There are a few ways to try to increase the download speed in BitComet.
Open up your firewall and add the application to the Exclusion list. This will remove filtering for traffic.
Always use a port higher than 30000 and make sure the direct connection is checked. Additionally UPnP needs to be enabled as well.
Find a torrent that has many peers. This is the primary way to increase the download speed for a torrent.
Use the VIP Acceleration. It might cost money, but you will always download at the full speed provided by your ISP.
