Image: Radical SR3 xx cockpit with brake bias adjuster (bottom right)
A typical scenario in sim racing is having a car with similar specs to your opponent, but you’re still struggling to come out on top. Forget feeling like the other drivers know some sort of magic secret, though. Much of the time gained per lap is actually from braking and the subsequent corner speed.
In today’s article, we’re going to look at the one setting that can greatly impact both braking distance and overall car handling in a turn: the brake bias setting. This setting, which is often overlooked, can make a significant difference in your lap times.
What is brake bias and how can you set it up for any track?
Braking is the critical moment in every lap, as it can make or break your lap time performance. In races with cars that have similar engines (especially single-manufacturer category racing!), it’s not easy to gain an advantage on the straights. Braking is where you can really make up time.
With the right brake bias setting, you can improve your braking distance, and ultimately gain an edge over your competitors.
Every part of your car setup plays an important role in how it behaves under braking and acceleration but, if you’re using the wrong bias settings, it can make the car feel nervous or unlikely to stop where you “feel” it should.
Having too much brake bias towards the rear can cause the rear wheels to lock, resulting in sudden oversteer upon turning. This can also make the car feel as though it requires more braking, but applying additional brake pressure may not help. On the other hand, having too much bias towards the front can cause the front wheels to lock, which is also undesirable. It’s important to find the right balance of brake bias for optimal performance.
Different brake bias settings can greatly affect the handling of the car when entering a corner on any track. To find the best setting for you, it’s important to experiment with different settings and understand how they impact the car’s behavior. Through testing and understanding the effects of brake bias, you can fine-tune your setup and improve your lap times.
Brake bias is a setting that determines the distribution of braking force between the front and rear brakes. A brake bias of 50% means that the front and rear brakes are applying equal force. By adjusting the bias towards the front or rear, it can lead to advantages in specific situations or disadvantages if not used correctly. It’s important to note that the brake bias setting can affect the car’s handling, braking distance, and overall lap time.
The perfect car to demonstrate this is the Porsche 911 GTE RSR as it’s not equipped with ABS (anti-lock braking) and so, it’s easy to lock up the tires. In fact, it’s such a handful that if you can get this car setup right you should be able to drive just about any car in iRacing!
Adjusting the brake bias towards the front can help stabilize the car during braking as it shifts more weight onto the front tires, increasing their grip. This can also lead to shorter braking distances. However, it’s important to note that increasing the front brake bias too much can cause the front wheels to lock, which is detrimental to performance. Finding the right balance is key to maximizing the benefits of the brake bias setting.
If you lock up the front tires by going too far forward with the bias setting, (make sure your audio settings emphasize tire noise!) your tires will lock up leading to the car carrying on in a straight line, leaving the driver unable to steer the car.
Only when braking pressure is reduced (by modulating the brake pressure through the pedals) can the car grip again. In racing, this is the better option than having the rear tires lock because too much bias to the rear usually ends up with the car horribly uncontrollable and prone to spinning.
Having the brake bias favors the front of the is the less risky and higher performing option and therefore the preferred setting for most drivers.
To find the right bias settings in the sim, most drivers get up to speed and then adjust the bias until they can make all 4 tires lock. If you’re in a place where the “true” bias is now set to around 50% (the front and rears are equally as likely to lock) then now you can play with the bias to tease out that extra bit of performance.
Increasing the bias towards the front might make the car stop more quickly but it might make the car understeer under braking too. Pushing the bias back then will give you more oversteer and a better turn-in at the corner entry. You’ll find that the margin between understeering and creating oversteer on the brakes becomes finer and finer as you progress with your settings. Ideally, a good end result is a bias setting for “big” stops (where you really need to scrub off some speed after a long straight) and a bias setting for medium to high-speed corners (where a small amount of oversteer is preferable).
Brake Bias Settings: Summary
- Maximum brake performance is at the point just before the tires lockup
- Tuning the brake balance is about managing the braking at the threshold
- Locking the rear tires will cause a sudden uncontrollable oversteer
- Racers prefer slightly more front bias because when the front brakes lock up the car remains stable, giving you the time to detect the brake locking and be ready to modulate your brake pressure.
- To set up your brake bias properly, pay attention to what the car does during the braking phase and corner entry.
- Spinning tends to mean too much bias to the rear, while huge understeer means the front brakes are locking.