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Hlspwn
26-05-2015, 22:57
Ok so I had a few hours play tonight, finally worked out what's been bugging me. Not sure if anyone else has noticed this, but there is a problem with how cars are braking.

As an example, I drive the Mc P1 down a start finish straight. Let's say I am doing 120 miles an hour. Stamp on the brake with no abs, tyres are locking a little, stopping fairly straight, sometimes a bit of a tug on the steering\squirrel as the car is slowing. Keeping pressure on the brakes just below 60-30 mph it's like one of the calipers has locked a rear wheel, and the car just spins like the hand brake has been yanked on. So I have tried this in a few other cars, and I keep getting the same issue.

This is totally unrealistic, if I can stomp on the brakes from a very high speed, and keep it in a straight line, why oh why does it do this weird handbrake skid at the end?

Azure coast, and California highway really suffer from this, and it's probably why I really have felt that these two courses have been not very playable or realistic.

Btw this is not a result of changing down and locking the rear, this happens if I just hit the brakes hard and leave the car in what ever gear it is in.

Does this affect others? Is it a bug in the physics?

Bounty
26-05-2015, 23:03
Not something I've tried myself and it might not be the issue but maybe try moving the brake balance forward?

TrevorAustin
26-05-2015, 23:03
Actually I have. CHanging the Brake balance will make it worse/better, however surely this should happen at high speed, not urban road speeds, even does it with ABs on. The whole emergency stop as a learner would be a bit of a disaster area if this happened outside, or are we missing something. I have never, in real life, seen a car swap ends like that at low speed, several times at high speed though.

dyr_gl
26-05-2015, 23:05
You´re supposed to brake strongly initially and start easing off towards the end. Cars have more downforce and grip at high speed.

If you are struggling with this, reduce brake pressure, move bias forward, tweak diff settings or change trail braking option.

eracerhead
26-05-2015, 23:05
The slower the speed, the greater the propensity of the brakes to lock. In the P1 the weight bias will be coming forward under braking. As the aero effect comes off the rear of the car, the downforce on the rear tires lessens causing instability.

If you want to compensate for this, you can put the brake bias back a bit, reduce your brake pressure a little as you slow or adjust the front dampers to prevent weight shift. And also watch your corner entry speeds.

edit: ^ninja'd

Hlspwn
26-05-2015, 23:13
I agree, about the cornering, and yes you should be lifting towards the end of braking but this was an extreme example in a straight line.

Yes weight transfer would lighten the back, but at 40mph in a p1, even with no abs, would the car spin over 90 deg. Some thing is not right.

Even if the brakes were locked the car would slide, most likely going straight on, not do its weird 90 deg turn?

Btw not just the p1

..AST..reaper
26-05-2015, 23:15
Would be better to title the thread "am I braking correctly". Answer=no, this isn't need for speed. A few bugs doesn't mean it's safe to assume that lack of understanding is the dev's fault also.

Physics are everything in understanding car behavior: horizontal load, lateral load, momentum, spring tension, acceleration, deceleration and on and on. That's what makes these games so much fun.

Hlspwn
26-05-2015, 23:18
You´re supposed to brake strongly initially and start easing off towards the end. Cars have more downforce and grip at high speed.

If you are struggling with this change trail braking option.

What does that do?

wraithsrike
26-05-2015, 23:21
The car has no weight pushing it's momentum once the forces decrease ( speed lowers) they fore if your still stamped on the brakes the wheels will lock, try easing off the brakes as your speed decreases.

As for the car sliding one way or the other, maybe one tyre or brake is hotter or colder than the other , at the end of the day this is not a bug it is however driver error.

Spirit X
26-05-2015, 23:25
I think it could be a bug. It only happened to me a couple of times but I think it's part of the non-loading setup issue.

