E-fan

[ltdakheel]

I WOULD LIKE TO REPLACE THE CLUTCH FAN WITH E-FAN but i ,m woundering if it,s easy or not , and if done should notice increase in HP some guys said about 18 HP gained, and can i use e-fans from 2007 yukun , does it effect the battrey or the alternator because the car desiged with out e-fan and i know the take high ams , please advise and tnaks all

omar

2007 voy denali

[GMT 360]

The e-fans generally require more power (up to 40A instead of 5A) = higher output alternator, modified or new wire harness, reflash of the PCM type of stuff. Plus the fan control runs through the headlight driver module, you'll have to check that for capacity as well.

The current fan consumes 18 HP while doing 4,000 rpm (fan speed not engine speed), it would be rare for you to have that kind of fan speed unless you regularly tow, and if you are into towing you don't want to give up the airflow. In the real world your average fan rpm is going to be 2000 rpm or less, meaning at best you'll gain 4 HP minus the additional load of the alternator.

Some of the other members into tuning may be able to offer some suggestions, this is what I know.

[Nukedog]

My Efan truck had more ballz with 3.23 gears than my clutch fan TB with 3.42...

An alternator does not spin harder or easier based on load. It provides a constant output based on the rpm and the amount of under or over drive.

[Nukedog]

PS - www.pcmforless.com has shown an average of 10 to 14 RWHP more with the Efan option...

[GMT 360]

PS - www.pcmforless.com has shown an average of 10 to 14 RWHP more with the Efan option...

Yeah, I was just looking at that chart - the measurement is taken at 5500 rpm - but there is no measurement for fan speed which would indicate the amount of load specifically from the clutch and the actual gain from changing the clutch.

What I'm basing my comments on is practical experience. Think about often you actually hear your fan. For it to become audible it has to be turning 1500 rpm, equivalent load at that speed is 1 HP.

Not knocking pcmforless - they have a great reputation, but they also have something to sell and I don't, so if there is a way to interpret the data to look favorable for their market you can bet they're going to do it. :D

If you plot out the actual fan load from the current clutch over time and compare it to the electrics and measure the area under the curves for comparision the actually HP gain will be significantly less than the max/peak gain they post.

There are conditions at higher speeds when the load from the clutch actually drops, it is not a linear upward progression; this info popped up when the federal regulations for determining reportable HP changed. It used to be we could just run a bare engine and measure HP, now you have to determine all the parasitic losses from every component on the Front End Accessory Drive and subtract those from peak engine output. The load from the clutch at 5,500 engine rpm will cut in half when your engine is doing 7,000 rpm.

[JOETENO2]

Wow! Now that was alot of information. I purchased a e-fan kit due to the fact that it's hot down here and the need for a/c is great. I haven't had time to install mine yet(work too much...I'm working now) because I'm too busy. I'm planning to install mine with a thermal setup(no computer flash here) due to the fact that when I install my LS7, I'll need a new ecm(more fees to flash the ecm). So I say, why pay double for something that will be used on one vehicle? I started to just hook it up to a lighted switch and connect it to the ignition side but with a thermal, I can have it run a little after the engine shuts down(kinda like ford trucks useto do).:m2:

[ltdakheel]

thanks guys good info the
i dont like to modify the car , a like it as is it, but the problem is here in kuwait the summer is hot very hot it,s about 50 deg c plus minus i have no problems in winter the car running very well but starting from may until these days october believe me guys it,s very noisy specaily in the city i mean highway cooling by nauture , i have astro van 97 i replaced the cultch van with E-FANS i can notice the defrent but because it doesnt have electric cultch fan it,s was easy ,,

really i dont know what to do ????

[Nukedog]

GMT360 - pcmforless is not trying to steal peoples money. They are very honest and hard working. I have had Efan vehicles and it does make a difference in RWHP and in fuel mileage. Doubt whatever you want. I have seen/ felt the difference and i can tell you i am no fool when it comes to automotive common sense...

[GMT 360]

GMT360 - pcmforless is not trying to steal peoples money. They are very honest and hard working. I have had Efan vehicles and it does make a difference in RWHP and in fuel mileage. Doubt whatever you want. I have seen/ felt the difference and i can tell you i am no fool when it comes to automotive common sense...

I'm not trying to suggest they are stealing peoples money. What I base my posts on is practical experience with the fan clutch component. If there is specific technical data related to this component it is likely I have it because it related to my job. (Although since GM moved the Engineering for this vehicle to Mexico I wouldn't be able to pull up information on the current fan clutch because it's no longer my project).

Note the chart here, this represents the fan horsepower consumption at speed. As I mentioned before your fan has to be turning 1500 rpm just to hear it, (how often do you really hear it?) If you look at the top end of the hp curve notice the rpm is up by 4000 and 14 hp. The top speed of the fan clutch is only 3600 rpm. It is also unlikely the fan will run at that speed all the time - you just aren't doing enough work full time to demand that kind of output. So... you can only recover 14 hp if your fan is going full bore all the time, otherwise the hp savings is going to be far less when you average out the load on the engine over time.

http://i122.photobucket.com/albums/o274/dmcdrmtt/Fanhorsepower.jpg

I'm not putting this information here because I'm intending to get into a pissing match over who knows what. I came here because I do have some hands on, technical experience (from 2000 to 2006) with a component that members here would like to get some information about.

