I've been thinking about the new Prius' elimination of the coolant thermos and how they went to using exhaust heat to speed up the warming up of engine coolant. Obviously they think its a superior way of doing things. So, I started googling and found a drivetrain display picture taken by some autoshow goer.
Detroit Auto Show and Prius 2010
Of course my question is how can we make a cheaper rip off of it?
If you ran your engine coolant to this heat exchanger it would work, but at some point you'd want to stop drawing heat from the exhaust. So, you make a seperate loop that you can close off with some valve (automatic or not). But, now we still have a problem because that coolant is now going to get really hot and probably build up some pressure once the valve(s) is closed. So, do we run an addition closed loop with different high temperature coolant through the exhaust heat exchanger and run that to another heat exchanger to warm the coolant. This is seemingly what Toyota did, but now that loop is going to need a pump... blah blah its getting more complicated ($) by the minute.
Anyway, these are my initial ideas on it. I'd love to hear some of yours to see if we can use their technology on our rides.