mstieg Posted May 8, 2012 Report Share Posted May 8, 2012 All points are valid. It just depends which way to skin the cat. I prefer the electric fans for the reasons stated, but also am leary of them going out, since my secondary did - Thanks Rich for finding and fixing that years back! Best support for elec. fans is to rebuild/replace em and check the wiring. I also plan to run a radio bezel switch in parallel so I can opt to override the temp sensors if I want it cooler or in a pinch if a sensor fails. If MPI, one could go "crazy" and have the EMS use an extra output to control the fans if for some reason the temps went above a set temp, but that's only a bandaid response since a cooling prob. needs to be addressed and not covered up by more fan time!! (this applies to anybody using a fan switch, especially if only using a switch and no sensors - no thanks) For most, the simplest and cheapest is best, which I also agree with in general, but don't like the blades of death always making noise. So long as overheating is being prevented properly, all options are good when done right. Worst option is keeping the stock elec. fans untouched after all these years. Link to comment Share on other sites More sharing options...
ucw458 Posted May 8, 2012 Report Share Posted May 8, 2012 If you do the all 3 fan mod then one fan going out isn't a problem. I found recently during a hot week I had driven my SQ all week with the primary fan unplugged. Forgot to plug it back in after tinkering, oops. But I didn't have any cooling problems. The other 2 fans still did the job and kept the engine cool. Link to comment Share on other sites More sharing options...
racer_amx Posted May 8, 2012 Report Share Posted May 8, 2012 Clutch fans are best if you dont want the hassle of watching the temp guage like a hawk Link to comment Share on other sites More sharing options...
Killtodie Posted May 8, 2012 Author Report Share Posted May 8, 2012 Reason for the flex fan is, simplicity, less complication going to an SR14 radiator. As far as over heating, I had a few times where my car overheated for no reason, I believe it to be my main fan seizing up for whatever reason. Caught it one time where it was spinning, Hit it loose, no problems. This happened 3, maybe 4 times. I didnt know that mechanical fans robbed horsepower. Now, a flex fan, flexes at high RPM and has less resistance and moves a lot less CFMs so doesn't it not cause more HP loss at higher RPMs? Link to comment Share on other sites More sharing options...
strang3majik Posted May 8, 2012 Report Share Posted May 8, 2012 Also, no matter what way you look at it, even with a flex fan, the flat spinning disc is still spinning at engine speed, so, when the blades go flat at high rpms its not doing much for cooling anyway, and is still putting more resistance on the engine robbing power. Clutch fans have the benefit of going into a near free spin at full throttle as the clutch slips on sudden changes in RPMs, so, they don't rob nearly as much power, just, as Shelby said, keep a constant amount of air flow across the engine. Link to comment Share on other sites More sharing options...
MikeMeyerhoff Posted May 8, 2012 Report Share Posted May 8, 2012 I prefer electric for the power and effeciency reasons. I don't think there is much difference in reliablity between the two and if there is, its offset by the extra amount of wear put on the water pump. Link to comment Share on other sites More sharing options...
Komeuppance Posted May 8, 2012 Report Share Posted May 8, 2012 http://www.b2600turbo.com/images/g54bfans.jpg According to Indiana's post a clutch fan will flow 3433CFM @ 2000 RPM. 1568CFM @ 1000 RPM. FSM specs a clutch fan at 2800RPM with a pulley speed of 4000RPM, at 149*F. Where does your car idle at?? One 12" slim cheapo ebay electric fan will pull 1700-2000CFM. Get two of them going and you have some cooling power. Or a 16" Taurus fan, 2500CFM on low, 3800CFM on high. BTW, the intercooled radiator is better than the non-ic radiator. More fins per inch, 27% better cooling capability. -RobertReplacing worn out parts(electric fans) with less worn out parts(clutch fan) and noticing an improvement is not a real example. Even when using AC there's an electric fan going... someone should convert it to an ultimate cool-clutch fan!! -Robert Link to comment Share on other sites More sharing options...
