Well as they say, always learning!
Bought in an MX-5 NC hydraulic steering rack and despite sharing the floor pan with the RX-8 there's no way this would ever fit as it mounts different and is too narrow-----------game over for that idea then!
Still determined to lose weight and have a manual rack, I stripped an RX-8 rack and have made it manual and also now understand how the RX-8 rack can steer via the steering ECU without the driver knowing !
If you look at the picture with the arrow, you will see a spiral and this runs the shaft up and down within a sleeve with ball bearing races so when the rack gets a signal from the ECU the motor can wind the rack automatically.
This spiral (arrowed) is why with no power the steering will not self centralise and needs physically winding back on the steering wheel when there's a fault making the car undriveable
I also found that the quill shaft , whist it looks one piece is a sprung loaded two piece shaft which must be to absorb road shocks back up to the driver with no power on the rack and being forced round this could potentially have sheered leaving me with no steering at all
To convert I had a smooth bore brass sleeve turned up which fits up the end to stop the spiral interfering (circled)
The two piece quill shaft is now welded together and I have chopped off the motor plus removed the six big magnets from inside the motor tube , dumping lots of weight in the process.
I now have a completely manual rack that will have no fitting issues to get it back on the car:)
At brands in December I will know if it gives me the extra driver feedback I hope I will now have.