Serial.write() does different stuff with bytes and ints.
That there. An int is 2 bytes. A byte is, of course, 1 byte.
So, Serial.write(160) will output the integer value 160 as two bytes of data.
But you want a single byte of data output, so as Pauls said, cast it to a byte with Serial.write((byte)160) and it will output the byte value 160 as a single byte of data.