Twice when I took my BAC Mono to Snetterton (invitational in career iirc) the game loaded a setup for a completely different car (no idea which). It took me a while to figure out what had happened but I finally realised when I saw that tuning options were available that don't even exist on the Mono like front wing. Anyway, when I was braking I experienced exactly what you describe. It would brake straight for a bit and then wham, like someone pulled the handbrake and instant spin out.

Personally I closed the game and rebooted to sort it out but sounds like you may have this happening persistently. That sucks.

Hlspwn
26-05-2015, 23:26
Answer=no, this isn't need for speed.

Physics are everything in understanding car behavior: horizontal load, lateral load, momentum, spring tension, acceleration, deceleration and on and on. That's what makes these games so much fun.

Lol no it's not NFS, and I am comparing this to Real world driving. I learnt to drive before many cars where standard with ABS, I will just drive around it in game for now.

I think I would be hard pushed in snow, to get a car to do that, unless it was on a gradient or steep camber. Weird?

ibby
26-05-2015, 23:28
A video with telemetry on would probably be helpful. ;)

wraithsrike
26-05-2015, 23:30
Lol no it's not NFS, and I am comparing this to Real world driving. I learnt to drive before many cars where standard with ABS, I will just drive around it in game for now.

I think I would be hard pushed in snow, to get a car to do that, unless it was on a gradient or steep camber. Weird?

Would you be driving a P1 or any other car 120mph in the snow? Trust me if you do it will lock up and slide and you won't be coming on here to tell us about it.

From what I can read from your posts what is happening ingame is 100 % correct and how it should be, give the developers some credit this is a sim.

JimStick1
27-05-2015, 00:03
Something to keep in mind is many of the default setups have the cars brake force set around 90%, sometimes even less. Set it to 100% and the tyres will lock under hard braking.

TrevorAustin
27-05-2015, 00:03
I think you're all missing the point. I absolutely certain if i stamped on the brakes of a p1 doing 40mph it would stop.
It's a standard part of the uk drivung test for learners! Do you think they teach them to gradually ease off the force doing a compulsory emergency stop.and before anybosy says thats onky only a focus or a ka, exactly, i would expect a p1 to perform considerably better. Now slamming your brakes on at high-speed, thsts different. But not what is being talked about.

..AST..reaper
27-05-2015, 00:38
It's not about stopping from 40 to 0. G force is significantly higher coming from 120-0. The car rolls forward to front suspension (horizontal load) under the massive transfer of weight, back lifts up, ergo significant oversteer and snap into corner. Stay in school kids.

..AST..reaper
27-05-2015, 00:40
Original post says he applies equal or increasing pressure as the car slows. Exactly opposite of what should be done. You might get away with that in some road cars with ABS but a P1 is on the razors edge already.

MULTIVITZ
27-05-2015, 01:00
Sounds like sidewall collapse to me, try inflating the tyres and maybe addding a bit of camber. I assume you checked the telem for front bumpstops touching. Bouncing off one would put you in a slide if your shocks are poorly dialed in! Jmtc

eracerhead
27-05-2015, 01:10
Even if the brakes were locked the car would slide, most likely going straight on, not do its weird 90 deg turn?

Trouble is, you're locking the fronts only and the rears are unweighted; they're going to come around. This is classic oversteer.

MarleyMoo
27-05-2015, 01:31
I think you're all missing the point. I absolutely certain if i stamped on the brakes of a p1 doing 40mph it would stop.
It's a standard part of the uk drivung test for learners! Do you think they teach them to gradually ease off the force doing a compulsory emergency stop.and before anybosy says thats onky only a focus or a ka, exactly, i would expect a p1 to perform considerably better. Now slamming your brakes on at high-speed, thsts different. But not what is being talked about.

