will a 1.6 vtec head on my d15z1 make my car quicker if i run it on a programmed p28 ecu

 

Nope, it'd make the car completely gutless to drive. The Z1 head's combustion chamber is much smaller than either of the vtec heads (D16Z6/D15B & D16Y8). So putting on another head will actually lower compressions considerably.