LSD accel and decel=ramp angle?

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I'm a bit confusing with figures in the LSD tunning section. They begin with initial torque and that's clear but then the accel and decel side with no unit. It looks similar to the way that CUSCO or KAAZ show their LSD spec. as"ramp angle"in the data sheet. So I'm wonder about number from 0 to 60 in those section mean the locking percentage or the ramp angle.
Can anyone help me to clarify this?
Thanks...
 
I wont say that this was necessarily the wrong forum, however you might get your answer faster if you asked this in the settings and tuning subforum. Actually, I'm glad you stuck it here because it could become a rather interesting discussion topic. Things have been kinda slow going lately. So 👍 👍


I'll begin by stating that I generally drift with a stock LSD, occasionally a 2-way. So my actual LSD tuning experience may be somewhat lacking compared to those that might pop by to ridicule my comments later. :sly:

Ignore the following comments in the quote (used to be part of this post), and read rsmithdrift's comments in post 11.
me
Anyways, I always held the belief that it was the locking factor. The value would then represent the maximum applied torque difference between rear wheels compared with total applied torque. A torque fraction, if you will.

ie)
Setting the accel to 40 would give one wheel a maximum of 70% of the torque, and the other would recieve a minimum of 30%. The actual split could be anywhere within those bounds depending on the circumstances, but not exceeding those bounds.
Continuing the example, a setting of 15 would allow for 57.5% to one wheel, 42.5% to the other. You split the difference.
(btw, I assume by your question you already understand this, I only posted it for the benefit of others that may not).

This theory would explain why I find it easier to break the tires free with a very low accel or decel setting than a higher one (on the occasion that I use a full customize LSD). The inside tire is being supplied with excess torque when the difference is low, like say 20 or less, something like that.

This is just supposition, and may very well be wrong, but I hope it might help in some form or another. Just another case where PD didnt give us quite enough information....
 
Well, i consider LSD tunning to be crucial to drifting in GT4 and also in reality, so that's why i post the thread here.
At beginning i thought that it was locking factor they represent, as i can handle the countersteering speed more, i try to set them to higher value but lower initial torque to correspond with those in CUSCO LSD spec. (ex. 8kgf initial torque and both 55 degrees in accel and decel) and it's under the circumstance that assuming the LSD works as clutch type.
Though it's hard to break tires free with this combination, but once you break free you can make the drifting with more aggressive angle and last longer compare to stock LSD. But it requires more speed when entering a corner.
 
so, when tuning the LSD, do bigger numbers mean there can be a greater difference in torque to each wheel? sort of like how tankspanker explained it.
the lower the number, the closer each wheel spins to the same speed in a turn?

and is a 2-way LSD always locked under acceleration and deceleration?
 
blotto3000
the lower the number, the closer each wheel spins to the same speed in a turn?

and is a 2-way LSD always locked under acceleration and deceleration?

nope on the first bit there. if both wheels spun the same speed you would be unable to turn. The outer wheel in a turn necessarily rotates a greater number of times than the inside tire (under grip scenarios). The speed differential of the wheels is not determined by the vehicle's differential, but by the vehicles steering angle around the turn. Infact, the differential gets its name for allowing a speed differential between two wheels located on the same axle.

It is only the distribution of torque (and the final gear ratio, I suppose) that is affected by the LSD. Two similar sounding concepts that are actually quite different.

the second bit is correct. 2-way LSD's offer 50/50 torque split under accel and decel.
 
im confused again. does locked mean the wheels spin close to the same speed?

would raising or lowering the number make the wheels stay closer to the same speed under the situation you are adjusting?

and for drifting what is best, letting the wheels spin at the different speeds or stay closer to the same speed(maybe not the same speed but doesnt allow them to differ much)?
 
blotto3000
im confused again. does locked mean the wheels spin close to the same speed?

would raising or lowering the number make the wheels stay closer to the same speed under the situation you are adjusting?

and for drifting what is best, letting the wheels spin at the different speeds or stay closer to the same speed(maybe not the same speed but doesnt allow them to differ much)?

FORGET ABOUT SPEED! it's all about torque!
How Differentials Work
 
TankSpanker
Anyways, I always held the belief that it was the locking factor. The value would then represent the maximum applied torque difference between rear wheels compared with total applied torque. A torque fraction, if you will.

ie)
Setting the accel to 40 would give one wheel a maximum of 70% of the torque, and the other would recieve a minimum of 30%. The actual split could be anywhere within those bounds depending on the circumstances, but not exceeding those bounds.
Continuing the example, a setting of 15 would allow for 57.5% to one wheel, 42.5% to the other. You split the difference.
(btw, I assume by your question you already understand this, I only posted it for the benefit of others that may not).

