If a Turkish Double Loop is added to both ends of bowstring, how much will it add to your draw length?

A what?    

Killdeer  

Exactly the same as putting on American double nocking points?        

It won't add anything to the draw length. How could it? It's essentially nothing more than replacable loops for the bowstring.
I don't see any advantage to using it with today's bowstring materials. If your loops are worn there is either something wrong with the nocks - if they are worn prematurely -  or the string simply needs to be replaced.

Guy