As much as it sucks mag times are the most consistent thing we have to compare vehicles. In the real world there are thousands of factors involved. You may walk someone today and tomorrow get beat by the same vehicle. You have temperature, tire inflation, warmth of the engine, state of the tires, and so many others.
Note: Street racing is not condoned or to be talked about on this forum. I'm sure all your races were at tracks,
but just thought I would let you know.