This theory would explain why I find it easier to break the tires free with a very low accel or decel setting than a higher one (on the occasion that I use a full customize LSD). The inside tire is being supplied with excess torque when the difference is low, like say 20 or less, something like that.

Wrong, wrong, and wrong. Ok, GT4 has this ticker at the bottom in the tuning menu that explains the setting at hand and how to use it. But I'll post anyways for those too lazy to read it, also I'll explain it alot better than they will.

Note: this is long so for the short version just read the notes. But if you want to understand why, read it all.

You have it totally backwards. You're sort of right on how an LSD works but wrong with how to tune it in game.

This tuning is make or break with drifting so getting it right is crucial. This may explain why you keep having wheelspin understeer, lack of speed, and snap overcorrection problems. A tight LSD makes the car alot more stable, adds alot more throttle control, and will make the car hold its speed better while drifting, but locking it will mean that the car will not turn w/o wheelspin and looses some manuverability. Having a loose LSD will create the opposite effects and make the car alot more manuverable and alot easier to wheel spin but alot harder to get oversteer, too loose will cause "peg legging" or one wheel burnouts and consequently, understeer. Go buy a '83 Nissan 300zx and don't modify its diff. Then try to drift it to feel what an open diff feels like.

Also, the reason lowering your accel setting makes burnouts easier is because you're "peg legging." And the different LSD's like the 2 way doesn't mean locked all the time. 1 way means that it only works under accel and is open during decel. 1.5 way means that it is normal under accel and very light under decel. 2 way means that you have the same moderate amound of LSD affect under acceleration as you do under deceleration. In all cases the amount of acceleration LSD affect is the same.

Now back to the actual tuning in game.

Initial Torque: This setting determines the responsiveness of the LSD's application. A higher setting means more responsive and tighter at rest. (at rest meaning when no accel or decel force is being applied) I try to keep this between 10 and 30. (depending on car at hand) Setting this too high will cause the car to loose manuverability but will make drifting a little easier. This also is a factor in total strength of the LSD. Example, if initial is set at zero there will be no responsiveness so therefore you will have no LSD effect (i.e. open diff). If you set this at 60 (max) your LSD will be locked all the time and will not need to respond to accel or decel, if you do either of these the accel and decel settings become irrelevant.

Note: intial affects both accel and decel. Increasing this will make your car looser during wheel spin, but tighter all the rest of the time(i.e. understeer), and will also decrease manuverability.

Accel: This setting determines the max strength the LSD is capable of producing during acceleration. The minimum setting (5) means open diff. The max setting (60) means locked diff. I run this between 40 and 60 for drifting. Don't set it above 40 for racing! The tighter this is the more stable your car will be under wheel spin and the more throttle control you will have over your drift and more control in gerneral. Warning: locking the diff means you will not be able to turn the car under acceleration w/o wheel spin, this is why you keep it midle range for racing, lock for show drifting purposes only.

Note: increasing your accel setting will make the car looser and more stable during wheel spin. If your car feels too twitchy while drifting, increase your accel settings.

Decel: This setting determines the max strength the LSD is capable of producing duing deceleration. The minimum setting (5) means open diff. The max setting (60) means locked diff. I run this between 10 and 20. The tighter this is the more stable your car will be under braking. Warning: don't set this very high or you will create understeer while braking making braking drifts impossible. Also, don't set this to zero or you will get "peg locking" or one wheel brake or e-brake lock which will also create understeer and also make braking drift impossible.(You ever see a F1 car lock up the inside front tire? Well it happens in the rear too) A low value will be perfect for locking both rear wheels with e-brake application or large rear brake bias w/o out creating understeer while braking.

Note: increasing this will make the car more stable under braking, but too much will create understeer. Also, none at all can create understeer as well.
 
gosh.......your engeneer?:crazy:

......I think I just keep it with stock, I first tried out to put all at minimum, then at max, and then just see what I want more, and set the little indication bar more towards my preference lol:lol: But I think this is also why my old mercedes, why it always has ONE wheel spinning during corners while drifting, it always seems like it's the exhaust or ssomething, but now I know it's LSD
 
TankSpanker
I'll begin by stating that I generally drift with a stock LSD, occasionally a 2-way. So my actual LSD tuning experience may be somewhat lacking compared to those that might pop by to ridicule my comments later. :sly:


thanks for that rsmithdrift. 👍 👍

The LSD has always looked like a bit of a black art to me. Never did fully understand the thing and how each of the settings affected the other. I was just going off of assumptions and a few 'best guesses'. Your explanations help immensely, I'll have to go fiddle with some settings sometime this weekend and see if I can come to the same conclusions now that I know what I should be sorta feeling from the car. Maybe I wont be so tentative to install a fully customiable LSD now.


