Braking Differences in GT5 are Non-existent?

[Griffith500]

I'm guessing most players would get frustrated and / or confused by variable brake temperatures, so that might be another reason why it's not implemented (along with the fact that it's near impossible to actually work out the temperature characteristics of a given braking system on a specific car.)

I would be happy with a semi-generic system, that takes into account brake diameter, disk & pad material and brake fluid. Then there could be two brake upgrades - "competition" which works to mitigate fade on a stock car at near stock specs, and "racing" which allows the use of much higher braking powers for longer.
I suppose manufacturers might get pissy about these generalisations, though! Of course, you could model brake cooling based on an open-wheeler, such that cars will have similar fade properties assuming similar tyres, weight and disk size.

It really does open up a whole new world with brake temperature modeled. Cold brakes somehow seem to make driving on cold tyres that much easier, and the eventual advancing of braking points when pushing "too hard" adds a new dimension to balancing individual lap times and overall pace.

I'd like to see the brake balance controller "fixed", though. We need an overall power setting as well as a bias setting - or at least allow for more fine-grained adjustments in the lower power region in particular. It's not quite that simple in real life, but that's what it effectively boils down to.

 

[YamauchiSanFan]

you have to manually handicap some cars which has worse brakes IRL to replicated that difference, for example an american junker might have brake force of 3F/1R compare to a NSXR with 4F/2R.

It does kind of sucks they didn't have realistic figures for each car stock but what can you do.

I like this idea and tinkered with it. What I found is that for ever value of 1 you decrease from the default on both tires will result in about one car's length of braking differences when stopping from 100mph (i.e. going from a 5/5 to 4/4).

If you have the same braking force on every car, then all that really DOES matter is the rubber.

Weight plays just as much of a role.

I'm curious about how off this actually is. Now, obviously, this isn't accurate to real life, but it would be hard to determine why that is the case.
Is it because of a problem with the way brakes are modeled? Or is it because all cars in the game come with a (inaccurately set) brake balance controller? Or is it because all of the cars can be equipped with identical tire compounds?

All of the above, and to a very great extent, the weight of the cars. The weight of the cars does not seem to be taken into account at all for braking. I can understand them not modeling the differences in braking technology between the cars, but there could easily be a way to adjust braking behavior using weight as a major determinant in the brake modeling.

GT5's ABS acts like a stability control system because it's perfect. Older ABS systems will react slower, or will not be as sensitive to locking on the rear axle, or will have any number of other differences to GT5's ABS. The same as stability control.

It's interesting that you mention this because in an episode of Best Motoring they were showing how the NSX would dive into corners so much better than other cars when racing. However, when they did tests on the cars stopping to a complete stop, the NSX did poorly because the ABS was too aggressive at the slow speeds and wouldn't lock up hard enough to get the car to a complete stop. The NSX would go from 100mp to 50mph in a hearbeat, but kept rolling along from like 10mph to a standstill.

 

[Exorcet]

It's not surprising. Skidpad is more or less the same. You will always get the same g no matter the car, even if it's a van. The only exceptions being race cars and car with wings.

 

[BWX]

I like this idea and tinkered with it. What I found is that for ever value of 1 you decrease from the default on both tires will result in about one car's length of braking differences when stopping from 100mph (i.e. going from a 5/5 to 4/4).

You are leaving out a lot of variables, such as ABS setting on or off. If ABS on, then set to 1 or highest setting, somewhere in between? Then what about other aids in the game.. do they have any affect? That doesn't even cover brake pedal distance pushed (pressure) or if you're just slamming on brakes. If slamming brakes then you must be using ABS as ABS off requires modulation.

I always use no ABS- and I use very low brake balance setting such as 3f/1r because I have a G25 and that is the only way to adjust for a touchy brake pedal even though I modded the spring.

So basically, for instance- when setting brakes to 6f/2r the brakes will just lock up at the same pedal distance where setting them to 3f/2r will allow more room for modulation. The car won't stop any faster with higher settings with ABS OFF, it will just lock brakes sooner in the brake pedal travel.

With both low and high setting when fully depressing pedal, you get full braking power. You can still lock them up with ABS OFF and sett to 1r/0r, it just happens lower in the brake pedal travel.

