Brake Wear

[Fischfix]

break wear is a very common thing in racing and lot of series have to deal with that kind of issue.

i know this has been mentioned before in several threads but no i a specific thread dedicated to this issue.

so here it is.


BREAK WEAR :)

[AndroidXP]

http://www.lfsforum.net/showthread.php?t=17510, for example... ;)

[wark]

For future reference, it's "brake" :razz:

But yes, of course... eventually.

[nikimere]

I don't think too many series suffer from brake problems any more.
The compounds used these days to make the pads and discs have ensured your brakes remain fairly consistent for the duration of a race.

[AndroidXP]

But I wouldn't exactly consider half of the cars in LFS race prepared at all. Stock cars with stock brakes should indeed suffer from brake fade/wear.

[Dru]

I don't think too many series suffer from brake problems any more.
The compounds used these days to make the pads and discs have ensured your brakes remain fairly consistent for the duration of a race.


I'd disagree to a point...

Short races sure people don't wear out their brakes, but if you have the wrong disc/pad combination, or the otherway, you do not use your brakes as you should, then you will get higher than expected brake temperatures which will then of course cuase fade and wear on the brakes..

+1 is brake wear ever gets introduced, but it's likely not to have too much effect on short sprint races

[Fischfix]

sorry, thats a spelling problem then. because i really!!!!! searched before starting this thread.

[nikimere]

But I wouldn't exactly consider half of the cars in LFS race prepared at all. Stock cars with stock brakes should indeed suffer from brake fade/wear.
That's very true. I was thinking from a racing car point of view. :shy:

[rovens]

Well all racing cars suffer braking issues when the brakes arent in the correct temperature range.

[Woz]

I don't think too many series suffer from brake problems any more.
The compounds used these days to make the pads and discs have ensured your brakes remain fairly consistent for the duration of a race.

Bathurst with the V8, the teams HAVE to change the pads durinmg the race!

Also we need heat build up so you get brake fade

[harjun]

I would like an option of some fat ass brembos

[Jamexing]

But I wouldn't exactly consider half of the cars in LFS race prepared at all. Stock cars with stock brakes should indeed suffer from brake fade/wear.

The no ALMOST prep point is quite true for the slowest car in LFS aka the painfully slow mini lookalike. But check the more decent cars like RB4, XRT, FXO, LXs, FZ50 and RA and they aren't exactly stock. With a wide range of springs, ARBs and adjustable dampers, they are very track prepared cars, with money well spent to make sure the perform well on the track and remain usable on the street. Why would one spend thousands on suspension and extrem performance road tires and somehow magically neglect to upgrade at least the brake pads to suit? If I were to use my road car on the track I definitely won't miss out on a set of Brembos/AP Racing brakes and of course, adjustable brake bias.

If there is one important factor that sets the apart from full blown race cars is the lack of visible rollcages. Rollcages are illegal for road use, but some track ready cars (e.g. Porsche GT2 996) come with integral chrome molybdenum rollcages that are so well hidden by internal trim they could easily pass as legal and counstable plodd wouldn't ever know if he didn't ask or try to check it out carefully. BTW, if I were to track my road car I definitely won't miss out on chassis stiffening too. Strategically placed braces make all the difference with minimal weight penalty.

The road cars in LFS should be considered track prepared cars, NOT stock OEM cars. It's good that LFS allows all this freedom of adjustment as it allows us to better explore, enjoy and discover the limits of LFS's physics engine. If there is one good way to cover for poor physics is to simply use the setup to fudge things until the right feel is acquired. That's why from us sim racers' point of views, less setup choices would be all loss and no gain. Of course, this doesn't mean that non-realistic adjustablility should be allowed, but since ARBs, springs and adjustable (4-way or even frequency sensitive) dampers are so widely used today, it's simply absurd to disallow what someone could achieve with his OEM car with a few well chosen aftermarket modifications.

