EDITED.

I was reading in a magazine about a feature car 300zx had a electric water pump installed on his car which stayed running after he switched off the motor to cool everything. Now I was going to mention the pumps name but after searching for more info on it I found this:

http://autospeed.drive.com.au/cms/article.html?&A=0569

Which is where a review of the product would have been:

From Site
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We recently spent a great deal of time and energy extensively testing the newly-released Davies Craig Electric Water Pump. The story in this issue was intended to be Part 1 of a 3-part series on this interesting device.

Testing of the pump was carried out on two different cars on both the road and dyno.

As a courtesy, we showed Davies Craig the test results that we had found.

Unfortunately, because of their responses, we now feel that we cannot bring these stories to you.

Thinly veiled threats of legal action from large companies can do that.....
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So im thinking it didnt do very well, but there would be other companies who make them as well. I wish we knew more on the results of this test.

Heres some more info on the pump:
http://www.are.com.au/products/Parts/dc_waterpump.htm

 

Half way down this page they get some flow results from different electric water pumps.

http://www.are.com.au/feat/techt/research&dev.htm

 

The reason your water temp is rising after you shutdown the car ether is that water cooled turbos dissipate most of their heat to the water being flowed through them after the car is shutdown. In the past with non-watercooled turbos you left the car running to allow the oil and bearing to cool gradually which would reduce coking and bearing wear. With watercooled turbos when the car shuts down with no cool down time or even with some the cooler water that is now not moving through the radiator is drawing in the remaining heat from the turbo bearing. Becuase the water is no longer circulating the net effect is that your water temp goes up until the bearing is cooled and then the water will stabilize and then drop. This is the case with all watercooled turbos.

 

totally agree.. want to help that cool down process abit..