well SHEEPFISH, your problem might not have to do nothing with the router, cus downloading from different p2p networks gets you different speed, it depends on the amount of ppl sharing that file. so first try to find a torrent with a big ratio (big amount of seeders and small amount of leechers) and check the speeds you get.
if you find out the speeds are only affected by the router then what you need to do is open some ports in you router (emule: 4662 -tcp 4672 - udp, utorrent has random port). to do that look here:
http://www.portforward.com/routers.htmand see if you got the port open test here:
https://www.grc.com/x/portprobe=hope it helped.