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Spirit X
23-05-2015, 16:33
Limited Slip Acceleration Lock
So the onscreen help for Limited Slip Acceleration Lock says 'High settings here give the car better traction coming out of corners but limit your ability to turn.'

Now I've been reading various guides and watching vids to teach myself setups (which is actually proving to be really bloody confusing and contradictary a lot of the time) and this morning I spent a couple of hours playing with the LSA, the result of which was rather unexpected. In short, the opposite of the onscreen help quoted above seems to be true. When setting the LSA very high (say around 95%) I found that coming out of slow corners was really hairy and I had to be very respectful to the throttle in order to ensure I didn't spin it. However, when I then took the LSA down very low, I found that those same corners were much more forgiving on exit and I could be pretty aggresive with the power and get away with it. This was tested with the RUF CTR 3 by the way, in case that's relevant.

Can someone please explain in reasonably plain English why it seems to be backwards like this? There's clearly something I don't understand about how it works and until I do, I'm going to really struggle to understand how to apply it properly to my setups.

Limited Slip Preload
This one seems more straightforward but I just want to clarify: when I release the brake just before I turn in, it's during that turn in phase when I haven't applied the throttle yet that the LSP determines how the car behaves (along with the front slow rebound and the rear slow bump as the weight shifts off the front of the car)?

As always, thanks for any wisdom. You're a good bunch :D

yusupov
23-05-2015, 16:37
im not a setup guy at all & i have also heard "be sure to [raise/lower] LSD to loosen up the cars"...usually lower, & thats what ive been doing, but i do remember one person who was sure they should be raised.

Machinist90
23-05-2015, 16:39
I raised the LSD to tame the Lotus 98T a bit...haven't tried a low setting but high seemed to have helped with me..I'll go try the low to see what that gives

EDIT:well I'll be damned,seems you're right,lower does feel more forgiving,thanks mate!

Umer Ahmad
23-05-2015, 16:39
Voila

http://forum.projectcarsgame.com/showthread.php?25676-Easy-Differential-Tuning-(reduce-spinouts)

yusupov
23-05-2015, 16:42
so if you want a squirrelier car you raise acceleration diff?

Spirit X
23-05-2015, 16:42
Exactly Umer, that first post states the exact opposite of the in-game help text. So which is it?

t0daY
23-05-2015, 16:45
Im not sure, but I read somewhere that there is a mistake on the onscreen help. Ive experienced the same problem with the z4 gt3.

The sentence would be make more sense this way: (Low settings here give the car better traction coming out of corners but limit your ability to turn)

I think they interchanged something on LSA and LSP, but I am not quite sure^^

Spirit X
23-05-2015, 16:46
Im not sure, but I read somewhere that there is a mistake on the onscreen help. Ive experienced the same problem with the z4 gt3.

The sentence would be make more sense this way: (Low settings here give the car better traction coming out of corners but limit your ability to turn)

I think they interchanged something on LSA and LSP, but I am not quite sure^^

That would certainly explain it if that were the case.

t0daY
23-05-2015, 16:47
That would certainly explain it if that were the case.

It is a big IF :D

Machinist90
23-05-2015, 16:53
whatever the case this post totally changed my experience with the Lotus 98 T,cheers :glee:

Spirit X
23-05-2015, 16:57
whatever the case this post totally changed my experience with the Lotus 98 T,cheers :glee:

This (http://forum.projectcarsgame.com/showthread.php?26764-Best-tuning-setup-for-Lotus-98T-Renault-Turbo-(post-cars-you-want-me-to-tune)) will totally change your experience with the Lotus 98T (if you haven't seen it already).

Machinist90
23-05-2015, 16:59
This (http://forum.projectcarsgame.com/showthread.php?26764-Best-tuning-setup-for-Lotus-98T-Renault-Turbo-(post-cars-you-want-me-to-tune)) will totally change your experience with the Lotus 98T (if you haven't seen it already).

tried that but felt a bit twitchy,i'll try that setup with my own LSD settings to see how that feels,thanks for the suggestion

Sp4mD4gger
23-05-2015, 17:02
To go around a corner the outside wheel has to travel further than the inside wheel, that's why we need the differential.
If you lock the diff accel to 100 it will force the inside wheel and outside wheel to rotate at the same speed, therefore the back will slide out (oversteer).
This can be balanced on the throttle but is not advised to have 100 setting in a race car. This will also destroy your tyres.
There is no perfect setting, each person drives different, car is different, corners are different, experimentation is the only answer.
Experience will give you a ball park figure, eventually.

yusupov
23-05-2015, 17:05
tried that but felt a bit twitchy,i'll try that setup with my own LSD settings to see how that feels,thanks for the suggestion

if you look he has accel at 100%, according to this thread 0% (or at least much lower) is a better idea

Spirit X
23-05-2015, 17:08
To go around a corner the outside wheel has to travel further than the inside wheel, that's why we need the differential.
If you lock the diff accel to 100 it will force the inside wheel and outside wheel to rotate at the same speed, therefore the back will slide out (oversteer).
This can be balanced on the throttle but is not advised to have 100 setting in a race car. This will also destroy your tyres.
There is no perfect setting, each person drives different, car is different, corners are different, experimentation is the only answer.
Experience will give you a ball park figure, eventually.

Wow, what a great, succint explanation. Thank you.

