That's easy.
Mine had 150 hp and a max speed of 160 km/h. Afterwards it did 175 km/h, so, bare with me on this, 160:150=1.0666 and 175:1.06666=164.06
164.06-150= 14.06
O crap, your right, I miscalculated.
But seriously, I had no means of measuring the hp, except maybe my calibrated ass, but me and my friends found that the 4R was faster in accelleration and top speed.
Most gains were at mid through high rpm's. And yes, most gains will be torque.
I do not know what you mean with "you can't feel hp". Feel free to come over and drive my 4R with the 2JZ swap. If you cannot feel that amount of hp gains you're most likely dead.
Roger