Replying to Need some help with my setup

So I have all my plans to build my rail, but I have some questions on my setup.

First, I'm not too sure my parents would be thrilled to have a huge drop in stuck in my backyard all summer.

I do have a decent hill in my backyard I could probably use as a drop in.

I was thinking I could just roll out the turf on the grass then use the hill to get speed. Would I be able to get enough speed? Anyone have any success with this?