I do stage rallying.
The car is carburreted with a single fuel line (no return) but my calculations show there is plenty of fuel flow through the sensor so accuracy should not be an issue. At idle it might be inaccurate but I can work around that (sensor operates from 5 to 150LPH and is something like 0.6ml/pulse).
The wheel sensor is on the front wheel so no wheel spin and I don't lock brakes 
I did consider using a GPS for either distance or time logging but I think it unnecessary.
It sounds like a single UNO board will do the job and that the should be no issue with speed/ missing pulses.
I guess I can check the speed of the Loop() section using mills() just to be certain.