JCurry

iTrader: (6)

I have a 87 n/a rx7 and I was wondering if you can take out the original fan and put in an electric fan, if so where can I get these out and does it give you hp, and also about how much labor are we looking at in this job.

Thanx Justin

Icemark

it does not give you any HP when you add the draw of the electric fan. In fact cheaper electric fans that do not free wheel when not powered, will often add more drag to the car, and reduce top speed and gas mileage.

An e-fan also requires a thermostatic switch or controller so that the fan is only on when needed.

An E-fan replacement is not recommended on a FC with a stock alt.

You should only replace the factory fan if the factory fan clutch has failed or you need the extra room for some reason. As covered in countless threads (in other words please search before posting next time, the search function is found in the upper right hand corner of the page) the factory fan is better than 90% of the aftermarket fans out there.

Labor to properly install an e-fan and replace the stock fan should typically be 2 to 4 hours depending on the mechanic. Most mechanics charge between $50-$75 and hour.

anobii

I'm not disagreeing, I just thought i'd list the benifits on the other end of the spectrum. The weight of the clutch fan adds stress to the water pump bushings and can cause the pump to fail prematurely. Also (at least on gm cars) I've seen on several occasions where the clutch and fan came off of the fan shaft and shredded the radiator, and in one instance cut a gash in the hood. If PROPERLY installed It works the same as the clutch fan as it should only engage at lower speeds or in non moving conditions. It's more of a reliability mod than a performance mod. The extra draw on the alternator, if used with a good fan (black magic, flex-a-lite) should only be 3-5 amps depending on the size used. I personally dont trust local mechanics as far as i can throw 'em. Everyone has a degree of dishonesty and most mechanics dont really care about your personal application, (ie make sure you find someone you really trust).

just my personal experiance.

-E

Icemark

3 to 5 amps???? For a replacement cooling fan???? Try adding a minimum of 10 more amps to that. Most any electric cooling fans draw 15 to 20 amps. If you have an electrical fan only drawing 5 amps, it is not powerful enough to cool a car (and probably not even powerful enough to draw air through the climate control/air conditioning system. Even the mini electric supplimental fan found on some FCs draws almost 10 amps.

There is almost no stress on the water pump with a viscous clutch fan as found on the FC. Do you understand how the viscous clutch fans work? Do you understand that the fan free wheels at speed and when the tempature of the air coming through the rad is below the fluid spec??? That means no load what so ever when the air coming through the rad is cool enough. And it would not be just concerned with coolant temp. It is controlled by air temp.

And you hardly can compare a GM vs a Japanese car for reliability and proper engineering. Hell GM couldn't even make the rotary engine work for them to sell it. Even a common overhead (single or twin) cam piston engines were out of their ability to manufacture only 15-20 years ago.

An electric fan should be absolutely in no way be considered a reliabilty mod on a FC.

MountainTurbo

That's not quite true... GM had the quad-4 engine that was a DOHC setup over 15 years ago... not too bad power wise, put out 180HP in highest form, but kinda hard to work on.

And it's not really a matter of CAN'T, it's a matter of cost vs. effeciency. For GM, it's more effecient to keep working with engines that they've "perfected" than to switch to a new design.

Hence, the fact that the LS series is still pushrod instead of an OHC config. They figure if they can get the same power and fuel economy out of the pushrod configuration as an OHC configuration, and do it for a lower price (for them), why switch?

Why I don't necessarily agree with their thinking, it doesn't make them incompetant as engineers. It just makes them a corporation, with corporate thinking

Icemark

The Quad 4 was one of GMs first twin cam engines... The Japanese were building twin cams engines back in the 60's and single cam engines in the 50's.

And the BS of GM keeps what they have perfected is just that. Ford used to say the same thing and has phased out almost every single OHV engine because of emissions and mileage concerns. GM will be forced into the 80s sometime soon as well.

But my response was mearly pointing out that replacing a Mazda OEM clutch fan because of a poor GM design that once launched a fan blade though the hood (of countless GM cars and trucks) is not well thought thru.

MountainTurbo

It may seem like BS, but when GM can have a 405HP engine that gets 25 MPG city, 29+highway MPG, and is a Low-Emissions vehicle, it's hard to argue with that. Look at Honda's S2000, it gets slightly worse gas mileage, has a worse power-to-weight ratio, and outputs higher emissions.

I know your response was regarding the fan switch, but I get tired of hearing how "outdated" pushrods are when many of the engines using them are more efficient than a lot of the OHC engines out there (we're talking power to weight, MPG, etc, not power-per-liter which is kinda pointless).

Just like I get tired of hearing domestic guys bash my car simply because it's japanese.

Icemark

Despite how far off topic this thread has gone (which he really should have searched for anywaY) Just think of what the GM V8s would be if they were DOHC.

I mean if Toyota can get 300 HP out of only 4 liters on their 2nd V8 (an amount twice the HP of the GM 327 V8 motors were doing until the very late 80's early 90's), think of what GM could have done on their larger capacity motors.

Don't get me wrong, on the engineering thing either. I worked for a supplier for GM for a while. I can say first hand that GM is the best engineered product in the world. Anyone can build a great car with great quality parts.. Toyota/Lexus, Dalimer/Mercedes have proven that, but it takes real engineering skill to build a relaible average car or truck with the updated old technology and cheap parts that GM does. Any other manufacture could never engineer a car with as cheap parts as GM does and have it even margionally safe and acceptable to the public.