No. You are missing the point. The point is this car has a wing pushing down on its butt. The wing gives more grip at the rear wheels so they don't slide at high speeds. When you slow down the wings don't work so you have to ease up on the brakes. The average UK learner doesn't drive a car with aero at speeds where aero works.

cerbrus2
27-05-2015, 01:36
I sort of agree with the OP in the fact that a P1 shouldn't be doing this at 40 miles an hour. I'm pretty sure if I go and stamp on the breaks of a p1 at 40mph it will stop dead. However I don't think the OP is thinking about this logically. It sound like you are breaking from 120 mph and its when it gets to around 40 mph that the car is spinning on you. That would make sense, wile the car will stop dead from 40mph. you are not breaking from 40 MPH you are breaking from 120 mph and the car is already unstable. all the cars weight has gone forward, the down force and mechanical grip has gone from the rear wheels and because you haven't let up on the breaks and reduced breaking pressure, the rear end has no where else to go but forward sending you into a spin, and it just so happens to be around 40 mph when the rear end decides to overtake the front. Some Pedal setups are horrid for break feeling. Especially as most pedals are on a progression switch, the further the pedal goes down the harder you break, and as you know from driving a bog standard car. when you break the pedal hardly moves at all, as it works off of pressure not travel. so sometimes its hard to judge. Stiffer pedal springs help, but they still work off travel and not pressure like they should. You can get conversions for some pedal manufacturers. but these are pricey and not worth it if you ask me. If you fined some cars like the P1 keep getting unstable on you. try Trail breaking instead. I fined i have to trail break most cars on Snetterton as you are coming straight off a bend onto a breaking zone, and its easy to loose it. give it a try.

TrevorAustin
27-05-2015, 09:15
No. You are missing the point. The point is this car has a wing pushing down on its butt. The wing gives more grip at the rear wheels so they don't slide at high speeds. When you slow down the wings don't work so you have to ease up on the brakes. The average UK learner doesn't drive a car with aero at speeds where aero works.

Not at 40 miles an hour it doesn't:)

Luke Townsend
27-05-2015, 10:09
Sounds to me like the rear wheels are locking as you've still got the brake pedal fully down. That's not what racing drivers do. It's only iRacing (I can't find any real-life graphs at the mo, but close enough for this), but see http://theansweris27.com/analysis-of-a-lap-around-brands-hatch-indy-pt-i/ - the 3rd graphic down shows the brake pedal (red line) goes on fully when the Z4 GT3 starts to brake, then he reduces brake pressure gradually as the car's speed reduces to the speed he wants to drive through the corner.

If it was faster to keep the brake pedal fully down till the corner speed then a racing driver would do that, but it isn't as the rear wheels would lock up. And if the wheels lock then all bets are off - if there is any camber in the road or any other car/external factor at all then the car is not going to stop in a straight line.

The reason the rears lock is that braking fully from 120mph puts a massive weight transfer on to the front "axle" - the back gets light. The rears lock and will come round. That's what you're seeing I think. And also why it doesn't happen if you are going at 40mph and THEN apply maximum braking - there isn't the same weight transfer at slow speed.

jimmyb_84
27-05-2015, 11:11
I also throw into the mix brake temperatures, a P1 has carbon/ceramic discs, were the brakes up to full temperature?

I also suspect the rears are locking up

..AST..reaper
27-05-2015, 12:35
And having carbon ceramic on my car I drive to work everyday, if I stomp on them as you describe, I would take out every car in the 4 lanes around me and end up in the wall on the highway. I've only used 20% of the CCB braking power even in aggressive driving.

wraithsrike
27-05-2015, 12:48
And having carbon ceramic on my car I drive to work everyday, if I stomp on them as you describe, I would take out every car in the 4 lanes around me and end up in the wall on the highway. I've only used 20% of the CCB braking power even in aggressive driving.

And you drive your car at constant high speed whilst being on and off the brakes hard in every day Road conditions do you?

You really are comparing apples and pears here.

DIXON76
27-05-2015, 12:49
Try riding the brake on lap 1 to get some heat into them. By that i mean 50 feet before your actual braking points press the brake while on the gas, i don't mean press the braking peddle all the way down, just do it enough so it causes friction.

