sharingan 19

iTrader: (16)

Recently I installed the Nissan Quest/Mercury Villager Efan. I used the factory thermoswitch writeup and wired it to low speed. I substituted the stock fan switch for a subaru unit w/ the same thread size that comes on at 194*
With the stock fan/shroud I would barely get past 180* driving around town. The Efan would come on around 198* and quickly drop to 185* and turn off. The subaru switch is 1 cm shorter than stock which probably accounts for the varience but thats another thread...

It cooled fine driving aroud the city, cycling every few minutes. but once I got on the interstate, the temps just kept rising , it was gradual but they only went in one direction....up. It seemed like the switch only read to a certain temp, and past that it wouldn't do anything. I let it cool down (the fan came on), and got to where I was going. I wired the fan to a manual switch . Testing it around town I found that if the Efan ran constantly I would see the same temps as the stock fan (178-185).

Once I got on the interstate I shut it off. I've read numerous times how the fan "shouldn't have to run at all at interstate speeds"....bullshit. Once again the temps crept up and up and up. I stoped, made a make shift cooling panel and hit the road again, took a little longer, but once again the temps increased. At this point I just flipped on the fan to see what it would do....to my surprise it brought the temps from 217* down to 185* and held it there for the rest of the trip.

For the record, I have a koyo rad, freshly flushed cooling system, Quest Efan, waterpump and thermostat replaced 2 years ago, (no condensor)(no fmic) (no undertray).

I have my theories (centering around shroud design) but I'm interested to know whats goin on here....

3vil

iTrader: (4)

just curious, do you have your lower diffuser on?

sharingan 19

iTrader: (16)

I edited the original post to state that I do not. However, that is not the problem (or the solution). I didn't have the under tray when I had the stock fan/shroud and I still had the a/c condenser installed then.

Rob XX 7

iTrader: (8)

I have tried 2 efans in my car now, with 2 different shroud set ups, unless it is cold out the fan will always need to come on

the stock fan works better

sharingan 19

iTrader: (16)

Good to know, thinks for the info.

No here's where the theory comes in...I don't think the stock fan is better, blade design hasn't changed THAT much in the past 20 years but surely they've made SOME improvements. What i will say is that I think the stock shroud is better....and specifically better at making use of "free" air.

The stock shroud allows are to flow through easily which at speed is wonderful, but it also seems to hurt suction, anybody every walk in front of the stock fan and feel it pulling you in? lol. These low-profile efan shrouds sit close to the rad and don't let air fly through so freely, this seems to present somewhat of a problem at high speeds, but at low speeds provides supeior suction.

6 one way, half dozen the other? ...perhaps, but I'll admit I was partially seduced by the "efficiency of the Efan", the ability to run when needed, and and shut off when appropriate. Guess thats just a Canadian fairytale....(not a slight towards Canada, but a reference to temperate climates where just about any cooling solution will work)

SirCygnus

iTrader: (1)

i dont know man, when i had teh stock setup and no shroud, the temps would stay pretty low. around 190. when i got my corksport rad with shroud, it would creep to 200+, untill i put the stock undertray back on. once i did that, the temps stayed at a rock solid 186.

i dont have an efan fyi.

jackhild59

iTrader: (7)

Much horseshit is written about fans not being used on the highway, how the mech. clutch fan 'turns-off' at speed, how the efan 'becomes a restriction at highway speed' etc.

For the record, a properly functioning temp controlled clutch fan cannot completely disengage. It also can never completely lock. The range is expressed as fan rotation speed vs. fan shaft speed and is given as a percentage. In a standard duty fan, the range is from about 25% of shaft speed (slow) up to about 75% of shaft speed (fast). A 'super heavy duty' clutch made for towing vehicles or trucks will range from about 35% to about 85% of shaft speed. They never lock, they never disengage.

So when the stock fan clutch is 'disengaged' it is still delivering about 1/3 the maximum airflow capacity of the fan. At this point it is likely consuming less than 1/10th of the energy (Hp) the fan uses as maximum capacity. That is still a very good deal.

