Switching to electric fan, better performance?

justice · Post by **justice** » Thu Sep 28, 2006 3:28 pm

My 87 shorty (just turned 150000 miles) is running good and runs cool as well. Would I see any kind of performance improvement if I were to switch over to an electric fan? I'm assuming this would allow me to remove the fan, clutch and shroud that are currently in the van(which would seem like it would make it easier to work on...

astrozam · Post by **astrozam** » Thu Sep 28, 2006 7:03 pm

I've read that there should be a small h.p increase, are you thinking of putting in one of those killer Taurus fans? Locdock
just picked one up in this thread...

http://astrosafari.animegrafx.com/bb/vi ... highlight=

astro-jason · Post by **astro-jason** » Thu Sep 28, 2006 9:04 pm

I can tell ya that the taurus fan is awsome. I put one on the astrovette,it had two fans one pullin and one pushin for the a/c. I removed both fans and installed just the taurus fan and it works great. I can also say that they are loud, thats all you hear in front of the van you cant even hear the engine running. Jason

SoCalli V8 · Post by **SoCalli V8** » Thu Sep 28, 2006 9:59 pm

You may get a small hp increase but not enough to feel, and if you live in a hot climate or tow stuff I would not recommend it.

But if the above criteria does not apply to you go ahead and try it out, you may have to fab up some brackets to support the fan, as I do not recommend mounting through the fins with those silly ties. (the fan will eventually cause you rad to leak, due to vibration)

peter · Post by **peter** » Sat Sep 30, 2006 3:46 am

I think that the electric fan install is a crap shoot unless you go with the biggest, baddest set up possible. You may think that your set-up is ok, then you find yourself towing 5,000 lbs up and down mountains in 105* ambient temps. With the a/c being powered by your sbc. Now, it ain't all that great anymore.
I'm not saying it's impossible to achieve perfect cooling with electric fans (which I also run), I'm just saying that you never really know if your set-up is gonna keep you cool in worst-case scenarios unti you actually experience the worst-case scenario.
When I went to the 06' Campout this summer, I was a bit disappointed with my cooling system (which I had previously touted as being easily up to the task). 85*F ambient temps, a/c on and we were stuck detouring thru rolling hilly regions at 35-45 mph because of the flooding in PA. No, it didn't overheat per se. But the temps were much higher than I was accustomed. And it was only 85* outside. And while I was towing a loaded Tramper, I figure it only weighed about 2,500 lbs. What if I had been towing the full 5,000 lbs max, and the temps outside had been 95*? I insist that you never really know until you've gone thru worst-case scenarios, especially if you're running an 8 in the truck. Heck, Dean had trouble keeping his 4.3 cool if I remember correctly.
Another thing. Electric fans will cause a power drain on your engine when they're running. An additional 30 amps has gotta put an extra drag on an alternator which is already trying to keep up with DRL's and a wattage-hungry electric fuel pump. I wonder what the hp gains really are WHEN the fans are on.
What do you all think?

LiftedAWDAstro · Post by **LiftedAWDAstro** » Sat Sep 30, 2006 7:09 am

Well Peter...I really didn't have too much trouble keeping the van cool. I did have some minor issues...the waterpump was on it's last legs (we changed it out at Bob's), the engine never got above 210, the tranny was only up to about 195 and I am pushing way more drivetrain than anyone else plus towing a 3500# trailer AND hauling another 250# of tools and supplies AND hauling at least 500# of wood...so yeah she was a little warm! I will be swapping to an electric fan as well this fall and will be dialing it in to make it cool right. If Bill and I can make our vans run cool with electric fans then everyone else will be able to as well!

peter · Post by **peter** » Sat Sep 30, 2006 5:58 pm

Like I said, Dean. Worst case scenario. If you can keep her cool in 95* temps while towing 5,000 lbs with the a/c on, then you're definitely on the right track. Otherwise, you're just plain lucky....
Again, I'm not saying it's impossible to run cool with electrics. I'm just saying beware...

