know specifics on that (Ponyboy on here runs one in his 5N95 and has posted pics).

Good luck.

 

[vristang]

As far as the noise goes, it seems to me that the shroud is fairly responsible for what you are hearing. My friends flex fan is quite loud, and mine seems pretty quiet.

Issues that I have found in my readings...
1) Depth of fan in the shroud - the fan blades should be covered by the shroud, but not significantly deep in the shroud.
2) Gap between the outer tip of the fan blade and the shroud - I am going by memory on this so I may be a little off, or just dead wrong, but I think I saw between .25" and .5" listed as ideal in some sae paper.

These 2 issues will also have a substantial impact on airflow. There will no doubt be some tradeoff between airflow and noise.

I wish I understood it a little better, so I could provide a better answer.

jason