So the LSA % is telling it how much 'wheel matching' to do and depending on how you drive, you might want a lot or you might want a little. Now I think I understand why I don't notice much difference between high and low settings unless I'm really aggressive with the throttle.

yusupov
23-05-2015, 17:11
its a very good explanation but if you lack any common sense like myself youll still be just as confused

does having the wheels match mean faster acceleration out of corners?

Spirit X
23-05-2015, 17:16
its a very good explanation but if you lack any common sense like myself youll still be just as confused

does having the wheels match mean faster acceleration out of corners?

No. As SP4M said, if they match exactly you're going to lose grip because the left and right wheels travel different distances as you corner, so they need to spin at different rates. You need to experiement with the setting, I don't think there's a golden answer.

Machinist90
23-05-2015, 17:27
if you look he has accel at 100%, according to this thread 0% (or at least much lower) is a better idea

I tested it and indeed much much better with 0%,100% felt sluggish and spinouts weren't rare,more loss of power coming out of the turn as well with the wheelspin

mister dog
23-05-2015, 18:42
So we can conclude the onscreen help is confusing then? It says high settings improve traction whilst you actually have to put the slider down towards 0% to reduce oversteer out of corners due to acceleration.

Spirit X
23-05-2015, 19:49
It is confusing yes but your synopsis is not correct. It's possible that what you said will sometimes be true but by no means is it a rule of thumb. Depends on the car in question and how heavy your right foot is.

choupolo
23-05-2015, 22:39
I have found 0% to be much more stable accelerating out of corners - for whatever reason! Default/mid settings left me needing to be very cautious with my right foot (finger)!

My favourite settings so far:

LS Accel: 10 I want to see how high I can go on this without inducing power oversteer.
LS Decel: 50 I find lowering this too much leads to the back end stepping out while trail braking.
LS Preload: 120 Again lowering this too much leads to the back end stepping out in fast neutral balance corners.

I think the in-game comments on the LSD are half right, but on some cars having the diff lock too aggressively means the inside wheel (locked with the outside wheel) over-rotates, reducing rear grip and giving power oversteer.

Having a fully open diff allows the inside wheel to rotate independently and allows an easier corner exit on the power, but I do notice on 0% that you get some swinging engine revs getting back on full power too early.

Spirit X
24-05-2015, 03:00
I'm sure no expert on this yet but the few hours testing I've done has lead me to realise something important: judge your setting by the lap times, not the feel of the car.

I was sticking with zero too because I preferred the feel of it but then I decided to give the LSD some proper investigation. I was going from 90% acceleration lock down towards 0% in steps of 10% and each step it felt a little more spongey and each step I ran another half second faster until I hit the right spot for the car I was using! Once the rear starts to feel a bit loose, you're not necessarily losing time. Give it a try.

Umer Ahmad
24-05-2015, 03:11
so if you want a squirrelier car you raise acceleration diff?
Yes. That will make it squirrelier on the EXITS

Umer Ahmad
24-05-2015, 03:11
so if you want a squirrelier car you raise acceleration diff?
Yes. That will make it squirrelier on the EXITS

DreamWeaver
24-05-2015, 13:57
The way I think LSD works, is that higher (100%) gives faster acceleration at the expense of a car that is harder to control during acceleration (hence better traction).
The opposite with lower LSD is that the car is easier to control but ultimately slower (hence less traction).

What that means in praxis, high LSD tends to brake the rear away without tyres fully spinning. Can come quite sudden without any warning.
While low LSD gives spinning tyres even before the rear brakes away and is easier to handle.

Sp4mD4gger
24-05-2015, 14:56
The way I think LSD works, is that higher (100%) gives faster acceleration at the expense of a car that is harder to control during acceleration (hence better traction).
The opposite with lower LSD is that the car is easier to control but ultimately slower (hence less traction).

What that means in praxis, high LSD tends to brake the rear away without tyres fully spinning. Can come quite sudden without any warning.
While low LSD gives spinning tyres even before the rear brakes away and is easier to handle.
Your first paragraph, appears to be in reverse. So let me illustrate.
A low LSD setting will help you get around the corner, and the car may feel "spongy", it will not help your launch out if the corner, for that the LSD has to be higher, so find a setting that gives a little slip, and balance with throttle.
Anbody who watches Top Gear will never see the Stig deliberately let his tail slide in a corner, unless it's to correct understeer.
Old saying"Fast is loose".

JeyD02
24-05-2015, 15:14
It all depends. It's true that having higher LSA will increase traction but at the same time it'll create more torque power. So let's say that with a acceleration lock of 50% you'll need to depress the gas 30°for its maximum turning turn 5 of track a (let's imagine for the sake of this argument) without spinning out. However with a acceleration lock of 100% youll need 15° of depressed gas so it'll give 100 of maximum corning potential to turn 5 for track a. Notice how you have to consider that having more LSA you need to adjust your throttle control because you have more power(torque) on hand so that say you Def need to be gentle or less aggressive. *a bonus effect= it decrease the steering radius.

Meanwhile if you have the steering more straight the car will launch with much more propulsion and traction whole having a higher LSA and it won't snap spinning out.

DreamWeaver
24-05-2015, 17:58
Well, my experience in pcars boils down to

- LSD low, car is easier to handle at the expense of acceleration.
- LSD high, car accelerates faster (if handled appropriately) but needs more delicate input.

Sp4mD4gger
24-05-2015, 18:38
Well, my experience in pcars boils down to

- LSD low, car is easier to handle at the expense of acceleration.
- LSD high, car accelerates faster (if handled appropriately) but needs more delicate input.

