lsd question

[satchelmcqueen]

i love driving the 70 challenger and the only problem i have is the bad under steer.

tell me if im right in my tweeks. ive raised the rear and lowered the front. ive also put lsd initial to 50
acc to 30 and decel to 10

so my questions are... do i have the ride height backwards or is it correct to induce more over steer? and the lsd initial....is the value related to the amount of pedal i give? in other words if i set it at 20 would it not kick in until i went 20% with throttle?

ty

 

[787bcgr]

Remember that both initial torque and accel play a role in under and over steer, the higher each of these values are, the more likely the chance for under steer. Try decreasing accel a bit more. Also consider the weight distribution of the car. If I'm correct, the challenger is a front heavy car, which is a reason for it's under steer on entry and snap over steer on exit. A softer rear spring rate should help with transferring weight to the rear, and neutral to negative rear toe helps with corner entry. Rear camber helps in kicking out the rear tires too. A higher front compression rate helps get the nose of the car to dip more, aiding in corner entry, while higher front extensions helps with corner exit. Rear extension, when increased, increases over steer, while rear compression increases under steer.

 

[GTP_CargoRatt]

https://www.gtplanet.net/forum/showthread.php?t=203009

This is an excellent guide written by a real race driver that knows a thing or two about how the LSD works. He has done in depth study and testing in this area so rest assured, you can trust what he says. He also gives great tuning advice so be sure to read his tuning guide also.

https://www.gtplanet.net/forum/showthread.php?t=167421

 

[claudiorz]

Remember that both initial torque and accel play a role in under and over steer, the higher each of these values are, the more likely the chance for under steer. Try decreasing accel a bit more. Also consider the weight distribution of the car. If I'm correct, the challenger is a front heavy car, which is a reason for it's under steer on entry and snap over steer on exit. A softer rear spring rate should help with transferring weight to the rear, and neutral to negative rear toe helps with corner entry. Rear camber helps in kicking out the rear tires too. A higher front compression rate helps get the nose of the car to dip more, aiding in corner entry, while higher front extensions helps with corner exit. Rear extension, when increased, increases over steer, while rear compression increases under steer.

Mmm... you got most of that wrong :/. More lsd accel = more oversteer whilst more lsd initial = more understeer. Also, for controlling weight transfer you have to tune the dampers, not the spring rates. Finally, high front compression rate means the nose will take more time to come down under braking so it induces understeer, high rear extension increases understeer and high rear compression increases oversteer.


For the Challenger I would recommend first of all to lower that initial lsd rate, 50 is way way too much and you will be understeering all the time. You want to start with something like 10 and see how it goes, and I would also say that 30 accel is pretty high and you will be suffering from corner exit oversteer, so lower it. On sport tires you should be somewhere between 10-20, and 15-25 for racing tires.

Then you can modify the weight distribution to something rear-biased so the car is less likely to oversteer on corner exit (and as a bonus, it will be faster in a grid start due to better traction), and if you are still oversteering on corner exit, add some positive rear toe.

Also a high front extension and low front compression (you can start with something like 8-3 for example) so the car suffers less from corner entry understeer, and something like 2-3 or 3-4 anti-roll bars to help mid-corner understeer. This can induce oversteer if your rear dampers are too high, so fine tune it using rear toe and initial lsd until you find yourself comfortable with it. Brake balance is also useful for corner entry understeer, more rear biased = more oversteer.

Springs can be used too to increase oversteer or understeer. They are backwards in GT5, so higher front = more oversteer and higher rear = more understeer. Personally I don't like running too extreme spring values on anything that isn't race tires, but sometimes for really understeery cars it can be useful to raise the front rate and lower the rear if everything else doesn't seem to be enough.

Finally you can raise front camber and lower the rear camber for better corner entry, but do not lower the rear too much or you might end up spinning in a sweeper.

Hope it helps.

 

[GTP_CargoRatt]

Mmm... you got most of that wrong :/. More lsd accel = more oversteer whilst more lsd initial = more understeer. Also, for controlling weight transfer you have to tune the dampers, not the spring rates. Finally, high front compression rate means the nose will take more time to come down under braking, high rear extension increases understeer and high rear compression increases oversteer.


For the Challenger I would recommend first of all to lower that initial lsd rate, 50 is way way too much and you will be understeering all the time. You want to start with something like 10 and see how it goes, and I would also say that 30 accel is pretty high and you will be suffering from corner exit oversteer, so lower it. On sport tires you should be somewhere between 10-20, and 15-25 for racing tires.

Then you can modify the weight distribution to something rear-biased so the car is less likely to oversteer on corner exit (and as a bonus, it will be faster in a grid start due to better traction), and if you are still oversteering on corner exit, add some positive rear toe.

