Hmm..you could use 2 smaller turbos, probably off of a 2 liter engine? So, that'd be pretty inexpensive.
As far as the feed to the intake, maybe a box around the carbs? Otherwise I think the carbs need to be special set up to handle the pressure - with the box, it's the same pressure inside and out? I dunno. Just thinking outloud.
I like the idea, thats for sure!
Planning some new things for your coupe, eh?
-Sam.