[Vain]

1. At least in germany rollcages are allowed in normal traffic. I drove a race prepared car in normal traffic for several months because of the lack of another car. You never get used to the looks of people when you come to school with a car that has no interior but one bucket seat :tilt: .
2. LFS's roadcars aren't allowed on any track. No roll cage, no external hooks, no hooks for the engine hood, no external off-switch for the fuel-pump, no fire extinguisher, you can't race those anywhere but on trackdays. Racing the XRT is illegal in about every civilized country in the world. It's a road car, not a race car.
3. On topic:
Brake fade and wear is essential and I hope it's in the pipe for patch Y. I could nicely feel the brake pads of a BMW E30 wear away during a 2 hour drive when I did my race driver's license. The temperatures were alright since the E30 has a good cooling system for the brakes, but the wear was excessive. It's interesting to feel the pads wear away lap after lap until I had to stop. Those were production parts though. But quite some Porsches had to throw the towel before me because of brake-fade :tilt: .

Vain

[X tempor]

i think brake wear is a fantastic idea, also brake temprature and warping/cracking should be considered too this would make longer races in the road cars for LFS pit manditory in order to cool the brakes down. some may think this idea is pointless or will ruin game experience but lets not forget LFS is a race simulator, brake ware temp and cracking due to brake overheating would make LFS more realistic!

[wark]

pit manditory in order to cool the brakes down.

Stopping and sitting still isn't going to do any good if your brakes are overheating. :scratchch

[Jamexing]

1. At least in germany rollcages are allowed in normal traffic. I drove a race prepared car in normal traffic for several months because of the lack of another car. You never get used to the looks of people when you come to school with a car that has no interior but one bucket seat :tilt: .
2. LFS's roadcars aren't allowed on any track. No roll cage, no external hooks, no hooks for the engine hood, no external off-switch for the fuel-pump, no fire extinguisher, you can't race those anywhere but on trackdays. Racing the XRT is illegal in about every civilized country in the world. It's a road car, not a race car.
3. On topic:
Brake fade and wear is essential and I hope it's in the pipe for patch Y. I could nicely feel the brake pads of a BMW E30 wear away during a 2 hour drive when I did my race driver's license. The temperatures were alright since the E30 has a good cooling system for the brakes, but the wear was excessive. It's interesting to feel the pads wear away lap after lap until I had to stop. Those were production parts though. But quite some Porsches had to throw the towel before me because of brake-fade :tilt: .

Vain

1. Last time I checked rollcages are NOT allowed in Australia (land of silly speed limits applied to all the wrong places to maximize revenue, NOT safety). Germany is a different story, relative to pretty much everyone else it's car heaven.

2. Never said anything about disagreeing with PROPER implementation brake fade and wear. Any important physics improvements from aero to turbo modelling to Torsen differentials gets my vote.

3. No it is NOT true that roll cages are absolutely necessary just to legally drive on racing circuits. Of course they are mandatory in full blown races with cars and drivers competing seriously with each other. There are many roadable cars that are quite commonly run on open track days where poeple like members of car clubs are allowed to run free on the track at much higher pace then draconian (and often made up with moneymaking, not safety in mind) speed limits would allow. People (especially the more skilled ones) do go fast, though still below full race pace. Cars like the Lotus Elise come with no roll cages and are still used for the track. Well, they are actually more track car than road car, with no luggage space, tiny cockpit and suspension that telegraphs every little undulation to you. As for brake wear and fade, try the CCBs (Carbon Ceramic Brakes) from Porsche 997 turbo and Ferrari 430. And please, don't try to track your BMW with OEM pads again. Sheer wastage and reduces both fun and safety. Try these:

http://www.tirerack.com/brakes/brakes.jsp?make=Hawk&model=HP+Plus+Race+brake+pads

WAY better for track use, if you don't mind a bit of noise and dust. :)

4. When was the last time you got cars in say the TBO class with OEM 2 way adjustable dampers? So it's obvious they are TRACK cars, just not race cars.

[AndroidXP]

But we also all know that the available setup options are far from being finalised. Gear ratios adjustable in 0.01 steps anyone?

[Jamexing]

But we also all know that the available setup options are far from being finalised. Gear ratios adjustable in 0.01 steps anyone?

As far as I'm concerned, suspension steering and tire settings, etc should remain, though if things go my way all the track driven road cars in LFS would have homologated ratios and preset gearsets to choose from. And final drive would be limited to a few choices that the car(s) in question could use properly.


Of course, 0.001 gear increment adjustment isn't terribly realistic, but that simply not the most pressing physics issue now. There are aero, suspension geometry (need 3D suspension with 3D motion and of course bump steer), etc that are much more pressing and would affect LFS racing much more. And of course brake wear and temps, fade, etc.