It's more like a pedal travel linearity setting than overall brake power setting, so it doesn't affect stopping distance overall, but it would affect stopping distance if pedal were pushed partially down exactly the same distance for each test. That is with ABS OFF mind you. It would be difficult to prove this with video, but try it yourself.

 

[shirakawaa]

With ABS off in order to lock tires at a given brake level threshold (for example 75%) in some cars you actually need to increase the brake power setting. Also there are differences between different cars: I find that older ones need a higher setting than modern sports cars (for example the premium Honda NSX 2nd gen street version) on sports tires to lock their tires.

I usually use something like 4/1 or 5/2 too.

 

[Tornado]

All of the above, and to a very great extent, the weight of the cars. The weight of the cars does not seem to be taken into account at all for braking.

That is because, for the most part, weight has almost nothing to do with braking distance.

 

[RacingManiac]

That is because, for the most part, weight has almost nothing to do with braking distance.

Is that because its braking power and traction governed? I guess weight will only enter into account when the wheels locked up and the car started sliding?

 

[Tornado]

That is exactly right. The braking system is only as powerful as the weakest link, and the overwhelming majority of the time the weakest link is the tires. The link Scaff gave a few posts ago goes to a topic where this is all discussed in great detail.

 

[Scaff]

Weight plays just as much of a role.

No it doesn't.

All of the above, and to a very great extent, the weight of the cars. The weight of the cars does not seem to be taken into account at all for braking. I can understand them not modeling the differences in braking technology between the cars, but there could easily be a way to adjust braking behavior using weight as a major determinant in the brake modeling.

No its not.

A cars weight is actually a relatively minor factor when determining stopping distances. How that weight is distributed and transferred under deceleration are both more important than the weight itself.

However both of these are far less of a factor than the road/tyre interface.

This has all been covered in numerous threads before and the physics of it both clear and proven.

Here the easiest one to start with...

http://www.stoptech.com/tech_info/wp_brakebiasandperformance.shtml


...oh and don't triple post, use the edit button and/or multi-quote.


Scaff

 

[Destinkeys]

I get it... a 3 ton dumpster traveling at 150 mph comes to a complete stop just as quick as an 970lb F1 car. On the same tires, that is!

Yeah, right.

 

[Kerch]

I get it... a 3 ton dumpster traveling at 150 mph comes to a complete stop just as quick as an 970lb F1 car. On the same tires, that is!

Yeah, right.

It's true, according to high school physics at least.

 

[Tornado]

I get it... a 3 ton dumpster traveling at 150 mph comes to a complete stop just as quick as an 970lb F1 car. On the same tires, that is!

Yeah, right.

Yes, actually.

 

[RacingManiac]

I get it... a 3 ton dumpster traveling at 150 mph comes to a complete stop just as quick as an 970lb F1 car. On the same tires, that is!

Yeah, right.

Its not that straight forward, but the concept is generally true. Most cars will have enough braking power in their braking system to far exceeds the forces needed to stop the car at speed its capable of going. The tires they used also should be able to support that. If both cars' braking system is rated to their respective weight level, and both have tires that are equally capable, then the tire capacity should be the limit of the braking ability, and weight should not factor. Downforce wrecks that concept a bit since by adding normal force on the tires you are actually increasing the grip, which is a big factor why F1 cars can slow down so dramatically at speed.....

 

[Scaff]

I get it... a 3 ton dumpster traveling at 150 mph comes to a complete stop just as quick as an 970lb F1 car. On the same tires, that is!

Yeah, right.

Did you actually bother to read anything I posted or were you just aiming for smart-arse?

At what point did anyone say that weight was not a factor? Or that cars of differing weights would stop in identical distances?

The answer to both is no-one.

Weight and weight transfer are both second order factors in the calculation of stopping distances, as such while they play a role it is a very secondary one to the frictional co-efficient generated by the tyre road interface (however weight or rather load to be accurate, is a factor in this).

If you want a nice example of the two take a look at the stopping distances for a 5,600lb Range Rover Sport and a 2,000lb Elise.

Range Rover Sport
30-0 mph (ft.) 28.24
60-0 mph (ft.) 115.63

Lotus Elise
30-0 mph (ft.) 27
60-0 mph (ft.) 110

Hmmmm a difference of 1.24 feet from 30mph and 5.63 feet from 60mph, more than enough to be accounted for by environmental and driver differences and certainly not a million miles away from each other at all, despite the Range Rover weighing over 3 times that of the Elise.

