Originally Posted by Richard L.
Agreed. Maybe a power/torque vs rpm graph would make it more clear.
Indeed. With the stock turbo on the STI, you're better off shifting at about 6000 to 6500 rpms. Running the car to the rev limiter in every gear is actually slower.
In some cases, like autocross, it actually makes sense to spend some time at really high rpms- even banging off the rev limiter. If there's a section of a course where you will be on the rev limiter for 2 or 3 seconds, it's a lot faster to just do that than upshift and immediately downshift again.
Now, multiply "a couple seconds" on the rev limiter times a few times per run times a bunch of runs and it's easy to see how a few det events could weaken the ringlands and eventually kill them completely.