3->2 shifts are a bitch, sorry that happened. I did that on track in a E36 M3 race car. It was well set-up and I had thousands of track miles in it without issue. Never knew the S52 could hit 11k RPM... It can once. This is the biggest downside to manuals IMO, as much as people talk about "traffic" as the reason.

 

Yeah, i just figured there were protections in place to avoid blowing the engine. Admittedly i hadn’t thought through how exactly that would work.

 

my closest experience was years ago letting a friend drive my exige at Willow Springs.
Going to turn nine @100ish downshifting from fifth supposedly to fourth he goes 5th to 2nd.
I grabbed the shift lever just as it was starting to go into the gate and pulled it over, in neutral And saved the car.
scared the sh-t out of me .

 

I overrev'd my 991.2 earlier this year, the gears are spaced really close together (a consequence of Porsche using the 7-spd box as a basis for the 6-speed...) so on track especially when bumpy and G loaded it's easy to miss. I did 3rd instead of 5th going downhill on the Nurburgring but I wasn't at 9K when it happened, closer to 8500.

I calculated my over rev to be in the 10.5 to 10.7K region, I caught it quick (much quicker than OP in the video) but regardless that's a lot of cycles the engine does at excessive speeds. Still, if you were ACTUALLY at 9K when you shifted (I assume it would be been a bit before as you weren't on the limiter) 3rd to 2nd is a bad deal... at 9K with no clutch slip that is nearly 12.5K RPM. There is a lot of energy required to spin the engine that high that quick so that will lower the ultimate peak RPM but still you're probably looking at 11.5-12K which is not survivable.

I've seen a DME report of a car that did 11000+ and it held together for 4 track days then it blew a rod through the case. I thought long and hard on mine but it's difficult when the car is running normally. I've since done 4 Nurburgring track days and one at Spa, 750 track miles plus 2000 road miles and it's still fine. But I know it may well blow up at some point in the future, it's impossible to say as a lot depends on luck of the draw.

 

From the Diamond to the Racetrack: The Story of CJ Wilson Racing - Front Office Sports

 

what exactly gets damaged? piston hits a valve i pressume? bending the valve? bending a rod?

 

That's exactly what happens. Even if the OP was able to get the engine started and it seemed fine, problems may reveal themselves later. That's why Porsche applies the 200 engine operating hour metric after a mechanical Over Rev before they can have confidence to state that there is no lasting damage.

Listening to the audio, it didn't seem that bad (to me). I was trying to hear if the rear wheels locked up which can happen on mechanical over revs along with clutch slippage.

Here is the take away from this thread. 1 sec in range 3 equals total engine failure.

I am sorry that the OP had this issue and I hope he keeps us updated with pics of the engine parts after disassembly.

 

He went way above range 3. That’s just the last range that’s recorded.

 

Since all of the power is out, it may just need a new Flux Capacitor. That should bring the power back.

All the best OP! Hope you’re able to get the baby going again.