Why does the flatplane v8 have the same racing exhaust as the crossplane v8? It is stupid as the pulses would arrive at the collector in an uneven manner, and it is heavier.
A flatplane v8 would have a exhaust manifold similar to that of a inline 4. Didn’t it use to have that some builds ago?
Yes, V8 FPs currently use the same exhaust headers as V8 XPs, that will be fixed 
So it’s just the visual stuff that’s wrong, not the calculations behind them?
They should still be correct! V8 FPs have higher exhaust efficiency and race exhausts have only little advantage over long tubular.