986 Forum - The Community for Porsche Boxster & Cayman Owners

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- - Under Pulley (http://986forum.com/forums/showthread.php?t=21681)

Quote:

Originally Posted by Bob O

Now on to the fun stuff, like driving it and seeing if there really is a noticeable difference in power. I haven't had time to get more than a few miles on it after the install to see if everything was put back together right!. More "butt dyno" info later.
Bob

When I installed mine by "butt dyno" didn't feel the difference, but my Power Steering fluid as a whole lot cooler at the track and the car ran 10 degrees cooler as well.
The lower coolant temps were a pleasant surprise. I suppose it has to do with longer coolant dwell time in the radiators.
Happy Boxstering,
Pedro

The reason why the coolant temps are lower with the under pulley is due to the reduced impeller speed of the water pump at hi RPM.. The impeller's diameter leads to cavitation at higher RPM with the stock drive ratio. The same goes for the power steering pump.