Horsepower = Torque x RPM ÷ 5252
edit
Or at least that's what I thought..
On topic..
There are any number of series where they lean on the limiter and while it goes against my grain, the people who should know say it doesn't hurt the engine.
I would have said the same but had to learn that some engines don´t like it -for example Hondas K20 (S2000) engine will not stand bouncing of the limiter for extended time.(Valve spring failures )
Concerning the fact that engine hit the limiter, it is because of the level of downforce choosed and the drag it induces. Choosing a longer gear will only cause worse acceleration without better speed. They only take a margin because of KERS and when you're following someone - sorry I don't know the english word... suction? or aspiration maybe?
During my day job I measure production car engine noise during accel runs. I can see very accurate rpm data from looking at the freq vs time.
For most new/current gen engines, when you accelerate WOT in a fixed gear the engine will rev quickly up to the initial rev limit and then it will rev slowly up to the the ultimate limit. The difference between them is 100-200 rpm. This little rev range allows hard accel up to the initial point, and then smooth/accurate reving up to the ultimate limit. The slow rate of accel allows a very soft and precise ultimate limit. Also, after you hit the initial limit the car accel does not go to zero, it simply reduces to a smaller positive acceleration. This greatly reduces the abrupt engine/chassis shock that you get when a limiter drops you to zero accel.
Also, as far as I can tell, every manufacturer lies and adds 500 rpm to the actual engine speed before they display it on the tach. If a tach redlines at 7000 and the needle appears to peak at exactly 7000 during accel then the actual engine speed was around 6500.
Not sure how much of this applies to F1. I never see or hear any abrubt hit against a rev limiter so they must have some kind of careful/soft algorithm for hitting the limiter when the driver upshifts a split second too late.
the gearing is also a balancing act because when the race starts, cars are heavy and don't accelerate quite as quickly. they may not be able to hit the limiter at the end of a long straight. by the end of the race, the picture may be very different, and a lot more like qualifying (minus the drs)
