You idiot.
Just finish what you started, and keep it to one project at a time. You are quickly going to find out what happens when you have numerous projects running on the same car at the same time – nothing ever gets done, and what does get finished gets done half-assed. If you really want to play with cars, this is an excellent learning experience. Even if the 305 implodes, so what? Stop changing your mind every 2 minutes, and your 1st car need not run 12s. Most cars don’t, even if their owners say they do.
I, along with just about everyone here, told you not to buy the nitrous, so yes, get rid of it.