I've discovered a strange behaviour of brake force range in car setups.

It seems to depend on the restriction you put. The only cars it's affecting are GTRs and FBM.

Example (FXR):
0% restriction - max force 3287 Nm
50% restriction - max force 2651 Nm

Also, with 50% restriction the slide can't be moved all the way to the left, there's a gap.

Someday when I was playing with Tweak, I've found out that LFS engine is very, very flexible. As you pointed, it adapts to lower power, but not for every car.

Hmm is this new or did no one notice?

It's probably been there for ages but nobody cared to report it as a bug, since it's not that important?

I have noticed this long time ago, but never really thought it would be a bug, as I thought it would effect to live settings or somewhat something similar. Also, it effects also when using tweak and only giving more power from the engine

Quote from Flame CZE :

It's probably been there for ages but nobody cared to report it as a bug, since it's not that important?

I was thinking same, but all of suddenly, everybody wants to be it fixed ( including me ) so...

....ehhhhh --->

Quote from pasibrzuch :

Someday when I was playing with Tweak, I've found out that LFS engine is very, very flexible. As you pointed, it adapts to lower power, but not for every car.

I second this, also it adapts to increased power, depending the tweak and version ( 0.6B for example )

Springs, dampers, brakes, all affected by power to weight.

It's just LFS working out how to provide a suitable maximum braking force that can lock up the wheels. A car with downforce needs more braking force to lock up the wheels if it has more power, because it can go faster and have more downforce.

It's a sort of bug I suppose, because adding an intake restriction shouldn't really affect the setup you can make for a particular car. I guess max braking force should only depend on the max power before any restrictions are applied.

It's odd that sims set brake force so that it can lock wheels. LFS does it, and Assetto Corsa does it too. Yet high downforce cars CAN'T lock their wheels at high speed. A better approach would be for sims to simulate brake line pressure, effective disc radius, and disc-pad friction to generate a torque that can be compared to the torque capacity of a given tyre as if varies with load/camber/slip etc. It's too simplified otherwise, and the replacement equation isn't much more taxing.

An F1 car, for instance, can't lock up it's brakes at 200mph. It has too much downforce, and the brakes will not overcome that no matter how hard the driver presses.

Quote from tristancliffe :

An F1 car, for instance, can't lock up it's brakes at 200mph. It has too much downforce, and the brakes will not overcome that no matter how hard the driver presses.

Driven many F1 cars?

No, but that has nothing to do with it. Weirdo.

Thanks, I like to be different.
The F1 car (or any car with "high downforce") can lock the brakes at any speed, it is dependent on traction...eg...slicks in wet weather.
In LFS you can adjust the maximum braking force from low to locking...and you can do the same on real cars too by changing parts...no matter how much downforce it has or how fast it is travelling..

If you would like to chat some more with this weirdo then feel free to pm me...I can be even weirder in private.

Quote from Anthoop :

...and you can do the same on real cars too by changing parts...no matter how much downforce it has or how fast it is travelling..

Nope. The rules in F1 are written in such a way that it's practically impossible (as in, impossible in practice) for a driver to lock the brakes at high speed (e.g. 180+ mph) in normal conditions because they simply can't apply enough pedal pressure to overcome the tyre grip at that speed.

Max pedal pressure = x hydraulic pressure = y brake torque given coefficient of friction and effective radius etc < torque capacity of warm slicks on a dry track pressed down by about 1200kg.

Whilst you probably could swap master cylinder sizes and caliper piston sizes to make it lock at any speed, the teams don't do that because the drivers would lose the ability to modulate the brakes at low speed.

Even an F3 car cannot lock the brakes at 140mph with max pedal pressure.

That's why the shape of a brake trace in a high downforce car is like a triangle - hit the pedal as hard as you can, and then bleed off pressure as downforce drops.

And, leastly, angular momentum (inertia).

Quote from amp88 :

Nope. The rules in F1 are written in such a way that it's practically impossible (as in, impossible in practice) for a driver to lock the brakes at high speed (e.g. 180+ mph) in normal conditions because they simply can't apply enough pedal pressure to overcome the tyre grip at that speed.

I was not taking rules into consideration ...just giving the fact that you can lock the wheel if there is enough braking force.

Quote from tristancliffe :

Whilst you probably could swap master cylinder sizes and caliper piston sizes to make it lock at any speed, the teams don't do that because the drivers would lose the ability to modulate the brakes at low speed.

Are you saying that a (conventional pad/disc) brake will perform best within a certain range?

Quote from Anthoop :

I was not taking rules into consideration ...just giving the fact that you can lock the wheel if there is enough braking force.


Are you saying that a (conventional pad/disc) brake will perform best within a certain range?

Yes, if you modified the cars to generate enough brake torque then they could lock the wheels. But my original point is that it's silly to calculate that torque in LFS as it's not realistic.

Sort of. If you had a set up that could generate the hundreds of bar needed to lock the wheels with human leg strength, then the drivers would find it very difficult to generate just 15 bar at corner entry - just the weight of their foot would probably be enough. And as they don't want to lock wheels, they don't do that.

