Well there are a number of things that would help. Are you actually being able to connect to trackers? If so it probably would not be an issue with your router. But if you go to speedguide.net they have tweaks that can speed up your cable modem.

Also the client you are using could be an issue too. For instance I know with the abc Client that if you use more than 80% of your upload ability then your downloads suffer.

If you can catch me online you can contact me, aim: storytailer