Now you changed your original statement,do what you want, I'm done.

DreamWeaver
24-05-2015, 21:15
Hmm, did I?
To be honest, I don't see the contradiction.

:confused:

Rift Racer
25-05-2015, 00:41
I always found these explanations felt correct when adjusting....

204353



(*Stolen from Another Car game)

So, for example, I like cars to turn in instantly and oversteer a lot, so I generally up the accel and drop the decel...

Go out in the BAC Mono for example and try to do donuts on the spot, the accel diff won't allow it at default settings, you get about halfway round then the diff messes it up for you lol. Coming out of fast bends at full throttle it's like you've got traction control on, you can actually hear the engine change as the diff helps you out of the corner without spinning.

yusupov
25-05-2015, 00:48
thx greengo, reading that combined w/ the info in the thread i feel like i finally have a slight understanding of this

MULTIVITZ
25-05-2015, 00:48
The LSD is a vital part of a race cars performance. Not only does it lock the wheels together, forming a sturdy platform to work from, it has to work in unison with other components.
Having the preload set right insures it engages at the desired time/load/engine torque on and off throttle. The percentage determines the ferocity of engagement that the preload has thus ajusting the slip. Adjustment increase in either accel or decel will tighten the effect of the other slightly. Not all diffs are the same, even ones that operate the same! if a car has good grip it can run a heavy diff, but just be aware the cars anti lift and anti squat characters can be infienced heavily through diff settings.
Getting the diff set right is the crowning glory of a setup and often makes or brakes a cars driverbility. The diff keeps the inside wheel turning and the outside one to, depending on its load and dynamic camber, either wheel can influence the cars thrust angle though its tyres slip angle. Examlpe: car needs high rear rebound and consequently the inside rear wheel gets lifted in low speed hard turns. The influence that tyre has on slip is deminished so any toe given to the rear will effect the slip angle of the outer wheel and its eventual direction. Rear toe in helps steady the sway reducing the rear slip angle, applied to positive camber angled rear wheel setup(or a favourable dynamic camber from the inner wheel) it can cause the opposite slip effect under throttle, giving an increase in slip angle leading to oversteer. This is useful for tight turns(and any speed turns!) in wide rear wheeled cars with a correctly set diff. Toe is dynamic on most chassis as cornering load alters and axle position changes, setting toe influences the amount the chassis gives to its wheels.
Too much diff gives oversteer or torque steer (the body shell twists about the axle!!) Too little lets the wheels break away early on acceleration. Deceleration setup techniques are broad and complex for me to go into tonight maybe another night. Thanks for reading, I hope it helps.

MULTIVITZ
25-05-2015, 01:20
Sorry, you said talk about it a bit....:rolleyes:

Sp4mD4gger
26-05-2015, 02:25
The LSD is a vital part of a race cars performance. Not only does it lock the wheels together, forming a sturdy platform to work from, it has to work in unison with other components.
Having the preload set right insures it engages at the desired time/load/engine torque on and off throttle. The percentage determines the ferocity of engagement that the preload has thus ajusting the slip. Adjustment increase in either accel or decel will tighten the effect of the other slightly. Not all diffs are the same, even ones that operate the same! if a car has good grip it can run a heavy diff, but just be aware the cars anti lift and anti squat characters can be infienced heavily through diff settings.
Getting the diff set right is the crowning glory of a setup and often makes or brakes a cars driverbility. The diff keeps the inside wheel turning and the outside one to, depending on its load and dynamic camber, either wheel can influence the cars thrust angle though its tyres slip angle. Examlpe: car needs high rear rebound and consequently the inside rear wheel gets lifted in low speed hard turns. The influence that tyre has on slip is deminished so any toe given to the rear will effect the slip angle of the outer wheel and its eventual direction. Rear toe in helps steady the sway reducing the rear slip angle, applied to positive camber angled rear wheel setup(or a favourable dynamic camber from the inner wheel) it can cause the opposite slip effect under throttle, giving an increase in slip angle leading to oversteer. This is useful for tight turns(and any speed turns!) in wide rear wheeled cars with a correctly set diff. Toe is dynamic on most chassis as cornering load alters and axle position changes, setting toe influences the amount the chassis gives to its wheels.
Too much diff gives oversteer or torque steer (the body shell twists about the axle!!) Too little lets the wheels break away early on acceleration. Deceleration setup techniques are broad and complex for me to go into tonight maybe another night. Thanks for reading, I hope it helps.
Not really, everything you posted has been posted in this thread, kinda waste of time eh?

MULTIVITZ
26-05-2015, 03:02
No. Because if you understood it you would be one step closer to a tame Lotus turbo. Like the mint handling one I have. I've posted stuff about bump stops, but I wouldn't want to waste your time repeating stuff you've already covered, eh? If I get time I'll put up a replay of me driving the Lotus on my own, because I haven't heard anyone else launching it through all gears and experiencing the 60 to 120mph in 1 second!! It will get close to 1200bhp if its short shifted and gets a bit of over shoot. If you know what I mean? Nice, eh?

Sp4mD4gger
26-05-2015, 09:52
No. Because if you understood it you would be one step closer to a tame Lotus turbo. Like the mint handling one I have. I've posted stuff about bump stops, but I wouldn't want to waste your time repeating stuff you've already covered, eh? If I get time I'll put up a replay of me driving the Lotus on my own, because I haven't heard anyone else launching it through all gears and experiencing the 60 to 120mph in 1 second!! It will get close to 1200bhp if its short shifted and gets a bit of over shoot. If you know what I mean? Nice, eh?
I do agree that the Lotus turbo is a bit of a handful, and short shifting is neccessary in some cases, be rewarding to drive when tuned properly.
Could well be one of the most technical cars in the game.

