How To Setup The Perfect Tyre Pressures In ACC

It doesn’t matter whether you’re using a downloaded setup, or creating your own. One thing remains constant. And that is the need for perfect tyre pressures.

One of the most common instances of tyre pressures being incorrect. Is when someone is using a downloaded setup, or a setup from our ACC setups. And the track or weather conditions aren’t the same as those during the setup creation. In this instance, you’ll need to adjust your setup to correct your tyre pressures.

So first and foremost, let’s look a the optimum tyre pressures that you should be aiming for. Then I’ll show you how to achieve these tyre pressures with any car and any setup.

The perfect tyre pressures for Assetto Corsa Competizione

Dry Conditions

• GT3 Cars – 27.4 – 28.0
• GT4 Cars – 26.7 – 27.5

The above pressures are ideal for a dry day on track. These are the pressures that you should be aiming for while racing. Not the tyre pressures that you should use in your setup!

You will find that when you drive out on track, your tyre pressures will increase as you drive. This is because as they warm up, your tyres pressures increase.

You should ultimately set your tyre pressures lower than the figures above if the weather is hot. Giving them room to increase to the correct figures as you race.

If it’s a cold day, you may find the opposite happening. Your tyres may actually lose heat once you go out on track. In this case you should look to over inflate your tyres before leaving the garage.

Wet Conditions

• GT3 Cars – 29.5 – 31.0
• GT4 Cars – 28.6 – 30.4

Wet conditions will always make your tyres colder than dry conditions. You will be driving through water which has a much lower temperature than a dry track. And typically air temperatures will be cooler in the rain.

So due to wet conditions making your tyres cooler, we have to change up our approach slightly when preparing for a wet race. You should look to over-inflate your tyres in wet conditions to try and keep heat and pressure in while racing on a colder track.

Mixed Conditions

When racing in mixed conditions, it becomes much harder to judge the correct tyre pressures. Especially if you are facing a change in the weather mid race.

Typically, your best bet would be to look at the weather forecast and try to gauge whether your tyres will become hotter or colder in the upcoming weather.

If your racing on a wet track which is drying out. You can expect your tyres to start to increase in temperature. This in turn will increase your tyre pressures. In this scenario setting up your car with slightly lower tyre pressures will help offset the increase in temperature.

If the weather is flipped, and your racing on a dry track but rain is forecast or starting to fall. You can expect your tyres to start to cool down and lose tyre pressure. In this case you should slightly over inflate your tyres to keep some temperature in them

Why do you need correct tyre pressures?

How important are correct tyre pressures in Assetto Corsa Competizione? Extremely! In fact, ensuring you have the correct tyre pressures during every session is one of the quickest and easiest ways to gain lap time and preserve tyre life!

If you are racing with incorrect tyre pressures, even if its only off by 1 PSI, you open yourself up to a few negative scenarios. You could burst a tyre if your extremely over inflated. Lose pressure if your too far under inflated.

You will almost always be losing lap time if your pressures aren’t correct. And not to forget, you will almost always have increased tyre wear when at the wrong pressures.

Simply put. If you want to maximise your setup and your performance across a race weekend, your number one priority should be to run the correct and optimum tyre pressures.

What causes tyre pressures to change?

As I touched on above, there are a whole host of variables which cause your tyre pressures to change throughout a race session.

Tyre temperature

The main factor which will affect your tyre pressures is your tyre temperatures. The ultimate temperature of your tyres will dictate how much the air in your tyres expands, in turn increasing or decreasing your tyre pressures.

Weather conditions

The major variable which will affect your tyre temperatures is the weather condition. In dry conditions your tyres will be much warmer than in the rain, due to the cold water cooling your tyres down.

And when it’s a hot day vs an overcast day, the increase in air and track temperature will also increase your tyre temperatures.

Time of day

Following on from the point above, the time of day will also affect your tyre temperatures. Even on a completely dry day / night, the air and track temperatures will be much lower when the sun sets compared to midday.

If you are endurance racing, this time factor will be an element which you really need to be conscious of. You will find that you will have to increase your tyre pressures as night arrives, and decrease them as the sun rises in the morning.

How tyre pressures affect your car setup in ACC

Not only are tyre pressures crucial for maximising your grip and tyre life. They also affect your whole car setup when adjusted. With this in mind, you can adjust your tyre pressures to introduce or remove certain characteristics that your car displays.

Before jumping in to how your tyre pressures affect your car setup in Assetto Corsa Competizione. First let’s just quickly run through the tyre’s impact and how it works.