Maybe their might be something in this tyre/road thing after all.

It's true, according to high school physics at least.

Here's the physics for you, high school and not.
Easy - http://www.stoptech.com/tech_info/The Physics of Braking Systems.pdf
Not - http://phors.locost7.info/phors21.htm


Scaff

 

[lucag120]

I did a test at monza, stopping from 250km/h.

I used the cars available in arcade mode.

Most road cars stopped about the same, and then the Super GT nissan gtr stopped way shorter because of the aerodynamics.

I then used my f10, and it stopped VERY short.

All cars had Front:6 Rear:6, and ABS=1

So stopping distances are dependant mainly on aerodynamics in GT5.

If the brake controller is set at the same for road cars in gt5; then they will stop at a similar distance because they dont have aerodynamic parts on them.

This is because the brake controller gives the force the brakes applied to the tyres, and the tyres to the road. The weight of the car does not affect the stopping distance that much if all else is equal.

 

[Griffith500]

Did you actually bother to read anything I posted or were you just aiming for smart-arse?

At what point did anyone say that weight was not a factor? Or that cars of differing weights would stop in identical distances?

The answer to both is no-one.

Weight and weight transfer are both second order factors in the calculation of stopping distances, as such while they play a role it is a very secondary one to the frictional co-efficient generated by the tyre road interface (however weight or rather load to be accurate, is a factor in this).

If you want a nice example of the two take a look at the stopping distances for a 5,600lb Range Rover Sport and a 2,000lb Elise.

Range Rover Sport
30-0 mph (ft.) 28.24
60-0 mph (ft.) 115.63

Lotus Elise
30-0 mph (ft.) 27
60-0 mph (ft.) 110

Hmmmm a difference of 1.24 feet from 30mph and 5.63 feet from 60mph, more than enough to be accounted for by environmental and driver differences and certainly not a million miles away from each other at all, despite the Range Rover weighing over 3 times that of the Elise.

Maybe their might be something in this tyre/road thing after all.


Here's the physics for you, high school and not.
Easy - http://www.stoptech.com/tech_info/The Physics of Braking Systems.pdf
Not - http://phors.locost7.info/phors21.htm


Scaff

Where it will get interesting in the example between the Range Rover and the Elise is for repeated stops, one after another. Whichever vehicle has the most over-spec'd brakes, and / or the best cooling will be the victor!

By the way, the Physics of Racing Series is a great read, you don't actually have to follow the maths to appreciate it, either. 👍
The important lesson is that a given tyre can give a maximum deceleration that is more or less constant when expressed in terms of g, or g-force (technically an acceleration, not a force) irrespective of load, assuming the tyre can physically sustain that load. That's why weight is "inconsequential" for stopping distances.

I wonder if sticking the Elise's brakes on the Range Rover would allow it to stop as fast the first time. I.e., would fade creep in on the first stop...

 

[YamauchiSanFan]

Did you actually bother to read anything I posted or were you just aiming for smart-arse?

Scaff

I don't know the theory of braking physics at all, but all I have to do is drive my car. If I'm by myself and panic stop the car stops a lot faster than when I have four other people in it. Weight reduction kits increase braking distances significantly as well from what I've seen. I think the point of the poster countering you, along with myself, is that your commentary comes off as trivializing the issue of total weight on a vehicle in determining its stopping distance. Also, I must point out that for a "super moderator" you are coming off as quite belligerent. Not too cool.

 

[Scaff]

I don't know the theory of braking physics at all, but all I have to do is drive my car. If I'm by myself and panic stop the car stops a lot faster than when I have four other people in it. Weight reduction kits increase braking distances significantly as well from what I've seen.

I do know the theory of braking physics, I've taught it in the motor industry, in addition to which I have also carried out numerous testing sessions during product launch sessions on the actual numbers involved.

Your anecdotal reference misses out so many other factors, such as temperature, road surface, tyre condition, etc. All of which can and will significantly effect stopping distances.

I think the point of the poster countering you, along with myself, is that your commentary comes off as trivializing the issue of total weight on a vehicle in determining its stopping distance.

