Road Racing

Upgrades and Tuning Menu Flaws & Myths

The game gives you enough information to make a good build, but it puts the useful information behind the stats toggle and gives too much attention to ratings that should not be trusted.

The Performance Chart is a lie.

By this, I mean the Speed, Handling, Acceleration, Launch, Braking, and Offroad ratings.

They are not reliable when building your own car, and they are not reliable when comparing community tunes.

• A 10-speed transmission can raise the Launch and Acceleration ratings even if it makes the car worse.
  More gears = more weight, and also more shifting.
  Too many gear shifts can slow you down.
• The Acceleration and Speed ratings do not get updated when customizing downforce or gearing.
• The Handling number does not get updated when fine tuning improves or worsens the car’s Lateral G’s.

Focus on Horsepower, Weight, Lateral G's, and Braking Distance instead.

The tire-selection menu can lie about grip.

When you highlight a tire compound, the large tire graphic may say something like “Grip -0.10.” That is the misleading number.

Toggle the detailed stats and look at Lateral Gs and Braking Distance at the bottom of the menu. Those numbers show what the tire is actually doing to the car.

Rally tires are currently valuable for road builds because the menu treats them as if they have less grip than they really do, while their lateral Gs can be close to semi-slicks for much less PI.

The 0-60 and top-speed estimates are useless while choosing parts.

The gearing has not been tuned, the downforce has not been set, the differential balance has not been chosen.

I’ve seen top speed numbers that have been off by 50mph (in either direction) compared to the finished build.

I’ve also been able to improve 0-60 times every single time by adjusting gear ratios on the transmission.

My Build Order

I pick the car and target class, then work through the actual upgrade menus in this order.

I can swap engines and parts as many times as I want without paying. I do not check out until the entire combination makes sense.

Conversions

Engine Swaps

I check every engine swap before I commit to anything. I want to know whether the engine can fit the target class while leaving enough room for additional upgrades. Check which engines can use a centrifugal supercharger and prioritize those options, while comparing power to weight ratio.

Open the sortable Engine Swap Guide →

Aspiration Conversion

Drivetrain Conversion

For maximum performance, AWD is my default unless I deliberately want to avoid it. It improves launch and makes power easier to use. The differential gives me enough control to make an AWD car rotate instead of accepting the usual power-on understeer.

Widebody Kits

Using widebody kits is a judgement call. The reason to use it is wider rear tires, which helps with grip and handling.

The downside is added weight, increased PI, and lower top speed. I compare the complete build with and without it. The body kit only wins if the extra tire is worth the cost.

Aero and Appearance

Front Spoiler

Front aero is especially important because front grip is what improves turn-in.

Maximum front downforce costs less top speed than rear downforce, and the turn-in benefit is usually worth it – even on lower class builds.

As a bonus, it will usually decrease the PI for vehicles in lower classes.

Rear Spoiler

The adjustable rear spoiler will usually decrease PI.

For lower class builds (B class and below), I can set rear downforce to the minimum in the tuning menu and reduce the top-speed penalty.

At higher classes, I start with 0 and move it up as needed to maintain grip.

Tires and Rims

The only compounds I currently use:

Rear Tire Width

On AWD builds, I use the widest rear tires available. They can lower PI while improving lateral grip, braking, and acceleration. I would pay PI for that result if I had to.

For RWD builds, you will pay extra for this, but it might be worth it depending on the rest of your build.

Front Tire Width

More front tire width can increase front-end grip, improve turn-in, and reduce understeer. It also helps with launch on FWD builds. The PI cost is high, so it is one of the last things I consider and I only use it when the car needs it.

Drivetrain

Platform and Handling

Engine

After the rest of the build is taking shape, I use the Engine menu to fill the remaining PI. For handling builds, every choice is based on the finished horsepower-to-weight result.

Finishing Touches

Once the important parts are chosen, I use these options to move the build a few PI without changing the entire setup. The goal is not just to hit the class cap. It is to spend or remove PI while protecting horsepower-to-weight, lateral Gs, and braking distance.

SPENDING REMAINING PI

LOWERING PI

After every change, I use Toggle Stats and recheck the three numbers. Reaching the class cap is not an improvement if the cleanup part makes the finished car worse.

Gearing Comes Last

Aero and differential settings come first. Downforce limits the speed the car can actually reach. Differential balance changes how well the car accelerates. If I tune the gearbox before those settings, I may have to do it again.

Start with final drive

The gearing chart shows a maximum mph at the far right. That does not mean the top gear should always reach the far right edge. Once downforce is added, the car may not be capable of that speed.

Experiment with lowering final drive up to 20% to see if top speed increases. This checks to see if the top speed is being met in the second-highest gear. If the top gear isn’t where your top speed is met, then it goes unused. The first six gears have effectively been made longer for no benefit, which costs acceleration.

Individual gears

• First gear must launch without wasting the power in wheelspin.
• Each gear should be shorter than the last.
• The gaps should be larger in the early gears and get smaller toward the top gears.
• Watch where RPM lands after each shift. The engine should stay in its useful power range.
• A 7-speed is enough almost all of the time. Do not add shifts unless the PI reduction is worth it.

How I Test the Tune

A person cannot be completely objective, but I can be consistent on a small area. I use Narai-Juku Circuit because it gives me a sweeping corner, multiple chicanes, bumps that test the suspension, and most importantly, a hairpin.

The hairpin is the most rigorous test for a tune in my opinion because one corner exposes several potential problems with a tune. It will expose problems with braking, turn-in understeer, corner-exit oversteer, and acceleration as the car leaves. If the car can handle hairpin turns without any of those issues, it’s probably a good tune.

My comparison process

• Run the same course until the clean times are reasonably close. Within one tenth of a second is excellent, but the point is simply to stop comparing a perfect lap with a bad one.
• Average several clean attempts before changing anything.
• Save the tune before the change so it can be rolled back.
• Change one setting or one connected area at a time.
• Run the same test again and keep the change only if the average or the specific problem improves.

Speed-zone alternative

Find a speed zone with a good mix of corners. Pick a fixed starting point next to a street lamp, pavement mark, or another landmark. Start from a dead stop, run the zone, record the average speed, and repeat until the results are consistent. Then change the tune and compare the new average.

Fix the Problem You Can Feel

I describe the problem by the part of the corner where it happens. “The car is bad” does not tell me anything. “The front loses grip when I turn in” or “the rear steps out when I add throttle” tells me where to look.

The build creates the potential. The tuning makes it usable. The test tells me whether I actually improved it.