Oil cooler diverter valve

[Ali M]

Originally Posted by shimmy

The US guys I have spoken to have deleted the two OeM fans (to get better flow trhough)and replaced by a high flow Spal. Cooling problems sorted on hot days on track but occassionally get overheating at slow/stationary speeds on hot days

Originally Posted by stevenEK9

hard to find the optimum compromise i guess

i did read a thread online about someone who upgraded the Auxiliary fan to a SPAL fan that had a higher CFM rating - ran that combined with no viscous fan and a motorsport thermostat. seemed to do the trick

Reading both your replies there got me thinking. I am not very technical with these things so excuse me if I have some of fan types etc mixed up, just thinking out loud...

With both examples, both viscous (engine driven 'puller' fan behind radiator) and aux fans ('pusher' fan through AC condenser/rad) have been removed. This would increase the frontal area of AC condenser/rad that is exposed to direct airflow, as to me it looks like a large part of this is blocked with OEM aux fan plastic end 'casing'. Guess it is the same story for the plastic on outside of viscous fan 'frame'?

From both examples above it looks like this has helped airflow at speed.

In Shimmy's example, if this was a 'puller' fan, Spal or similar - possibly it struggles to drag enough air through at slow speeds for low speed cooling on hot days?

In Steven's example (which sounds like it could possibly have been a success), could replacing OEM aux fan with a large capacity pusher fan in front of AC be the answer?

This combined with Gorilla's point re coolant % mix and/or 'water wetter' - do you think it could allow retaining of AC? I am not really keen to change out rad to aftermarket unless it uses all the original mounts as don't want to be butchering the car fabbing up additional mountings. Not really buying the motorsport stat idea as once it is open, it should allow the same volume of coolant to flow.

???


Just to add, whether some peoples cars have had overheating issues on 'this day' at 'that track' or done X amount of laps etc, seems to me that it is pretty clear the S54 + AC setup is not enough to cope with track use in certain conditions with some driving styles/pace. All the others must be close (as shown by Paul's example with being behind the R8, briefly blocked from airflow) to the limits. Only exceptions seem to be CSL's with no AC.