The DCT is actually a split shaft manual transmission with 2 clutches that shifts via computer command and shift motors. It uses gears similar to a motorcycle and automatically shifts and applies the clutches for you. The noise you are hearing is similar to what you hear when you press the clutch and shift a large bike like a Harley.
The common misconception with a DCT is that the RPM change that feels like an automatic shifting is not the entire "shift" sequence but rather only the last part of it at the point when the transmission changes from one clutch to the other. The "Bang" (I actually describe it as a "Clunk") you are hearing is actually the transmission shifting the next or previous gear just prior to disengaging the engaged clutch and engaging the disengaged clutch. That clunk is the actual gear shifting. It is how a DCT works, the shift occurs something like this...
- Gear section 1,3,5 in 1st gear.
- Clutch 1 engaged, clutch 2 disengaged.
- Shift requested (either by computer or paddles).
- Gear section 2,4,6 shifts into 2nd (this is the clunk that you hear like large bike when you shift it while pulling the clutch).
- Clutch 1 disengages and (almost simultaneously) clutch 2 engages (this is when the RPM changes and you feel the finishing step of a shift).
The clunk is totally normal and part of all DCT's. It seems a bit louder in the Talon than a car but that is probably due to the smaller gearbox and lack of insulation so you hear just about everything going on back there.