[juventus1983]

is this for a tb?

[Nukedog]

is this for a tb?

The one www.pcmforless.com is selling is. I think PCMforless may have more and better experience than you. As 99% of the people in this world know at least 80% of the tech (as they call them) at dealerships no NOTHING and they damn sure don't have a clue about tuning anything as they are masters of the "plug and play" and of course code reading esxperts...LOL

[GMT 360]

is this for a tb?

The fan chart is for all 360 platform vehicles.

[juventus1983]

so the fans in all three engine combos are the same?

[GMT 360]

so the fans in all three engine combos are the same?

Yes, all engines, all vehicles.

[GMT 360]

The one www.pcmforless.com is selling is. I think PCMforless may have more and better experience than you. As 99% of the people in this world know at least 80% of the tech (as they call them) at dealerships no NOTHING and they damn sure don't have a clue about tuning anything as they are masters of the "plug and play" and of course code reading esxperts...LOL

There were times when I was in my office doing data analysis on the warranty reports and I'd have to read the repair orders - cracked me up to see what the techs wrote when it came to their opinion of why something failed - quite often they were citing non-existant parts within the component. Most often an opinion means nothing when it comes to real knowledge.

[Pepper]

Has anybody placed the efans on their Envoys? I would love to put some on mine. Please advice - if so, please provide pictures if possible. Thanks :eek:

[Spong]

Has anybody placed the efans on their Envoys? I would love to put some on mine. Please advice - if so, please provide pictures if possible. Thanks :eek:


I did them on my V8 Trailblazer.

Here's a thread with a bunch of pics

http://www.trailvoy.com/forums/showthread.php?t=28327

[superman_79065]

The one www.pcmforless.com is selling is. I think PCMforless may have more and better experience than you. As 99% of the people in this world know at least 80% of the tech (as they call them) at dealerships no NOTHING and they damn sure don't have a clue about tuning anything as they are masters of the "plug and play" and of course code reading esxperts...LOL



Dude....are you getting a kickback from pcmforless or something? No one is debating that they make a good product. This guy GMT 360 is just trying to share some knowledge.....

[juventus1983]

i think he was arguing that pcm4L has dynoed their set-up and has proof that gmt360 is wrong.

[Zibby]

gmt360,

Thanks for the information and I'm not bashing you but did you have anything to do with the 93 4.3L s-10 fan clutches? I can tell you first hand they suck! While i was in high school and college I replaced many of those POS. I gained 2-3MPG. And just to confirm it wasn't a mistake...i put it back on and lost 2-3mpg. Just about everyone's I replaced reported the same results(10+jobs). e-fans is the first mod i will make on any vehicle when looking for gas mileage. Surprising its one of the only mods you can actually feel in seat. Most of the time CAI or exhaust is just in your head.

[Pepper]

Thanks for the link/pictures Spong - love them... I have to install those fans. Just hope they will fit on my 03 Envoy n that they will make a difference. During summer in AZ the heat is High and AC sucks - my Envoy almost overheats - the dealer said that it was normal on this type of car.

[Nukedog]

Dude....are you getting a kickback from pcmforless or something? No one is debating that they make a good product. This guy GMT 360 is just trying to share some knowledge.....


Nope - i think GMT 360 is a ME or wishes he was one and just likes to put out unproven drivel to feel like he is one up on us instead of doing real world testing like some of us...:thumbsup:

[AlvinPCMforless]

I'm also a mechanical engineer.

I'll tell you from installing more than 20 of these kits locally. You will pick up at the very least 10rwhp across the board. I've had a handful pickup over 20rwhp but most are right arout 15rwhp.

I have results posted all over my section. That should prove more than a whipped up excel graph. I mean customers where right there with me when I ran the vehicle stock, installed the Efan and ran it again without even removing the truck from the dyno. You are removing a second order horsepower hog from your engine. You are also ridding yourself of decently large mass with pretty large moment of inertia.

Bottom line.. I don't sell anything i don't believe in and you can take that however you want. Plenty of customers who have either installed my Efans or had me install them will back me up on that.

[Nukedog]

Bottom line.. I don't sell anything i don't believe in and you can take that however you want. Plenty of customers who have either installed my Efans or had me install them will back me up on that.


Yep...

[juventus1983]

not to be negative but that guy is a douche

[Zibby]

I really don't want to bash the guy becasue maybe he has made the tests for GM to improve the fan clutch. I think the only reason GM doesn't do E-fans from the factory is price. They need to consider allot more then jsut a few horse power or few mpg when desiging and releasing a vehicle for prodcution. I'm sure as mpg and emissions get more strict e-fans will become standard.

And then on the other hand....I'm also a ME, and it wasn't more then a few years ago I graduted. I can say first hand we are all in trouble....I wouldn't trust 75% of the enigeers I graduated with to put air in my tires....let alone design and release anything on my truck.