Do you think that the fact that most of his miles are done at highway speeds might have far a more greater effect on his fuel consumption that than his e-fan?

Think about that for a minute. 1-2mpg is a very significant percentage increase. For me (average 16.7mpg), an extra 1-2mpg would be an increase of 6-12%. That's massive for such a minor change. If anyone claimed that from an e-fan swap I'd be highly dubious. If the real world economy benefits were as serious as that, then car manufacturers would not still be using clutch fans. In the new car market economy is everything, and no manufacturer is going to pass up that much improvement.

Actually I haven't seen anyone present solid, repeatable evidence that it is.

Theory not not say that at all. Scientific fact states that fuel economy (mpg) peaks at a particular speed that is different for every car. The more efficient the engine is and/or the more aerodynamic the car is, the higher that ideal speed will be. If you're interested there's good reading on this topic on this page.

Not surprising, since they were most probably revving their engine while sitting stationary. Not only is the fan one of the only loads on the engine at the time, the fact that they're not moving means a thermoclutch fan would have started to engage in response to radiator temp increasing. Under the same circumstances an e-fan would not be running until the temp rises enough to trigger the thermoswitch (assuming one is even fitted), so there'd be a noticable increase in response. Turning the e-fan on would probably result in a very different result. This test is pretty irrelevant though, since revving your engine while stationary isn't much of a performance measure. When you're using the engine to actually accelerate the car, the fan load (whether mechanical or electrical) is a tiny fraction of the load on the engine.

 

It seems to me that if the e-fan is clutched and freewheels at high rpms it shouldn't have much effect on rev speed, even in neutral. However, if it does appreciably slow the engine in neutral it should also appreciably slow the car (an NA at least) a bit through 1st, which is mostly where autox'ers live.
I installed my e-fan at the same time I did a bunch of other changes, so I don't know how much of my gains are e-fan related. (I'll see if I can borrow another RSCC member's g-tech and do a few test runs with and without. I'll post whether or not there's a measurable difference.)
I still think it's awfully nice to be cruising down the street and hear nothing but engine...

 

The terms "appreciably" and "a bit" mean exactly the opposite, so it's either one or the other. In this case it would be a bit, and a very small bit at that. The question should be whether it slows the car noticably. The only time it might do that is if the clutch was fully engaged, in which case an electric fan would be running too. We are still talking tiny increments of performance here, if any.

I can honestly say that between my exhaust and my stereo, I've never noticed any fan noise whilst driving the car.

 

is it the same for v8's and the like? It's funny because just about every mechanic I"ve talked to (doesn't mean I believe them or not) seems to always say. "Yep gettin rid of that there clutch fan and going to an electric fan will add horse power" I'm always like yeah whatever but after a while it's like if all these people think this then how can it not be true? And how the hell did this misconseption come about?

 

With some of the older V8 cars, it can be true. Many of them didn't use clutched fans, so the cooling fan actually did suck up quite a bit of power, especially in the higher RPM range. They were also very poor at cooling...

(Edit...Fix wording...)

 

ahhh gotcha. That makes sense. I'm guessing this is kind of like the turbo timer thing. In some aplications they are used with good benifits but not in all aplications but people just automatically assume that it is always needed.

 

Damn, I come back after 4 days or so and you guys are still going at it...

To answer some of my critics, particularly NZ and J-Rat:

Sure, I could have wired a relay into the system, still could if I wanted to. After about 3 to 4 years with the e-fan, however, I'm to the point that I never forget to turn it on when it needs to come on. I don't trust cheapo auto parts store thermo switches, and if you do, it's only a matter of time that the trust you put in that switch is gonna bite you in the ***...

Fuel economy? Eh, maybe a little, if that. I didn't install it for economy OR horsepower gains, I installed it to clean up the engine bay and the fact that I knew I didn't need a fan running most of the time...

I didn't trust the 17 year old clutch on the stock fan, either...

Yes, NZ, I know how the thermoclutch works...I also know that they wear out over time

In conclusion, an e-fan with a simple switch works for me. It doesn't work for the majority of everyone else, though, and I am NOT suggesting that anybody follows my lead, only bringing to light that it can be done this way if you drive almost all highway...

