While at the first gear, hold accelerate and take notice of your RPM (top gauge) and then your speed (bottom gauge). Despite your RPM red lining (meaning maxing out) you should notice that your speed is still going up. When you stop gaining speed, congratulations, you have found when you should shift to gear 2.

Before I get to the bone of this I will tell you this now, DO NOT DRIFT TURNS, you will be taking that turn slow as hell unless you've specifically customized your car for drifting.

When you take a turn or a curb, you must slow down, use your break. You will lose speed yes but this is why acceleration is important. Turning or taking a curb is faster when you slow down, steer, and speed up again MORE than drifting it. Understeer, is how much the car resists turning to keep itself stable; often times you will find this to be the case at high speeds. Oversteer, is how much the car turns in; when your car turns too much you will drift and lose control (this can also happen at high speeds if you carelessly shift gears while turning). "So does this mean I must always slow down to a CERTAIN speed each time I take a turn or curb?" No, not to an objective amount of speed, how much you slow down would depend on how much your car can oversteer or understeer; this is where handling comes into play, which we will discuss later down the guide.

As shown in the previous discussion, acceleration is important for taking turns; you slow down, steer towards the turn (with or without stepping on the gas), and when you're done you speed back up. This is why you must understand that even though an opponent can be ahead of you, you can easily overtake them when you reach the turns. So when you crash, don't be so hasty to restart. You can take 4 seconds to get back on the track and STILL catch up to them; in fact, majority of your enemies have bad acceleration so often times this will be the case for you. That is the power of acceleration.
If you've taken a peak at the upgrade shop, you probably realized by now why there's a long ratio gear upgrade which increases your top speed, and above it is a short ratio gear which instead lowers your top speed. That short ratio gear, at the cost of top speed, increases acceleration. Some of you might think "Oh so is it bad for drag racing then where there are no turns?" The answer is a soft: no (soft because it can also depend on what car you're up against but the difference would be huge for it to matter).

Acceleration also means that you will reach your top speed faster , and when you shift gears there is less of a lost of rpm; in racing, when you shift gears, obviously you're not accelerating (notice your rpm dipping when you shift gears, or when you clutch the rpm goes up meaning because the clutch isn't biting; no bite = no moving). On it's own it's not that crazy of a dip in speed, but obviously if you spend more time shifting than accelerating then your opponent is just going to leave you in the dust.

So does this mean you should go with the long ratio gear box or do you go with the short one? The answer is a hard: Whichever you're comfortable with or prefer. Either is good. Just be a good driver.

Luckily, this game kept this part simple. All you need to prioritize, is speed, and handling. You don't need to worry about understeer or oversteer as the game will handle that for you; the better the handling, the better control you will have over understeer and oversteer.

The less your car weighs the more your top speed and acceleration is. As important as it sounds you can put this at the bottom at the list because its contribution is minimal compared to the rest on this list like for example: downforce. Downforce is basically how much your car is being pushed to the ground by the wind when speeding. This is important because the more your tires are being pushed to the ground the more they're gripping on it, meaning better acceleration, speed, and more importantly it keeps your center of gravity low which is key when controlling your car's handling capabilities. The best cars with the best handling have the lowest center of gravity (probably).

Prioritize your differentials, sway bars, and then brakes. A good match for a good acceleration is a good brake so you can go from 200mph to lower and lower to 200mph in less than 30 seconds. Differentials and sway bars impact your oversteer and understeer the most when it comes to handling (the other parts aren't that far away though when it comes to contribution so be sure to later on upgrade them too).

When your wheels are spinning while under a turn, one side will be spinning faster than the other. The inner wheels (the side to the direction of the turn so right wheels if your going right) has less distance to cover when turning compared to the outer wheels, thus their spinning speed should be less than the outer one. What this also means is that the outer wheel needs more power to spin faster because it has a lot more ground to cover. This is what the differential covers, it basically manages how much power one side should have over the other when turning.

Sway bars on the other hand helps with the center of gravity mentioned earlier. When you turn, your car's weight is thrown away from the direction of your turn, that's just how physics work; this variable is called the car's roll. So sway bars, which is a part of your car's suspension system, helps minimize this rolling so that your center of gravity stays closer to it's center. Think of it as sprinting on foot: when you turn, you use your muscles to turn your body weight towards the turn; cars don't have muscles to control themselves that way, thus the sway bars.

When upgrading your engine, pretty much majority of the parts contribute significantly to these variables so I'll just give you a rundown of my personal choices to upgrade first. Also I'm not a mechanic nor a car guy so my knowledge on engines are pretty subpar.

- Exhaust & Intake manifold: Huge boost to power and speed
- Turbo: this is different from your NOS (which is the speed boost). Turbo, is something that automatically makes your car accelerate faster
- Camshaft: Lets your RPM hit further into the redline so you can reach your gear's top speed faster and shift less.
- For cooling either your radiator or oil cooling.

The gearbox you also would want to prioritize high on the list but it's pretty expensive so it's up to you if you want to do that first or do it last. Also yes I didn't prioritize NOS, you don't really need it. It's more of a power-up or a comeback mechanic than a necessity. Plus you'll be busy avoiding traffic a lot so you'll seldom find times where you could just rip the NOS for seconds straight.

If you want a proper introduction to ALL the car parts, I think this video is a great choice.

- When buying an auctioned car, be sure to inspect it physically. On paper, it might seem like a piece of junk, but when you inspect it, you might find some parts already customized, saving you money.
- Racing dirty (blocking their way, bumping into them, etc.) seems to increases chances of them asking for a rematch.
- You can ask for a fast travel, but it comes at the cost of your multiplier so use it wisely.
- You need to upgrade to an e-brake if you want to your handbrake to be a "press and hold" instead of the on or off. This is part of the game's sim and immersion elements.
- You do not need to accept the loan offered to you. When under debt a portion of your winnings are taken so your 1mil yen winnings will just be half of it. However, it can also be a strat to be in debt and get the "lose the race and I'll clear your debt" offer, which will allow you to keep the loaned money. Unfortunately idk how to trigger this.
- Braking isn't the only way to slow down when preparing for a turn. You can also just simply let go of the accelerator and naturally let the speed fall, or shift down a gear or two and then brake when needed.
- When you have the GPS on, you can press up 3 times to get 3 different levels of zoom. Useful if you want to know ahead of time if a turn is coming up without needing to look at the map too often.

https://steamproxy.com/sharedfiles/filedetails/?id=3234733276

I'm not a car guy, nor a mechanic. I just spent a lot of time tuning cars in Forza Horizon 4. So be sure to point out any mistakes in the comments or share your suggestions.

"Why tf did you write in detail so much some parts?"
Idk, just thought it might be useful in case you get into racing games. I'm not that into racing games but when I pick one up it's so easy for me to get invested into it; so I think knowing these things is useful so that you'll have transferable knowledge when picking up another racing game (kinda like fighting games). Or it could just be from my habit of coming from a research course background lmao.