Electric Fan???
#26
Engine, Not Motor
iTrader: (1)
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes
on
91 Posts
It also helps prevent heat soak at the track.
This is ALL COVERED in my writeup and I also think Aaron covers it as well in his. both can be found in this thread so READ!
#27
I'm a boost creep...
Join Date: Jan 2002
Location: Auckland, New Zealand
Posts: 15,608
Likes: 0
Received 8 Likes
on
8 Posts
After you shut down an engine, temperature spikes because coolant is no longer flowing rapidly through it and the rad. This spike lasts several minutes and if the car was already a bit hot before you shut it down, gets well into overheat territory since there is no way to reject the heat.
#28
Technician
iTrader: (1)
Join Date: Aug 2006
Location: Virginia
Posts: 1,008
Likes: 0
Received 0 Likes
on
0 Posts
Just to clarify: There is no benifite to running an E-fan after shut down of the engine? There is no degredation of parts beyond normal?
Wouldn't just turning off the engine and having the E-fan turn off be the same as with the stock fan system?
Wouldn't just turning off the engine and having the E-fan turn off be the same as with the stock fan system?
#29
Rotary Freak
Join Date: Dec 2006
Location: New Hampshire
Posts: 1,791
Likes: 0
Received 0 Likes
on
0 Posts
The water may get hotter but the engine isn't. There's no more heat being added from anywhere, but the heat from the metal engine parts is being conducted into the water, raising its temp. That's completely different to "overheating", and isn't doing any damage. The real problem from post-shutdown heat soak is heat being radiated off the engine and into all the rubber and plastic parts, which over time degrade as you'd expect.
Wouldn't just turning off the engine and having the E-fan turn off be the same as with the stock fan system?
#32
Engine, Not Motor
iTrader: (1)
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes
on
91 Posts
The water may get hotter but the engine isn't. There's no more heat being added from anywhere, but the heat from the metal engine parts is being conducted into the water, raising its temp. That's completely different to "overheating", and isn't doing any damage. The real problem from post-shutdown heat soak is heat being radiated off the engine and into all the rubber and plastic parts, which over time degrade as you'd expect.
Exactly. With proper maintenance, you wont have to worry about those plastic parts or rubber hoses. On a 15+ year old car, the damage is already done so trying to prevent something that has already taken place wont do any good. Maintenance is the only preventive measure.
Wouldn't just turning off the engine and having the E-fan turn off be the same as with the stock fan system?
#33
Rotary Freak
Join Date: Dec 2006
Location: New Hampshire
Posts: 1,791
Likes: 0
Received 0 Likes
on
0 Posts
Yes, I meant to say "coolant" instead of "engine". One of those rare moments were I overgeneralized instead of being too specific. The spike in coolant temperature is quite impressive from what I've measured. Well over 100 degrees as measured by the ECU for a few minutes after shutdown. A large water cooled turbo likely contributes to this. While I'm not worried about engine damage (though the coolant recover bottle fills up ) the whole engine bay becomes an oven with no airflow. Even a bit of airflow helps considerably.
As I stated before, if the proper maintenance is done, you wont have to worry.
#35
I'm a boost creep...
Join Date: Jan 2002
Location: Auckland, New Zealand
Posts: 15,608
Likes: 0
Received 8 Likes
on
8 Posts
I don't see how blowing 70-80degC air off the radiator into the engine bay can make that much difference. There's just far to much residual heat in the engine. And once the coolant at your temp sensing point cools below the switch-off point, the fan's going to stop anyway, and there'll still be tons of radiant heat in the engine bay. All I see is a draining battery...