ok well this isn't really a turbo but it is forced induction so here you go
http://www.electricsupercharger.com/index.shtml
i had an idea about this very same thing quite a while ago but never thought anyone would actually do it, you may be thinking its not a bad idea until you look at their price! not to affordable, on the other hand if you have half a brain you can do research into some good 12v dc fans(haha not computer fans) and if you could manage to build a setup to give about 350cfm(amout of air movement, i think 750cfm would equal about 2psi) you could probably see some decent gains for the money.. hmm i've got a 24v 230cfm fan....