Question for you racers regarding "Banging" sound at shifts

[Chuck W.]

OK... this has nothing to do with Boxsters, but I have searched the web and can't find the answer. When I was have been at race tracks and watch the newer Porsche races cars on the track I hear a loud "bang" or "pop" sound when they shift while racing. What is this caused by? TIA

[Racer Boy]

I'm guessing that what you are hearing is the ignition being cut for a very brief amount of time during an upshift. If the car has a sequential shift transmission, or a dual-clutch transmission, the driver keeps the throttle flat to the floor during the shift, but the ignition gets "cut" for a micro-second to unload the gears so the shift can be completed. That is why you hear the "bang" during the shift.

[JFP in PA]

Originally Posted by Chuck W.

OK... this has nothing to do with Boxsters, but I have searched the web and can't find the answer. When I was have been at race tracks and watch the newer Porsche races cars on the track I hear a loud "bang" or "pop" sound when they shift while racing. What is this caused by? TIA

You are hear the clutch less transmissions shifting. The race cars use a setup different then the street version of the PDK, which has nothing to dampen driveline sounds during shifting, resulting in loud noises when shifting. If you watch the FIA rally cars, which also use racing clutch less transmissions, you will hear a similar sound when they shift.

[Chuck W.]

Cool. Thanks for the info.