XR6 turbo

Hi do these same principles apply to the XR6 turbo eg calculating the Speed Density system with the calculator?

I'm not quite sure what you mean here sorry. The Ford engine itself is exactly the same as any other in terms of the way it operates and hence the way the fuel demands are affected by VE. Unfortunately though Ford saw fit to come up with their own unique way of defining the engine's VE which is different to how just about every other OE manufacturer does so. This won't stop you tuning the engine but it does become more challenging if you are making dramatic changes to the engine's VE.

Paul Yaw from Injector Dynamics wrote a nice (albeit complex) article on the Ford system that's in this link (scroll down to 'math doesn't suck') http://injectordynamics.com/articles/shelby-gt500/

Sorry I understand what you mean now but not quiet understanding what I ment I pulled a tune out of an XR6T and I found it a lot different to the demonstration.

I suppose my main question is, ( and I will read the link you posted ) but most of the customers asking me to tune there XR6T don't have major changes to the VE, I was just a little bit confused at how to manage the torque control and if I did find my target is slightly different to commanded where do I make the changes to do it correctly. ill have a read of the link and if im still a bit unsure ill try and get a bit more specific at what im asking. I use HP tuners, but ive looked at PCM tech and it looks a bit easier to navigate through and make changes but I want to get my head around the software I already have.

ill follow this up with a better question If needed after reading the suggested post. cheers as always for the reply.