ucw458 Posted May 9, 2012 Report Share Posted May 9, 2012 Reason for the flex fan is, simplicity, less complication going to an SR14 radiator. As far as over heating, I had a few times where my car overheated for no reason, I believe it to be my main fan seizing up for whatever reason. Caught it one time where it was spinning, Hit it loose, no problems. This happened 3, maybe 4 times. I didnt know that mechanical fans robbed horsepower. Now, a flex fan, flexes at high RPM and has less resistance and moves a lot less CFMs so doesn't it not cause more HP loss at higher RPMs? First of all you should have replaced that fan at the first sign of failure. Even if you get it to work again the problem will only get worse. As to your flex fan thoughts,Flex fans NEVER completely flatten out. It takes air pressure to flex the blades. Even at 50k rpm the blades will not flatten out. They will bend a little at 5k rpm but not much. They still use more HP as rpm goes up. The CFM on a flex fan increases with rpm. You do not need the extra air when going down the hwy. So that power used to run the fan is wasted. I put a flex fan on my 91 mazda b2200. The truck was slower, noisier and used more gas. So much so that I was angry at the performance loss every time I drove it. The flex fan made a semi peppy, ok truck into a turd that I hated driving. Replacing worn out parts(electric fans) with less worn out parts(clutch fan) and noticing an improvement is not a real example. -Robert But that's what we hear every time someone says clutch fans are better. "I replaced my broken electric fans with a clutch fan and it works so much better" Well duh Link to comment Share on other sites More sharing options...
Dred_85.5_TSI Posted May 9, 2012 Report Share Posted May 9, 2012 You might also consider that a clutch fan takes a lot of the load off the alternator. With our cars anything you can do to make the electrical system work less is good. This is especially true on a car that still has it's original alternator or wiring that is somewhat questionable. Pretty sure it is cheaper to replace a water pump than an alternator. Besides you should probably replace the water pump as a wear item anyway is you care about your car. That was a mistake I made with my 84, I reused the water pump after it sat for ~8 months. 30 miles later it was squirting coolant out past the seal. Link to comment Share on other sites More sharing options...
Dad Posted May 9, 2012 Report Share Posted May 9, 2012 Good point about the alternators and voltage, I wonder how many CFM's are lost due to low voltage in traffic idling with A/C on?? Link to comment Share on other sites More sharing options...
ucw458 Posted May 9, 2012 Report Share Posted May 9, 2012 Good point about the alternators and voltage, I wonder how many CFM's are lost due to low voltage in traffic idling with A/C on?? Considering that the clutch fan puts out less than 1500 cfm at idle and all 3 electric fans combined put out 4500+ cfm. Even if it was a 2 volt drop the electric fans are still pushing more air than a clutch fan at idle. Link to comment Share on other sites More sharing options...
Dred_85.5_TSI Posted May 9, 2012 Report Share Posted May 9, 2012 ^Hmm someone who actually knows how a thermal clutch fan works.http://www.daviescra...-b-content.aspx Link to comment Share on other sites More sharing options...
Komeuppance Posted May 9, 2012 Report Share Posted May 9, 2012 Take another look at the specs posted. The clutch fan is already fully "revved up" at 149F at the bimetal front. It's not going to magically spin faster LOL. -Robert Link to comment Share on other sites More sharing options...
ucw458 Posted May 9, 2012 Report Share Posted May 9, 2012 you are forgeting one fact,,if the engine needs more air flow the thermo clutch fan can and will produce it .lets do this how many of you have ever realy seen a thermo clutch fan actualy rev up when it need'd to ,, one of the best examples of this is almost any late model Astro van , at idle at almost every other stop you'l hear the fans start spinning up makeing a lot of noise as it does so ,,engine rpms didn't change only the rpms of the fan spining does And you are completely ignoring the mitsu documentation that was posted. Not every thermal clutch revs up. In fact no vehicle I've driven or owned that had a thermal clutch ever reved up the fan when it got hot. Some would lock up the clutch when hot and some would lock it up after the engine started boiling over. The info clearly shows a SQ fan clutch never revs the fan faster than the engine revs. So at idle the best the fan can do is idle speed. Which is less than 1500 cfm. Which is less than the 3 electric fans. http://www.b2600turbo.com/images/g54bfans.jpg Link to comment Share on other sites More sharing options...
ucw458 Posted May 10, 2012 Report Share Posted May 10, 2012 i'm sorry but my experiance is from a great many diff cars and a lot of years , i do not always restrick my self to speaking in Mits spesifications nor their limitations it's not nessarry that you beleave what i'm telling you or not but that does not make what i say wrong ,i have no reason to tell you wrong information I'm not saying you're completely wrong. I believe you when you say those clutches are out there. Just saying all the ones I've owned or driven didn't do that. And the mitsu one doesn't either. In a way I do wish more fan clutches were like that. It would have saved me some overheating problems for sure. Link to comment Share on other sites More sharing options...
