clokker

iTrader: (2)

Can't wait to see a v-mount that uses the mechanical fan, that should be....unique.

Rob XX 7

iTrader: (8)

clokker gets very offended if you dont use an e-fan

clokker

iTrader: (2)

Au contraire Rob, it's refreshing not to be the biggest Luddite in the room for a change.

DeaconBlue

iTrader: (31)

The biggest issue with E-fan conversions that I have seen are folks that want to do it on the cheap with questionable or salvage yard parts (no offence clokker). Then to top it off they do not upgrade the electrical system to handle the added load. I upgraded my electrical system as noted above in post #7.

I am using a Flex-a-lite Trimline #116 fan mounted in the opening of the factory shroud along with a Hayden #3651 controller. I installed a Flex-a-lite #32082 sensor adapter in my upper radiator hose for the water temp sensor. The car has an all metal CSF radiator and I installed a Stant 180 F thermostat.

Here is how I did it the conversion a couple years ago;

https://www.rx7club.com/2nd-generati...hroud-1028539/

j9fd3s

iTrader: (3)

actually i think an OEM fan is better than the aftermarket, as Mr Lyger alluded to, the black magic fan, which used to be popular, is also a POS. my friend bought one new, and in like 1,000miles it had already been repaired 3 times, and the car had gotten hot 3 times, which is just unacceptable. (the circuit board fried, the motor seized, and then it caught on fire once too)

i also have happened to notice that the JDM tuners tend to stick with the stock fan, although when they do go E fan, they use the FD fans.

RotaryEvolution

iTrader: (30)

nope, i don't think all e-fans are bad. one manufacturer, a big one has really given me a bad taste and bias against them.

because you don't really think about the drawbacks until you're cooking eggs on your engine, and no amount of diligence can really avoid that possibility. i've simply never seen a failing mechanical fan cause such a dramatic failure scenario as a faulty e-fan can. even a loose clutch fan generally will only cause a mild and slowly built up overheat situation, a locked failure causes cool running but a major loss of engine power.

when i do run e-fans now i do use OEM junkyard fans. i won't waste money on big names, because of flex-a-lite.

and v-mounts don't use the fan, they use static airflow through the bumper as the rest of the cooling system uses the fan. so yes, it is also about the only v-mount configuration that you could use the mechanical fan with still.


i'm not at all saying an e-fan doesn't have a place on the car but i am saying if you have a problem with it, you have to consider if possibly losing your engine is worth it. i've seen e-fans turn to the flavor of the month mod on this forum but i've also seen plenty of people create issues that never were issues by doing them, adding another reliability factor to a car that already has a stigma.

Aaron Cake

iTrader: (1)

EMS systems have engine protection if the coolant temp gets too high. In the event of a fan failure, limp mode or shut the car down.

Well, unless the ECU is old. Or a brand new Microtech.

I'm just against that stupid Taurus e-fan. I don't know why it became a seemingly good choice, but just search all the problems that thing has caused. There are far, far, far better choices out that work perfectly without overloading the stock electrical system.

fc323

Any good fan will always suck up alot of energy. I have one from a quest and the stock alternator would barely hang on. When it was night, it just couldn't cut.
The way i see it, you should at minimum have a better altenator(fd or otherwise) before installing the e-fan.

Rob XX 7

iTrader: (8)

The internet has made the fan famous, its crazy how popular it has become. Just google search taurus fan and you can read for hours

clokker

iTrader: (2)

Could you tell us what these "better choices" are?

jackhild59

iTrader: (7)

There is no magic efan. Pretty much you get what you 'pay' for: more air requires more current draw. Less current draw=less air.

The crappy quality and high profile failures of some high dollar efans is appalling given the availability of inexpensive, durable oem fan units. Popular choices are Taurus, MarkVIII Lincoln, Villager, Volvo, GM etc. You completely get that, as you are also using oem fans from certain GM cars.

I currently have a Hayden 16" efan that pulls 16 amps on my TII mounted in a custom fiberglass shroud. 16 amps completely overwhelms the stock S4 alternator when I want to run my A/C. And I do- all the time and usually on high. It's air movement is just barely adequate for cooling the car with A/C running. In 107*weather recently it's proven to be not quite enough fan. So another Ford 3G alternator is going on another RX7 in my driveway. My shroud is designed to mount the Vulvo 2-speed fan. I have one on the shelf to try. I do not know the amperage pulled by this fan, but I will find out as I set it up.

