LSD Set and Forget, or Retune?

[motzkopf]

So I'm about to dive into tuning the LSD(s) for my cars. Once I've dialed in my accel and decel, will I have to readjust when I change tires? Is dialing in the accel and decel only good for the weight, tire, and power setting at that time I just want to know whether I can keep my general LSD tune online when the max power, tires, and/or PP changes?

 

[SolidSnake7735]

So I'm about to dive into tuning the LSD(s) for my cars. Once I've dialed in my accel and decel, will I have to readjust when I change tires? Is dialing in the accel and decel only good for the weight, tire, and power setting at that time I just want to know whether I can keep my general LSD tune online when the max power, tires, and/or PP changes?

in my opinion, there is no set-and-forget with LSD. though it isn't all that necessary to make any changes to it when you change the power, PP. but when you change tires i believe it is definitely worth changing it up. Once you find the ideal initial torque setting, that should remain the same throughout your setups for that particular vehicle but the accel/decel should change with the tires along with the suspension as grippier tires can stand having higher spring and dampening rates

 

[Poontanir]

Having done some reading up on the topic, it seems race engineers want the diff to be as open as possible. Meaning if you have plenty of grip Don't bother with LSD; even then most run very little to no decel. I'd like to make sense of the numbers GT is using in respect to the engineering formulas I have found so I'm hoping I find time in my 18 unit schedule.

 

[CSLACR]

I usually don't move my lsd far from 7/11/5 on most anything anymore. It's my sweet spot.

 

[SolidSnake7735]

it depends on driving style just as much as the car.

on an S2000 i would have it at 5/55/10 but an M3 I'd have it 5/20/15 then an NSX 13/30/13

 

[Rotary Junkie]

So I'm about to dive into tuning the LSD(s) for my cars. Once I've dialed in my accel and decel, will I have to readjust when I change tires? Is dialing in the accel and decel only good for the weight, tire, and power setting at that time I just want to know whether I can keep my general LSD tune online when the max power, tires, and/or PP changes?

LSDs are a bit tricky. Higher settings (on accel/decel) are theoretically faster but too high results in being slower due to making the car more difficult to drive and/or impossible to drive.

You'll need to retune for different tires and power levels if your diff was aggressive enough in the first place. If not, you may well be fine.

 

[shmogt]

LSDs are a bit tricky. Higher settings (on accel/decel) are theoretically faster but too high results in being slower due to making the car more difficult to drive and/or impossible to drive.

You'll need to retune for different tires and power levels if your diff was aggressive enough in the first place. If not, you may well be fine.

Yes a retune for different tires is usually the case I find as well depending on how much HP and torque the car has.

One way around this I have found was set initial fairly low have acceleration very high and have the braking even higher than it. The revs will fly up but instead of burning up the tires it will just hit the rev limiter and try to rev more without spinning the tires faster. I do this style LSD on cars that are very fast acceleration to make sure they aren't spinning up the tires none stop. The crazier the car is the lower the acceleration compared to braking is.

For me I find initial is what is really gonna give you the problems. When I set mine in the higher levels the car almost always understeers when exiting corners. When I set it low but do the trick where braking is super high and acceleration is high the car will not understeer and I still get all the quick acceleration and faster speeds.

 

[MTLclllutch]

I usually don't move my lsd far from 7/11/5 on most anything anymore. It's my sweet spot.

yea pretty much at the same spot, i wouldnt call it the sweet spot as the spot it should start default! I have been fidling with the decel and some questions popped in my mind. eg, im pushing the card hard through corners and the back end comes out during hard throttle. So i let off and the decel kicks in. Do i want it to lock while im sideways during decel. For this to happen decel needs to be close to 20 or so. IF it does lock i find im able to get the car set and the power back on faster since i dont have to wait for the diff to go through the initial torque phase of unlocked to locked. ideas? Anyone with race time under the belt would probably know the answer.

 

[BBJR22]

just put everything to 5 its much better -__-

 

[MrGrado]

Recently I am typically using LSD values between 20 and 50.

 

[CSLACR]

yea pretty much at the same spot, i wouldnt call it the sweet spot as the spot it should start default! I have been fidling with the decel and some questions popped in my mind. eg, im pushing the card hard through corners and the back end comes out during hard throttle. So i let off and the decel kicks in. Do i want it to lock while im sideways during decel. For this to happen decel needs to be close to 20 or so. IF it does lock i find im able to get the car set and the power back on faster since i dont have to wait for the diff to go through the initial torque phase of unlocked to locked. ideas? Anyone with race time under the belt would probably know the answer.

I'm not completely sure what you're asking, but for racing, and TT's, I pretty much stay in the 5-10/8-15/5 department, usually running my 7/11/5.

LSD decel higher could theoretically add traction, I'm just not convinced it does in GT5.
Either way, I'd rather burn some rubber on the inside wheel here and there, then spin out, in any and all cases.

 

[Lambob]

My driving style requires a certain LSD / suspension setting, that won't penalize me for taking certain sections on the Nurburgring, like a bat out of hell. The first sector of the Nordschleife, (first 1:16s to split time in a 505pp), what ever setting allows me to get this time, I set. Often times, the Decel setting ranges from 9 to 12.

If I set Decel too low, the car will oversteer, or rubber band from too much frontend variables, as I take a series of chained chicanes, mid-off throttle.
If I set it too high, the car will understeer into the grass, but won't bend my chassis like a dollar store spoon.

