253mph Bugatti Veyron Coaster

goes up to 9 G's and i can't see a G suit

Arent centrifuges based around the acceleration force or does the cabin they are in rotate so the G's are vertical? Because the body can tolerate a lot of acceleration force as well.

[Mikey]

My understanding is that the primary function of the centrifuge is to exert vertical forces upon its payload, this is achieved by permitting the cabin to rotate parallel to the floor when it is at operating speed. However some accelerate pretty fast, but I don't think they accelerate at 5Gs, that would be an awful lot of strain on the apparatus.