It may seem as if I am 'trivializing' the area of weight in regard to stopping distances from your point of view, however I am simply putting it in the correct order of things. A vehicles total weight is a secondary factor is determining stopping distances, weight transfer itself is more important and both are 'trivial' (your term) when compared to the importance of the road/tyre interface.

It may not ring true to you, but that doesn't change the fact that it is true. As the physics and sources I have cited quite clearly show.

Now I'm quite willing (and able) to go into detail to explain exactly why this is the case, if people are actually willing to not dismiss it out of hand (and incorrectly).

This falls into the same fallacy that bigger brakes stop you quicker. As long as the braking system is currently up to the task, then the single biggest factor in determining stopping distances is the tyre to road interface.



Scaff

 

[Ubiquitous]

At some stages you just have to suspend disbelief in a game or sim because you will never get things perfect.

I would like braking to be better in GT5 certainly, but we can't have everything on a console and certainly not with this amount of cars.

It will evolve and improve over time though.

 

[niky]

I don't know the theory of braking physics at all, but all I have to do is drive my car. If I'm by myself and panic stop the car stops a lot faster than when I have four other people in it. Weight reduction kits increase braking distances significantly as well from what I've seen. I think the point of the poster countering you, along with myself, is that your commentary comes off as trivializing the issue of total weight on a vehicle in determining its stopping distance. Also, I must point out that for a "super moderator" you are coming off as quite belligerent. Not too cool.

He wasn't talking to you. He'd just posted a wall-of-text as well as some excellent links to braking articles, and someone else interjected with the dump truck example.

But yes, the difference is trivial compared to other factors. The big problem with a fully loaded car and braking is that many vehicles don't have electronic brake force distribution, which adjusts brake balance for load... though the rear brakes will not always be powerful enough to account for the extra load even with EBD.

The problem with braking on a dump truck is actually getting brakes powerful enough to lock the tires.

Oh... and finding race-compound tires in dump truck sizes.

 

[YamauchiSanFan]

He wasn't talking to you. He'd just posted a wall-of-text as well as some excellent links to braking articles, and someone else interjected with the dump truck example.

So he wasn't talking to me, does that mean I can't respond to him? I started the thread and I'm participating in a discussion. First you have him getting his back up and getting belligerent, and now you are telling me what I should or shouldn't be responding to. Remember, you both are moderating, not dictating, or am I wrong about this?

At some stages you just have to suspend disbelief in a game or sim because you will never get things perfect.

I would like braking to be better in GT5 certainly, but we can't have everything on a console and certainly not with this amount of cars.

It will evolve and improve over time though.

Oh yeah, I hear you on that. What happens with me personally is a lot of times I get so into the simulation aspect of the game that I take it too far. As a whole the game is so incredible and so much fun, and to be honest, is a lot more fun when you keep a more reasonable attitude about the game like you are suggesting. But we all get selfish and hope someone from PD will read our post and put a fix into the next update...LOL! :-)

 

[HuskyGT]

What I do is modify the braking strenght on each car to "match" the braking power it would have in real life. Another thing is to turn off the ABS on cars that don´t have it in real life. I take in consideration Brake size, Disc Brakes vs Drum Brakes, size and weight, and as I said, ABS vs non ABS. Its alot of work, but alot of fun. You can notice that all my cars brake in a different way. The only thing that would be cool is that we had brake fade.

 

[Scaff]

So he wasn't talking to me, does that mean I can't respond to him? I started the thread and I'm participating in a discussion.

Of course you can respond, however others do not need you to defend them should they have an issue with the manner in which I post. Which for the record is not belligerent at all.

I posted correct information on how the actual physics of braking operates, with sourced and referenced links. It was greeted with a reply that can be summarized as "Yeah, right", which prompted the very valid question on my part asking if the poster had read my posts or was simply attempting to get a rise.

I never called anyone anything, got my 'back-up' or was belligerent. I asked a question, that you have miss-interpreted that on behalf of someone else is not really my issue.

First you have him getting his back up and getting belligerent, and now you are telling me what I should or shouldn't be responding to. Remember, you both are moderating, not dictating, or am I wrong about this?

You seem to have a massive issue with moderation staff, as you were not told you could or couldn't do anything, Niky pointed out that my reply was not to you, that is all.

I would also strongly recommend that you take a little less time telling the staff what you think our job is and a little more on your own posting content.