The LSD tuning section of the Drift Reference is still empty. Do you have any objections to me editting my post with your comments to explain that section?
I'll give you full credit for it, of course.
 
The explanation was most helpful... funny thing though, I was setting up my car's LSD as it should be (Fro drifting) even before I knew what it was for. I just played around with it and what felt right I stayed with. That's what I do most of the time anyways...
 
Yeah me too + the fact that I never had real trouble with drifting, AND I'M JUST STARTING TO LIKE STOCK:dopey:👍 But honestly? I think it's still a bit confusing...but I'm>>:dunce:
 
I like stock, but the first part I will put on a car to help it drift is an FC LSD, and then depending on the horsepower I raise (for low horsepower) or lower (for high horsepower) the Accel setting.

If the car understeers when I get on the gas, I lower Decel a few ticks til it stops that.

I don't mess with Initial too much, generally 10 is a good setting, though I notice BMW's like it a little lower, 7 or 8...but it really doesn't change as much as the other settings do.
 
TankSpanker
thanks for that rsmithdrift. 👍 👍

The LSD has always looked like a bit of a black art to me. Never did fully understand the thing and how each of the settings affected the other. I was just going off of assumptions and a few 'best guesses'. Your explanations help immensely, I'll have to go fiddle with some settings sometime this weekend and see if I can come to the same conclusions now that I know what I should be sorta feeling from the car. Maybe I wont be so tentative to install a fully customiable LSD now.


The LSD tuning section of the Drift Reference is still empty. Do you have any objections to me editting my post with your comments to explain that section?
I'll give you full credit for it, of course.

Oh, none at all, please, go right ahead and post it. Any way I can help people with there drifting. And I'm honored that you learned something from me. From what I can tell your one of the best.

And that fully customizable LSD made all the difference in the world with my GT4 drifting. I went from 3 or 4 major mistakes per race, down to 1 or 2 at most, if any, just by playing with the LSD.

Anyways, I was never brave enought to mess with it either until about 1 year ago on GT3. After playing with the LSD settings, I can now drift continuously from start line to finish line on every track in the game with any FR car that has 300+ horsepower. Yes, even Complex String. Not only that but I have enough control to link multiple laps and change from speed to show drifting at will. I really wish I could upload the replays of it.(All above refering to GT3) The best way to understand it is to get a rear drive car on GT3 and play with the LSD setting on there. I normally use a 450hp 240sx fastback with simulation tires. But to get the feel for it start off with Hard Sports tires and gradually decrease grip. LSD affect is more accurately modeled in the GT3 physics engine than on GT4. You can feel the difference and affects alot better on GT3 for some reason. But it does make a noticable difference on GT4. Also the more power you have the more noticable the LSD affect is. I especially like it on my Mustang Cobra R.

And to whoever said it. Yes, I am majoring in Mechanical Engineering at Tennesse Technological University, for your information.
 
Thats funny, I'm in Memphis, and my girlfriend knew a guy in the Tenn. Chats here whose name was "Godhelpmeiminchatanooga"

Quite hilarious, that.
 
Onikaze
Thats funny, I'm in Memphis, and my girlfriend knew a guy in the Tenn. Chats here whose name was "Godhelpmeiminchatanooga"

Quite hilarious, that.

Yeah, that's about how I feel about this place. :yuck: :lol: I miss Florida.
 
rsmithdrift
And to whoever said it. Yes, I am majoring in Mechanical Engineering at Tennesse Technological University, for your information.

[offtopic]
good stuff. How far along in the program are you?
I'm doing the same at the University of Manitoba - needless to say, I've not encountered any courses explaining the inner workings of automotive differentials as of yet. :sly: It's all been heat transfer, fluid mechanics, stress analysis, and calculus :yuck: so far. Introductory courses, no instruction on actual mechanism design.
But, I'm starting the 3rd yr courses this fall, and that's supposedly where my program gets more practical and enjoyable. There's a few interesting electives this year that are open to me about automotive design and technology that I plan to enroll in.
[/offtopic]

anyways, I'll stick that in the reference now. good stuff and thanks again.
 