MULTIVITZ
27-05-2015, 20:06
It took me nearly 3 dozen adjustments of the diff to find the sweet spot in the setup to handle the violent boost. Its on 500nm preload, and needs it lol if the front lifts, its wheelspin time but fairly manageable on low front wing. At the moment its ok on flat tracks, might tune it for the ring, but worried about the plank lol I think the rear bumps are active!

Urban Chaos 2.0
15-01-2016, 16:51
Yes. That will make it squirrelier on the EXITS


No. Limited-Slip Acceleration Lock (LSAL), and Limited-Slip Deceleration Lock (LSDL), will lock the drive-axle wheels to the same rotation speed upon acceleration and deceleration respectively. In rear-wheel drive cars: The higher the LSAL/LSDL value, the less slip will be allowed to the rear wheels.

The effect of increased LSAL is the following: During corners, the inner drive-wheel will be forced to rotate at the same speed as the outer drive-wheel. This will increase the cornering radius (under-steer), but will prevent one wheel from turning faster than the other. This will help manage sliding out of corners. When LSAL is reduced, the opposite effect of what was described, will occur.

Things are a bit different with LSDL. Increased LSDL will lock the drive-wheels upon deceleration. This prevents either wheel from turning faster than the other, and causing a turning effect which could make the car spin out. This takes effect in corners as well under engine-breaking, and what happens in corners when the rear wheels are locked has been covered in the LASL section above. Decreasing LSDL will have the opposite effect of what was just described.

So no. Increased LSDL will not make for a more squirrely car.

Schnizz58
15-01-2016, 16:57
No. Limited-Slip Acceleration Lock (LSAL), and Limited-Slip Deceleration Lock (LSDL), will lock the drive-axle wheels to the same rotation speed upon acceleration and deceleration respectively. In rear-wheel drive cars: The higher the LSAL value, the less slip will be allowed to the rear wheels.

The effect of increased LSAL is the following: During corners, the inner drive-wheel will be forced to rotate at the same speed as the outer drive-wheel. This will increase the cornering radius (under-steer), but will prevent one wheel from turning faster than the other. this will help manage sliding out of corners. When LSAL is reduced, the opposite effect of what was described, will occur.
This is true but too high of a LSAL setting can induce power oversteer, which will indeed make things squirrelly on corner exit.

RacingManiac
15-01-2016, 17:00
No. Limited-Slip Acceleration Lock (LSAL), and Limited-Slip Deceleration Lock (LSDL), will lock the drive-axle wheels to the same rotation speed upon acceleration and deceleration respectively. In rear-wheel drive cars: The higher the LSAL value, the less slip will be allowed to the rear wheels.

The effect of increased LSAL is the following: During corners, the inner drive-wheel will be forced to rotate at the same speed as the outer drive-wheel. This will increase the cornering radius (under-steer), but will prevent one wheel from turning faster than the other. this will help manage sliding out of corners. When LSAL is reduced, the opposite effect of what was described, will occur.

Things are a bit different with LSDL. Increased LSDL will lock the drive-wheels upon deceleration. This prevents either wheel from turning faster than the other, and causing a turning effect which could make the car spin out. This takes effect in corners as well under engine-breaking, and what happens in corners when the rear wheels are locked has been covered in the LASL section above. Decreasing LSDL will have the opposite effect of what was just described.

So no. Increased LSDL will not make for a more squirrely car.

I think that depends on how loaded is the outside tire. Yes it is making the inside wheel spin at the same speed as the outside, but that means you are transferring torque to that wheel because the natural tendency without LSD is to spin the inside because its unloaded(path of least resistance). If your outside tire is already heavily loaded(mid corner, or bump, or curb) and you apply power, you can actually break traction and cause the back end to come loose.

Urban Chaos 2.0
15-01-2016, 17:42
@Schnizz58 & RacingManiac:

It all depends on the car's setup and the amount of power delivered. As I intended a simple explanation, I didn't bother to go into LSDL/LSAL counter-measures like sway-bar, suspension, or toe-in adjustments. But feel free to add whatever you'd like.

Schnizz58
15-01-2016, 17:48
Fair enough. In the game, I've had more issues with power oversteer due to too high of an accel setting than I have with inside wheelspin due to too low of a setting.

RacingManiac
15-01-2016, 17:55
Fair enough. In the game, I've had more issues with power oversteer due to too high of an accel setting than I have with inside wheelspin due to too low of a setting.

Ditto. Normally I'd have set the bar/damper first then drop the Accel locking to a point where I can apply power confidently on corner exit.

Urban Chaos 2.0
15-01-2016, 19:19
Fair enough. In the game, I've had more issues with power oversteer due to too high of an accel setting than I have with inside wheelspin due to too low of a setting.

I recommend keeping both LSDL and LSAL as low as possible. Fixing inner-tire wheel-spin in corners depends on the car and the track but it really shouldn't be an issue. You're either being extreme with LSAL, or the car is set up poorly elsewhere. Try adjusting the sway bars. Increase rear stiffness, and decrease the front. The car will turn in more sharply. Then soften the rear spring stiffness a bit, and stiffen the front.