Starting with an end to the double posts, I had to merge a number of yours yesterday. I hoped that the edit comment would have made it clear that double posting is not acceptable here, it would seem that I have to be a bit more clear on the matter.

In future either use the multi-quote option and/or the edit button, don't post comment after comment in the same thread.

Now please get back on topic and either provide some support to your contention that weight is a significant factor in determining stopping distances or discuss the information that has been provided.


Scaff

 

[niky]

So he wasn't talking to me, does that mean I can't respond to him? I started the thread and I'm participating in a discussion. First you have him getting his back up and getting belligerent, and now you are telling me what I should or shouldn't be responding to. Remember, you both are moderating, not dictating, or am I wrong about this?

I wasn't telling you you couldn't respond to Scaff. Sorry for the confusion. I was just noting that his post regarding smart-arseness was directed at a guy who seemingly ignored everything else posted thus far. He then went on to explain about weight in a matter-of-fact tone to the same guy.

You can indeed participate fully in the discussion, it's your thread. Let's carry on.

 

[BWX]

Properly implemented brake fade would solve most of GT5's braking "problems".... Maybe for GT6??

 

[Kevin****Theory]

Their's no such thing about braking point or where to brake!, it's all about the feel, you need to feel your wheels.

 

[BWX]

Their's no such thing about braking point, it's all about the feel, you need to feel your wheels.

There's no such thing about braking point? What does that even mean?

 

[StogyBear]

Weight has everything to do with braking. If a 4000 pound car and a 1000 pound car have the same tires and brakes relative to each car, the 1000 pound car will stop way quicker than the other, because those tires have 4 times the weight to stop.

Also the lotus and range rover example does not prove anything. Both cars aren't on the same tries. The Range's tires are 275 in width where as the lotus is a tiny 195.

 

[Tornado]

Weight has everything to do with braking. If a 4000 pound car and a 1000 pound car have the same tires and brakes relative to each car, the 1000 pound car will stop way quicker than the other, because those tires have 4 times the weight to stop.

Also the lotus and range rover example does not prove anything.

You see, this confuses me. You clearly have read what other people have written, so it isn't a case of you read the OP and then just responded to that. And yet you still decided to act needlessly (and incorrectly) dismissive when the facts are shown to you anyways.

Both cars aren't on the same tries. The Range's tires are 275 in width where as the lotus is a tiny 195.

Yeah. And the Land Rover likely doesn't handle weight transfer as well, being a 6 foot tall SUV compared to the 3 and a half foot tall sports car (particularly when the comments outright say "Noticeable front end dive" for the Land Rover). And the soft-roading 4X4 SportContact tires definitely don't provide as much grip as the Lotus' warm, dry road only ADVAN Neova AD07s. There is more to this than "OMIGOD THE TIRES ARE WIDER TEST INVALID," but weight isn't that deciding factor.

 

[Scaff]

Weight has everything to do with braking. If a 4000 pound car and a 1000 pound car have the same tires and brakes relative to each car, the 1000 pound car will stop way quicker than the other, because those tires have 4 times the weight to stop.

The tyres also have four times the load on them, increasing the grip they have available to them (an increase that is not linear and does however drop off).

That aside the tyres do not have to 'stop' four times the weight, the discs and rotor have to counteract that weight, and that is quite a different matter.

The phsyics involved in this has been posted many times now yet you have clearly either not read it or not understood it. That however does not change the fact (and it is one) that weight is not a critical factor in stopping distances and that how that weight is transferred and the tyres are both far more of a factor.

Weight and its transfer are critical factors in specing and setting up the brakes (particularly bias), that however is not the subject in question here and both these factors simply allow you to maximise the grip provided by the tyres.

Also the lotus and range rover example does not prove anything. Both cars aren't on the same tries. The Range's tires are 275 in width where as the lotus is a tiny 195.

Yes it does, it proves that with braking systems that are up to the job (and both are - something I know from personal experience), a heavier car on tyres with less grip can still stop almost as quickly as a track-biased car of light weight with better rubber.

The two factors at play here - the tyres and the weight transfer, the actual weight itself is a second order factor (by quite a margin).

You would also do well to read exactly what has been written on this subject, as no one has said that weight is not a factor, simply that it is not as big a factor as how the weight is transfered and far less of a factor that the rubber itself.


Scaff