• Danny Lee

Brake Bias - Often Ignored But Hugely Useful And Simple

Brake bias is the term given to the proportion of braking force that goes to the front and rear wheels and changing it can have dramatic effects on how the car behaves. On most cars in iRacing and other sims, you can adjust brake bias whilst out on track any time you like using controls you’ve set to your wheel or buttons. Learning to adjust your car’s brake bias multiple times per lap to suit each corner type is an easy way to gain time and consistency. However, if you’re thinking “hang on a minute, I’m barely able to string laps together without spinning or going off course, let’s get that sorted before throwing in things like brake bias”, then stop right there - incorrect bias could be causing you these problems and if you make the small effort to get comfy with changing bias it could help you a lot.

Before you can experiment with brake bias you’ll need to ensure you have set your buttons for doing so in your options menu. Look for the button bindings to set a button to increase bias, and a button to decrease bias. In iRacing you can see your current brake bias in the F8 black box represented by a percentage, which will move up and down when you press your bias buttons. It’s also visible on some car dashboards in-game, or if your FOV cuts the dashboard off you could use a phone dashboard to display your brake bias while you drive. Whatever you use, being able to see your brake bias will be important as you’ll start to memorise your bias settings.

And if this is starting to sound like hard work then it’s time for a little pep talk. It’ll take a little bit of concentration at first but once you incorporate brake bias adjustments into every lap, you won’t be able to live without it. Adjusting bias per corner is such a performance enhancing tool that Renault F1 got into trouble for doing it automatically without driver input. If I was to ban myself from touching brake bias for a whole race I would struggle to set the same consistency or times that I can with it. It’s at your fingertips, so why not use it? Let’s dive in.

Put as simply as possible, adding brake bias makes the car easier to control when braking and turning but also makes it more likely to lock a front wheel and run wide. Lowering brake bias gives the car more braking potential but is harder to control if trailbraking into a corner and lose the back end.

Here is a diagram of Monza. It has a good variety of corner types; Turn 1 is a slow chicane that has a heavy, straight line braking zone. The chicane that follows is somewhat similar but trail braking starts to come into play as it’s not quite so tight. Turn 4 and 5 are faster turns that need trail braking in greater measure. Turn 7 is a fast left-right-left chicane that needs a good entry, and the last turn Parabolica is a very fast, long corner with lots of trail braking. Monza is a great example of how Brake Bias can make life much easier when you start using it, as throughout the lap Monza’s corner styles get faster and faster as the lap goes on.

My brake bias settings for each section are shown as percentages, but don’t pay attention to the percentages themselves as they’re not really important, what really counts here is the change in percentage between each style of corners. Compare the brake bias used for Turn 1 compared to the brake bias used for the final turn. They are two totally different corner styles that call for two different bias settings.

In corners where the braking is mostly done in a straight line, such as at the end of a long straight into a hairpin, you’ll want to use less brake bias, whereas if the corner requires a lot of trailbraking then you’ll want to use more brake bias so you aren’t at risk of losing the back end when you turn into the corner with the brakes applied.

The best way to see the way brake bias changes the characteristics of the car is to try a lap around a circuit until you’re comfortable, then increasing or decreasing the brake bias by 5% and seeing the effect. In brake bias terms, 5% is a lot, so the effect should be obvious. For example, if I was to add 5% brake bias at Monza, I’d struggle to avoid locking the front tyres into the deep braking zone of turn 1. Whereas if I lowered brake bias by 5% I’d find the car very twitchy when braking and turning into the last turn.

Remember I said to ignore the bias percentages themselves on that Monza diagram and focus on the differences per section instead - this is because each car type, be it Formula, GT and so on may have a vastly different ‘baseline’ bias value which is considered normal for that car. For example, let’s say the setups for the Ferrari 488 GTE have a ‘neutral’ bias value of around 51%, in the BMW it might be 52%, in the Ford GT it’ll be 49% and the Porsche 911 GTE has a baseline bias value of around 57% which is completely different. If you were to go out in the Porsche GTE at Monza and try to use the exact brake bias settings I showed in the Ferrari 488 GTE, it will definitely end in disaster. I encourage you to start off with the ‘neutral’ value that you find already in the setup you’ve loaded for the track, and tweak it slightly to try and make every corner work best for you. If you struggle to remember what brake bias you settle on for each section of track, you could print out a track diagram and jot the values down so you have it for reference.

Brake bias percentage is usually represented by how much braking force gets sent to the front wheels. 50% means an equal split of braking force front and back, whereas 60% means 60% to the front, 40% to the back.

Lastly, don’t feel obligated to restlessly fiddle with the brake bias all the time. At Monza I make a good 4 or 5 adjustments per lap, but at Le Mans I only make adjustments twice per lap because that’s all I feel it needs. You could decide to adjust bias just for one particularly tricky corner and return it to the neutral position for the rest of the lap, and that’s fine - you’ll still be better off than if you didn’t bother.

If you haven’t dabbled with brake bias on the go before now then I hope this video inspires you to give it a try. It’s so useful for tuning out instability and front brake lockups and will definitely help you nail each track that little bit more. Please visit Youtube and subscribe, share this with anyone else you feel might benefit. Comment on Youtube if anything is unclear and I will respond, and leave feedback there if it helped you in anyway. Thank you very much for reading.

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