The 'efan to end all efans' from the Mercury Villager was a total bust for me. It pulls less current on high than the Taurus does on low. Less air too. I could not use this fan on my N/A vert with A/C and get adequate cooling. Maybe this fan worked fine for thin stock radiators with no A/C?

The low-speed on Taurus pulls 15 amps. No big deal, I could handle that current on the stock S5 electrical system in my 90 vert. If I hadn't needed A/C, I would have been finished right there.
High-speed on Taurus pulls 25 amps. S5 alternator was no longer adequate for this additional load.

People have problems with Taurus fan because they can't wire, they don't understand relays, they don't run adequate wire size, they don't understand how to use temperature controllers etc. I also suspect that the Taurus two-speed wiring is confusing. You must not send current to both the low and high speed circuits. I personally had a learning curve with fusing the Taurus fan.

Some people have no A/C condenser and cooler climates. Any efan will do for them. Wiring is not as critical if your fan only pulls a relatively small say 10-12 amps. Some people have magic radiators and seldom even have their efan activate...(clokker ).
Some of us however live in a hot, humid climate and want A/C. We have need of a real bastard-of-a-fan that can cool the turbo'd car and also dump the heat from A/C. Taurus and the Mighty MarkVIII fit this bill.

So, if efanbois will learn to wire a relay, or two, use adequate wire size and then figure out how to use simple temperature controllers, the Taurus fan won't be so frightening.

Aaron, do you remember the days when it was Gospel Truth from the old farts on this board that a N/A high compression motor simply could not be turbo'd without guaranteed certain disaster? *Someone* blazed the trail then others followed knowing it was possible if they stuck to solid principles.

Taurus efans are the same.


So don't be such an old fart about it.

peejay

Clutch fans move a lot of air at engine speeds.

Electric fans move a lot of air all the time.

Which is why I converted my car to electric fans. Note that I have yet to see an aftermarket fan that is worth its weight in used dogfood. I use OE fans.

If you're not wiring electric fans through a relay, with proper gauge wiring, well of course you're not going to have a good time.

My fans pull about 70a. Two dual-speed fans. Of course they are wired with 10g wiring and several high-current relays (was burning up the common 30a ones). But it pulls enough air that I can run the car on a dyno and finish a pull at a lower coolant temp than when I started. That is hardcore kickass airflow to be able to cool an engine off at WOT in real time with no vehicle speed. Which is what I needed, because my form of motorsport doesn't get much airflow but it does soak up tons of power.

I use an FC alternator. I also have an MSD (pulls big heaps current) and two fuel pumps. Voltage is not an issue except at idle because of the 3" crank pulley I have.

If a Taurus fan was causing charging system woes, something was wrong with the charging system or wiring.

peejay

Want an awesome single fan? Ford GT500 fan, 2013-up. (That is key, they were given a spec upgrade for 2013 and are an upgrade item for earlier models) You can buy them brand new from Summit for $200 or so. They're enough fan for a 600+hp engine with OEM-level expectations of noise, efficiency, reliability, and overhead. It is dual-speed with a resistor block built into the fan shroud, instead of two sets of motor windings like my Chrysler fans (and VW fans) use. There's a connector available from the dealer network if you don't want to use spade terminals.

It *looks* like it will fit on an FC radiator core just fine.

clokker

iTrader: (2)

In all this discussion, yet to be mentioned is the shroud.
Which is all too often not even present; I see lots of builds with a fan slapped directly onto the core (using those gawdawful push through zip-tie things).

There is a formula (which I no longer recall) that uses the diameter of the fan hub to calculate how far off the core the fan should be mounted to minimize the dead spot under the hub and maximize the fan's efficiency.
Practically speaking, the further from the core, the better the fan will work.

Practicality is also a major reason I'm so fond of the Volvo fan controller.
It's easy to snag the relay and all the associated wiring from the donor and transplant it into your car, with very little modification. All the wire is appropriately sized and if you use the Volvo fan (which I am on the Z), after connecting fused 12v, you're basically done.

And, long as I'm bloviating on the subject, you have to use a real trigger switch, one that is in contact with the coolant.
NOT those stupid probe things you jamb into the core between the fins. Those things never turn on/off at the same temp twice and, just like the thermoclutch, are only guessing at the coolant temp.

peejay

Which is why I use a manual switch Adjustable switches all have far too wide an on/off range. Fixed switches are generally the wrong temperature for what we want. Manual switches are not difficult. You check your gauges every six seconds when you check your mirrors, right? So it is no problem. In reality I only turn on my low speed fan either in competition or when I want the idle to drop lower at a light. High speed fan is competition-only.

