200rwkW and almost instant spool? A trio of variable vane GT15's should do the trick. And if that is still not enough instant spool then go down to GT 12's.

One of these is good for 100hp on a 600cc engine sucking through a 25mm restrictor. Without the restrictor it should be good for over 150hp.

Bear in mind that on our baby engine these things hit full boost at 6000rpm. That equates to a required volumetric flow of 1800 Litres per minute assuming perfect efficiency.

One of these turbo's will hit full boost on a 4 litre at 900rpm. Two of them at 1800rpm and three of them at 2770rpm or there abouts.

Looking at all this overly simplified mathematic mumbo jumbo its pretty clear that 200rwkW and boost off idle is not possible. It looks like regardless of which way you go, full boost will not be generated till around the 2000rpm bracket.

thanks fatnsticky and xcabbi -
I will go the standard xr6t route as it will be the easiest and i just want to bolt the sucker on and have some fun.
Have a 32,000km original tickford xr6 engine here now too
Wont that be fun! - Gotta look and see how much boost that can handle