I've seen many cars with a short piece of heater hose from the water pump directly to the manifold. I was just curious about this...why it is done, advantages, necessity???

I currently do not have this done and was wondering if I should.

 

Mostly, it's done out of sheer laziness, when people should have changed out their failed heater core instead.

So, no you don't "need" it.

 

lol...I also don't have a heater core but am just running the upper and lower rad hose. I heard somewhere the short hose is good because it permits a small flow of coolant when the thermostat is still closed.