A year or 2 ago RCJI had a article by Tom Wilkinson regarding some work he had done on thrust vs. pipe deminsions. I am trying to find out more about this, especially the deminsions. I beleive Wren also did some testing and had published the different dimensions for different size turbines. Does someone have this info they could share with me. Could you scan and email me?

Tailpipe from Tailcone
Pipe diameter
Convergence Diameter
Convergence Length

Thanks
Doug