TankSpanker
[offtopic]
good stuff. How far along in the program are you?
I'm doing the same at the University of Manitoba - needless to say, I've not encountered any courses explaining the inner workings of automotive differentials as of yet. :sly: It's all been heat transfer, fluid mechanics, stress analysis, and calculus :yuck: so far. Introductory courses, no instruction on actual mechanism design.

anyways, I'll stick that in the reference now. good stuff and thanks again.

Hey no prob. I'm starting my sophmore year. No we didn't have any classes on diffs or anything. :lol: I hate calculus with a passion. But in my sports car club alot of my buddies are import mechanics, or seniors, or just know alot in general. So I got alot of help from them. Most of the upperclassmen in our club (about 15) are on the Formula SAE team. So they build and work on a formula race car by hand two or three days a week. They get all kinds of stuff from there. One of them had a 50 page book on forced induction and turbo inner workings and areodynamics at hand and all that stuff. It was pretty cool.
 
wsctw
I'm a bit confusing with figures in the LSD tunning section. They begin with initial torque and that's clear but then the accel and decel side with no unit. It looks similar to the way that CUSCO or KAAZ show their LSD spec. as"ramp angle"in the data sheet. So I'm wonder about number from 0 to 60 in those section mean the locking percentage or the ramp angle.
Can anyone help me to clarify this?
Thanks...
just get a 2way like you would in real life.....like the drift king said in the drift bible
("but only after you completed the 180 and 90 degree turns") lol
 
i think rsmithdrift have made LSD more clarified to us, 👍 but i would like to add more about it as far as i understand those tricky numbers. Please correct me if i'm wrong. :sly:
First i agree with TankSpanker that locking factor is about torque. But the factor should vary with how much the differences you put on the throttle or brake.
If we take a look inside LSD, there is a set of pinion gears with cross shaft inside two pressre rings as shown in an exploded pic below.
lsd015xh.jpg

Both pressre rings have (4) symmetric cutouts at the edge.While accelerating it's the centrifugal force that makes the ring pressured by the shaft along one side of the angled cutout-and that's called accel side (on the contrary under decelerating the side pressured by the shaft is called decel side), then pushed outwards and makes the wheels locked through clutch plates as shown in pic below.
lsd027yn.jpg

So here comes the point, the ramp angle determines how fast a LSD comes to maximun locking factor(or almost 100% locked), and that correspond with the content of ticker at the bottom in the GT4 tuning menu that explains the setting-it's about how tight or loose the LSD is, not the locking factor itself. i.e. the value in accel and decel setting should be the ramp angle i think-set it with a more steep angle the locking factor will increase more rapidly while accelerating or decelerating.

These are information i collect from the web about the theory but i'm not quite sure if it is really reflected in the tunning option.
 
rsmithdrift
Wrong, wrong, and wrong. Ok, GT4 has this ticker at the bottom in the tuning menu that explains the setting at hand and how to use it. But I'll post anyways for those too lazy to read it, also I'll explain it alot better than they will.

What the text says is worthless if you dont know what you are changing

Initial Torque: This setting determines the responsiveness of the LSD's application. A higher setting means more responsive and tighter at rest. (at rest meaning when no accel or decel force is being applied) I try to keep this between 10 and 30. (depending on car at hand) Setting this too high will cause the car to loose manuverability but will make drifting a little easier. This also is a factor in total strength of the LSD. Example, if initial is set at zero there will be no responsiveness so therefore you will have no LSD effect (i.e. open diff). If you set this at 60 (max) your LSD will be locked all the time and will not need to respond to accel or decel, if you do either of these the accel and decel settings become irrelevant.

Note: intial affects both accel and decel. Increasing this will make your car looser during wheel spin, but tighter all the rest of the time(i.e. understeer), and will also decrease manuverability.

Accel: This setting determines the max strength the LSD is capable of producing during acceleration. The minimum setting (5) means open diff. The max setting (60) means locked diff. I run this between 40 and 60 for drifting. Don't set it above 40 for racing! The tighter this is the more stable your car will be under wheel spin and the more throttle control you will have over your drift and more control in gerneral. Warning: locking the diff means you will not be able to turn the car under acceleration w/o wheel spin, this is why you keep it midle range for racing, lock for show drifting purposes only.

Note: increasing your accel setting will make the car looser and more stable during wheel spin. If your car feels too twitchy while drifting, increase your accel settings.

Decel: This setting determines the max strength the LSD is capable of producing duing deceleration. The minimum setting (5) means open diff. The max setting (60) means locked diff. I run this between 10 and 20. The tighter this is the more stable your car will be under braking. Warning: don't set this very high or you will create understeer while braking making braking drifts impossible. Also, don't set this to zero or you will get "peg locking" or one wheel brake or e-brake lock which will also create understeer and also make braking drift impossible.(You ever see a F1 car lock up the inside front tire? Well it happens in the rear too) A low value will be perfect for locking both rear wheels with e-brake application or large rear brake bias w/o out creating understeer while braking.

