So; question, I understand that V8's grant you more power (typically) than a v6 or a four-cylinder. But if that's the case, then why do some racers out there use four-cylinder engines? (ex. Evo or STI) Is there more to it? I appreciate anyone's answer.

you can tune a 4 cylinder to make as much if not more power than a v8 for half the weight

Weight reduction bro!

These engines can provide enough power to have a good handling. In order that a good 4 cylinder is not as heavy as a V engine the balance is much better to go fast on corners…

Also a very important Point…. Turbo.
turbo 4 cylinders make a lot of power ( sti, evo, focus rs and many more) and it sounded line you where comparing them to natural y aspirated ( no turbo nor supercharger) v8’s like the one’s found in mustangs, challengers, chargers, camaros,comodores and some others

Im surprised you haven’t got the real answer yet…the sti and evo have turbo 4 cylinder engines because that is a regulation in rally. It has to be 2.0 liters (or 2.5 i forget). And tunners use 6 cylinders because you can easily make tons and tons of hp with them, like the jz engines which are small displacement i6 engines, which can make upwards of 1200 horse power sometimes…hope i helped..

The only racers that favor smaller engines race in a series that limits total displacement. For example, WRC limits engines to 2 liter engines that see production, thus rally cars are limited to 4 cylinder turbo engines. Group B rally cars had much bigger engines than today’s rally cars because they had less regulation. In addition, sometimes 4 cylinders is all you need. A 5000hp V8 would be completely useless on a loose surface rally stage, but it will give you the best performance on a drag strip. Sometimes power is not all you need in a race car and a smaller engine will better suite your needs.

You can make good useable horsepower with any configuration or displacement engine. I say useable because if you put an LS9 in a lightweight car you don’t get a good car. Balance, power to weight and torque matter when building a car. Unless you just want to smoke tyres and brake things.

A v8 typically produces more power, yes, but it is also heavier, more complex, and less fuel efficient (relative to 4 and 6). Each type of engine has it’s uses, and the type chosen is usually a compromise of many factors. Turbo 4’s can essentially replace the old v6 in most aspects, while turbo 6 and 8 are seen more and more instead of v10 and 12 non turbo. An engineer could give a more specific answer, but this general info is all you really need. Hope it helps.

Racing often have rules and regulations as to what type of car/engine can join.

I’ve seen V8 setups that had near-identical weight to turbo-four setups, both engines having the same peak power ratings. It’s not really about weight so much as each racing organization’s regulations, plus whatever the current zeitgeist of cars happens to be. Emissions regulations and the push for more technology in cars? Turbo fours start showing up everywhere. Competition designed around simplicity and reliability? Chuck a V8 in it, as seen in NASCAR, V8Supercars, 4x4s, etcetera. There are technological, situational, and of course cultural considerations.