Neil Bateman
27-05-2015, 12:58
Well all i can say is that i dont have this problem if my set up is right, that includes brake balance and pressure.

I also constantly move brake bias forward or backward during a lap depending on the braking and corner coming up, you cant have a fixed brake bias and expect the car to be balanced on all corners at all speeds.

Apoc112
27-05-2015, 13:07
It's been stated a bunch in this thread already, but I'm adding my +1 that OP is not modulating the brakes properly. As others have said, at low speeds, you lose downforce and it takes less brake pressure to cause the wheels to lock up. Several others have stated that the P1 wouldn't lock and spin in a straight line like this, but the real car also has ABS and half a hundred other computer systems keeping it in check. If you're driving in pcars with no assists, expect it to spin if you're on the clamps hard without some modulation or a little throttle compensation.

edit: you also state this is worse on tracks with some severe undulation... they're not as smooth as a race circuit, so it makes sense that a (basically) race-prepped car might have some issues unless you raise the ride height and soften up the springs and roll bars.

robertedell
27-05-2015, 13:13
Lol no it's not NFS, and I am comparing this to Real world driving. I learnt to drive before many cars where standard with ABS, I will just drive around it in game for now.



I learned to drive when most car did not have ABS and my earliest cars did not have ABS. If my cars did not brake fairly straight even when locked up I knew something was wrong and needed attention.

AB_Attack
27-05-2015, 13:19
Assuming it's not a bug, brake balance certainly sounds like the first thing to check on. And that is easy: drive fast forward, slam the brakes and observe if rear or front locks first (this is why a competent replay function matters (http://forum.projectcarsgame.com/showthread.php?27475-Better-replay-function-and-fuel-per-lap&p=939075#post939075)). Adjust as appropriate and try again. When both front and rear lock at the same time, you have good brake balance. Decreasing fuel load as you drive should make you expect moving brake balance backwards as the race progresses. Unless you pitstop for fuel. Then it depends....well, you get the idea.

wraithsrike
27-05-2015, 13:44
What amazes me is the amount of people that cry bug rather then look into there own short comings.

This is a racing simulation game the developers have really researched there stuff with the physics and to cry bug simply because you can't understand what is going or except others explanation as to what on is an insult to there work in my opinion.

Above is only my opinion but from many posts and threads on this forum it's clear a few really don't grasp what has gone into this game or even what style of game it is and if I'm honest think they know more than they really do, not a dig at anyone just my own view.

I know there are certainly issues but not everything you can't get your head around is a bug.

TrevorAustin
27-05-2015, 13:51
It's been stated a bunch in this thread already, but I'm adding my +1 that OP is not modulating the brakes properly. As others have said, at low speeds, you lose downforce and it takes less brake pressure to cause the wheels to lock up. Several others have stated that the P1 wouldn't lock and spin in a straight line like this, but the real car also has ABS and half a hundred other computer systems keeping it in check. If you're driving in pcars with no assists, expect it to spin if you're on the clamps hard without some modulation or a little throttle compensation.

edit: you also state this is worse on tracks with some severe undulation... they're not as smooth as a race circuit, so it makes sense that a (basically) race-prepped car might have some issues unless you raise the ride height and soften up the springs and roll bars.

While I agree with that, it also does it with ABS on, or I assume it's on. I drive with real assists, as this is a sim, and a good one, it should simulate all of that gadgety goodness too. Especially the fundamental stuff like not letting the rear lock up.

Edit: Actually I might be wrong about that, despite watching, and working in F1 for a million years- working a long time ago though - I didn't realise ABS had been banned. So that would explain my issues with the F1 car, and why I need better pedals, the TX brake pedal is utter shite, might as well map a switch on the wheel.

