My s3 (2002 75k) seems to lose power at around 4000rpm when I floor the accelerator in 3rd, 4th and 5th gear. It's fine in 1st and 2nd.
When I floor it the turbo kicks in and the needle flys up to 3500rpm (without any huge actual acceleration), then its hesitates around 4000rpm for a second and then it keeps accelerating like normal to the red line. The turbo sounds fine.
It feels like the clutch slips or something as the revs shoot up initially without any huge increase in speed. However, the clutch seems ok when I pull away and when I floor it in 1st or 2nd. No slippage I can tell. The clutch is very heavy though in general.
I did a test and floored it in 3rd up a hill and the acceleration dipped at lower revs this time, more like 3000rpm. Thats 1000rpm less than when on the flat.
I also have that over rev problem between gears - very embarassing as it looks like I cant drive!