Umer Ahmad
16-01-2016, 00:59
I'll explain another way, some people understand this way better:

ACCEL LOCK
SAFETY[-------------|----------------]PERFORMANCE


DECEL LOCK
PERFORMANCE[-------------------|-------------]SAFETY

In the above examples "SAFETY" means "LESS TURNING ABILITY" (and therefore lower probability of spin-out). "PERFORMANCE" means "MORE TURNING ABILITY" (and increased probability of spin-out)

You "gear heads" car nerds (like me) get too much into the technicals for the layman player. They really just want to know which way to set the slider so they REDUCE PROBABILITY FOR SPIN-OUT during: a. Corner Exits (on-throttle application) and b. Corner Entry (off-throttle coasting)

Ledbetter
16-01-2016, 04:11
I'll explain another way, some people understand this way better:

ACCEL LOCK
SAFETY[-------------|----------------]PERFORMANCE


DECEL LOCK
PERFORMANCE[-------------------|-------------]SAFETY

In the above examples "SAFETY" means "LESS TURNING ABILITY" (and therefore lower probability of spin-out). "PERFORMANCE" means "MORE TURNING ABILITY" (and increased probability of spin-out

Thank you. This is the opposite of another popular racing sim in which increasing either accel or decel lock increases what you describe as "safety," and it was driving me crazy. So, thanks!

DreamsKnight
16-01-2016, 09:49
i think this is the best explationation possibile. i went from the fog to the light.


https://www.youtube.com/watch?v=qj7pPh8FXTM[/QUOTE]

source:

http://forum.projectcarsgame.com/showthread.php?37837-Screen-by-screen-setup-guide

havocc
16-01-2016, 14:17
Thank you. This is the opposite of another popular racing sim in which increasing either accel or decel lock increases what you describe as "safety," and it was driving me crazy. So, thanks!

Gt?
I was on the same boat, i remember high diff lock helping a lot at corner exit especially with pad and digital throttle (shame on me), when i first set 100% diff here the cars started acting like a mad bull at corners... :D

Urban Chaos 2.0
16-01-2016, 18:37
I'll explain another way, some people understand this way better:

ACCEL LOCK
SAFETY[-------------|----------------]PERFORMANCE


DECEL LOCK
PERFORMANCE[-------------------|-------------]SAFETY

In the above examples "SAFETY" means "LESS TURNING ABILITY" (and therefore lower probability of spin-out). "PERFORMANCE" means "MORE TURNING ABILITY" (and increased probability of spin-out)

You "gear heads" car nerds (like me) get too much into the technicals for the layman player. They really just want to know which way to set the slider so they REDUCE PROBABILITY FOR SPIN-OUT during: a. Corner Exits (on-throttle application) and b. Corner Entry (off-throttle coasting)

Your explanation is INCORRECT. A low "ACCEL LOCK" setting icnreases turning ability, whereas a higher "ACCEL LOCK" setting decreases it. Sorry, but you don't know what you're talking about.

havocc
16-01-2016, 19:53
Your explanation is INCORRECT. A low "ACCEL LOCK" setting icnreases turning ability, whereas a higher "ACCEL LOCK" setting decreases it. Sorry, but you don't know what you're talking about.
High acceleration lock is unsafe at corner exit because if the grip isn't enough you will spin with both wheels with nasty results

Umer Ahmad
16-01-2016, 21:52
In this model, Preload is your MASTER slider.

Slide it RIGHT for LESS TURNING ABILITY (more locking) in both accel (corner exit) AND decel (corner entry) situations. Leftwards is the opposite behavior. (edit: i might be a little wrong on this explanation, requesting backup)

Preload is one i havent fully solved. I dont mess with Preload too much. I keep it towards the left for most cars.

(Anyone seen jussi or miagi?)

miagi
17-01-2016, 00:11
Hello, I am miagi and I shall be your diff-captain tonight... I guess.

Acceleration Deceleration lock:
Low Values means that the tires are "independent". One of them will create less slip if they are in the need of rotating at different speeds. Slip reduces the lateral performance. When you want to go round a corner nice and stable, put as little longitudinal forces or slip on the tire as possible. In simple words, a tire is not a good mutlitasker. It likes it more to either do acceleration/braking or cornering, both at the same time is worse. That is were low values = open diff helps.

Acceleration Lock:
0% = open diff, will when you hit the throttle in a corner, only sent as much torque to the rear outside tire as it can prop up on the rear inside tire (on a RWD car). Means if the car is heavy cornering up to the point that the rear inside tire is in the air, no torque will be sent to the rear outside tire. What is not a stupid move as that tire is already very busy keeping up cornering forces preventing the car from spinning out. That sounds so sensible that the logical question is, why not always do it like that? Well the disadvantage in that situation is that the drive can press the throttle as hard as he likes, nothing will happen. So he is missing one of his main control features in that situation.
Higher Values of 100% will lock the wheels together, and puts the power down more like solid axle. Now even in the most critical cornering situation, a touch of the throttle will sent torque to the poor outside tire that is already on it's limit with cornering. Logical outcome, the rear will come around. What in a well balanced car can be better than understeering off track. The actual advantage of higher lock values is that it put the torque better to the ground when the car is going straight. When left and right tire can only rotate at the same speed, cornering will get difficult, but so will spinning out on power on the straight.
So more dangerous but playable in the corner (good throttle control is important) but better "traction" when going straight again after the corner.
On some cars it can go so far that higher acceleration locking values might create some understeer on fast corner when the driver doesn't go off throttle.

