all depends on the setup, single cam turbo's can be fast, but d-series motors are inherently weaker and require stronger rods before a lot of power is put to the wheels...plus the transmissions are weaker, especially the differentials.
in my opinion its not worth building a turbo single cam because of their tendency to break. yes, you can get away with it but this is only on lower boost and a gsr motor with bolt-on's will be just as fast...plus you'll have reliability and power that is always there.
now, single cam vtec's with nitrous are another story...and i'm a firm believer that the cheapest way into the 12's is a mini-me + 50 shot + gutted crx. this way, if you break things you can just replace the bottom end easily without having to worry about pipes, turbos, etc.
my buddy just bought a 94 civic hatchback with a greddy turbo kit running 6psi of boost. Him and another buddy with a 97 prelude with a header air intake and an exhaust raced. He caught the car around 100mph and passed him like he standing still. It was fast but not that fast.
MY BUDDY HAD A GREDDY TD04 TURBO KIT WITH A CONQUEST INTERCOOLER,RC 440 INJECTORS, Apex'i VFAC/AVCR, AND 2.25 INCHES EXHAUST AND RUNNING 11POUNDS ON STOCK INTERNALS. DYNOED AT 229 WHP. 8.80 ON THE 1/8 OF A MILE A 80 MPH