L322 Electro Viscous Fan in a P38

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.

FEI

Member
Posts
17
So as i said in the other thread im planning on fitting the elctro viscous fan from the L322 4.2 SC into my P38.
Its fitted in the car now with permanent wiring to it and the controller still just lying in the passenger footwell.

The fan fits into the stock 4.6 cowling with some persausion from a heat gun in some spots to gain more clearance. I ended up with about a 5mm gap all round so its quite tight but i havent seen/heard it touching yet.

So we went for the first proper drive with the car yesterday. It was about 100km both ways and ambient on the way there was about 31 deg and on the way back 26 deg.

On the drive there with the hotter ambient.
How my software is set up currently coolant would warm up to about 96 deg when on a flat section to a slight incline, at that point im requesting about 900 RPM fan speed.
Then on a hill coolant gets up to about 98 deg and i then request about 1200RPM fan speed, as i go down the other side coolant quickly drops back down to 92-93 deg.
So i would call that a success.

On the drive back with the colder ambient coolant was constantly about 92 and then it climbs to about 96 on a hill and drops to about 88 on the way down.

So i still need to do alot of software optimization, getting the requested fan speed in relation to coolant temp graph correct is going to be critical and then i have to think about of all the error states that could happen and decide how to react to them.

One thing ive noticed is when at engine idle and im requesting 0 fan engagement the fan will sit in a slightly engaged state. If i then bring up engine RPM at a slight to moderate rate like pulling away at a robot(traffic light) the fan will stay engaged for a while until engine RPM reaches about 2400RPM. But if i pull away with full power the fan disengages almost immediately. So what im wondering is if that is not maybe caused by the solenoid on the fan being abit leaky. Its an old unkown history second hand fan that i got for cheap so i can see if this will work. If anyone could give some input on this that would be great. Will a new fan have a less "leaky" solenoid?
 
Some info ive found that might help someone do diagnostics on one of these fans.

Pin 1 : Grey : Hall effect sensor 12v+ supply
Pin 2 : Green : Hall effect sensor GND
Pin 3 : Blue : Hall effect signal out
Pin 4 : Black : Fan solenoid GND
Pin 5 : White : Fan solenoid 12v+

Pin 1 and 2 is basically power to the hall effect sonsor. Pin 3 is the signal output from the hall effect, inside the ECU pin 3 is pulled up to 12v+ through a resistor and then whenever the hall effect is triggered Pin 3 gets pulled down to GND by the hall effect sensor. The hall effect gives 6 pulses per rotation of the fan. Pin 4 is controlled through a mosfet that is sent a PWM signal, from my limited testing with the car just standing in the garage idling 3Hz PWM frequency seems to work best. Pin 5 is just connected to 12v+ battery power. The solenoid seems to use about max 1.6amps
 
Not sure if I've seen the other thread..
What's the point in putting this fan in to the p38?
In my opinion 98c is too hot.. the thermostat is fully open at 96c but you can't do much about that.
I think if i did things over, I'd look at an electric water pump, i think that would be an effective upgrade.. coolant flow at idle, in my opinion, is too low
 
https://www.landyzone.co.uk/land-rover/viscous-fan-speed.349729/ the other thread

Slight improvement in cooling ability because of larger fan diameter and better/more effienct fan blade design.
Improvement in fuel economy beacause of way more control over what the fan is doing and more effiecient fan blade design.
The ability to turn the fan off for wading. With the fan in a fully disengaged state at idle i can touch and stop the fan with my bare hand.
 
Back
Top