for those that aint seen inside a turbo.. (and want to lol).. heres a shot of the TD-04 (Renault Vel Satis) turbo in bits. (ciggy packet shown for size). estimated flow capacity is abt 290 cfm.. marked on the drawing are the areas to be machined to fit either a selected Garatt compressor wheel, or an -18t mitusbishi wheel, this will increase the flow to apx 500 cfm.. the exhaust turbine stage is fine for over 600 !.
these mods should be good to about 290-310 BHP at 65% compressor eficiency..
total cost ?.. hopefully about 70 quid.. a Captain Slarty Hybrid turbo - the easy way .
All good fun..
Joe.
http://homepage.ntlworld.com/captainslarty/tdo4-mods1.jpg