Pierre -- and Gwillard, too: Welcome to the Forum. I, and the others, enjoy seeing now folks sign up and chat with us, even if they're full of questions. We prefer it that way, in fact -- it not only helps broaden the knowledge base for land speed racers, but it allows us to examine openly our knowledge - and let others either show us the errors of our ways, or learn from the knowledge we've fought for and won. Feel free to be frequent visitors.
Pierre -- take your bike to Bionneville, just as it is (with safety and other required modifications performed, of course), and run it. Make as many runs as you can during that first event. Then you'll have a great baseline for the modifications you make later. For instance -- light weight doesn't necessarily make for highest speeds on the Salt, so you might find that you've got plenty of horsepower to give you the thrill of wheelspin at a buck sevent-five (or whatever). Sometimes a few of those moments do a better job of convincing a racer that ballast is required - than all of the talk we can make. And that's just an example.
So bring your bike, have a ball, meet as many of us as you can -- and lay yourself open to the addiction called Land Speed Racing. It's wonderful -- and it's pretty much guaranteed to be with you for the rest of your life.