i dont think the RSR was ever fitted with a 'crash' gearbox or 'dog-box' as we call it in the UK. The RSR has the same Type 915 gearbox as my own car. So heel and toe rev blipping will gain you time for slick gear changing but if you try slamming it through the gears it will detonate and any drastic downshifts can buzz the engine (know a track buddy who did that to his RS
)
A crash box is just the internals though Mark (straight teeth and uprated shafts/bearings)- there are straight cut versions available for nearly all cars to fit into the standard housings (straight cut are stronger so better for racing/high power - road cars don't use them because of the noise) It's only really since the 90's that racing gearboxes have been fully custom outside of single seater/prototype racing. I would be honestly amazed if factory Porsches didn't use them if regs allowed it (Just watched far too many onboards from historic races - must admit I can't hear it, athough some daft bugger did put all the spinny bits in the boot....).
I'd be even more amazed if the DRM cars
didn't have crash boxes due to the daft horsepower and the primative (by todays standards) machining and metal alloys available - Watch the onboard here and you can just make out the whine once the Capri gets to 4th/5th:
https://www.youtube.com/watch?v=fwDaozSeyfo, you can clearly hear it in Fabri's post too.
Bear in mind that the whole reason Porsches' Group C cars of the mid 80s' and later design ran spool-diffs was because even the best mechanical diffs of the time couldn't be relied on to survive an endurance race with ~7-800bhp
As to gearbox damage - it is posible to do, as while trying to drop my laptimes to equal that Michal chap I performed a few fluffed shifts and also a couple of rushed changes and slippage - which feels a lot like my Subaru when I've been over-exhuberant out of junctions, just with less burning smells
Deffinately managed to gert the gearbox to flash at me a bit while doing that.
I should note that clutch slippage from a rushed shift is not really the same as slippage from a knackered clutch, it is a lot more like what is depicted in AC.
I'll do some practice at Spa in the RSR either tonight or tomorrow I expect - will be interesting to see what I can manage against Manteos, Spa should suit his style more than mine!