dragonvan · Post by **dragonvan** » Fri Jun 08, 2007 2:07 pm

The most important thing about E-fans is the shroud! The whole point of it is to create a pressure drop accross the rad. Thermodynamics says pressure drop=temp drop and vice versa. The pressure drop actually cools the air as it is drawn accross the rad. That pressure drop is worth probably 40% in efficiency... if you really want I can whip out my physics books :-k

I just installed a Derale dual fan setup on my '02. They are wired with a third relay for series/parallel high/low speed. On high they sound like a siren, on low you can't hear them with the hood shut. Van now runs cooler than it did with the clutch fan. I haven't towed with it yet but don't expect problems. With the duals two speeds is easy and then you don't have to put up with the constant noise. The noise is one of the reasons I switched to efans, couldn't stand taking off from a light... always wanted to check that the landing gear was up

lockdoc · Post by **lockdoc** » Fri Jun 08, 2007 8:52 pm

I installed a controller from Delta Current http://www.dccontrol.com to manage my Taurus fan. The stock shroud covers most of my pre 95 radiator. I need no relays as it is a solid state unit that varies the output. Meaning it starts and stops progressively. So far in 85* with high humidity with front and rear AC it stays right at what the thermostat says it should. It actually only turns on when going up steep hills or idling for long periods of time. As for drain on the battery, it is pretty severe with everything running. The alt meter drops considerably. So far it hasn't done anything bad to the battery but I forsee it killing the alternator if I use the AC a lot. I has jumpers to control what temp it comes on plus you can wire to the AC or whatever to turn on to 50 or 100% power when engaged. A nice simple install and forget about it item.

Water Boy · Post by **Water Boy** » Fri Jun 08, 2007 10:18 pm

Went to DCControl.com. Never would have thought of using a variable speed fan controller. Most are on/off relays. Of course, relays are way cheaper than their controller, but what is the overall and long range goals....efficient and reliable.

Bookmarked

dragonvan · Post by **dragonvan** » Sat Jun 09, 2007 9:04 am

I don't like the variable speed controllers for the following reasons:

1. Cost
2. I don't like something deciding what speed my fans should be at.
3. Cost
4. I have read quite a few problems with especially perma cools controller but also everyone else's, most of them are great companies and waranty them even when out of waranty but I don't want it breaking on a trip far from home.
5. It is easy to cary an extra relay for a relay failure.
6. it is easy to cary a jumper wire with spade terminals for bypassing a controller or relay in the event of a failure.
7. K.I.S.S. is one of my mantras in life.
8. Cost

lockdoc · Post by **lockdoc** » Sat Jun 09, 2007 10:41 pm

dragonvan wrote:I don't like the variable speed controllers for the following reasons:

1. Cost
2. I don't like something deciding what speed my fans should be at.
3. Cost
4. I have read quite a few problems with especially perma cools controller but also everyone else's, most of them are great companies and waranty them even when out of waranty but I don't want it breaking on a trip far from home.
5. It is easy to cary an extra relay for a relay failure.
6. it is easy to cary a jumper wire with spade terminals for bypassing a controller or relay in the event of a failure.
7. K.I.S.S. is one of my mantras in life.
8. Cost

Maybe for some but to group all controllers together? That is very narrow minded thinking. Cost? Mine was less than $120 shipped. It included everything needed to install plus the option of setting the fan speed to what you want if you are that hard up for it. The relays needed to run a Taurus fan cost around $35-40 a piece and you need two. It is just as easy to carry a large gauge wire with alligator clips to run the fan in an emergency AND it is much less than a relay. I know this because it is how I ran it before I got the controller. Reliability? Mine has no moving parts at all like relays have. Not much to break. The examples of the system I own have been installed on custom 4X4 applications and have had great sucess with them over a year of use. KISS? I gaurantee my system is much more simple than anything you can build. The fact that you don't need a beefy relay to run a high amp fan let alone two for a two speed fan is the epitome of simplicity when installing an electric fan.

lockdoc · Post by **lockdoc** » Sat Jun 09, 2007 10:54 pm

Water Boy wrote:Went to DCControl.com. Never would have thought of using a variable speed fan controller. Most are on/off relays. Of course, relays are way cheaper than their controller, but what is the overall and long range goals....efficient and reliable.