I wish we could start the Nur halfway mid track, to test settings there too, without having to drive three minutes to get there.

 

[MTLclllutch]

I'm not completely sure what you're asking, but for racing, and TT's, I pretty much stay in the 5-10/8-15/5 department, usually running my 7/11/5.

LSD decel higher could theoretically add traction, I'm just not convinced it does in GT5.
Either way, I'd rather burn some rubber on the inside wheel here and there, then spin out, in any and all cases.

try this, take a car that has very good front end authority and throw the front of the car into a corner. With the decel up in the 20s it will lock once your car gets sideways and will hold the car at a constant angle or straighten it out. I have used this on a couple of tail happy cars and it seems to make a big difference. At decel 5 it just seems like the car continues to drift unless you take action counter steering hard.

 

[JayBear]

Does anyone understand anything about what the actual increment value represented in the tuning area? Example: The spring rate numbers are maybe 5.0 - Min and 20.0 Max. What is that? 5.0 what to 20.0 what? ftk's per mm? Or what about ride height? -25 to 15,....what? What is the increment of measurement?

Another place is the aero package. What does 50 or 85 mean? Is that 50 kilo's? When you have race cars producing 1000's of pounds of downforce(Formula's at 3000lbs), those numbers do not make any sense. This is especially made difficult when you see the same range in grandma's sedan as you do an R8 racer.

 

[CSLACR]

try this, take a car that has very good front end authority and throw the front of the car into a corner. With the decel up in the 20s it will lock once your car gets sideways and will hold the car at a constant angle or straighten it out. I have used this on a couple of tail happy cars and it seems to make a big difference. At decel 5 it just seems like the car continues to drift unless you take action counter steering hard.

Well, LSD decel only works when you're off the throttle, and generally speaking, I don't fully lift throttle to stop slides, because it slows you down to much, so I don't know.
I use a 5 decel because when I'm downshifting into a corner, I'd rather the inside wheel spins, and my outside (grip tire) keep it's grip.
An added benefit is a low decel rating allows the car to rotate more freely when trailing throttle into/through corners.

Does anyone understand anything about what the actual increment value represented in the tuning area? Example: The spring rate numbers are maybe 5.0 - Min and 20.0 Max. What is that? 5.0 what to 20.0 what? ftk's per mm? Or what about ride height? -25 to 15,....what? What is the increment of measurement?

Another place is the aero package. What does 50 or 85 mean? Is that 50 kilo's? When you have race cars producing 1000's of pounds of downforce(Formula's at 3000lbs), those numbers do not make any sense. This is especially made difficult when you see the same range in grandma's sedan as you do an R8 racer.

The only one I know that makes any sense is ride height, which is millimeters, the rest I assume to be generic numbers, just to be used as a min/max scale, nothing more.

 

[chuyler1]

Anyone that gives you ballpark settings simply doesn't drive enough cars and or tire compounds.

Every car is different. Every tire is different. Sometimes you can get away with using LSD settings for SH tires when you run SM or SS tires (or RH settings on RM or RS), but going backwards doesn't usually work well.

 

[CSLACR]

Anyone that gives you ballpark settings simply doesn't drive enough cars and or tire compounds.

Every car is different. Every tire is different. Sometimes you can get away with using LSD settings for SH tires when you run SM or SS tires (or RH settings on RM or RS), but going backwards doesn't usually work well.

-OR-
They like what they like. My preference to the way a car handles doesn't change from car to car, nor tire to tire.
Even on comfort tires, I still don't like going over 15 or so for accel, because it start kicking the back end too easily to really keep it on the edge, without going overboard more then I like.

 

[Motor City Hami]

Anyone that gives you ballpark settings simply doesn't drive enough cars and or tire compounds.

Every car is different. Every tire is different. Sometimes you can get away with using LSD settings for SH tires when you run SM or SS tires (or RH settings on RM or RS), but going backwards doesn't usually work well.

+1 chuyler - Very different LSD needs between drive trains and power. I tend to tune using two compounds harder of tire than I intend to race on because of what you described. Softer tires can mask an LSD issue. That's why it works better going the other direction - tune on harder tires - race on softer tires.

Online and offline can be very different, depending upon the car.

 

[JayBear]

+1 chuyler - Very different LSD needs between drive trains and power. I tend to tune using two compounds harder of tire than I intend to race on because of what you described. Softer tires can mask an LSD issue. That's why it works better going the other direction - tune on harder tires - race on softer tires.

Online and offline can be very different, depending upon the car.

I absolutely agree Hami. If you can make a car stick with the harder compound then it thrashes the competition on the softest tires. It is clearly evident with this axiom from my profession. Slow is smooth and smooth is fast. Smooth lines based on a great tune will definitely put a lower HP car across the line faster when the high HP car is wildly out of control. I guess that is why better qualifying times happen after spending the time on the hard tires tuning.

By the way, thanks for doing all that work compiling your car lists and tuning specifications along with the LSD information. Very very informative and helpful I might add.

 

[chuyler1]

-OR-
They like what they like. My preference to the way a car handles doesn't change from car to car, nor tire to tire.
Even on comfort tires, I still don't like going over 15 or so for accel, because it start kicking the back end too easily to really keep it on the edge, without going overboard more then I like.

My preference on the way a car handles doesn't change either, but I find it necessary to use different settings on different cars to get that preferred handling. I usually end up with low settings, but they will often vary by 2-5 clicks between cars of the same power and drivetrain class. I just don't see a set it and forget it value that can account for jumping between tire classes and or power classes.