Your tyres are the one area of your car that touches the surface of the track, and how much of your tyre is touching the surface dictates how much grip you have. For example, under inflating your tyre will mean that more of your tyre’s surface is in contact with the race track.

Under-inflating also softens your tyre, giving your car more bounce. Very similar to softening your springs and dampers. The opposite is true as well. Over-inflating reduces the contact patch with the track surface, and causes your tyres to be much stiffer.

What we as sim racers want to achieve is that perfect balance between too soft and too stiff. Getting just the right amount of contact patch giving just the right amount of grip and tyre life. So let’s look at the setup characteristics of an under-inflated and over-inflated tyre.

Over-inflated tyres – Too much PSI

• Tyre feels stiffer
• Less dampening over bumps and kerbs
• Less rolling resistance
• More responsive under the right circumstances

Under-inflated tyres – Lower PSI

• Car is softer over bumps
• More dampening, meaning more bounce
• Increased rolling resistance, meaning more drag
• Reduced tyre life
• Reduced ultimate grip

How to correctly setup or adjust your tyre pressures in ACC

This section is the meat of this guide. Here I’ll run you through the exact process of how to adjust your tyre setup to get the optimal pressure. I’ll run through this in steps so you can literally follow through the process, and repeat this whenever you need to.

Step 1 – The baseline run

The first part of your tyre pressure setup will be to load up your setup, whether the safe or aggressive preset or one of our setups from SimRacingSetup.com. Try to match the fuel load with the fuel load that you’ll be racing or qualifying with.

Ensure the track conditions match those of your upcoming race or qualifying setup. And then take to the track for a few laps which we refer to as our “baseline run”. Drive at least 3 laps, but ideally 5 plus to get a baseline tyre pressure reading.

Have the tyre pressure readout displayed on either the HUD or on your dash so you can see the pressures after your baseline run. After completing your baseline run, note down the tyre pressures of each tyre and head back to the garage.

Step 2 – Adjust your pressures

When in the garage, calculate the difference between each wheels tyre pressure and the optimum range stated above. From there, either increase or decrease your tyre pressure in the setup menu be the difference.

Once you have adjusted your tyre pressures by the difference between your baseline readout and the optimum pressure. Head back out on to track for another run of at least 3-5 laps.

Again, pay attention to your tyre pressures to ensure they are closer to the optimum range. If they are still out, head back to the garage and repeat this step.

Step 3 – Pay attention to tyre temperature

Once you feel that you have the perfect pressures to keep your tyres in the optimum range, you should complete a longer run. In this run you should look at your tyre temperatures to ensure they stay in the optimum window.

The main purpose of this run is to ensure you aren’t overheating your tyres which will result in a loss of tyre life.

You can watch your tyre temperatures using the HUD, which will show a live reading of your tyre temperatures. The colour of the tyre in the HUD will change with the temperature.

If your tyres are too cold or loosing temperatures, they’ll appear blue. Your tyres will often be blue when you leave the pits. If they are in their optimum temperature window they’ll be green. And if they are getting too hot they’ll appear yellow.

You’ll also be able to see your brake temperature with the smaller HUD icon beside each tyre. If your brakes are running cold, you can start to lose heat from your tyres. And if your brakes are consistently hot, the heat will bleed into your tyres.

Top tip: You can always use your brake temperature to increase or decrease your tyre temperatures if you’re struggling to maintain the optimum temps other ways.

On this final run you will want to ensure your tyre temperature remains in the green, optimal working window throughout your run.

Once you have completed a run where your tyre pressures remain in the optimal window, and your temperature remains in the green zone. You should be achieving optimal performance from your tyres. Then you can move on to other aspects of your car setup.

Step 4 – Constantly check your tyre pressures and car setup

As a final note, you should be consistently checking your tyre pressures and your car’s behavior after making any setup changes. Adjusting different parts of your setup, including your tyre pressures will affect how your car handles and behaves. This means that further tweaks may be required after making setup changes.

Conclusion

That will do it for our Assetto Corsa Competizione tyre guide. By following the steps above, you will be able to take any setup, either preset or one of our custom setups. And you’ll be able to adjust the tyre pressures to achieve optimum performance whatever the weather.

The setups found on our site are already optimised for certain conditions, meaning they’ll perform very well under certain circumstances. They may however require adjustments such as tyre pressures to work to their full potential under different weather and grip conditions.

If you are looking for professional custom car setups for Assetto Corsa Competizione, check out our custom setups.