Slightly more than lairy cams. Monster engine.
That is the basic premise of the engine. High lift + long duration cam shafts that would be unsuitable for a road car were it not for VTEC. Everything else is build to suit the concept, the short stroke, high piston speed and short runners on the inlet.
You can get 185bhp+ out of Clio 1.6 16v/Lupo GTi if you wanted, it just wouldn't perform well in the low RPM range or have the ability to return good MPG.
I love Honda engines, I think they are the best N/A road car engines available. The basic concept is pretty straight forward and as with all N/A engines more power is available in one of two ways...more displacement or more RPM.
The VTEC advantage is lessened in a race car as the need for good low RPM driveability and good MPG go out the window. It's possible to make a 1300cc Polo engine produce 180-200bhp with enough RPM and cam lift.
So the advantage does come from the cams. It just so happens the rest of the engine is pretty well put together as well. Audi are now using a sliding cam shaft that brings the same benefits, with the engine having a split personality for economy/power.