Deceleration Lock:
So this is the same when coasting, off throttle or braking. Here higher lock values can bring stability in the corner or understeer, depending how you'd like to look at it. Downside is that on some cars it can have the negative effect that it creates stability but only up to a point and then both tires lose traction in one rather violent move that is very hard to manage.
I rather like more open deceleration lock and do the balance with setup options. It lets the car be agile and creates less slip on the rear axle, so that the rear tires can focus only on cornering forces and keep the car stable. But on some cars, the stability option provides advantages.

Preload:
Preload should mean that the system is engaged even if there is no torque difference between those two tires. 100% lock and high preload and done is the solid rear axle. Now both wheels will be locked together like on a go-kart, making it hard to even push the car around on the parkinglot. (Unless the definition in pCARS is different then I'm sorry).

I hope that was somehow helpful, if not check out that puppy:

http://youtu.be/yYAw79386WI

Alex Hobbs
17-01-2016, 00:43
Goddammit miagi you ninja I was gonna post this:


https://www.youtube.com/watch?v=-OgwYDthblU

(Yes I'm aware I had months, shush ;) )

DreamsKnight
17-01-2016, 01:40
At the end is simple:

-ACC lock help you in this turns where the situation say: please give full throttle to exit. But if you do the car go outside the track. Increasing it (to the right) help the car to turn in less space, you can give full throttle without fear. Driving the feeling is similar the start of an oversteer. But it isn't.

-dec lock help to enter inside the turn with the brake pressed, and without the tail that go away like a woman in those days. :D

Mahjik
17-01-2016, 15:40
A lot of good info in this thread....

The main things to consider is what makes a fast lap. All things considered equal, the driver who is at full throttle the most will turn the fastest lap. That sounds obvious, but it's not always. When tuning the diff, you want to use as much Acceleration Lock as you can drive for that specific track. No one setting will be ideal for all tracks. I typically start by putting it dead center, practicing and seeing how it feels. If I don't have any issues powering out of the corners, I increase it until I do. If I have issues at the center, I decrease it until it feels good.

The goal is that you want as much power to both drive wheels as possible when using the accelerator. Deceleration Lock is more of a driver preference.

Jussi Viljami Karjalainen
17-01-2016, 18:37
Do I need to read through everything and only comment on what the others may have missed (I'm pretty sure miagi and Alex would have covered just about everything), or should I just say what happens? =)

I'll just quickly say that remember that 100% acc or 100% dec doesn't mean you have "100% locked diff", it means that the locking effect (maximum "extra" torque transferred to tyre with more grip) will be 100% of the torque fed into the differential. The only way to get a "100% locked diff", a spooled diff/no diff in this model is to run essentially infinite preload. And very high acc lock does make it harder to initiate a turn when you're not overpowering the grip, but as soon as you start getting to the edges of grip it can really yank the car around because you can force feed a lot of torque on the outside tyre. I noticed this very nicely when karting last year (solid rear axle), the car was really difficult to get to turn initially with power on, but when the engine got into the power range and especially if I leaned hard on the outside to lower the grip of the inside rear tyre the kart almost instantly wanted to get into a slide. So yeah, high acc lock = clunky with low power input, capable of sudden grip loss and unstable rear with high power input.

BigDad
18-01-2016, 13:06
https://youtu.be/qj7pPh8FXTM
This taught me heaps , hope it helps you guys .
Hope its not been linked already ,lol .



Yep post 48 , cheers DreamsKnight .

Jussi Viljami Karjalainen
18-01-2016, 13:21
I had a few issues with that video, it's good but it leaves out a few points:

There are some issues with that video:

"All the modifications of any diff setting have one target: Improved balance" <-- I disagree, maximizing the amount of power transferred to the ground is actually a really important concern as well. Also using an AWD car (Audi R8) to demonstrate RWD issues is a bit... Yeah. Well, it works at least. =)

FWD accel lock behavior depends on the cars as well to some extent, the Focus and Megane for example (possibly due to low grip tyres) need quite a bit of accel lock to be able to put any power down when exiting a corner, and it can actually reduce understeer on power, the extra torque being sent to the outer wheel behaving similarly to torque vectoring. With a very open diff you'll just spin the inside wheel and don't get any actual work done, and still get tons and tons of understeer. Clio with its super grippy tyres and very low power though is indeed a bit different.

Decel lock behavior is described correctly, but he forgets to mention that it's not just when you're braking that it works, it's also when you're just lifting off the throttle. So it affects the stability of the car and the turning behavior whenever you're not on the throttle.

In the preload bit he shows how oversteery the car is when you don't have any preload and come into a corner without any throttle, and how it settles down when you have a little bit of throttle to stabilize it. Did he have any decel lock on though? The first demo is a demonstration of what happens when you have neither decel nor preload and have high engine braking, which is generally oversteer in an RWD car. Preload can be used to correct that, but so can decel lock. To showcase a situation that focuses just on the preload behavior, he should have entered the corner with the clutch held down. Also his partial throttle entry is actually closer to showing what having 0 preload does to the car's balance when ignoring the decel and accel lock effects. He also neglects to mention that adding preload also affects the power side of things, so you can get similar behavior to increasing accel lock. Basically, preload sets the minimum level for locking, both accel and decel, and sometimes if you set preload high enough to reduce lift-off oversteer you can also get power on oversteer at the same time.