Your experience with the efan on the highway is very valid and tracks exactly with mine. I have a 2 row Griffin Radiator in my car with a Taurus 2 speed fan. A/C condenser is intact and in place. My intent was to allow the fan to be able to completely shut off at highway speeds. This happens in cool/cold weather, anything under approximately 65*. At any temp over about 90*, the low speed of the fan never shuts off. I can live with that.

Location of the fan switch will influence how much the fan runs at speed. Put it nearer to the outlet of the rad and it will cycle more, put it near to the inlet of the rad and it will tend to run more constantly. Put the sender in the waterpump where the coolant is a mix of the return from the radiator and the hot coolant that is bypassing the thermostat and you get the best sampling of the engine temp.

Temperature of the switch must be appropriate for the location or temps will not be controlled accurately. IOW if you put a 185* switch in the radiator inlet, the fan may run constantly, even when the thermostat is nearly closed and fan cooling is unnecessary. Put that same sender near the rad outlet, the fan may not come when it needs to, as the coolant temp is already lowered by the rad. In this location, the engine may over heat.

Put that 185* switch in the waterpump and it will see the average temp. Now we control the engine temp, not the coolant temp. The fan will run when the average temp comes up. That is really the best spot. The other places may be used, but the switch temp must be changed. A 195* switch would be fine for the rad outlet. A 165* sender would work on the rad outlet.

I have done it both ways and currently use a 195* switch on the radiator inlet tank.

jgrewe

iTrader: (1)

Not needing a fan at highway speeds isn't BS. We don't even have fans on the FC's we race. A properly designed system shouldn't need a fan above about 35 mph. You need to be sure that all the air that hits the front of the radiator has to go through it. A radiator with no shrouding in front of it acts like a wall at high speeds, the air will do its best to just go around it. The front grill will supply plenty of air to cool the engine if all the air that goes through it has to exit through radiator. I have not looked at a stock FC in a while but I bet putting that undertray back on will solve your problem.

Rob XX 7

iTrader: (8)

Jack mentions something that some do not consider, not only a AC condenser but also some with a FMIC

A car with no AC and no front mount would have a much easier time keeping itself cool

Aaron Cake

iTrader: (1)

Something is odd here...I wonder if the fan shroud is blocking air through the rad?

Every e-fan equipped RX-7 I have built/helped build has only run the fan around town. On the highway, natural airflow through the rad is enough. HOWEVER, the only fans I have used have been the GM Pontiac 6000/Oldsmobile/Buick fan I have on my car, and then the aftermarket 17/18" circular shroud less fans. I am not a big fan of the aftermarket circular shroud less fans, but they do seem to work fairly well. I'd never put one on my car though (the fan choice was left up to someone else). My e-fan only comes on after initially entering the highway (hard throttle off the ramp then a reduction in speed) or just after exiting the highway (heat spike from constant light load going to varying load and reduction in airflow). It never runs when I'm driving on the highway. Now, my shroud doesn't cover my entire rad. It only covers an area just a bit bigger then the fan itself (impose a square over the circular fan). Perhaps this is why? Note that I have a 3" thick FMIC with big end tanks, stock oil cooler and Fluidyne rad.

Maybe the e-fans with shrouds that cover the entire radiator simply don't allow enough air to pass through unless the fan motor is running?

Rob XX 7

iTrader: (8)

it could be, most electric fans position the fan itself within a inch or two of the radiator, combined with a shroud and it does block alot.

When running they cool pretty good, but highway has always been my gripe

jackhild59

iTrader: (7)

You may be very very good at the racing thing, but you are not helping the noobs. Most of what do is not applicable to the street; most of what we do on the street is not applicable to the track.

This is another case of applying race car practice into street car theory. You duct. You race. but do you race at 35 mph? No. Do you have an A/C condenser in front of your radiator? No. Does your non-existent A/C condenser dump 16,500 BTU's of additional heat into the 'ram air' feeding the radiator? No.

