The GBP turbo inlet pipes are designed for builds with upgraded turbos and SD tuning. They must be installed with the engine out of the car. They are a true 2.5″ immediately transitioning to 3″ and there is nothing else on the market for the OEM 2-bolt compressor housings that are even close in sizing. They are a hand fabricated tube inlet pipe ported for a completely smooth transition from the intake to the turbo compressor inlet. Each set can be custom ported at the flange to exactly match whatever compressor inlet size you desire. The set in the pictures below has been matched to 56mm. You can see the smooth flow from the 2 bolt flange into the pipe itself. Each set is custom ported for to customer spec.