New Guy,1988 Audi 5000 turbo quattro Olympic Edition Station Wagon

[audi_5000]

so thats my new ride,
have a few problems such as a stalling issue
it idles fine. but its 5 speed so when im driving and go to push in the clutch the rpms just drop right down and it stalls out
this moslty happens only when i press the clutch.

any ideas on what this may be?
also when im really giving 'er go get going fast it seems to just quit at 4,000 rpm? is this because of the ecu limiting my rpm?
i want to get this car going faster?
can i get more boost or chip my ecu?
can i get a bigger turbo and better wastgate?

any ideas and input would be appreciated.
thanks