Also a high front extension and low front compression (you can start with something like 8-3 for example) so the car suffers less from corner entry understeer, and something like 2-3 or 3-4 anti-roll bars to help mid-corner understeer. This can induce oversteer if your rear dampers are too high, so fine tune it using rear toe and initial lsd until you find yourself comfortable with it. Brake balance is also useful for corner entry understeer, more rear biased = more oversteer.

Springs can be used too to increase oversteer or understeer. They are backwards in GT5, so higher front = more oversteer and higher rear = more understeer. Personally I don't like running too extreme spring values on anything that isn't race tires, but sometimes for really understeery cars it can be useful to raise the front rate and lower the rear if everything else doesn't seem to be enough.

Finally you can raise front camber and lower the rear camber for better corner entry, but do not lower the rear too much or you might end up spinning in a sweeper.

Hope it helps.

That little piece of info is highly debatable and should not be stated as fact.

 

[787bcgr]

Higher accel values increases understeer due to the differential working more to maintain equal wheel spin, the higher the value, the closer it is to lock. The thread posted by Cargo also explains it in more detail.

 

[claudiorz]

Higher accel values increases understeer due to the differential working more to maintain equal wheel spin, the higher the value, the closer it is to lock. The thread posted by Cargo also explains it in more detail.

Higher accel values will result in outside tire spin, which will result in the outside tire wanting to "overtake" the front of the car, which will result in more corner exit oversteer, therefore you should use high accel setting with grippy (racing) tires and lower it a bit with sports, because the grip threshold will be lower and the outside tire will spin easier. If you run low accel you will be baking the inside tire but the outisde one won't spin, and because of that it will be much harder to spin when accelerating out of a corner. At least that's what I've noticed, and actually is what most people use when tuning.

 

[claudiorz]

That little piece of info is highly debatable and should not be stated as fact.

Well, I didn't mean to make it sound like the absolute truth, but it's what I've been observing. I've been tuning some really understeery cars on racing tires lately (Enzo, McLaren MP4-12C and many 4WD cars that don't want to turn) and it's been working for me to raise front springs (amongst many other things, of course) to help with the understeer. It seems to make the front of the car much less lazy on corner entry.

 

[787bcgr]

I find cars more understeer prone with higher acceleration values. I mostly use high values ( above 35) for cars with 450 + horse power. I also mostly tune on low grip tires, and find that lower values help in maintaining overall balance throughout a race.

 

[GTP_CargoRatt]

Well, I didn't mean to make it sound like the absolute truth, but it's what I've been observing. I've been tuning some really understeery cars on racing tires lately (Enzo, McLaren MP4-12C and many 4WD cars that don't want to turn) and it's been working for me to raise front springs (amongst many other things, of course) to help with the understeer. It seems to make the front of the car much less lazy on corner entry.

Well, that's fine, whatever works for you. But you shouldn't state that as fact, that those settings are backwards in the game because others, like myself, believe otherwise. I have also tuned the Enzo and I can tell you my spring rates are about equal. I tuned out understeer by way of the LSD setting mainly along with toe and camber.

 

[Motor City Hami]

Thanks for the support CargoRat.

I have put a lot of time into tuning in GT5. The only three settings that I will say with 100% confidence that work the way I have described them in my guides are the three LSD settings. Read the LSD tuning guide and your tunes will instantly get better.

As for all other settings in GT5, I know what works for me, but the rules don't apply to every car. That's one of the odd things about GT5 is that for some cars, tune settings seem to work more like real world and for other cars you have to go to extremes to find the quickest settings. Plus, my method, Praino's method, Dr. Slumps, all the guys at Clueless, trackripper, digitalbaka, RKM all work. It kinda seems car dependant a bit. I think it has more to do with which cars we have real interest in. As a tuner, if you like a car, you spend more time with it.

 

[GTP_CargoRatt]

No problem Hami. You taught me, and taught me well and really helped me out in the beginning. You never steered me wrong, so I know where to send people when they need help, especially with LSD settings.

 

[MrGrado]

i love driving the 70 challenger and the only problem i have is the bad under steer.

tell me if im right in my tweeks. ive raised the rear and lowered the front. ive also put lsd initial to 50
acc to 30 and decel to 10

so my questions are... do i have the ride height backwards or is it correct to induce more over steer? and the lsd initial....is the value related to the amount of pedal i give? in other words if i set it at 20 would it not kick in until i went 20% with throttle?

ty

Look for ready built tunes for this car. Try them and also mix the settings up a bit (like LSD settings from tune 2 on tune 1 etc).

Trial and error is the best way to find good LSD settings on very high torque cars, especially american cars from 70's.
Try:

all settings high
High initial, low accel, low decel
high initial, mid accel, mid decel
low initial, high accel, low decel
... etc.

I have a tune on a 70's muscle car with high initial and mid-low accel and decel. With this set up the differential will not be in free spool so much but will still give good turning while active.

I generally use higher than normal LSD settings for old muscle cars and high power MR race cars.