In reality it is impossible to lock up a tyre with brakes working normally (I mean you don't have any of the two brake pump or lines or callipers failing which would make the pedal suddenly softer) with a GP2 car when putting a brake bit at about 90bars. Possibly you would lock up if you put 110 but let's be honest, you need something like 120kg on the brake pedal for 90bars, you would need 150kg on it for 110...good luck

More seriously tristan is right, you rarely lock up on the brake attack exept with low df cars (i.e F4) or abnormal situations (slick + wet) but you are most likely to lock up end of brake with less load on tyres and even more when you turn in as you are now in combined G situation. That's why drivers have to have a degressive braking shape.

Quote from tristancliffe :

Yes, if you modified the cars to generate enough brake torque then they could lock the wheels. But my original point is that it's silly to calculate that torque in LFS as it's not realistic.

How can it not be realistic if you can do the same thing in real life...that is the part I did not understand.
If I have more traction then I can use more braking force before the wheels will lock...in LFS I can go mild to wild on every car...why would you want to put a lower range...and how would you choose that range?

Quote from tristancliffe :

Sort of. If you had a set up that could generate the hundreds of bar needed to lock the wheels with human leg strength, then the drivers would find it very difficult to generate just 15 bar at corner entry - just the weight of their foot would probably be enough. And as they don't want to lock wheels, they don't do that.

Yes.
Heavy load will need big brake...big brake harsh with light load....traction dependent...

It almost sounds like you don't know how brakes actually work , from drivers leg to contact patches.

"Almost sounds like...." careful now, that could be taken as a compliment.

Was it my laziness at the end of the post that you were not happy with...or am I wrong to think that the maximum retardation of a vehicle is ultimately down to traction?

More importantly- what about LFS?
Why would you want to change from what it is now?
You can have someone using keyboard/mouse using on/off brakes set with a low braking force.....you can also have someone with a pedal (that has better modulation) using a higher braking force...you can run the BF1 on SO3 and KY1...if I put a chicane on KY1 would you use the same braking force as you did at SO3?

No, ultimate braking force is limited by pedal effort required in real life on high downforce cars with normal (incl. F1) brake set ups.

No, I don't change braking force in LFS. I set it so I can't quite lock wheels in the high downforce cars at top speed, but after that I never change it.

For realism purposes, talk of mouse users is redundant. Cater for them, but mouse driving has no place in regard to "realism".

I thought that was completely normal. Anyone who played with tweak has seen the brake force limits and other settings limits go nuts. Not surprised it does for regular restriction the opposite way too, seen on GT2s GT3s.
Less power, lower maximum brake force limit, or any other setting limit.

Quote from tristancliffe :

No, ultimate braking force is limited by pedal effort required in real life on high downforce cars with normal (incl. F1) brake set ups.

No, I don't change braking force in LFS. I set it so I can't quite lock wheels in the high downforce cars at top speed, but after that I never change it.

For realism purposes, talk of mouse users is redundant. Cater for them, but mouse driving has no place in regard to "realism".

We can go round in circles...
If I have less traction I use less braking force...
I suggest you try a different braking force with different set ups...

I used the on/off brake example to show a point that you ignored...

in a way you are wrong, you should see tyres traction like "how much longitudinal force my tyres can handle before sliding too much" (i.e locking in braking instance, also note that a tyre need to slide to provide some force).

So basically if your brake system is powerfull enough to provide enough torque moment to create a force on the contact patch that would be higher than this sort of friction limit, yes your are right, your braking event is limited by your tyre grip.

If your braking system is not able to provide such a braking torque, then your maximum deceleration is dictated by your brake system.

In real life, as Tristan is trying to explain you, on the big brakes attack as you get massive tyres load (also bear in mind you have load transfert that give even more grip to your front tyres) you are nearly never limited by your tyres but by the brake system as you would need to put a crazy amount of force on the brake pedal to have enough brake pressure to actually be able to have the brake torque required to get over your tyre grip. Then as you lose some load (less downforce + less deceleration & load transfert) you have to release the brakes as this time your tyres friction is the limit. That become even worse when you start turn-in as your tyres are now working in combined G situation.

The thing is that Tristan is using LFS as a simulation and isn't using the small things you can do in it you can't do in real life. Exept in Nascar or Endurance sometimes (i.e : need harder brake pad to last 24hrs), you never change any part of your brake systems to adjust their efficiency for a particular venue.

Quote from MoMo92i :

in a way you are wrong..............., yes your are right, your braking event is limited by your tyre grip.

Yes....we can go around in circles.

No matter how fast the vehicle is travelling or how much traction it has....we can use a braking system that can provide enough braking force to overcome the traction...real cars...(racing rules or how it should be done are not a consideration).

Of course the brake that can lock the wheels when there is maximum traction will be sensitive when there is minimal traction (without some help).

Look at it another way....
When the real racing car runs around the track in wet weather he will use the brakes in a different way than when running in the dry.....presume for a moment that it will always be wet...would the brake system be designed differently from the outset?