And Rat, you run perfectly good cars into the wall, so it's kind of ironic you're judging my setups

 

i recomend using a escort fan,you can cut it to fit the old shroud i have in picture, the benifits are you can see everything going on in your bay , does not help horsepower one bit it just makes easy to change belts and other items,mine does not drain the alt, because i have a thermo switch on it with a relay to set to your deired temp you just run the car when the temp gauge hits 1/4 you just turn the dial on the thermo then the fan kicks on it only kicks on at a certain temp,so you dont have to work your alt all the time ,then i have a override swicth on it just incase anthing fails . i run it all the time with the ac on with no problems dont use a efan if your not going to have a thermo switch,my car is a gxl t2 conversion ,please trust me on this put a thermo switch $17 at autozone,it very straight forward all you need aswell is a switch for inside the car and a relay , use heavy gauge wire,heres some pics,we are from waterbury ct.

 

Ooooh! thats hitting below the BELT!!

 

There's a real simple way around that problem: don't use cheap thermoswitches.

If/when my thermoclutch dies I'll most probably replace it with an e-fan purely for cost reasons. I won't use a thermoswitch though, instead I plan to use this adjustable voltage switch to operate the fan based on the thermosensor's voltage.

 

When I descide to bite the bullet and get an electric fan this is what I'm going to do. I think this diagram is by nz but it's easy to fallow and it gets rid of the fear of if your cheapo thermo switch fails because it's got an led that lights up if its running and a manual switch just incase it does fail! Very cool setup!

 

Yeah yeah, I know better. (That's what I get for posting after midnight) OTOH, we NA guys do appreciate every little bit of power we can get...

Sounds like you're running a system similar to Blue TII's old fart cannon. (big single) My exhaust note was right around 94Db while free-revving in neutral last I checked. The roaring of the stock fan was most of what I heard from the engine bay. I have a decent stereo, but most of the time I'd rather just listen to the car.

 

Nope, dual 2.5" mufflers.

 

i realy recomend the autozone thermo switch my buddy had it in his car for 3 years without a problem, then i decided to put i have no problems i have a overide switch on it,all i do is start the car and go, very simple i dont put parts on my car untill i have seen the reliability first,$17 is cheap but it simply works,i dont now why it just works for all the 7s in waterbury ct,

 

I run a flex-a-lite black magic in my TII and love it. I have it run with a thermostatic switch to regulate itself, but I also have a manual control switch for when I AutoX or what have you. That couple with my Griffin aluminum rad works great to help keep engine temps down. I personally couldn't see spending the money it takes for a good e-fan if you are still using a stock rad.

On a side note, it's cool that there are other aircraft mechs in here. I'm an aircraft electrician for the AF. Needless to say, some other guys in the local 7 club like to ask me about wiring questions.

Zach

 

I know this is really late and everything but thanx for letting me know all this stuff.. I was about to consider getting an e-fan but now that i know its best to replace the rad first then worry about the fan.. Since the stock fan can with stand up to 400 hrspwr anyway.. what's the point of upgrading now when i'm well below it in my N/A.. :-D

 

what do you guys think about this one?

http://cgi.ebay.com/ebaymotors/Proco...36676723QQrdZ1

 

Buy it now 37 bucks?!? riiiight.. I would pass..

 

but why? what makes it so inferior to the others?

 

You get what you pay for. A little more info on the fan like operating RPM and current draw would be nice. There aren't too many 2500cfm(measured how) 16" fans that cost $50 delivered.

 

Yeah, there are different ways to measure fan output. My money says its an AutoZone special, not worth the time or money.

 

After reading 95% of what was said in this thread I know 2 things

1. NZ seems to know what he's talking about (I ain't f'n with him)

and

2. If your worried about fuel economy then you should be driving a prius and not a 7.

sorry just my 2 cents I ain't raggin on no one

 

So if I dont spend atleast $100 on a efan, it wont do the job correctly. I'm just tying to get the facts.


how about this

http://store.summitracing.com/defaul...&part=MRG-1988

 

he wasn't saying it wouldn't do the job right just because you don't spend $100 he is just saying it would be hard to believe... and everyone should know by now you pay for what you get... so just don't expect it to do the job you want for so little.

 

If you're on a budget, used OEM fans are your best bet. Use a tape measure and take some LxWxD measurements of your radiator space and go pick-ur-parting.
Find a ~16" efan off of a scrapped car at the salvage yard or ebay.