[Mk2] [Turbo] Upgrade stock radiator fans?

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rossonza
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[Mk2] [Turbo] Upgrade stock radiator fans?

Post by rossonza »

My understanding is one of the giant fans is for A/C (which im removing). Is there a lighter/better flowing cooling fan i can fit to the radiator? something a bit more slimline. the stock units are GIANT
shinny
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Re: [Mk2] [Turbo] Upgrade stock radiator fans?

Post by shinny »

It's not as simple as "one fan is the aircon fan". If your car originally had aircon, then it will control two fans, not one, and does so in a more sophisticated manner. You could convert it to use a single fan like a non-aircon car (by replacing the rad temp sensor, replacing the aircon ECU with a shunt from a non-aircon car, adding a cable for the heater valve, replacing the heater fan switch and maybe doing something in a fuse box) but I've no idea why you'd bother!

If you want to change the fans, I would consider that separately from air-con removal. Personally, I'd suggest that you don't really need to upgrade the fans for cooling performance on a road car as a good condition rad is amply sufficient to cool healthy stock and lightly modded engines for road and light track use.

Of course you may like to replace the fans with something lighter and more efficient, and I'm not sure I'd blame you :thumleft:
pbmr2
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Re: [Mk2] [Turbo] Upgrade stock radiator fans?

Post by pbmr2 »

The stock fans are also ducts all in one. The reason they seem so large is so that when they are on the area of the rad they pull air through is larger.
The spaced out fins allow better airflow when the fan isn't running.

Replacing them with proper pull Spal fans will have a higher CFM which will mean the fans are on for less time. They will still need to be ducted though.

The non AC cars have 1 fan on the driver's side, you could simply leave the other fan off the car.

Don't forget to bridge the plug for the AC pressure sensor in the frunk. Or leave the sensor on the plug. If this isn't done then the fans will run all the time. The AC ECU does this. see Shinny's post for changing the behaviour of the system.
rossonza
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Re: [Mk2] [Turbo] Upgrade stock radiator fans?

Post by rossonza »

pbmr2 wrote:The stock fans are also ducts all in one. The reason they seem so large is so that when they are on the area of the rad they pull air through is larger.
The spaced out fins allow better airflow when the fan isn't running.

Replacing them with proper pull Spal fans will have a higher CFM which will mean the fans are on for less time. They will still need to be ducted though.

The non AC cars have 1 fan on the driver's side, you could simply leave the other fan off the car.

Don't forget to bridge the plug for the AC pressure sensor in the frunk. Or leave the sensor on the plug. If this isn't done then the fans will run all the time. The AC ECU does this. see Shinny's post for changing the behaviour of the system.


Sure,

it was more the weight of the damn things that shocked me. Think ill leave the one fan off. and look at a spal + duct setup in the future.

yeah id read about the fans running constantly, so ill try and locate the sensor. :thumleft:
rossonza
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Re: [Mk2] [Turbo] Upgrade stock radiator fans?

Post by rossonza »

Sorted a replacement alloy radiator. Just looking for duct/spal fans now. Any recommendations?
androo007
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Re: [Mk2] [Turbo] Upgrade stock radiator fans?

Post by androo007 »

Surely the fans only come in when needed, i.e stationary or overheating. By standard measures the radiator is cooled by airflow of you driving, not the fans. Or am I mad.

I don't see the point in upgrading whatever unless it's to cool down an overheating engine a little faster (which isn't solving the problems anyway)
rossonza
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Re: [Mk2] [Turbo] Upgrade stock radiator fans?

Post by rossonza »

androo007 wrote:Surely the fans only come in when needed, i.e stationary or overheating. By standard measures the radiator is cooled by airflow of you driving, not the fans. Or am I mad.

I don't see the point in upgrading whatever unless it's to cool down an overheating engine a little faster (which isn't solving the problems anyway)


my main issue was mine was rusted...and buying 2nd hand radiators in similar shape wasnt ideal for me :-)
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