Mach 1.7 equal how many g forces?

No . Mach Number is a non-dimensional measurement of SPEED. G-Forces is a measurement of Acceleration.

Mach Number is Speed of the aircraft divided by speed of Sound. Therefore it is non-dimensional. Speed is measured in Miles-per-Hour or similar. So when you divide Aiplane Speed(MPH) by Speed of Sound(MPH), then the dimensions divide out.

G-Forces is a measure of the Rate of Speed or the amount the airplane speed increases per second. It is measured in Miles-per-Hour-per-Hour.