NSXchink

sorry for noob question

i have a fiero e-fan, i was wondering if has the same performance on my air condition, as the stock fan that runs with the motor?

or should i upgrade the e-fan, like black magic.. or whatever..

Marcus_F

Depends. Do you live in a climate that regularly reaches 105+ degrees all summer? If so, nope. If you live someplace where it's cool, it doesn't matter. The way to determine whether it works as good as stock is to measure the coolant temperature. I did that with a RAYTEK Pyrometer and in my "100+ degree every day of the summer except when I'm in Phoenix, where it's 110+ degrees" environment, the Black Magic Fan not was as good as stock.


The Southern California Rx-Club Beach BBQ is August 20th.
The last biggie B4 SevenStock.

Sideways7

iTrader: (7)

The stock fan (I assume you are talking about the rad fan) is at least as good as any e-fan on the market. It can hold up to anything texas can offer (115+). Also, dont believe people that say the stock fan robs power. It is only engaged when you are stopped. The only real reason to get an e-fan is if your clutch is bad and you just want to open up some room in the engine bay.

NSXchink

no my summer is about 80,90,100 somtimes in summer, Virginia..

im using a Fiero fan, some I'm trying to figure out was it a mistake in changing my stock to the Fiero fan..

Maybe my frion is low cause my A/C sucks *** lol..

I dont think my Fiero fan blew as much air as the stock fan did.. Iono..

NSXchink

i heard the stock fan robs power.. i've seen plp changed to electric fan..

it does clear up alot of room in the engine bay..

but i wonder how many people here uses Fiero fans?

I'm trying to figure out if the Fiero e-fan is pushing the same amount of air inside the car as the stock one..

2slow4stock

iTrader: (18)

Dude, it doesn't rob any horses at all! Theres been a tread about this and the stock fan is best of all. The only reason to get rid of the fan is like what sideways when the clutch goes bad. I mean unless you REALLY need the room in your engine bay then its not really nessasary to take out. The e-fan is way smaller than the stock fan, so the bigger the fan the more room the air has to blow around the radiator. But if my clutch didn't go out then I would still be using my stock one.

RacerXtreme7

iTrader: (2)

Your answer is simply NO. There are very few electric fans that people use able to move as much air as the stocker does (though there are several fans able to move as much or more, but are $$$). Like sideways7 said, the stocker really only drains power at a stop (when temps go up and fan engages). Your fiero fan is weak compaired to even middle grade electric fans. Go with stock or an electric that moves at least 2800 cfm (Black Magic Flexi a lite, and it STILL doesn't move as much as a stocker).

~Mike.........

coldfire

iTrader: (1)

i think he is talking about the A/C fan, isn't he?

in that case i'm sure the fiero electic fan is just as good as the stock FC electric fan.
you should have BOTH the stock clutch fan and then an electric fan for the AC condensor.

Aaron Cake

iTrader: (1)

http://www.aaroncake.net/rx-7/efanmyth.htm

All fans basically work as well as each other, as long as they are not undersized. Really, the fan is only used during idle, stop and go, and low speed driving. The only time you are going to run into trouble is if you use a fan that is ungodly small (ie. many Honda fans). For the most part, almost any fan with a shroud that came from a decently sized car (the "Fiero" fan is actually common amount many GMs from about 1980 until the mid 1990s) will work fine.

Switching to an e-fan will not gain you any power or cooling capacity (engine temperature is regulated by the thermostat no matter what fan you run). It's just a cheap way to repair a failed stock fan clutch, or make room for longer engine (ie. 20B), FMIC piping, etc.

adrock3217

Which fan moves as much or more? I have lots of $$$.

Aaron Cake

iTrader: (1)

Spend it on something useful.

Then go to the wreckers and get an e-fan off a Pontiac 6000/Oldmobile Royale/Pontiac Grand Prix/AM, etc. etc.

Or just use the stock fan unless it's broken.

adrock3217

Well see, the idea of my 7 build up is to do everything the best way, especially something like a cooling fan..I don't really want to use the stocker, I like engine room. If there is nothing that cools better, I'll keep it. If there IS..I'd like to know

Aaron Cake

iTrader: (1)

The stocker is the best way.

And it's not a matter of "cooling better". The fan is only used under low speed conditions and idle. As long as you have a fan with that much capacity, you will be fine. MOST fans that come on large vehicles are perfectly suited. I could swear that I already posted this.