Tman Posted May 10, 2012 Report Share Posted May 10, 2012 so the fact that most of have used both and believe the clutch fan is the best option means nothing? Link to comment Share on other sites More sharing options...
Metric-man Posted May 10, 2012 Report Share Posted May 10, 2012 Flex fans are stupid, they mame people all the time. Clutch fans are pretty standard still , electric fans are going to be an upgrade but need more attention than a clutch fan. If your vehicle is swapped by a flood (driving through standing water)and a clutch fan is submerged, your engine will stall.(an electric fan will just shut off) Clutch fans and the way they are attached, place more stress on the water pumpand leave less room for a frontal impact. The clutch fan silicon fluid is temperature sensitive but there are different temperature grades available. Link to comment Share on other sites More sharing options...
JohnnyWadd Posted May 10, 2012 Report Share Posted May 10, 2012 (edited) If your vehicle is swapped by a flood (driving through standing water)and a clutch fan is submerged, your engine will stall.(an electric fan will just shut off) Flood driving that? sounds scary. Clutch fans are pretty standard still , electric fans are going to be an upgrade but need more attention than a clutch fan. Exactly. If you want a cheap easy way to go the clutch fan and shroud is a good option. No messing with the temp sensors and wiring and relays. The clutch fan is running all the time when the car is on. The electics are running when the lower radiator is hot enough to trigger the sensors and close the relay, so there is the potential for less temp spikes too. The fans may have better cubic feet per minute on paper when all working properly. But they are not running all the time, so actual cubic feet per minute is what? Depends on the relays, wires, grounds, temp sensors, are the plugs connected? Sitting at idle the clutch fan is breezing the radiatior when the electrics are waiting for the lower radiator to get hot enough. (unless you wired the sensors together or intalled lower temp sensors) Edited May 10, 2012 by JohnnyWadd Link to comment Share on other sites More sharing options...
Killtodie Posted May 10, 2012 Author Report Share Posted May 10, 2012 I'm just going to give the flex fan a try one of these days. Might as well take the time to get my electric fans out, clean them up from the grime and grease and see how a flex fan feels. Link to comment Share on other sites More sharing options...
JohnnyWadd Posted May 10, 2012 Report Share Posted May 10, 2012 I'm just going to give the clutch fan a try one of these days. Might as well take the time to get my electric fans out, clean them up from the grime and grease and see how a cluth fan feels. fixed^^ Link to comment Share on other sites More sharing options...
ucw458 Posted May 11, 2012 Report Share Posted May 11, 2012 so the fact that most of have used both and believe the clutch fan is the best option means nothing? The thing is that's just an opinion. I've been stating my opinions as well but have backed them up with some facts. You can find the info online talking about how much power engine fans rob and fuel economy decreases from using them. I posted that info in another thread. FYI this isn't the first time toadie started a thread on this topic.http://www.starquestclub.com/forum/index.php?showtopic=112141&st=0&p=1094232&hl="flex%20fan"&fromsearch=1entry1094232 2 years ago Link to comment Share on other sites More sharing options...
Killtodie Posted May 11, 2012 Author Report Share Posted May 11, 2012 nope and I never got anywhere with that one. and i thought a flex fan and a clutch fan where the same thing Link to comment Share on other sites More sharing options...
IntercooledFlatty Posted May 11, 2012 Report Share Posted May 11, 2012 i run an electric cluth fan Link to comment Share on other sites More sharing options...
JohnnyWadd Posted May 11, 2012 Report Share Posted May 11, 2012 (edited) i run an electric cluth fan thats just an opinion Edited May 11, 2012 by JohnnyWadd Link to comment Share on other sites More sharing options...
Shelby Posted May 11, 2012 Report Share Posted May 11, 2012 i run an electric cluth fan there are such animals but you misspell'd clutch Link to comment Share on other sites More sharing options...
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