In here Finland company that imported these cars when they were new, offered these turbo kits, those were installed into new cars and if I remember right those had factory warranty. It is R-Sport turbo kit.
We had also Ford Sierras with 1,3 litre turbo engine, that was called Stockman turbo as Stockman was company that imported those cars and installed turbo kits. It was something to do with taxes at that time also.
Of course my memory could be wrong in some details, getting old you know
Turbo installation is not difficult, compression is tad too high, 8-9cr would be nice for high power turbo installation. Cylinderhead is ok, pistons need to be changed, some VW Beetle race pistons will be ok for B230, only that hole in piston is 1mm different size, easy to mod. For B200 I don't know what would be cheap and forged pistons that would also fit in. Perhaps something from B19A could do, even those are not forget, but under 1bar I think that no problem if you have 8.5:1cr if 10:1 and even with programmable ignition and injection there is possibility to piston meltdown, forged pistons are better there.
B200 rods are weak part, something to do with this low friction desing also, piston guides rod somehow and it causes vibrations to rods. (rods, thing that connect piston and crankshaft?)
Good old B19 is almost impossible to destroy too. I will build B19 or B23 based engine some day, 300hp is something I will hunt, getting money and knownledge for that is taking time though, perhaps few years later I will have it