The key to any electric fan install is wiring: http://www.aaroncake.net/rx-7/efaninstall.htm

iceblue

I like the black magic fan. 200$ if you want to spend it. Or a flex straight drive fan.

I disagree with not freeing up any HP. I know on your sight Aaron you state that it "causes more alt load and so on". It takes allot more engine load to turn the fan then it does the ALT. So by freeing up the weight, and resistance, the fan takes to turn from the motor, which in return should speed up revs and some HP. Same idea as lighter fly wheel. Less weight to spin motor quicker. Sure this has been debated and is debatable. I see people are trying to state it doesn’t rob any and it free spins. Yes if there is enough resistance coming through the RAD it is free spinning but is still some weight to turn. For you that do not know, look at the sensor strip in the front. When this heats up the fluid changes temps and it titans up causing the fan to grab and cause load. Use a torch on here a little and start turning it by hand. Or bettor yet, grab the fan and start the car. As the motor warms up the fan will slowly start to grab as it heats up the sensor strip on the clutch, keep hanging on it will rip it out of your hand and almost rip your arm off in a minute. Give it try. So yes during free mode it pulls very little engine load but some in deed. When it heats up it pulls a good bit of load.

I agree with using the stock fan unless you need to free up room or the stock fan is dead.

iceblue

Always build a setup to allow the RAD to do the cooling work and leave as little required from the fan as possible. This is a well planed setup.

RacerXtreme7

iTrader: (2)

Go ahead and use junkyard e-fans, but if you get serious about making power and run a front mount, don't bother posting "why does my engine temps keep going higher?". Search and you'll find guys running front mounts and making 300~400 rwhp range that weak electric fans aren't cutting it. You'll also see in very hot climates some guys reporting higher temps with Feiro type GM fans and mostly stock turbo cars. For a stock or close to stock car with no front mount the junk yard dog fans work fine. But what about that rare moment your traveling cross country and your going up a mountain for 15 or so minutes longer in high alt thin air??? I bet it'll run warm, why compromise your system? You can get stock fans and shouds on here from members almost FREE. If your running heavy mods and/or run a front mount and/or AC, use a stocker or get something that moves some air. For those wondering what electric fans move enough air (2500 cfm higher) go to Summitracing.com or jegs and look. Usually they list CFM ratings.

~Mike...........

kontakt

Just because you already posted that, doesn't mean it answered his question. If you don't know off the top of your head what fans draw over stock, then just say that, and that it's not worth looking up, or if you do... then just list the fan.

Aaron Cake

iTrader: (1)

Without getting into it, it takes EXACTLY the same amount of power to turn the fan, whether that comes from an electric motor or directly from the eccentric shaft.

Let's say that you claimed 2HP was freed up by converting to an e-fan. Obviously you didn't, but let's just assume.

So it takes 2HP to spin the fan.

2 HP = 1490W

So we need a ~1500 Watt motor to spin the fan.

1500W @ 12V is 125A!

So if the fan REALLY took 2HP, then the electric motor turning it would be sucking 125 Amps from the electrical system...Not even bothering to mention that the alternator can supply nowhere near this amount of current...

But wait, there's more...

The alternator and electric motor are not 100% efficient. Most automotive motors are about 60-75% efficient, as is the alternator.

So assuming the motor is 75% efficient, you are actually sucking 1875W, or 156.25A at 12V to turn the fan. The remaining 25% is WASTED. It is burned up as heat.

Now, if we assume that 100% of this power is coming from a 75% efficient alternator that is being turned by the eccentric, we are actually using 2343.75 W to spin the "2HP" fan, which is in reality ~3.14 HP. At 12V, that's 197.8 A, by the way.

So we're using MORE power to spin an electric fan then the stock clutch fan.

And of course, the clutch fan is freewheeling when it is not needed, so it is actually only "constantly" sucking a tiny amount of power from the engine. You'll get more speed by not eating lunch and thus saving the weight in your stomach.

Same idea, but in practice it's a HUGE difference. The flywheel is many times heavier, and they try to reduce weight on it's outer circumfrence. Think of a light flywheel as not forcing the engine to turn such a large lever.

Try and spin an alternator connected directly to a typical e-fan by hand. This makes about as much sense as your statement above.

Aaron Cake

iTrader: (1)

Engine power has nothing to do with the size of the e-fan required. It is the lack of flow caused by the restriction of the front mount that does it.

