Electric Radiator Fan - to shroud or not to shroud?

[xr4tic]

1 hour ago, Vicleonardo1 said:

Need a bit of clarification. Why do the Spal controllers suck? Any reason to replace one that is working? 

 

I had one on my E39 M5, I had a lot of issues getting the PWM to work, it basically would only run full speed, and eventually just stopped working.

 

I've talked to other users that had the same issue.

[AustrianVespaGuy]

Returning to the original topic, and coming from someone who is a engineer for engine cooling radiators and fans, the Spal pusher doesn't need an extra shroud in order to direct the airflow from the fan through the radiator (as it sits basically right up against the radiator), however what WOULD be very helpful for such a setup is recirculation shields on the SIDES of the radiator to prevent the hot air inside the engine bay from coming back around by the headlights and getting sucked back into the fan again.  You want to keep all of the air feeding the fan as fresh, cool air and not air pre-warmed by already having gone by the hot radiator/engine/exhaust/etc.  I've been meaning to do this on my car since I put my Spal pusher fan in the nose but still need to tackle this particular project.