Note: increasing this will make the car more stable under braking, but too much will create understeer. Also, none at all can create understeer as well.

i have to disagree with what you are saying. It is my belief and experince that a higher number setting on the LSD causes it to act as an open diff.

check this link: clicky

I know this link is for a different game, but it explains MUCH MUCH better than i can how an LSD "locks". the only real difference between that write up and GT4 are:

A. Clutches = Initail torque. I havent really mess around with the inital torque much yet some im not sure if a higher setting (ex. 60) would be more clutches or less.

B. the ramp angles in GLP go from 30-80 where GT4 goes from 5-60. Basicly, the lower the number in GT4, the more you will be able to use the gas pedal to drive the car.


hopefully this was a worthwhile post...

edit- it helps when you put the link you are talking about in the post
 
Shoes_98ls
What the text says is worthless if you dont know what you are changing



i have to disagree with what you are saying. It is my belief and experince that a higher number setting on the LSD causes it to act as an open diff.

check this link: clicky

I know this link is for a different game, but it explains MUCH MUCH better than i can how an LSD "locks". the only real difference between that write up and GT4 are:

A. Clutches = Initail torque. I havent really mess around with the inital torque much yet some im not sure if a higher setting (ex. 60) would be more clutches or less.

B. the ramp angles in GLP go from 30-80 where GT4 goes from 5-60. Basicly, the lower the number in GT4, the more you will be able to use the gas pedal to drive the car.


hopefully this was a worthwhile post...

Listen, that is real life, this is GT4. You people seem to think GT4 is more realistic than it really is. IT'S A GAME AND IT HAS TO BE PLAYABLE BY ALL PEOPLE, NOT JUST THOSE VERY FEW WHO KNOW WHAT RAMP ANGLE IS.

For normall people, a lower number translates to less effect. So that's the way they did it in the game. So that it makes it more common sense. The ticker makes perfect sense, even to my friend who knows nothing about cars. I had him read it and even he knew what affect changing things had.

I have tested which is the locked diff. side in GT3 and 4 and the tuning setup is the same. In both games with everything set to 5, Only one tire spins (i.e. Peg Leg) and only one trail of smoke and car understeers with wheelspin. With everything on 60 both tires are always spinning at the same rate and both tires smoke and the car won't turn w/o wheelspin and is very lose (ie. oversteer) with wheelspin. What you posted refers to ramp angle and real life. What I posted refers to how the game makes this tunable for all people. INCLUDING THOSE WHO DON'T KNOW MUCH ABOUT LSD.

THE TICKER MAKES SINCE. DO YOU WANT ME TO POST WHAT IT SAYS?
 
is it the inside or outside tire that spins tho?

that makes a HUGE differnce.

ps. please dont talk down to me, i know how to read thank you very much 👍
 
Shoes_98ls
is it the inside or outside tire that spins tho?

that makes a HUGE differnce.

ps. please dont talk down to me, i know how to read thank you very much 👍

On level 5 its the inside for sure.

Sorry, I didn't imply that you didn't know how to read. :lol: I just thought you might be reading the wrong one, or having a problem relating it to the diff. settings.
 
haha ok 👍

i didnt mean to say "you suck" for the post i quoted if you read it as that. i was just posting what works for me and tried to back it up with the info i used to base my settings off of.

my way works for me, so regardless of who is right as far as how the diff acts... i guess that is all that matters :)

back to drifting lol
 
Exactly. Bottom line. PLAY WITH IT TILL IT WORKS FOR YOU.

Knowledge is the key, but only experience can turn it. The key is usless if it cannot be turned. Also, you cannot turn a key that doesn't exist.
 
rsmithdrift
For normall people, a lower number translates to less effect. So that's the way they did it in the game. So that it makes it more common sense. The ticker makes perfect sense, even to my friend who knows nothing about cars. I had him read it and even he knew what affect changing things had.

The official GT4 manual confirms this, it has quite a good section on diff settings and quite clearly states that in the GT4 settings a lower value means a lower effect.

I quote

"It might be difficult to understand that a lower value actually improves the effectiveness of the system. To enable you adjust these values more instinctively in GT4, the order has been reversed. This may irritate purests, but it simplifies settings (and the underlying theory) for the rest of us."

From p83 of the UK version of the official guide.


Hope this helps

Regards

Scaff
 
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