Luke Townsend
27-05-2015, 14:18
Edit: Actually I might be wrong about that, despite watching, and working in F1 for a million years- working a long time ago though - I didn't realise ABS had been banned. So that would explain my issues with the F1 car, and why I need better pedals, the TX brake pedal is utter shite, might as well map a switch on the wheel.

ABS was banned in F1 in 1993. Senna was driving then, as were Prost, Mansell, Brundle and the like. So yes you must have stopped working in F1 quite a while ago? :cool: The ban caused quite a furore at the time, I remember. The fact drivers rarely lock up without ABS in modern F1 shows how supremely talented they are, in my book (even Maldonado :D).

As well as ABS, the P1 has stability control. Maybe that was off. Unfortunately "real assists" doesn't show which aids are on and which are off - would be useful if the game did this. Try turning on all assists and pulling the same full-on braking in a line (preferably with a video in cockpit view with telemetry on) and we can see how it does. It should be pretty unspectacular if the game is right.

RomKnight
27-05-2015, 14:21
to see which are on/off switch to an external cam and turn the hud on. you should see the icons in the little motec display

TrevorAustin
27-05-2015, 14:26
ABS was banned in F1 in 1993. Senna was driving then, as were Prost, Mansell, Brundle and the like. So yes you must have stopped working in F1 quite a while ago? :cool: The ban caused quite a furore at the time, I remember. The fact drivers rarely lock up without ABS in modern F1 shows how supremely talented they are, in my book (even Maldonado :D).

As well as ABS, the P1 has stability control. Maybe that was off. Unfortunately "real assists" doesn't show which aids are on and which are off - would be useful if the game did this. Try turning on all assists and pulling the same full-on braking in a line (preferably with a video in cockpit view with telemetry on) and we can see how it does. It should be pretty unspectacular if the game is right.

I was working with Benetton (well actually Cosworth) 88-92 and we had it then:) now you mention it I do vaguely remember all the fuss after I had finished. And no I didn't do anything exciting, well it was exciting, but not race exciting:) just Cosworth IT stuff with the truck trailers.

But a Cosworth race engine in the old Northampton factory at full revs on a bench is a sound I will never forget!

And as regards them locking up, yes doesn't it! Genuinely quite incredible.

Luke Townsend
27-05-2015, 14:46
Superb, Trevor! :) Must have been really great days! :) Totally off-topic but the sound of F1 engines in those years was incredible. I saw F1 in the flesh a few times from the mid-80's to the early 90's. The speeds were crazy, but it's the sound I remember most still.

Howie
27-05-2015, 14:51
What happens to a Lamborghini Gallardo when you switch traction control off?
https://www.youtube.com/watch?v=I86mQZJWabU

TrevorAustin
27-05-2015, 14:57
Superb, Trevor! :) Must have been really great days! :) Totally off-topic but the sound of F1 engines in those years was incredible. I saw F1 in the flesh a few times from the mid-80's to the early 90's. The speeds were crazy, but it's the sound I remember most still.

The sound was incredible, I used every possible excuse to just stand and listen as close as possible. In my opinion of watching F1 for over 35 years the best days along with the mid 70s, of F1. Great personalities, loads of overtaking, and amazing sounds, absolutely amazing.

dyr_gl
27-05-2015, 15:07
What happens to a Lamborghini Gallardo when you switch traction control off?
https://www.youtube.com/watch?v=I86mQZJWabU

Really relevant and helpful in a thread about braking:rolleyes:

Luke Townsend
27-05-2015, 15:29
Well, I've just tried this for myself - P1 at Silverstone, 20 litres of fuel, cold tyres (can't be arsed to warm them up for each run, but cold tyres would make this worse wouldn't it).

3 tests - each time from 160mph to zero with brake pedal fully depressed for the entire deceleration. Each time driving in the centre of Hangar Straight. Here's what happens:

(using wheel+pedals. Steering assistance off and braking assistance off in all tests)

Test 1
ABS on
Stability on
Traction control on
Stops dead straight from 160mph, no lockup during braking

Test 2
ABS off
Stability on
Traction control on
Wheels lock during braking but stops almost straight - just a few feet to the side at the end

Test 3
ABS off
Stability off
Traction control off
Same result as test 2, i.e. wheels lock but ends up stopping almost dead straight.

