What type fuel system are you using? Carbureted or injected? Is it a dead ended fuel system? I would think the flow meter might give erroneous data with a dead ended carb setup as very little fuel is moving in such a big line. If it's injected, most I know of are loop systems where there is a return line to the tank, so again- inaccurate data on flow. For accuracy there, injector pulse width is used to get accurate metering, which is what the computer uses.
As for the wheels, it might be beneficial to have all the wheels monitored, which would allow for seeing uneven locked brakes and wheelspin. You didn't specify what type of racing you are dealing with.