It's 15 per cent driveline loss. Not hp.

Was the 138 hp dyno uncorrected?

Observe.

First look at this dyno plot:



Initial reaction: "Wow! 190 to the wheels from a B16!"

Now view the same plot, corrected for atmospheric conditions and elevation:



And that's out in California. In more temperate climates in a cooler shop environment, not accounting for the temperature, humidity, etc can inflate the numbers a lot.

One last thing: the car in question is a '91. No VTEC. It's not going to gain as much from a cam as an F22 with VTEC.