So I’m learning how to tune myself (very slowly & not very well) after using the ForzaTune app for many years. I will probably continue to use it to generate a base tune and then drive and adjust from there.
One thing I noticed the other night while tinkering around, was that especially on cars that have a rear weight bias (mid & rear engine) changing the rear brakes setting to a lot more in the rear shows in the simulated numbers of having a significantly shorter braking distance. However when I went to test drive the vehicle, the back brakes will lock up extremely easy and I lose control of the rear of the car almost every time.
I commonly find I have to have the front brakes in the 50 to 54% towards the front range, yet the simulation number show the shortest braking distance with bias at somewhere between 40 and 48. I always drive without ABS off btw.
I understand these factors can be affected by suspension spring rates and other items. But it just seems weird the simulator is ALWAYS showing shorter distances on the 100-0 of 30 to 40 feet, yet the car is completely uncontrollable under even light braking and definitely does not stop quicker.
Any idea why the simulation numbers think rear bias on rear weighted cars is so much better? Even though under real driving it’s completely incorrect. Heck it even shows better numbers on heavily front weighted cars with rear brake bias even though it’s not as significantly far down the chain.
Honestly with the brake distance numbers i dont pay attention to. Rear engine cars i tend to run between 51 and 55% because it feels right. Just keep doing what ur doing cuz ur on the right path
Thanks for the speedy reply. So basically those simulated numbers are bogus. They must be coming from somewhere, right? So the only decent way to tune is basically set up your car, drive it around, tinker & change, drive it around, repeat… I’m guessing the simulated numbers are just junk then, weird.
Your brake balance will depend of what type of car you re driving.
You don t want your front ones to lock under heavy braking and you also don t want the rear ones to lock first as it will throw the car all over the place.
You want to adjust the brake balance for both front and rear to lock at the same time, if needed.
For front engine car with rwd, you usually put the bias towards the rear (48%) in order to help the front brakes that are already under heavy stress while braking suffering from the weight shift.
Hope it helps and that i make sense
The bias will also be determined by the way you drive. Experiment with different bias and also pressure to see what suit you the best.
Theoretically because if you feed the brakes in the pads heat up creating better bite, the cars more settles and the weight transfer more gradual because you’re using the smaller rear brakes more but it doesn’t work that way, if it did the race teams and manufacturers would set the brakes up like that.
The more front basis you have the better your car will stop (to a point) it’s more about creating maximum usable pressure at a realistic distribution a quick way of setting the car up that a friend of mine uses is to set the bias to match the weight distribution and he swears by it… I’m not to keen but try it, then start with about 135% pressure and increase it until you’re happy with the rate you scrub speed at.
One thing to remember is that a rear engine car with a rear brake bias will want a lower pressure, some toe and a higher decel diff lock to keep it stable.
This is my hypothesis to explain the wonky calculation numbers.
Back in FM5, the brake bias slider was backwards, i.e. 54% on screen actually meant 54% REAR brake, NOT the usual 54% front.
In FM6, this has been corrected. 54% on screen means 54% front.
I am suspecting that the this has been corrected in the TUNE, but not in the calculations. Therefore everything about the tune and tuning screen is correct . . . except the brake distance calculations on screen.
So if the car’s rear end behaves erratically on heavy braking that is a sure sign that there is excessive rear bias. Use the friction circle telemetry screen to determine which direction the bias should go.
Another thing that will affect stability on the brakes is suspension. You could have the best brakes in the world but if your suspension set up is poor it’ll behave like a bucking bronco.
Too stiff in the front you run the risk of locking over bumpy sections… To soft in the front you run the risk of unloading the rear tires which will then lock causing the rear to break loose.
Some cars will naturally squirm when you’re right on the limit of grip like the Lamborghini Gallardo other naturally want to put you into the wall… Like the 458 Italia… Pig in stock form.
brake bias is simple, if the car oversteers when you apply the brakes you need more front bias, 52 to 55 usually fixes it. if your car understeers when you apply the brakes you need more rear bias 46 to 48 usually fixes that problem. so far in forza 6 48 to 52 seems to be a good range.
Don’t forget that lots of things can affect the brake balance too. A soft car will require a different balance to a hard one and likewise difference damper settings will also affect how the weight transfers during braking. Also, the placement of the engine and overall weight balance has a large factor on which end will lock first.
Ideally, you want to play with the chassis first until you’ve got that sorted then adjust the brakes accordingly so that the fronts just lock up under extreme braking.
The way I test it is I tune my brakes for when I a braking. Nothing more. I just go fast and hit the brakes as hard as I normaly do, downshift as I normaly all in a straight line and lower the bump on the side that’s locking up 1st/ the most.
