MS SQL, ADO & Delphi 5

Is there a formula or could someone share with me any insights on the
resources required by a Server and its workstations when running a Delphi
app using ADO.  This app is pushing between 4000-6000 records while updating
3 or 4 support files (counters and statistical fields).  It's running
anywhere from 6-15 user (tyically 12+).  It's experiencing server timeouts
on transactions which get progressively worse as users increase until no one
can effective produce work.

Any help, guidance or reference source would be most appreciated.