There are no "clutches" in a viscous coupling diff as such. Unlike clutch pack diffs they also require a difference in wheelspeed before anything happens, so they never lock the two axle speeds together unlike preload for example, they just sent more and more extra torque to the slower side as the difference in wheelspeed increases. The effect is indeed quite subtle and progressive, so it's harder to feel the changes than with normal clutch pack diffs, but they do work to transfer extra torque to the slower axle. Based on what Casey has said, the coupling effect at 100% should be about 100 Nm @ 50 rpm wheelspeed difference. Applied to the tyre size of the McLaren P1 and assuming a linear rate, that means roughly 100 Nm of coupling for every 6.6 km/h difference in wheelspeed between left and right.

Not a bad video at all, it hits the major marks, but unfortunately leaves quite a few important bits unmentioned.

BigDad
18-01-2016, 13:32
Thanks , but it taught me heaps and if i didn't post it i wouldn't have got your knowledge on the matter , so now i learn more .
Thanks Mate .

DreamsKnight
18-01-2016, 17:33
i think it's time to do a jussi tip section, a jussi statue and an official fanclub.

havocc
18-01-2016, 17:39
In the preload bit he shows how oversteery the car is when you don't have any preload and come into a corner without any throttle, and how it settles down when you have a little bit of throttle to stabilize it.

So adding preload is the way to prevent tail losing at very slow corners? (e.g bus stop, La Source, 1st chicane at Monza etc...)

Jussi Viljami Karjalainen
18-01-2016, 17:54
It can help, depending on how exactly you're losing it (what inputs you're giving the car).

havocc
18-01-2016, 18:04
It can help, depending on how exactly you're losing it (what inputs you're giving the car).

I brake in straight line, lift the brake and steer without giving throttle and the rear loses grip and spins

Mahjik
18-01-2016, 18:31
I brake in straight line, lift the brake and steer without giving throttle and the rear loses grip and spins

Which car?

It sounds like you have the rear unloaded from heavy braking, then you are applying too much steering into the corner with the unloaded rear. If so, that's not really something I'd tackle from a diff setting perspective.

havocc
18-01-2016, 18:34
Which car?

It sounds like you have the rear unloaded from heavy braking, then you are applying too much steering into the corner with the unloaded rear. If so, that's not really something I'd tackle from a diff setting perspective.

M1 Procar for example, moving brake bias a bit more to the rear could be a solution?

Mahjik
18-01-2016, 18:48
M1 Procar for example, moving brake bias a bit more to the rear could be a solution?

Yes, I would move the brake bias a few clicks rearward and stiffen the front springs a tad to help with the front dive under braking. You might check the deceleration lock and see where that is set, but I'd start with the brake bias and the stiffening the front a little.

There are many ways to attack this type of problem, but that's how I would start. Some cars, like the older vintage cars don't have large slip angles so you have adjust your driving style a little to suit them but the M1 isn't quite in that group.

Jussi Viljami Karjalainen
18-01-2016, 18:51
M1 Procar for example, moving brake bias a bit more to the rear could be a solution?Brake bias to the rear should make it even easier to spin on entry. But yes, increasing dec lock or preload should help with that to some extent at least. Too much preload though can affect the acceleration side as well, so keep that in mind. How much is too much? One can only find out by testing. =)

Other things that can affect it would be overall spring bias between front and rear, rear rebound damping, sway bars, and tyre pressures, among other things... Do you have the setup available anywhere?

DreamsKnight
18-01-2016, 19:32
One thing i'm learning is setting differential at minimum and doing al the setup. After doing everything i use them as last source to find something more and not a problem solver.

For brake i usually move forward to solve iusse with tail and Rear rebound softer.

havocc
18-01-2016, 19:47
One thing i'm learning is setting differential at minimum and doing al the setup. After doing everything i use them as last source to find something more and not a problem solver.

For brake i usually move forward to solve iusse with tail and Rear rebound softer.

A good differential setup can mean 2-3 or more seconds difference on a single lap, should be one the first thing to tune properly

Jussi Viljami Karjalainen
18-01-2016, 19:59
The thing is though that "properly" can mean different things depending on the rest of the setup. =)

blinkngone
19-01-2016, 23:15
I didn't change anything but the accel(48) and decel(54) locks as Havocc suggested. I used the BMW M3 GT at Silverstone National and lowered my WR TT time by almost 8 tenths. Thanks Havocc!! I realize each car/track will be different but cool anyway and the car was much easier to drive as well.

blinkngone
20-01-2016, 01:24
Adjusted my Silverstone International (BMW M3 GT) setup and lowered my best TT time over .200, pretty good because I kinda suck at this track and was getting nowhere. Used 67 decel and 23 accel. I am going to keep practicing and hopefully when Patch 8.0 comes out I will be ready.
Thanks everybody who contributed on this thread.

havocc
21-01-2016, 08:29
Brake bias to the rear should make it even easier to spin on entry. But yes, increasing dec lock or preload should help with that to some extent at least. Too much preload though can affect the acceleration side as well, so keep that in mind. How much is too much? One can only find out by testing. =)

Other things that can affect it would be overall spring bias between front and rear, rear rebound damping, sway bars, and tyre pressures, among other things... Do you have the setup available anywhere?

And bus stop strikes again this time with marek Lmp1, considering that track is quite uneven at that point will a softer rear swaybar do the job?

