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Pandemoniac
10-23-2007, 10:58 AM
A long time ago I had heard that the radiator fan turns on during boost in our cars. Now I've heard from somebody else this may not be true.
Does the fan come on or not? I've got an '89 shadow if it makes any difference.

JDAWG
10-23-2007, 11:22 AM
yours doesnt but L bodies do due to the smaller rad

turbovanmanČ
10-23-2007, 12:36 PM
I've never seen or heard the fan come on during boost, this is interesting. How do I know, dyno, ;)

The usual problem is they come on too late and let the engine get toasty warm, :(

Big_P
10-23-2007, 02:34 PM
Adjustable fan controller FTW!

or,

Manual fan switch FTW!

Spraynlog
10-23-2007, 02:49 PM
The manual fan switch mod is a great one for the track days!

If you have an early 2 blade fan, go to the JY and get a later model one from an A/C car, they bolt right in and flow a LOT more air.:nod:

JDAWG
10-23-2007, 03:29 PM
Yea they do let the damn engine get to warm. Im getting ready to do a manual switch on mine. It doesnt come on till like 3/4 gauge.
Anyways I read that on tdg.

4) GLHS LM turn the cooling fan on as soon as the car sees 3-4 psi of boost. This was done to head off overheating- the GLHS had very small radiators and fans.


But cant say I have exp with this, not an L body guy

Pandemoniac
10-23-2007, 10:25 PM
I saw that quote from donovan's site, I guess that's all. I was thinking/hoping it did, I'm making a water/air IC system and was wanting the fan to come on during boost, but didn't want it to run all the time. This is a daily driver with a/c and everything.
How about some sort of pressure activated switch? Does anyone know of any switch that's triggered by a low pressure that I could use? If so where to get it and part#?
Here's my IC setup: http://boostedmopar.com/forums/showthread.php?t=11412

Murphy
10-23-2007, 10:48 PM
I thought it was at WOT?

Pandemoniac
10-23-2007, 11:02 PM
I could easily set up a switch that's triggered at WOT but I'd like my fan to come on any time it sees boost, even at part throttle, since this car's a highway cruiser too. I want fast, yet bulletproof and reliable (I understand how hard that is)

Pandemoniac
10-30-2007, 10:08 AM
looks like I'll go with a hobbs switch off ebay to control my fan.

ShadowFromHell
11-02-2007, 10:13 PM
also... a easy way to make it work stock is just to ground out the fan relay like the comp does to turn it on. Most of my TD's get that mod in the summer and I just run the fan all the time. Then there is no forgetting to flip the switch, because the comp can still control it.

86Shelby
11-02-2007, 11:35 PM
also... a easy way to make it work stock is just to ground out the fan relay like the comp does to turn it on. Most of my TD's get that mod in the summer and I just run the fan all the time. Then there is no forgetting to flip the switch, because the comp can still control it.


Ding ding ding! We have a winner! Have the switch on the ground side of the relay running in parallel WITH the computer. :thumb:

1 bad day
11-03-2007, 05:03 PM
if your going over half on heat, then you need to fix your cooling system....mine did that and I replace the thermostat with a new one and flushed my cooling system with a garden house....issue went away totally

moparzrule
11-03-2007, 05:27 PM
+1 to that, somethings wrong. Why would you want to put strain on the alternator in boost or at WOT? Those are the times you want the most power! If you said you'd like to turn your fan off at WOT that would make more sense! Because in WOT you are more that likely moving down the road meaning air is coming in cooling the radiator.
Someone mentioned about the 2 blade fan VS the other one. I specifically went to the junkyard to pull a 2 blade fan because they weigh half as much! My fan never comes on unless I'm sitting idling a lot anyway, and when it does that 2 blade fan pulls plenty of air, only turns on for like 30 seconds if that and then has everything cooled back down.
One other thought, a custom calibrated ECU you can have control the fan schedules anyway. Since I run a 180 thermostat I have my fan kick on at 200 and off at 185. Factory is like 220 on and 200 off something insanely hot like that.