Download speed is dependent on:
1. Your maximum download speed.
2. The server's upload speed.
If you are downloading a torrent movie from me and I only allow my torrent client to upload at 56k and no faster, then guess what? You will not be able to download the movie any faster.
The thing with torrents is if there are no available slot for you to connect to then you will be stuck in a queue until a slot is avalialable. -