I totally agree. It's hard to beat the stock fan in almost every case. I've seen plenty of big FMIC cars have cooling problems at low speeds and idle with almost every kind of fan.

adrock3217

What about that big Vintage Air (3700CFM) e-fan? Stocker still better? Vintage is my last look at E-fans, if the stocker is better than that, I'll stick with it.

iceblue

1. Nice post Aaron Cake

2.I totally agree as I am trying to solve this exact issue now with a FMIC running stock fan.

RacerXtreme7

iTrader: (2)

I see what your saying, but I would have worded it differently. At least I’m hoping your not trying to say what you wrote. Specifically "Engine power has nothing to do with the size of the e-fan required."

Yes an AC condenser or front mount inhibits flow to the rad, and a weak e-fan will compound the issue. But lets say if you had none of the above restrictions on a stock cooling system with a "weak" e-fan and it works fine (your temps are OK), then you up your horse power significantly (lets say another 100 hp), your temps WILL go up. A radiator is a simple heat exchanger, and if your water capacity does not go up (rad upgrade) when you induce more load (heat) as in making more power (because all the power in ANY internal combustion engine is simple expansion from HEAT within the cylinders) you need to increase air flow to take the heat away from the rad. I'm sure you know this, I'm just clarifying for others reading




My point is simply this, YES the junk yard low CFM electric may work for some people. But it’s a marginal system. We all have different driving styles. Yes it works for these who drive "sanely" or civily, but if you drive it like you stole it (like me ) most likely it wont cool enough. Especially if there’s an AC condenser and / or front mount OR if you plan on getting a front mount.

To each there own, if you want to downgrade your cooling system to make more room in your engine compartment or *think* your gaining power by it, by all means, its your ride. But if you want to clean up your compartment and do not want to downgrade or lesson your cooling capacity, get a fan with some useful CFM pull.

And for you LAZY bastards who read threads but want other people to search for you here are just a couple:

Flex A Lite Black Magic FLX-150, pulls a healthy 2800 CFM. A lot of people use this on our FC's and they seem to do OK. Granted some have seen a slight lower temp using STOCK fan, but with upgraded rads on high horse cars these work fine.

Flex A Lite FLX-398 2,500 CFM, I'd recommend making a shroud for it or retro fit to stock shroud. This would work fine on stock or mild modded cars.

Flex A Lite FLX-295 If its fits? It pulls an amazing 4,600 CFM!

Flex A Lite FLX-180 (the one I'll most likely use) pulls 3,300 CFM.

All these I found at Summit Racing, there’s CRAP loads more and more brands with similar specs. Look for your self. Also Jegs sells almost all the same units as Summit, do your own price comparison.

~Mike..............

RacerXtreme7

iTrader: (2)

Those with FMIC and cooling issues theres a couple ways to fix it.

1: the cheapest and a pretty effective way is to shroud off your heat exchangers. You can use plastic (polycarb, lexan, etc, basically anything that can withstand a litle heat) , aluminum, or fiberglas and the more expensive carbon fiber. A shroud from the front opening of the nose of the car to the FMIC, then a shroud between the FMIC to the next heat exchanger be it your AC cond. or Rad. And finally a shroud from your rad to the fan. you'd be amazed how well this works!

2: of corse, a upgraded Rad. Several direct drop in's available, Koyo, FLUIDYNE, MAZDASPEED, MAZDACOMP, etc. then you can of corse always go custom and may save a buck and have even more cooling capacity. Several use the GM or Ford V8 radiators from BeCool, Griffin, Howe etc. I personally went with a full race type rad that is universal. Its a dual pass unit and a thick core and dense fin count. Also, because its a dual pass, both inlets and outlets are on the same side unlike the Griffin and Becool GM/Ford based radiators were the inlets/outlets are on opposite sides. https://www.rx7club.com//showthread....ight=dual+pass

3: AIR FLOW!! Use the stocker, or get a fan with close to equivilant or more airflow. No I don't know the airflow of a stocker ( my best guess based on CFM ratings used on some e-fans that deliver simular cooling is around 2,950 CFM) BUT, sinse its limited by engine RPM so is its CFM at idle and low engine speeds. Were a decent sized e-fan can be working at max RPM when its needed most (like idle and slow driving) when your engine RPMs are low.

~Mike..............

iceblue

I just did this the past few days. We will see how things work out.

Already had a KOYO

Was running stock. This is one of the reasons I do not like our stock fans. When you need it cruising and idling it pulls very little air. This is the main area the car has been overheating in traffic in 98 degree weather in FL at 100% humidity.

staticguitar313

iTrader: (2)

Sealed ducting does wonders, otherwise the fan just pull air through the cracks.