[MULEDAWG]

Wiring in a second set of engine fans


So thanks to @Caddylack I was able to install OEM coolant fan in ole MuleDawg, which I’m thankful for. Now after removing my older smaller fans, troubleshoot & throwing a piss fit… ( the fans were indeed good, wiring was faulty).
So this got me thinking, why not use these fans for more cooling?

So my question to the Impala/ Caprice/Roadmaster supa friends:
Would I run into any engine performance issue if I installed my original (10 inch diameter) in front of my radiator. I would put them either on a switch in the cab or wire into my old air pump system and have them run all the time.
The fan word work in PULLING verses PUSHING.
If ran to switch mosdef it’s going through a relay for safe… let me know what you folks think…

 

[buickman1]

If your car needed more cooling than the two puller fans, I would consider going through the cooling system first, and making sure everything is working properly.

 

[Marky Dissod]

So this got me thinking, why not use these fans for more cooling?

Why do you think you need more cooling?[/QUOTE]The vast majority of the ISSF has been very satisfied with the 150Watt electrical primary fan and the 240Watt electrical secondary, especially when programmed to both be on before 212°F.

If your car needed more cooling than the two puller fans, I would consider going through the cooling system first, and making sure everything is working properly.

Does your coolant looks like it's carrying a lot of crap in it?
Because the two puller fans should be enough.

If you want to add a fan, add a fan to the ATF cooler.
GM's ATF cooler is barely adequate at best. Its location doesn't help either.

Would I run into any engine performance issue if I installed my original (10" diameter) in front of my radiator?
I would put them either on a switch in the cab or wire into my old air pump system and have them run all the time.

If your fans were on 'all the time':
you would certainly gain no performance advantage; it's been tried, and shown to be worth nothing (pre Aug 2009)
your fans would not last as long
they're designed and programmed to turn off over 48MpH because they are less effective than a 48MpH headwind
(and might wear out even more quickly if left on over 48MpH)
our fans were designed to work as puller fans

 

[Marky Dissod]

Those using 160°F thermostats trade a few MpG in exchange for transmission longevity and performance consistency.
If you are using a 180°F thermostat, and want to keep the fans on 'all the time', you'd achieve pretty much the same thing with a 160°F thermostat and reprogramming the fans to suit that thermostat.

 

[MULEDAWG]

If your car needed more cooling than the two puller fans, I would consider going through the cooling system first, and making sure everything is working properly.

BuickMan1, everything is fine I just wanted to add front fans on a switch control as a backup to my OEM fans that all..

 

[Marky Dissod]

BuickMan1, everything is fine I just wanted to add front fans on a switch control
as a backup
to my OEM fans that's all.

As a backup?
Even though this has not been shown to be necessary, this is still a very different story.

As backups to the puller fans, they would not need to turn on before the puller fans.
If the electrical wiring were properly upgraded, and the pusher fans were to 'backup' the puller fans,
the pushers would still would not need to be on under 212°F unless one or both of the puller fans 'quit'.

Have your OE electrical fans been reprogrammed, or not?

 

[MULEDAWG]

No, they haven’t been reprogrammed and I am wanting to get my PCM reprogramed but haven’t gotten to that part of the project & I would also need the information on that. Does anyone have “flash setup” that they have applied to their caprice or impala? If so please forward it to me. Thanks again

 

[Marky Dissod]

No, they haven’t been reprogrammed, and I am wanting to get my PCM reprogrammed, but haven’t gotten to that part of the project & I would also need the information on that.

pcmperformance.com has been tuning since 2005 with an excellent reputation, and is one of the few remaining that still tunes OBD2 LT1 pcms.

 

[storm9c1]

I would advise against running fans on the front of the radiator. I've tried this before on 2 different vehicles. In both cases, I determined that the front fan(s) block the radiator at highway speeds. The result is that engine slowly climbs hotter and you never figure out why. You suspect the engine is running too lean. Then you do a million things to the cooling system. No improvement. Until you remove the front fans. Don't make my mistake and chase your tail. It causes more problems than it's worth.

Keep in mind that I tried this on two different setups. One setup had 2 electric pullers. One setup had a mechanical puller with HD clutch. Both ran hot on the highway until I removed the front setup and just let the pullers do their jobs.

I agree with others, if you car is still running hot, figure out the root cause. As I've mentioned in other threads, don't trust the stock gauges. The temp gauge on these cars is notorious for going out of calibration. Use a cheap IR gun from HF to double-check actual temps.


Side notes:
Electric pullers can also inhibit airflow if they are running at highway speeds. They aren't turning fast enough and the airflow at 55-70 MPH will try to push them at a different speed than the natural speed of the motors, thus overheating them and/or burning the brushes. The PCM commands the fans off above 38 MPH (or thereabouts) for a reason. The only exception I've noticed (not well documented) is that high AC head pressure will force fans running even at highways speeds.

Wiring up a set of LEDs to the relay inputs or outputs (I have this on all of my cars) will let you monitor and learn what the fans are doing. You can even do so temporarily using solid copper cat5 conductors or bell wire shoved into the terminal and then reinstall each relay. I like to use the ground reference on the relay input for safety on permanent installs. In this case, you can also send a ground signal to the relay (as the PCM does) to manually turn on the fans from the driver's seat. So you only need one wire per relay running into the passenger compartment. Forcing a ground signal to the relay will set a silent code though. But it should not turn on the CEL.

 

[Marky Dissod]

Get your pcm reprogrammed - not just for the superior fan settings; you don't know what you're missing.
Mind, at least 99% of the people who get tuned wished they'd done it sooner.

On top of the radiator bracket, when the hood closes, there should be a gasket.
On either side of the radiator, there should be 'curtains', or something.
Under the radiator, there should be a long central air dam.
Any air that sneaks around instead of going through the radiator will make your cooling system 'underperform'.

I'd even consider temporarily removing the fans behind the radiator long enough to spray a high pressure H2Ohose through the radiator / condenser from back to front, in case that would help clean them out.