Jussi Viljami Karjalainen
21-01-2016, 15:22
Depends on the rest of the setup and what exactly happens when control is lost. It could, but then again LMP1 cars don't run that much to begin with.

havocc
21-01-2016, 16:17
Depends on the rest of the setup and what exactly happens when control is lost. It could, but then again LMP1 cars don't run that much to begin with.

I noticed it happens when i go on the first right curb and is probably caused by the stiff default setup of the Marek, anyway marek can go to hell, i have a new love :D

I picked the Toyota and copied setup from DB, lowered brake pressure and started a 15 laps race, after 10 laps i was 2nd after a 4 laps battle with the 3rd, but i went out of fuel at lap 13 and had to pit for a "splash and go", i went down to 4th and while battling with 3rd i had a spin at la source because tyres were at 50% wear but managed to recover quickly and end the race at 4th, that was a hell of a race :rolleyes:

PTG Baby Cow
23-01-2016, 20:46
I recommend keeping both LSDL and LSAL as low as possible. Fixing inner-tire wheel-spin in corners depends on the car and the track but it really shouldn't be an issue. You're either being extreme with LSAL, or the car is set up poorly elsewhere. Try adjusting the sway bars. Increase rear stiffness, and decrease the front. The car will turn in more sharply. Then soften the rear spring stiffness a bit, and stiffen the front.

Actually you have it backwards. Your goal is to effectively have them as high as possible. This will result in the fastest tune if it can be achieved. Lower setting you are using less propulsion forward. Less accelleration

hkraft300
24-01-2016, 12:41
I'd say set the locking %-age at what feels good. Too low and you get inside wheel spin and high tyre wear (try FGulf at Imola). Too high, you get a stiff diff and it gets a little snappy for my liking.

Diamond_Eyes
29-01-2016, 13:58
Out of interest check 1:20/6:33

https://www.youtube.com/watch?v=RYFSgF0FHfs&feature=em-subs_digest

Jussi Viljami Karjalainen
29-01-2016, 14:06
Doesn't really need any acc lock when his preload is that high (you can always transfer at least 200 Nm more to the tyre with more grip) and he's putting even more extra lock on the dec side to calm the car down when not on the throttle. That's one way of dealing with the twitchy/oversteery setup the Z4 GT3 has by default, I tend to use more normal diff settings and make the car more balanced via springs and dampers.

MULTIVITZ
10-08-2017, 18:39
That's true Jussi, low accel is fine with good preoad and planted rear end. I like to use a highish deccel that acts as ABS if one rear wheel loses grip under trail braking, but not too high as to hamper turning on a crucial tight turn, or stop the rear from raising and making the front brakes lock because of poor forward weight transfer.
Yeah someone could check the post dates? Who cares.

blinkngone
10-08-2017, 19:03
Hi MULTIVITZ, welcome back. I am usually over 50% on deceleration lock and low acceleration lock of around 25% and adjust accordingly. I don't use preload much though. My throttle control isn't much, more like a switch, on or off:D

hkraft300
10-08-2017, 22:00
Yeah someone could check the post dates? Who cares.

Good to have you back mate.
Timing is impeccable, with PC2 looming on the horizon :)

Alfisti
16-08-2017, 20:18
Interesting topic as i have just solved a LOT of my understeer issues by reducing decel lock to almost zero. I always felt like I was fighting chronic understeer (I driver with all nannies on) so in an effort to loosen things up i went this route and voila, I can turn now.

hkraft300
17-08-2017, 00:21
ABS and SC off the cars will come alive.

Alfisti
17-08-2017, 14:27
ABS and SC off the cars will come alive.

Yes i suspected as much because whilst i am competitive online, every so often a really good driver joins in and despite hitting my apexes and pushing very hard, I am left for dead. I just don't have the turn in I need. I struggle to hold onto powerful cars without the nannies with a controller, Wife bought me a wheel but i need to brace it, i suspect this is my next step.

hkraft300
17-08-2017, 15:25
Sounds like you've met TexasTyme214.

With ABS you can easily push too much.
Also instead of SC, try TC. Remember with TC in game, 1% = nanny mode and 14% = party mode. Powerful cars can still overwhelm the TC though.

That said: plenty guys use the assists and are still super quick.

Alfisti
17-08-2017, 16:22
Still some secret sauce in settings too, after reduce DECEL to near 0% and seriously adjusting the fast bump settings to settle down the rear end, I dipped into the high 5's at bathurst, so shave a full second off my best time and there's more time there as i adjust to the new grip levels and turn in.

Castrol r
18-08-2017, 10:21
I run no aids in car mainly tc3 cars
I have a good few top 10 times in time trail on Xbox
I run mine at o -100 ride the curbs ,drive over the grass ,brake hard it all helps .and tbh I think it's a bit to mush help .
All most like a cheat

Jussi Karjalainen
04-09-2017, 22:17
Still some secret sauce in settings too, after reduce DECEL to near 0% and seriously adjusting the fast bump settings to settle down the rear end, I dipped into the high 5's at bathurst, so shave a full second off my best time and there's more time there as i adjust to the new grip levels and turn in.Might be, but people have done low twos and threes with the accel lock in the 50% region as well... If it helps you though, then sure. =)

Daynja
19-09-2017, 02:01
so if you want a squirrelier car you raise acceleration diff?


Yes, the wording is incorrect in pcars 1 help.

Higher (moving the bar right) allows the wheels to independently spin allowing a car to move more in a corner but this obviously can cause too much wheelspin which munches tyres and can cause you to spin out (over steer)




Edit: Ive just noticed I've replied to a very old post. LOL I need some sleep