I found this trifecta system.

Pick any track and you then record the placegetters for a month on a sheet of paper or spreadsheet if you prefer. At the end of the month you take the top six and wheel them using any pick 3 lotto wheeling system. The one i use is Steve Player Lottery systems and I select the boxed 3 with 6 numbers which gives me 20 sets of 3 numbers at $3 each.

I made over $6000 last year using this method. And So far this year I've made $2560