[masraum]

Automotive engines are usually designed to run reasonably well through a given RPM range. For most cars, I think that's 1500-4000, some higher, some, a bit lower. A lot of that is based on various compromises and intended use. For higher performance engines, you get bigger valves, bigger cams, higher compression, and more RPMs for more pedestrian stuff, it's all smaller and lower.

Back in the day with carbs and distributors, you kind of had a limited range of what you could do, especially with the ignition timing. Now with computers, they can control the ignition timing not in a fixed way based solely on RPM, but also based on load and slews of other factors. I think that's a big reason why modern motors can perform better in a wider range of conditions and RPMs. Computers can now dial in any timing they want (within the programming) to maximize power and combustion for conditions. Computers and fuel injection have also been able to work their magic in the same way. Then take into account that many modern motors have some sort of variable valve timing and ways to make the intake tracts longer or shorter or any number of other changes that basically give you two motors in one. One set of parameters can allow the motor to be a low RPM performer and then another set of parameters can maximize the motor to run at higher RPMs.

Also, think about how a lot of modern turbo cars have small, quick to spool, efficient turbos bolted to motors with relatively high compression engines compared to back in the day when you had huge slow to spool turbos bolted to very low compression engines.

That makes a big difference too.

And if the car isn't a turbo, but is supercharged, well, those start making power right away.