Overboost

[skyphab]

Originally Posted by JN2009

ok,ok .I was thinking that's they make like the M5.The annonced a 507hp but in real it's 400hp.507hp is with the M button.

That's right, but this is a different concept. The M5 produced 507hp constantly, in M-Mode. At least as far I know.

[kyleb350]

So there must be a certain RPM where the overboost cuts off so it doesn't exceed the original 340HP. If the overboost were to carry to redline, the max HP would be increased a bit as well I can assume? My guess is to not creep up to M3 HP figures and cut down on heatsoak.

[skyphab]

Originally Posted by kyleb350

So there must be a certain RPM where the overboost cuts off so it doesn't exceed the original 340HP. If the overboost were to carry to redline, the max HP would be increased a bit as well I can assume? My guess is to not creep up to M3 HP figures and cut down on heatsoak.

Your point is also one of my questions, but I couldn't find any answer yet.

BMW says 450+50, let's assume the air pressure will switch back to normal again at 4'500 rpm (this is where the nm starts to drop). So, if the engine really keeps 500nm up to 4'500rpm you will reach 320HP instead of 288HP at that point, which is quite an increase, I think.
On the other hand it means, that you have to climb another 1'500 revolutions to get the last 20HP out of the engine, which sounds a little bit strange...?

But since we're also talking of regularities here my guess would also be, that the max HP-output won't change with overboost.

[JN2009]

Originally Posted by skyphab

That's right, but this is a different concept. The M5 produced 507hp constantly, in M-Mode. At least as far I know.

Anyway, soon we will have the answer of all our question .

[BlackFlash]

I think the idea of the overboost is just to bring on additional torque earlier such that you hit max HP sooner (i.e. at lower RPM).