flex fan vs. electic
Elder User
Joined: Jan 2006
Posts: 629
Likes: 0
Originally Posted by Torque1st
Not really, it is because of sidewinder engines in FWD vehicles and lack of space in others. Where possible the OEMs still use the T-clutch fans. There are some now using hydraulic driven fans using wasted PS pump power. However the only really good way to run an E-fan is under computer control. OEM wiring is much better than most aftermarket wiring because they have to stand behind it for warranty reasons.
Turns out that carmakers are moving toward electrical power for everything...though electric AC compressors still require 42 volt systems, so we only see them on hybrids. Hydraulic power is slowly being phased -out.
The control issues that you mention are the key: an electric motor can be controlled to provide output as-needed, versus engine-driven hydraulics that have constant paraitic losses as long as the motor is running. Delphi says that their electric power steering uses 3% of the energy of a hydraulic system.
Chevy touted efficiency (both cooling efficiency & a small bump in MPG) & noise as the key benefits of their switch to e-fans on their full-size trucks a few years ago.
Interestingly, alternator and their associated belts have steadily increased in size as the electrical demands of new vehicles has increased. So nothing is free...
Last edited by pronstar; Jan 5, 2007 at 09:37 AM.
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
Originally Posted by pronstar
...Interestingly, alternator and their associated belts have steadily increased in size as the electrical demands of new vehicles has increased. So nothing is free...
Some of these improvements like the computer controlled fans have an added cost also, -complexity and along with it reliability losses, repair costs, and initial cost.
I think the PS pump hydraulic fans were looked upon as a stop-gap since the new 36/42VDC electrical systems were not ready and that PS pump sitting there running 98% of the time over a relief valve was a huge waste of power. Electrical PS etc is a big efficiency boost (complexity/reliability/etc again tho) and having a battery sitting there is like having an accumulator in a hydraulic system. It can give a sudden shot of power when needed.
Elder User
Joined: Jan 2006
Posts: 629
Likes: 0
Originally Posted by Torque1st
Hehe, don't we know it!
Some of these improvements like the computer controlled fans have an added cost also, -complexity and along with it reliability losses, repair costs, and initial cost.
Some of these improvements like the computer controlled fans have an added cost also, -complexity and along with it reliability losses, repair costs, and initial cost.
As things get more and more complex, replacing entire modules seems to be he norm, and these modules are expensive. The days of diagnosing & repairing problems are slowly vanishing. Instead, we've come to the point of throwing parts at the problem until it gets fixed.
How many times have we heard stories of "well, it didn't trigger a code so we can't figure out what's wrong with your car?"
It seems that finding a good service/repair technician is becoming very difficult. There is a real need for good auto technicians these days, which explains the steady increase that shops and dealerships are willing to pay them....but this also increases the repair cost for the consumer.
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
I have found a few good ones around in my area. They are treasured, but at the same time I don't bother them with any menial work, I let others do that so they can spend their time appropriately. I also expect to pay them for their knowledge.
Throwing parts at a problem or "shotgunning" is expensive and the last thing a person wants to do. Even without codes the good guys can think a minute and spot that common link and replace the proper part.
Throwing parts at a problem or "shotgunning" is expensive and the last thing a person wants to do. Even without codes the good guys can think a minute and spot that common link and replace the proper part.
Thread
Thread Starter
Forum
Replies
Last Post
dimora
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
33
Jun 20, 2015 04:34 PM
4x4Subaru
1967 - 1972 F-100 & Larger F-Series Trucks
10
Apr 23, 2004 04:03 AM