As for brakes, brake bias should remain as it's not too terribly hard to get an aftermarket supplier to fit adjustable bias. Though the ability to adjust brake force down to 1 newton is OTT. We should get a choice of pads, say sticky, good when cold, quick warming and sticky but short lived pads for sprints. Then we should get pads that give less peak friction and poorer cold performance but more consistent and powerful once warmed up, lasting long and well under prolonged and severe braking. And also a compound or 2 in between.

[mikey_G]

Adding brake wear is a very good idea, because it makes driving the stock cars a lot more difficult and you have to resort to more engine braking (without blowing up the transmission offcourse :)).
Here are some ideas:
As the heat goes higher, the braking force should go down in lfs.
As the wear continues, so does the travel before any braking takes place (like if there is 5mm wear, the brake only starts working after 5% of travel).

Also while your at it, don't forget about knockback in the braking system. Here (http://www.youtube.com/watch?v=6Dv3whihq8I) you can see a vid I ripped which explains it.

[mrodgers]

As the wear continues, so does the travel before any braking takes place (like if there is 5mm wear, the brake only starts working after 5% of travel).
Just a note, that is not how it happens IRL. Most cars use a hydrolic system which never goes out of adjustment. The pads are always touching the disc, thus there is no difference in pedal travel as pads wear.

[Osco]

Adding brake wear is a very good idea, because it makes driving the stock cars a lot more difficult and you have to resort to more engine braking (without blowing up the transmission offcourse :)).
Here are some ideas:
As the heat goes higher, the braking force should go down in lfs.
As the wear continues, so does the travel before any braking takes place (like if there is 5mm wear, the brake only starts working after 5% of travel).

Also while your at it, don't forget about knockback in the braking system. Here (http://www.youtube.com/watch?v=6Dv3whihq8I) you can see a vid I ripped which explains it.

5mm of wear on your rotors? I'd say they're gone..:scratchch

I would like an option of some fat ass brembos

want rice with that?


+1 for this, I took the miata to the track yesterday and got some fade during the last laps, not the best of feelings when you enter the corner faster than intended...

[mikey_G]

@nighthawk
Indeed, didnt really think it through, scrap that idea.

@osco
the 5mm was just for an example

[UnresponsiveBeeVictim]

want rice with that?
Brembos/big brake kits are rice now? :scratchch

[wark]

Just a note, that is not how it happens IRL. Most cars use a hydrolic system which never goes out of adjustment. The pads are always touching the disc, thus there is no difference in pedal travel as pads wear.

David Coulthard had to retire from Malaysia because his brake pedal was hitting the steering column (due to brake wear).

[tristancliffe]

Lets say someone has worn brakes (pads and or discs). They press the brake pedal, and slow down. Then they come off the brake pedal. As they do this, three things happen.

1. The pressure in the braking system disappears.
2. As the master cylinder piston comes back, fluid from the reservoir replaces the additional fluid used to overcome wear.
3. The disc/pad clearance is caused by slight imperfections on the disc 'throwing' the pad away (by thousandths of an inch).

Thus, you end up with more fluid in the system to take up the wear, so the pedal is in the same place.

If his pedal actually moved further down they either have a VERY peculiar design (unlikely, but not impossible), or air was getting in the system which had to be compressed first. A tiny (and I stress tiny!) amount of air might cause a long pedal without completely ruining the brakes.

Either that or the fluid had been boiling locally, and air had been produced that way, causing the same as above.

[Jamexing]

Brembos/big brake kits are rice now? :scratchch

Oh, the silliness that genuine car enthusiasts get for upgrading their cars, even when the mod is perfectly logical and generates very significant increase in performance. Lack of of fade under hard use is always a good thing. Improved pedal feel and better wear thanks to quality stainless steel brake lines and 4-6pot calipers are a great bonus. The ability to fill in those 18 inch wheels shod with sticky 235/40/18 tires is just a bonus in addition to the improved overall braking performance.

[sinbad]

Brake overheating causes as great a problem, if not greater, than actual brake wear. Be it brake fluid overheating to near boling point and the bubbles having a serious effect on the efficiency of the hydraulic system, or resin in pads melting, which would give the glazing effect you see. Neither of these things is wear per se, but unfortunately I reckon you need a variable resistance brake pedal for these things to work properly in a sim. How else would you be able to determine if the pedal feels soft.