Now, I am being very careful to keep the steering dead straight, and using a piece of track that is both flat and straight. Repeating test 3 with the steering turned just slightly, the rear end comes round and I end up in the kitty litter.

To me, all this seems exactly as expected. If I knew how to make a video I would, but anyone in any doubt please test it for yourselves.

madmax2069
27-05-2015, 15:51
Probably not the best video to use


https://www.youtube.com/watch?v=mKiTAcXK6M4

The one thing they dont show you is that if you apply the maximum amount of braking force in a car with ABS off without locking up the wheels it will usually stop in a shorter distance then a car with ABS on (the reason why is how ABS works). Ive seen ABS equipped cars still lock up.

MarleyMoo
27-05-2015, 17:32
Not at 40 miles an hour it doesn't:)

It's a fake problem.

Hlspwn
27-05-2015, 17:34
Not long finished work, managed to get a few sneaky peaks at the thread through out the day. Firstly thank you to everyone who has made constructive suggestions and criticisms lol, forums these days are a mine field.
Driving some cars and tracks has not felt right, from this I started experimenting, and witted down my gut feeling and observations to the weird problem I explained with the braking.
Let me clear a few things up as the assumptions seem to have got a little out of hand. I would not normally brake so hard, I am not some noob.
I understand about weight transfer, with all assists off I can understand that wheels can and will lock and a car can swap ends. But on a road car I would not expect individual wheels or both rears to lock without the front. There are so many variable's in braking its almost impossible to say what could or would not happen on my previous statement, so lets go off what's expected.

When I had this problem It felt so unrealistic I inherently said to my self that's not right.

Under testing on a straight I have had this happen under 50 mph in the p1, keeping the wheel dead straight with no other steering input. I can not believe that there would be enough load on the front to remove such traction on the rears, all the wheels should be in contact with the track at those speeds. To have the car spin how it does on a dry track can not be right, modern brakes are designed to distribute the braking force in road cars, normally if the brakes have locked they are all locked. Not only that with the grip from the tyres on the P1, its just not adding up.
So its very difficult to convey to all the forum readers what I am experiencing, i don't have any data for my self. All I can do is try and video it with the telemetry on.

Oh for all the trollers, the weekend car that I don't actually own, but I sometimes get to drive (IRL) has carbon ceramics, and on the very rare occasions that I put it in CST it does not spin 90 degs even if the brakes bite.

MarleyMoo
27-05-2015, 17:46
...But on a road car I would not expect individual wheels or both rears to lock without the front. There are so many variable's in braking its almost impossible to say what could or would not happen on my previous statement, so lets go off what's expected.

... modern brakes are designed to distribute the braking force in road cars, normally if the brakes have locked they are all locked.

Wrong expectation. Without ABS or some limited slip differential there's no reason wheels would all lock up at the same instant. Try putting brake bias fully front or rear, turn off ABS. The side overly biased will lock up first.

Luke Townsend
27-05-2015, 18:07
Under testing on a straight I have had this happen under 50 mph in the p1, keeping the wheel dead straight with no other steering input. I can not believe that there would be enough load on the front to remove such traction on the rears, all the wheels should be in contact with the track at those speeds. To have the car spin how it does on a dry track can not be right, modern brakes are designed to distribute the braking force in road cars, normally if the brakes have locked they are all locked. Not only that with the grip from the tyres on the P1, its just not adding up.
So its very difficult to convey to all the forum readers what I am experiencing, i don't have any data for my self. All I can do is try and video it with the telemetry on.

