How much bhp gain do you need to achieve xx increase in kmh or vice versa?

If you have read Estimate Engine Horse Power (bhp) from the Quarter Mile Trap, here is what is means for your lancer (this can be applied to any other car).

Qtr Mile Speed	Weight Including Driver (Kg)
	1310	1360	1410	1460	1510
80.00	115.41	119.81	124.22	128.62	133.03
81.00	119.79	124.36	128.93	133.50	138.08
82.00	124.28	129.02	133.77	138.51	143.25
83.00	128.88	133.80	138.72	143.64	148.56
84.00	133.60	138.70	143.79	148.89	153.99
85.00	138.43	143.71	148.99	154.28	159.56
86.00	143.37	148.84	154.31	159.78	165.26
87.00	148.43	154.09	159.76	165.42	171.09
88.00	153.61	159.47	165.33	171.19	177.06
89.00	158.90	164.97	171.03	177.10	183.16
90.00	164.32	170.59	176.86	183.13	189.40
91.00	169.86	176.34	182.82	189.31	195.79
92.00	175.52	182.22	188.92	195.62	202.31
93.00	181.30	188.22	195.14	202.06	208.98
94.00	187.22	194.36	201.51	208.65	215.80
95.00	193.25	200.63	208.01	215.38	222.76
96.00	199.42	207.03	214.64	222.26	229.87
97.00	205.72	213.57	221.42	229.27	237.13
98.00	212.15	220.24	228.34	236.44	244.54
99.00	218.71	227.06	235.40	243.75	252.10
100.00	225.40	234.01	242.61	251.21	259.81
101.00	232.23	241.10	249.96	258.82	267.69
102.00	239.20	248.33	257.46	266.59	275.72
103.00	246.30	255.70	265.10	274.51	283.91
104.00	253.55	263.22	272.90	282.58	292.26
105.00	260.93	270.89	280.85	290.81	300.77

Do you notice any relationships? For example, as an illustration,

To increase your quartermile times by 10kmh or 6.2mph, you need to increase flywheel bhp by 32bhp.

or

To increase your vehicle weight by 50kgs, means that you decrease your quartermile time by 1mph (or 1.61kmh) or 50kg of static weight takes up 5 flywheel bhp.

I'm sure that you can see many relationships can exist in many ways if you are interested in improving the performance of your car. What is more important is that you should be realistic with the kind of expectations relating to improving performance.