if you have a tuner, it can be reset. From the factory its set at 222 degrees. Diablo:
you will see two tabs:
Top tab is Cooling Fans AC Off, click on it
sub tab:
High MPH HS FAN ON 222.79 degrees is default value
Low MPH HS FAN ON 222.79 "" ""
all that means is below 8 mph or above 8 mph per their website
Go back to the orginial two fan tabs:
Lower tab is Cooling Fans AC on, click on it
only one sub tab:
HS FAN ON 222.79 degrees
It reads like this on my diablo tuner
Im running a 180 tstat so I will set all my values at approx 185 degrees. Just waiting for my summit pulley come in to do that at the same time. When you take the clutch fan off, the bottom of the shroud actually drops out, (2 piece) so the clutch fan can slide out from the bottom in one piece (clutch, fan) Removing the clutch fan Bolt, facing the engine, mount the spanner wrench at (Alternator side) to turn clockwise to loosen. Its left handed thread.