That is so strange! As I say in a post above, I tested this today at Silverstone with all assists off, stopping the P1 from 160mph to zero, brake fully depressed all the time. Default tuning of the P1. And it stopped in a straight line (wheels locking in the process but nowhere near a spin). Only when I tried it again while turning slightly did it get out of control and the back end came around. If I knew how to video it I would. Maybe difference between platform (I'm PC) or controller (I have a T300RS wheel and pedals)?

Where are you testing btw? Might even be the road surface/slope coming into play - it could be something very small.

Sparky28
27-05-2015, 18:22
i'm going to test this tomorrow because I don't believe this is a wrong in the game or b wrong to real life either

If you stopping from high speed the rear will always go light my first car an 2001 astra van used to do this infact I nearly lost it a few times with rear locking

Hlspwn
27-05-2015, 18:28
That is so strange! As I say in a post above, I tested this today at Silverstone with all assists off, stopping the P1 from 160mph to zero, brake fully depressed all the time. Default tuning of the P1. And it stopped in a straight line (wheels locking in the process but nowhere near a spin). Only when I tried it again while turning slightly did it get out of control and the back end came around. If I knew how to video it I would. Maybe difference between platform (I'm PC) or controller (I have a T300RS wheel and pedals)?

Where are you testing btw? Might even be the road surface/slope coming into play - it could be something very small.

Playing on a PC
Logitec G27, pedals, h shifter
Was doing it on all tracks
When I get on later I will get some specifics

Zeiss
27-05-2015, 20:34
One thing I've noticed is that the braking is considerably more effective (simplified?) than in Assetto Corsa. I found myself over braking in Pcars due to it. Whereas I would need to start braking at say the 150 meter board in AC, I can start at 100 meters in Pcars. Also, AC, R3E etc seem to lock up much more than in Pcars. I rarely get brake lock in Pcars with or without ABS. Having put so many hours in those two titles, Pcars just feels strange. Having not driven real race cars, not sure which is accurate.

Luke Townsend
27-05-2015, 21:20
Playing on a PC
Logitec G27, pedals, h shifter
Was doing it on all tracks
When I get on later I will get some specifics

Hmmm. Would have thought you would get similar behaviour to me then (Thrustmaster T300RS and pedals).

Luke Townsend
27-05-2015, 21:31
Well, I've now made a video of what happens when I turn off all assists (braking assist off, steering assist off, ABS off, stability control off, traction control off) and brake (brake pedal fully down) the P1 in a straight line from 160mph. P1 is on default tuning setup.


https://www.youtube.com/watch?v=lPko-4gF8us

That's Hangar Straight at Silverstone and it feels very flat and it's not on a slope.

Screenshot showing the option settings with all assists off:
204845

The P1 stops very straight with no driving assists when braking fully on a flat road while steering dead ahead.

Why the OP is getting different behaviour (car spinning once it gets down to around 30-60mph) I don't know. Maybe he could do a video with the telemetry on like here and we can look for differences (tiny steering input maybe - probably not but just as an example). BTW, my first YouTube video - anyone that hasn't done one before, I just downloaded FRAPS (www.fraps.com) today to make it and it's easy to use (F9 stop and start recording). The free version of FRAPS limits videos to 30 seconds I think, but enough for this.

CRU5557
27-05-2015, 22:08
https://www.youtube.com/watch?v=qar11y-8SOs Hard braking 0:20

Hlspwn
29-05-2015, 19:37
Hi guys, sorry only just picking this back up. I downloaded fraps too on Wednesday night, going forward think I will buy it.

