Try running your Harley at 80% WOT for 10K hours. It would be lucky to make it 500 hours.
It might at 800 or 1200 RPM. You can do 100% throttle on a gasoline spark ignition engine no problem (with sufficient cooling) it's the high RPM that'll wear it out. Diesels don't like being over 80% throttle (with black smoke coming out.) I think it's something to do with the combustion temperature getting too high.
Turbo chargers are bad. They increase the intake pressure which means the engine has to be built stronger to handle it or the compression ratio has to be lowered. They end up doing really low like 16:1 compression which kills your efficiency and you're not much better off from a gasoline 10:1 compression.