Kenteth

or efan, but keep the debate elsewhere, I don't want a flame war.

Basicaly my 10 blade s5 locked up last year and i ran a puny efan over the fall and winter season without any problems. Yesturday was very nice out (60 degreeish) and we took it out. I was running pretty hard, once a steep incline at high revs (sustained over 6.5k) and granted I figured the (newly replaced) waterpump was probably cavitating, I watched the thermastat climb to just over 210, after geting to teh top of the hill, I cruised in 5th for probably 10 miles before i decided to just stop... did't cool down until I sat at idle along side a road.. Under normal conditions it reads just under 180 with the sensor running between the rear port and BAC.

It just seems like, albeit water cavitation, it still should have kept cooler than that. I doubt 210 is too hot for the car, but i was curious-- since it is a new (reman rather) waterpump that i installed last week.

I'm assuming the clutch fan is going to be FAR more efficient than this efan, its a given to me. But my only efan is locked/broke and *SCREAMS* at anything above 5k.

What the characteristics of the efan, I remember one is an on/off clutch, and one is a gradual clutch. Which would be better for cooling in a "spirited driving" condition?

NZConvertible

Gradually increasing fan speed as the cooling requirement increases is always a better way to do things. Mazda actually upgraded from the 1st Gen's on-off clutch to a gradual type for the S4 and then went back to on-off for the S5, probably for cost reasons.

In reality both seem to work just fine, and neither should be required for "spirited driving" when you're going fast enough to not need a fan.

ddub

I'm just going to give my experience with the e-fan and that's it. I don't understand why so many people seem to think of them as inefficient or not as good as the clutch fan, honestly. When you have a properly functioning cooling system and set the e-fan up with a thermo-switch it seems to work just the same as the clutch fan to me, my temps are actually cooler with the e-fan but not overly cool. I have my e-fan set up to click on when the stock gauge is at about 1/3 or about 190º via my water temp gauge, it usually is only on for a matter of seconds before the temp is back under this and it clicks back off (this is of course in normal/spiritied driving, during stop-and-go driving it could be on for longer since there is less air flow).

In fact, my e-fan wont even come on for long periods of time under normal driving, and I don't even have an underbelly tray. My thermostat IS functioning properly before someone thinks it's just open all the time or something like that. But really I see no difference between the e-fan and clutch fan. My s4 clutch fan worked fine and the e-fan was used mainly to get more space and I haven't regretted doing it.

My .02

Kenteth

Just re-read my post. It should have readed that my only clutch fan screams above 5k, no an efan.

As for that, I've read that it takes at least 2800cfm at stop and go to keep a rotary cool. Any comments? Seems like fans along that range are around ~$100, compared to a $25 clutch fan I could find used... meh... I'm im college so every buck counts.

ddub

Yah I read it, but you also said at the top "or efan" so I gave my opinion.

Anyways, I daily drive my 2nd gen to college every single day in stop-and-go traffic and my $15 perfect condition junkyard Escort e-fan is doing pretty damn good. Don't know the specs on it, though.

NZConvertible

Because many e-fan installations simply aren't. This has got nothing to do with e-fans being bad in general, it's simply people who do bad installations. They pick the wrong fan, install it poorly, wire it poorly or all of the above. The difference is that the stock fan was designed by a team of trained and experienced engineers who made sure it works right, not by some backyard mechanic who just read on the internet how great e-fans are. If it's done right, an e-fan can work perfectly, but it can't work better than a healthy stock fan, because that already works perfectly.

As it should. A fan is a fan, no matter how it's driven. It just needs to be the right fan installed and operated the right way.

Then the stock fan was obviously on it's last legs and couldn't do its job. Many people seem to totally misunderstand cooling system mods and expect them to make the engine run cooler. Unless it was overheating, it should run at the same temp as before because it should be regulated by the thermostat. Cooling system mods should only change the cooling system's capacity, not temps.

And neither would the stock fan, something else many seem to misunderstand. Fans are only there for low-speed driving when there's not enough air being pushed through the radiator by forward movement. If you're getting hot enough to engage the fan at speed, you have a cooling problem.

If you do it right, there shouldn't be. But as I said above, the biggest difference between the stock fan and an e-fan is who designed and installed it.

Kenteth

I'd like to go back to a clutch fan for at least the summer, something reliable. So the s4 gradual clutch fan will mount up ok to the s5 wp pulley? Any tips on buying a used s4 efan from the forum/ebay?

Kenteth

How can I test my surrent s5 fan? I just assumed it was locked up because it would make the waterpump pulley squeel after 5k... I can turn the fan while holding the clutch mount, but there is alot of resistance. Any way to test it?

ilike2eatricers

The s4 clutch fan and pulley will not fit on an s5 waterpump. The hole in the center of the pulley for the s4 fan is too small to fit over the larger s5 nub on the waterpump. I forget if you can just switch the fan and leave the pulley on there. The only reason I know is because I have tried it.

EDIT: I think either scott89t2 or aaroncake made some posts about how to test the clutch fan. Are you sure the pulley is squealing? Or is it the belts? Do you have a dual alt pulley? Maybe your wp bearings are shot or your pulley is warped?

Kenteth

Ahh crap...

Well I was planning on only swapping the clutch and fan itself, not the pulley.

ilike2eatricers

hey check out my edited comments since I was editing while you posted.

Kenteth

Hmm, oh... well it was the belts that were squeeling. Its a reman waterpump, the wp has been working fine.

NZConvertible

You just did. The fan should be able to basically freewheel when the clutch is cold. If it's hard to turn you need a new one.

Going back to your original question (which fan is better), I was talking to a fan engineer who has a lot of experince in designing and selecting fans for commercieal HVAC, and asked him about the two different designs. He said that since the cooling load didn't change, and the resistance the fan acts against (A/C condensor and radiator) didn't change, the change from eight blades to ten was almost certainly done just for noise reduction reasons.

tecknomage

ditto