Go to the IHPVA home page and click on the Building tab. Scroll down to plans under the How-to Help and Guides heading and you will find a link to Rick Horowitz's Thunderbolt trike plans. I've seen other plans posted so searching may turn up some more options. Good luck with your build1
Don
"it's important to understand what makes them fast. It's more important to understand what keeps them from going faster." DS