a rally car now days uses tiptronic shiting (paddle shifting) i doubt a rally driver even lets off the gas pedal between shifts. and if he doesn't let of the pedal the bov wouldn't see any vacuum anyway. so that is why there is no bov in a rally car.

 

got to let off the gas some time

 

when they stop maybe, other than that while shifting most turbo's rally cars have are not fluid bearing, they use ceramic ball bearings which aren't affected as much with pressurized air coming back through the system (i.e no blow off valve)

 

dude rally cars do have blow off valves... I was watching rally yesterday at my girls house on her 55 inch hdtv hehehe
and heard hella crazy ---- when the announcer wasn't talking. like wastegate chatter mmmm I like that sound, and heeeeelllllllllllllllaa blow off valves. hks ssqv's you can set so they dont let taht much air out between shifts.

thats probably what they had... I saw quite a few hks stickers too.