Bookmarked

What swayed me to this controller over the relay setup is that the Taurus fan needs a higher than average relay to run it. They cost around $35 and you need two of them if you want two speeds that the Taurus fan can supply. Couple that with the cost of wiring, connectors, sensor and switches the cost comes out around the same. I decided on the simple one.

dragonvan · Post by **dragonvan** » Sun Jun 10, 2007 9:07 am

What controller are you guys running?

My setup doesn't require quite the high current relays that the taurus fan does. The relays that come with the fans and temp controllers are 40A relays and can be had for about $10-15. I have a spare as 2 came with the fans and 2 with the controllers. The fans are rated at a max of 25A each at startup, also they come with a 25A fuse, note running they are much much lower than this. I haven't tested the current draw yet but I doubt it is even that high.

I did look at the Dakota Digital controller. It seemed the best of the bunch as far as having the fewest complaints. It only does high/low not true variable and requires either their sensor or one in use by a VDO gauge. These sensors would have to be screwed into the head or block.

My logic says fans cool the rad, not the engine, therefore fans should be controlled by rad temp. Let the thermostat control engine temp, that's what it's there for. I wanted to control the temp of the Rad based on the temp of the rad. My engine hasn't gone over 197F yet that I know of. The low kicks in when the rad temp at the probes hits 170-175 and the high at about 195, I haven't seen the high kick in yet but we haven't had too hot of temps yet. The probes are by the water inlet. This way I am using the rad as a heatsink and letting the thermostat in the engine control engine temp. I could set the fans at even lower temps to provide more of a heatsink effect.

On the late astros the thermostat starts to open at 188 and is full open at 206, this is considered a 195 thermostat. On other GM v6 with factory e-fans and 195F thermostat the low speed kicks in at 112 or 117 depending on vehicle/engine and high at 223 or 226. The LS1 vettes and f-bodies have a 189-207 thermostat (almost identical to the astros 188-206) and the low comes on at 206! high at 235! this is engine temp remember as the PCM is controlling the fans based on the engine coolant temp sensor.

Yes relays do fail. Since entering tech school in 1996 I have replaced about a dozen relays. Not many considering the thousands of cars I have worked on. About 9 or 10 of those were fords. They had several years that they were getting cheap relays from low bidders that weren't sealed relays and then they mounted them in high moisture areas. You do the math... I sealed the one relay I used that looked like it might not be and all of them are mounted in a box that only has an opening at the grommet where the wires leave. This is mounted behind the drivers side headlights right in the very corner. Short of a high water crossing I hope I don't have problems [-o<

I figure the 3 relay setup has worked out for GM for almost 30 years so it can't be too bad. I simply am using 2 temp controllers instead of 2 screw in switches in the heads, or the PCM.

BTW - I think if you found a good custom programmer... he could enable cooling fan support in the PCM and you could just add the terminals in the PCM connectors and the 2 relays as I think the circuit is in the PCM and the pins on the PCM itself. He would also be able to set them to turn on at whatever temp you wanted. The PCM would be monitoring from the ECT sensor of course. Around me there is no one that could have done this for me and I don't have time to learn all that would be needed to mod the firmware for the PCM.

I am very interested in what variable speed controller you guys have as I might want to switch at some point If they look like a better solution than my current setup.

Chevy & GMC Vans

Chevy & GMC Vans

Switching to electric fan, better performance?

Switching to electric fan, better performance?