I’ve been tuning for quite a while, but I still haven’t really figured out what the overall stiffness of the anti-roll bars do. I know that changing the front and the rear roll bar stiffness relative to each other changes how much oversteer/understeer the car has, but when I experimented with the overall stiffness, I didn’t notice any change, or if there was I didn’t see the difference.
So how would the car drive differently if I changed the anti-roll bar stiffness from:
F: 23.00
R: 20.00
To:
F:13.00
R:10.00
It would be fantastic if I knew what would change. Thanks!
stiffer roll bars would react quicker to changes in body movement , softer is more lazy , well in real life anyway , how it is in forza physics i have no clue
ABR’s link the suspension of the two wheels together and limit the difference between the compression of the two springs. When you turn left, the right wheels will compress much more than the left (due to the shift in weight). When you stiffen the anti-roll bars, this will cause the right and left springs to compress at similar rates, potentially preventing the car from swaying too far.
However, if the bars are too stiff, it can pull the wheel(s) away from the road, causing loss of traction and understeer/oversteer (depending on which wheels lose traction). Too loose, and you risk the car’s weight being tossed around, causing instability and potentially rolling the car (hence the name Anti-Roll Bars).
As others have said, experimenting is the only way to know for sure how tight or loose the ARB’s should be. Suspension, Tires, Brakes, and Weight are all factors that will affect this, so make sure you are only changing one thing at a time so you know for certain what that change did to the car.
ARB’s are used to keep the inside wheel from raising the ride height compared to the outside wheel. The ARB helps compress the inside spring, instead of letting it expand. Without this, the car will rotate, or “roll” about it’s roll center. Not desirable, unless you need lots of mechanical grip, such as a low speed track with steady, gentle corners, or rain. Going too stiff on ARB’s can actually lead to a car rolling over when using curbs in high load corners.
Lowering the anti-roll bar setting will increase body roll, and higher settings will decrease body roll. It’s that simple.
Look at the suspension telemetry screen. If the bar is filling up completely while the suspension is loaded down mid corner you need more roll stiffness, and increasing the ARB settings is one way to do that. However, if the bar is barely moving off center while loaded the car is probably too stiff, and reducing ARB settings is one way to soften the car. I say “one way to…” because spring stiffness, ride height, and damper bump settings also play a part in managing suspension travel and body roll.
When you get the overall stiffness where you want it, then do your small adjustments for handling balance.
ARB are used to provide extra SUPPORT in addition to the springs during cornering only.
Use springs to support the car during acceleration and braking. Depending on the weight distribution and acceleration/braking capabilities of the car, the front and rear spring rates will differ. These spring rates will NOT be ideal in cornering because of the spring rate differences.
ARBs are used to balance the front/rear spring rates then fine tune the under/oversteer characteristics. Heavier the car, higher the spring rates + ARB combination. Taller the car, higher the ARB should be.
FWD will likely understeer less with a higher REAR ARB than the front.
RWD will likely oversteer less with a higher FRONT ARB than the front.
Then use damping to control the rate of those changes. Not getting into damping in this thread.
If you are unable to feel the changes after increasing/decreasing ARB values (by a significant amount) then the spring rates and/or the damping values are likely TOO HIGH, rendering the ARBs ineffective.
Lap a track in the same car for good 10 laps or so to get baseline feel. Then change front or rear ARB in +/- 5 increments to see which direction you prefer. Then tune ARB in +/- 3 increments, then 2 or 1 for really fine tuning if you are sensitive enough to feel that small a difference.
+, if the car has a lot of body/chassis flex, any suspension updates will not be as effective. If it is an old car consider adding roll bars to stiffen the body/chassis before stiffening the suspension.
Too soft will oversteer, too stiff will understeer, as with springs. ARB-stiffness depends on tiregrip as well as car-weight. Give a car moore grip and it will need stronger ARB-settings
