the TBE is the entire exhaust from turbo all the way to the tail pipes.The TBE is split into 2 parts. From the turbo to the centre part of the car is the downpipe and sports cat. thisis where the erformance gains to be had.From the centre part of the car to the tail pipes is the cat back exhaust. 2 types of cat back. resonated=2 silencers, non resonated =1 silencer. thsi is the noise part of the system