You haven't even looked at a stock FC in a while, and you don't run one on the street. Keep your betting money in your pocket. I have 2 FC's, N/A. Both have stock underpan and all stock ducting in place. Both run excellent A/C that will freeze your *** off. One has the stock rad, clutch fan and shroud with a clean relatively new stock radiator. One has a massive Griffin rad and a powerful efan. Both stay cool, but neither one will function at any speed without a fan.

Rob XX 7

iTrader: (8)

makes you wonder how the car would do to put a electric fan on the radiator and use the stock shroud, defeats the aesthetic purpose but would make for good data

jackhild59

iTrader: (7)

Hey Aaron-

Come to Dallas and help me sort out the Taurus fan on the highway-I will buy all the beer!

-Jack

jackhild59

iTrader: (7)

I actually considered trying that with the Mark VII fans that I was playing around with. Seems like a good Idea, but I really had grown fond of having all that access to the engine bay.

Rob XX 7

iTrader: (8)

my taurus fan is doing pretty good on the highway, the fan is regulating temps which I am not crazy about, now that I got my own laptop again I am going to try playing with the fan setting to see if I raise it a little bit at a time to see if the car can sustain temps without the fan running

FelixIsGod29X

iTrader: (50)

Put a undertray on then go for a drive on the highway.

Rx-7Doctor

iTrader: (13)

Anyone have an experience with this type of controller for a electric fan?

http://www.mikeszshop.com/auto_cool.html

http://losangeles.backpage.com/AutoP...rature/9999680

jackhild59

iTrader: (7)

Rethinking what you said: The hub on my Taurus fan is pretty large. This is a design decision on part of the engineers. The reason for a large hub is as follows: there is little air moved by the blades in the center of a fan, most of the air is moved at the outer portion of the blade. Under high static pressure conditions, there is actually reverse airflow through the center of the fan. Thus the hub is made larger. This blocks the reverse flow but detracts very little from the capacity of the fan. Under high static pressure the fan is more effective. Could the hub of my Taurus fan be blocking some of the free airflow? Hmmm. Food for thought.

Is the GM fan a large hubbed fan or is it small hubbed?

jackhild59

iTrader: (7)

This is the Mercedes of controllers.

http://www.dccontrol.com/fancontrol.htm

Rob XX 7

iTrader: (8)

so many stock computers have infinite control of the fans, the stock control of the fan settings on my Pontiac are great, I will look into the Wolf a little more but I think it just sets on and off temps, not percentages

jgrewe

iTrader: (1)

jackhild59, we aren't discussing rocket surgery here, just simple cooling problems. The factory shrouded the radiator pretty well, after all these years, and various projects done to these cars the basics need to be checked.

When you add AC equipment to the mix just about every new car's system is designed to have a fan kick on low when you turn on the AC. Mainly for the AC to function when you aren't moving. The OP doesn't have AC.

One thing I've seen with the circular shroud fans is guys don't put them right against the radiator. You lose most of the effiency of the fan because its easier to pull air from the edge of the fan than through the core of the radiator.

I'll still bet that the lower pan will solve his problem.

championadrien

iTrader: (29)

Thank you! I thought I was the only one having this problem.

I have a Taurus Fan and it cools like a beast in the city, but on the freeway, unless its cold out or there's a negative incline, the temps start to hover around 190* and I end up turning on the fan.

Also if I were to turn on the Air Conditioning, which works marginally well, it starts to go up even faster and eventually I have to turn on the fan. And sometimes if I'm running AC, on the freeway, up an incline, and with the fan on, it still continues to rise to around 205*.

I made my own cooling panel and it works beautifully in the winter, but it has a hard time keeping up with Summer + AC running. I'm modifying to promote airflow, but I never thought of the E-Fan Shroud as being part of the problem.

Rob XX 7

iTrader: (8)

205 under full load with the ac on is not bad

jgrewe

iTrader: (1)

I just re read the original post. I'll bet 5 forum bucks that at high speed the air is crawling right under the radiator like it is a wall, the electric fan can only draw air through the core in the area it covers and that may not be enough to cool the engine at the power level on the highway.