Go to the Brodak site and order yourself a set of .008 stranded lines and make them 52 feet long. There will be less drag then when using the dacron, the length will drastically slow down your lap times, and you'll be happier.

If you still use the short lines, and have way too much speed to fly, try putting the prop on backwards. Many light trainers have more power than necesary for the straight and level, that will slow em down too.