Loaded Pcars went straight into free practice with the P1, picked the Bugatti track at random. Probably not the best selection as the start straight has some camber.
Observations were that I could not recreate what was happening the last time I played. Slamming on the brakes from 160 resulted in full lock up, in straight line. Further down the straight at various lower speeds that car and wheel tugged to the left about 30 deg.
Distinct difference from my previous experience. When the car was half spinning there was no ffb movement from the wheel, half spin was a lot faster as if hitting a patch of ice, or the handbrake being yanked on locking both rears. As it was late and I could not recreate what had happened before I did not bother doing a vid.
I have F9 on standby though, when I get on later tonight I will do another comparison at silverstone.
I will keep testing as there must be a trigger to this happening, what I did notice and I do not understand why? When I did the wheel calibration again, On the pedals only the clutch registered on screen. When fully depressing the brake and accelerator nothing came up on screen.
When I calibrated the pedals the previous time all three pedals showed. Could this be part of the problem? I also noticed that auto clutch had turned its self on, as previously I had it turned it off?
Also wanted to mention when this happened, I had tried lots of different cars and track combos?

Luke Townsend
29-05-2015, 21:09
Very interesting new findings! You're closing in on the issue I think. Be interesting what you get at Silverstone for a direct comparison - dead flat there as far as I can tell. It does begin to sound like some kind of controller issue, and calibration of the pedals should show all 3 pedals - it's curious how they work and yet do not display on the calibration screen.

Hlspwn
31-05-2015, 09:21
Friday night I end up doing quite a bit of career, coming second in my first kart championship, then been invited to lots of other races. Before I went to bed I ran a free practice at silverstone with the P1. Straight away the wheel movement did not match that of what was on screen.
So I quit the game, when I went back to the desktop there was a message saying that windows was low on system resources, did I want to disable windows aero.
Cancelled the messages reloaded the game through Logitech profiler as I always do, went back to silverstone with the p1, and everything was back to normal. On the same straight as your self same result, dead straight braking. Not really much lock up, no matter how hard I braked.
Back on the PC this morning I have checked the windows system and application logs, and there is nothing directly linking to project cars, or the low resources.

Luke Townsend
31-05-2015, 09:41
That's so strange!!! I have no idea what the problem with resources could be - although I do sometimes get those Aero messages too when I alt-tab between Project Cars and other tasks, and if I do it enough then Project Cars sometimes crashes (so I avoid Alt-Tab as much as I can now). But I guess it is good at least that when everything is working right you are getting correct braking behaviour.

I have thought about using one of those apps that stops everything else running when gaming, in order to get maximum performance, but so far not looked into them. Might be an idea possibly.

unknwn
31-05-2015, 09:50
Testing P1 braking. Assists off, Silverstone straight, default car setup, warm tires. Without ABS, rear locks up at around 100km/h if I don't decrease brake input. The car starts spinning like using handbrake. Which is exactly what I expect from a relatively high downforce car with too high rear brake bias (P1 has 52% brake bias which indicates - the rear will lock:)). This lock can be easily avoided by releasing brake input as the speed decreases or by adjusting brake bias or by using ABS. With ABS the rear becomes skittish instead of locking (which is expected when ABS gets activated). I vote for no bug, but expected behavior;)

Edit: with ~56% brake bias the rear doesn't lock up for me.

Roger Prynne
31-05-2015, 10:11
That's so strange!!! I have no idea what the problem with resources could be - although I do sometimes get those Aero messages too when I alt-tab between Project Cars and other tasks, and if I do it enough then Project Cars sometimes crashes (so I avoid Alt-Tab as much as I can now). But I guess it is good at least that when everything is working right you are getting correct braking behaviour.

I have thought about using one of those apps that stops everything else running when gaming, in order to get maximum performance, but so far not looked into them. Might be an idea possibly.

RAZER CORTEX: GAME BOOSTER (http://www.razerzone.com/gb-en/cortex/game-booster) is what you want.. I've always used it to close all the crap down (need it on my aging PC) and it's very configurable, never had any probs at all.

Luke Townsend
31-05-2015, 11:52
RAZER CORTEX: GAME BOOSTER (http://www.razerzone.com/gb-en/cortex/game-booster) is what you want.. I've always used it to close all the crap down (need it on my aging PC) and it's very configurable, never had any probs at all.

Many thanks! Sounds ideal.