lookie what I found! Turbo specs! Yeah, I know it's a bit high on the engineering side of things, but it even gives a rough compressor map. :D
Look at the RHF5, that's what they're supposedly putting into the MS Mx-5's.
http://www.ihi-turbo.com/turbo_RHE-RHF.htm
there's a coupel Engineering guys on here I know....