Please please PLEASE find me that formula! I have a "cooling woes" car at work and I keep saying we need to move the fans (which are shrouded) back away from the radiator so they can pull, and this is met with resistance "oh it doesn't matter, let's not waste time on that." Having solid formulas would help me greatly in my Cause.

DeaconBlue

iTrader: (31)

Is it a clutch fan conversion like the FC? This "formula" works for me

https://www.rx7club.com/2nd-generati.../#post11399547

clokker

iTrader: (2)

My info/data comes from the early days of watercooling PCs, long before you could just buy kits and slap em on.
The most popular radiator was the heater core from a '60s Pontiac Bonneville and aquarium pumps were about the only choice.
There were a couple of truly obsessive guys who extensively sensored their machines and then tried endless variations of fan config/speed, loop routing (video before or after the CPU?), etc.

Anyway, it was generally decided that you wanted the distance of the fan off the core to be between 1 and 2 times the diameter of the blade hub. Closer and performance decreased but further than 2 times away just stayed the same.


We don't have the luxury of such space. I couldn't mount my fan the theoretically correct distance of 6" because the engine is in the way.
Deacon's elegant solution is about as close to ideal as we can get.

BUT, it should be noted that data and conclusions from those experiments is not directly comparable to a car...your PC is (presumably) stationary and ambient temp is easier to control. Also, PC fans have much smaller hubs than our efans do.

It is undeniable however that moving the fan further away has a beneficial effect and is worth exploring if you have some space to play with.

jackhild59

iTrader: (7)

Here you go.

jackhild59

iTrader: (7)

Help me out.

Your *fans* pull 70 amps. You are using a stock FC alternator? Please clarify, because S4 outputs 70 amps, S5 outputs 80 amps. With either of these alts, you have not enough current available to run the engine or any other systems.

What is missing from the picture?

thanks

Jack

clokker

iTrader: (2)

Jeez Jack, all that mathy/sciency stuff is very convincing.

It jibes perfectly with my explanation if the following minor correction is applied:

What I Said divided by cosine of What Jack Said equals What Jack Said.

Of course, to be fair, we were concerned with two different phenomena.
We were interested in minimizing the dead spot under the fan hub and you want to equalize draw over the shrouded core and I'm not sure the two are the same.
But as I said, I'm not sure how relevant my experience is to this example. Two 120mm PC fans totally cover the Bonneville core, the shroud was basically just four walls used to hold the fans off the core. The shroud was never going to be a restriction in the sense that some of it covered the matrix.

Your formula seems to definitively define a minimum distance but does not cover what might (or might not) happen as the minimum is exceeded.
It'd be sweet to put a thermal imaging GoPro in the cars nose, pointed back at the rad face and then do some tests.
I'd bet it shows a hot spot right where the fan hub is, a spot that would shrink, to one extent or another, as the fan is moved further from the core.

Whether it would make a tinkers damn to coolant temps, I don't know.
There are so many uncontrolled variables in a moving car in the wild.

Rob XX 7

iTrader: (8)

Maybe the space contributes to the stock fan working so good

Rob XX 7

iTrader: (8)

Someone mentioned the mustang fan, i like the flaps i think the flaps are key to highway performance. I think i would like to try one out

jackhild59

iTrader: (7)

If you note, the hub in my example is out about 30% further than the calculated minimum, so the area under the hub is flowing pretty well. If you want to be more precise, add the hub area to the shroud area and re-run the calculator.
Once you attain uniform face velocity across the heat-exchanger, you are pretty much done.

But there is more-I postulate that the angle of the air leaving the fan can cause turbulence in the engine bay, leading to increased static pressure under the hood and thus reduced air-flow through the radiator. That is why I have a 'weak' efan with a custom shroud. The shroud is fiberglass and fits my crossflow manifold perfectly. It stands the efan vertical under the hood, yet takes up far less space than the stock shroud. It also can be removed with the fan attached in less than 1 minute, including raising the hood.

peejay

70a is only a rating. I actually have a S5 alternator but it can put out 100 amps according to my amp clamp.

peejay

http://www.summitracing.com/oh/parts...ts/model/gt500