Aftermarket Hi Flow Rad Fan help

[unspankable]

So I'm trying to figure out how to rig in an Spal high CFM fan but I don't know how the fan control module functions and were I would interface the fan/extra relays and wiring with this module to keep everything happy.
The shop manual doesn't provide any information on the module.
Anyone smarter than me have any input? How is the duty cycle of the fan controlled? PWM? Some of the aftermarket fans available from Rock auto as direct swap in don't have a module and there is a 2 pin plug connected straight to the fan so can I just bypass the fan module without pissing the ecu off?
I know how to run switched 12V to a relay and into the fan.

 

[unspankable]

 

[Capri to ST]

Here's a cooling fan table showing fan speed in relation to engine and air temperature that I ran across at some point, I don't know if this will be helpful to you, but I will attach it here just in case it is.

 

[unspankable]

Here's a cooling fan table showing fan speed in relation to engine temperature that I ran across at some point, I don't know if this will be helpful to you, but I will attach it here just in case it is.

View attachment 62580

Thanks Buddy I saw that. It's what tipped me off about PWM control. Appreciate it

 

[Dialcaliper]

To be honest, you could probably just wire the PWM control wire to the trigger wire on a normal relay to get full fan speed whenever the control signal is sent. You might need a pull down resistor between the relay trigger and ground to prevent a short - the PWM signal should be high enough frequency that the relay coil will just see it as a lower voltage and trigger normally. (Otherwise you might need a capacitor as well)

Alternately you can use the Mishimoto diagram and a separate switched relay or just wire it straight to the output of the cooling fan relay (which should be perfectly safe, it’s a 60A relay circuit that powers the factory fan), both of which will give you full fan whenever the ignition is on.

 

[unspankable]

To be honest, you could probably just wire the PWM control wire to the trigger wire on a normal relay to get full fan speed whenever the control signal is sent. You might need a pull down resistor between the relay trigger and ground to prevent a short - the PWM signal should be high enough frequency that the relay coil will just see it as a lower voltage and trigger normally. (Otherwise you might need a capacitor as well)

Alternately you can use the Mishimoto diagram and a separate switched relay or just wire it straight to the output of the cooling fan relay (which should be perfectly safe, it’s a 60A relay circuit that powers the factory fan), both of which will give you full fan whenever the ignition is on.

Yeah I was thinking this but would ideally like to maintain the ability to vary duty cycle if possible so I'm looking at all the options.
Thanks for your input.
Does anyone know offhand what the factory fan is rated static cfm wise?
Want to make sure what I'm going to do is actually an upgrade

 

[M-Sport fan]

Interested in this as well, since I could control runaway temps/heat soak with a more powerful fan and a fan switch, and would not need an aftermarket radiator (except for getting rid of potentially leaky crappy plastic end tanks).

 

[XanRules]

Also interested. My assumption is that you can't just wire an aftermarket fan of the correct size into the factory fan shroud, is that correct?

 

[unspankable]

Also interested. My assumption is that you can't just wire an aftermarket fan of the correct size into the factory fan shroud, is that correct?

Not sure yet. I don't see why not. Limiting factor would be wire gauge and fan relay rating. Just need a PWM capable fan. I emailed SPAL and they didn't get back to me. Looking at a flexalite but until I find out what our stock fan is rated at there's no point continuing.

 

[XanRules]

Cool. I could be talked into upgrading in a year or so, but I don't like any of the aftermarket "fan shroud" options that don't actually direct air into the fan - conversely, stuff like the Mountune just uses the woefully inadequate factory fan with the perfectly functional factory shroud. So I figured the best of both worlds would be a decent aftermarket radiator with the OEM fan shroud or something similar.

 

[unspankable]

Yeah my plan was to utilize the shroud