The resistor is located between pin 4 and 5 of the chip. Depending of the capacitor value, the resistor could have diferent values. Mine is/was 100k. In therory the frecvency F=1/(R X C X 1.5) Hz. <F is frecvency in Hz, R value of resistor in ohm, and C the capacitor>. In reality, the value of frecvency depends of a chip internal resistor connected to pin 7. That`s why , when removing, pin 7, frecvency increases a bit. So the above formala is no longer valid after pin 7 was removed for an exact calculation. The speed must be ajusted empirically, as you feel it.
In my case (EU hazard switch) with 100K resistor , the F is 1.43Hz => the period is 0,7sec. So for each 100K added , the delay will be 0,7 sec. For 50K 0,35sec. With 100K fix+ 50K var, the period is between 0.7sec and 1.05sec.