That takes real engineering skill.

MountainTurbo

I apologize for kinda hi-jacking the thread.

I agree that GM's engines are insanely large in many cases, but that doesn't make them un-efficient. 300HP out of 4 liters really doesn't mean much. It doesn't matter if it's 4 liters or 400 liters, what matters is the power-to-weight ratio as well as fuel economy/emmissions. If you can get a 4 liter to put out the same power as a 5.7 liter, yet the 4 liter still ways more and has lower fuel economy, what's the point, and which engine is REALLY more efficient? Power-per-liter once again is WAY overused as a measure of efficiency.

I absolutely agree with pretty much everything else you just said.

I apologize again for kinda going off, I just get tired of hearing everyone say how crappy domestic stuff is and how much better such and such a car is just because it's japanese or has "newer" technology. (I know this was not really your intention, I at first thought that perhaps you were forming opinions without a lot of facts, which I know is not true now).

Just like I get tired of people thinking my car is unreliable just because it's a rotary.

anobii

Okay first off, sorry, make that 11.2 amps, I read the amperage for the 7 inch fan off of the back of the box I got my fan in. It was 5.5 amps and I assumed there were probibly some that were better...MY BAD.

some specs
http://www.absoluteradiator.com/FanStore.asp

Second, I'm not a dumbass and I know full well how a viscous clutch fan works. I also know how an electric fan works and even how to tie my own shoes.

Weight does not just dissapear when the fan free-wheels, it still weighs like 3 or 4 pounds.... pressing down on the waterpump bushings. Wether it turns all the time, some of the time, or none of the time, its still there, and still promotes wear, theres no way around physics. But hey, if it aint broke dont fix it.....right.

And now my $2.00 on the GM thing (sorry i even used the comparison). GM has done some dumb things but axeing the rotory wasnt one of them. In the early 70's when Chevrolet had aspiritions to put a 4 rotor 400hp in a vette there was a "fuel shortage", along with ever tightening federal emissions requirements. The rotory was not feasable to build as the 454 big blocks of the time were makeing as much power and had compareable gas mileage. Notice they stopped putting big blocks in cars in 1973. The 1975 Chevy monza was sceduled for production with a 2 rotor 150 hp rotory and agian it wasnt feasable, the 231 buick v6 made more power and got better mileage. It's pretty sad not much has changed since then. The rx8 with its whoppin 247 hp, gets an average 14 mpg from 1.3 freakin liters, thats not so good. But what is good is 27 avg. mpg from a 400 hp old school pushrod 6.0L v8. I love my rx7, I really do, and i'm sorry this post got so far off topic, close it if you'd like, but I just felt the E-fan thing was on trial by a one sided jury, and it needed to be properly reprisented. But hey I guess you cant win 'em all.

No hard feelings

-E

J-Rat

iTrader: (2)

AWSOME!!! Another E-Fan THREAD!!! YAY!!

RXSevenSymphonies

iTrader: (2)

So.. my stock fan is always running... I assume the clutch is broken...

bingoboy

quite a trick to get the stock fan to run without the engine. that must be the free'est spinning clutch ever .

scathcart

Low emissions? It is not considered a low-emissions engine.
Fuel economy is hardly related to the engine. Take a look at their 6th speed overdrive... nearly 0.50:1. This is not comparable to the honda S2000, as a larger displacement/stroke engine such as the 5.7 has the torque to lope around at near-idle speeds on the freeway (thus netting the great MPG); a high-revving sports car engine such as the S2000 just doesn't have the stroke or displacemnet to tolerate those low freeway/city revs, so obviously it'll use more fuel while needing to rev higher.

I am not impressed with 405 hp out of 350 cubic inches... and look how long it has taken GM to get to these power levels.

Fact is: in-block cams have too many inherent losses to ignore; they are by far an out-dated engine.

I also take issue with the fact the you compare fuel economy of cars... that has nothing to do with the engine; it has to do with the whole package of the car: the weight, the drivetrain, the aerodynamics... Why don't you compare thermal, volumetric, and BSFC's of the engines themselves based on engine volume and see exactly which engine has better engineering?

Lame comparison... fuel economies of vehicle's to compare engines Makes about as much sense as this:

Most diesel 18-wheelers net a higher freeway mpg of diesel fuel AND make gobs more hp and torque than chevy's 5.7 liter, and yet, we don't hear you spouting off about them?

scathcart

Zero load is an impossibility due to the existence of gravity on the surface of the earth, so the fan will always spin a little bit when the engine is turned on, it is just the resistence to stopping the fan that is essentually measurable (or in better terms, measurement of friction dynamics at given temperatures)

SureShot

It must be an S4.
The stock S4 fan clutch pulls, but with some slippage, all the time.
As the bi-metal on the front sees more heat, it reduces the slippage.
At about 4500RPM the clutch hits its torque limit & maintains the ~4500 the engine revs higher.

The S5 & some aftermarket S4 clutches freewheel when they are cool. The clutch is more on/off. (like an e-fan)

BoostedRex

Go to a junkyard and buy a '95 Ford Escort electric radiator fan. The thing is HUGE and fits our radiators perfectly. Plus it has two speeds. On the high speed the fan will jump out of your hand if you aren't holding on to it tightly. Very good value and very very effective. Plus they average going for about $25! Can't beat that. Best of luck to you.

Zach

Aaron Cake

iTrader: (1)

Thread closed. I'm sick of fan threads every day. If another mod feels it should be open, go ahead.