I'm going to make one myself and was wondering why I haven't heard someone else try this already. May be I'm missing someing but it doesn't seem particularly difficult to come up with one. I plan on using two solenoids (for low and high boost) map switches, and possibly a pressure transduces and led display and remote switching. Can someone think of why this hasn't been attempted or am I oversimplying the project?

 

it probably takes a very good understanding of electronics design to undertake something like that. I you have the knowledge and time I would go for it. If it works, post the design and spread the wealth.