[Osco]

Brembos/big brake kits are rice now? :scratchch
it is if you have them just for 'teh brembos' or to justify a shedload of decals on your car...

anyway, +1 for this

[evilgeek]

+1

road cars should start the race with good braking power that fades if the brakes get hot.

race cars should start the race with poor to moderate braking power that improves as the brakes warm up to operating temperature, and should only fade if they get very, very hot.

complete failure should also be possible following a collision that in real life might cause a hydraulic fluid leak.

[Hyperactive]

Aaaand: brake squeel :)

[Vain]

Aaaand: brake squeel :)Even huge FEM-simulations that take days to calculate on super-computers don't produce real brake-squeel behaviour. Many major car manufacturers tried it, but not a single virtual brake ever squeeled similarly as a real brake.
It's just not known to mankind how the geometry of a brake, temperature and speed work together to cause brake-squeel. If Scawen managed to approximate the squeeling behaviour of a brake accurately he'd be the first in the world. :tilt:

That said, I'd appreciate a simple model that involves random factors a lot. :thumb:

Vain

[duke_toaster]

Bathurst with the V8, the teams HAVE to change the pads durinmg the race!

It's because they have mandatory refuelling and tyre changes in the other races, so for the enduros they have to make a mandatory brake pad change. What next, mandatory engine change :p

[DragonCommando]

Even huge FEM-simulations that take days to calculate on super-computers don't produce real brake-squeel behaviour. Many major car manufacturers tried it, but not a single virtual brake ever squeeled similarly as a real brake.
It's just not known to mankind how the geometry of a brake, temperature and speed work together to cause brake-squeel. If Scawen managed to approximate the squeeling behaviour of a brake accurately he'd be the first in the world. :tilt:

That said, I'd appreciate a simple model that involves random factors a lot. :thumb:

Vain

*coughs*
Then why do I know?

Brake rotors on high performance cars are made to wear faster,
I know, I changed a set last week because of it. I also changed the pads.

The brake pads actualy eat away at the rotors and constantly make them thinner, this isn't as exessive as it sounds but its fast enough to warrant changing them regularly, in some cases, mostly with full out race cars, every race.

This means that the surface of the rotor is constantly trued, now how does a "flat"(relatively) surface make a squeal when another flat surface makes contact? Because both surfaces are flat.

The edges of the pads on high performance brakes are champfered, but it doesn't take long for that to go away, after they become flat they are contacting the rotor with sharp edges, these edges bite into the material of the rotor and cause vibration, sound is vibration, so you get brake squeal. even with the bevel still there, cold brakes tend to squeal because the hardness is higher when the brakes are cold, so there is a short time between when they heat up to optimal temperature and when they lose the chamfer that they don't squeal.

I have drum brakes on my Motorbike, and they squeal when they are cold, however, after a while of riding it, I have noticed they squeal even when warm now. The edges of the shoes are not chamfered any more.

When I replace brakes on a road car, if the customer chooses cheap brakes, I was always taught to bevel them if they don't come that way, So the customer woulden't complain about squeal when he starts driving after the car was cold. Infact, even the high performance brakes I changed wheren't beveled, but they where OE pads, so I installed them without modifying them. They squealed when we pulled the car out of the shop.

[wheel4hummer]

Brake rotors on high performance cars are made to wear faster

The main focus in designing high-performance brake rotors is not to make them wear faster, but to provide better stopping power. Were those rotors you replaced steel, or ceramic-composite?

[DragonCommando]

The reason they wear faster is because if both materials wear at relitively the same speed, they provide better stopping power, if you use hard steel the pads will glide across the rotors, if you use a softer steel or another material that wears faster, than the pads will bite into the rotor and provide greater stopping power.

But yes, they where steel, the owner of the car got the "Mid range" package for the rotors, but opted up to the high quality pads.

The car wasn't going to be used for intense racing, they just wanted to be able to stop if they decided to speed a bit. :scratchch

but everything was Brembo high performance, even the original parts we took off.

[wheel4hummer]

Hmm, I didn't realize that brake rotors were made out of so many different alloys. I just did some searching on Google, and there are so many different kinds of brake rotors.

[DragonCommando]

It's not realy part of my job (yet), But I've been doing alot of research on alot of different aspects of cars and how they work, I've done research on everything from Engine braking to turbo chargers.

If I haven't researched it yet, I will have before I'm done.