Grippy
(Banned)
- 381
- Australia
Here, I primarily discuss rear wheel drive cars only; simply because that is what I tune regularly. And in km/hour not miles/hour. Thanks
LSD, the Limited Slip Differential is designed to limit loss of tyre-to-the-ground traction by controlling the differences in rotating speed of the left and right wheels that are fixed at the opposite ends of the axles linking up to the centralized LSD. Without an LSD your car is normally using some form of an open differential. This open differential does not restrict wheelspin very well if at all and will always be worse for hotlapping due to its inability to effectively reduce wheel speed differences in the left and right wheels under power. Now, when you push a powerful car to its limit, by hotlapping around a corner, an open differential lets the wheel with least resistance have even more power from the engine(this is unfortunately the wheel making least friction with the ground). This results in wheelspin and likely a smoking tyre(extreme loss of grip). That's how cars work and it's an inefficient design. Slap on a mildly locked LSD and U-turns are slightly disadvantaged but wheelspin is drastically reduced and you do get faster times around every corner because of this.
1. What I want to know is which wheel is most likely to get you drifting around a corner, by spinning? 2. Which wheel will get you understeering more if there was wheelspin. Does understeer come mid or late apex and from which wheel? Why? Inside or outside wheelspin? Do they change on flat and lightly banked corners?
Ive been using the data logger and tuning a whole slew of cars. I've got set 1 to RPM, steering angle, wheel speed RL, wheel speed RR, Accelerator in that order (top-down). I haven't been able to tune the LSD in combination with the suspension in a satisfactory manner. I AM looking for the bleeding edge on my competition, the "physics exploit" of LSD tuning, if you will. SPECIFICALLY if I take a LEFT corner, in the data logger the best I can do across my cars, I still get the inside RLwheel spinning around 20-30km/hr faster than the outside RR wheel on some corners, corner exit (unwinding the wheel) where I'm always near/at full throttle. Track was Bathurst. At first glance this is obviously not good for traction and hotlaps. How can I change this to the perfect, ideal of having the outside wheel spin ~20km faster than the inside wheel, possibly deifying laws of physics IRL and exploiting in-game physics to turn corners faster?
You can say "tighten the diff" but the problem there is going to be massive understeer, exponentially with every tighten of the diff and bad response especially on the turns up the mountain and very quick The Esses at Bathurst, which is one of the points you can gain allot of time.
I came to this conclusion after finding badly tuned Lsds seeing wheespin difference in excess of 60km/h (usually smoke occurs) and tuning that out to qhere I am now. So far found 20-30km/h on certain corners was all I could reduce it to without seriously hampering it in the turns and just getting slower hotlaps because of a more locked diff.
As for brakes I remember a few times I practiced trail braking, in certain cars I borrowed it was a success others difficult I'm sure the LSD decel value is responsible along with a bit of brake bias but I do not remeber what. Can someone explain this how to tune all rwd cars for trail braking technique?
LSD, the Limited Slip Differential is designed to limit loss of tyre-to-the-ground traction by controlling the differences in rotating speed of the left and right wheels that are fixed at the opposite ends of the axles linking up to the centralized LSD. Without an LSD your car is normally using some form of an open differential. This open differential does not restrict wheelspin very well if at all and will always be worse for hotlapping due to its inability to effectively reduce wheel speed differences in the left and right wheels under power. Now, when you push a powerful car to its limit, by hotlapping around a corner, an open differential lets the wheel with least resistance have even more power from the engine(this is unfortunately the wheel making least friction with the ground). This results in wheelspin and likely a smoking tyre(extreme loss of grip). That's how cars work and it's an inefficient design. Slap on a mildly locked LSD and U-turns are slightly disadvantaged but wheelspin is drastically reduced and you do get faster times around every corner because of this.
1. What I want to know is which wheel is most likely to get you drifting around a corner, by spinning? 2. Which wheel will get you understeering more if there was wheelspin. Does understeer come mid or late apex and from which wheel? Why? Inside or outside wheelspin? Do they change on flat and lightly banked corners?
Ive been using the data logger and tuning a whole slew of cars. I've got set 1 to RPM, steering angle, wheel speed RL, wheel speed RR, Accelerator in that order (top-down). I haven't been able to tune the LSD in combination with the suspension in a satisfactory manner. I AM looking for the bleeding edge on my competition, the "physics exploit" of LSD tuning, if you will. SPECIFICALLY if I take a LEFT corner, in the data logger the best I can do across my cars, I still get the inside RLwheel spinning around 20-30km/hr faster than the outside RR wheel on some corners, corner exit (unwinding the wheel) where I'm always near/at full throttle. Track was Bathurst. At first glance this is obviously not good for traction and hotlaps. How can I change this to the perfect, ideal of having the outside wheel spin ~20km faster than the inside wheel, possibly deifying laws of physics IRL and exploiting in-game physics to turn corners faster?
You can say "tighten the diff" but the problem there is going to be massive understeer, exponentially with every tighten of the diff and bad response especially on the turns up the mountain and very quick The Esses at Bathurst, which is one of the points you can gain allot of time.
I came to this conclusion after finding badly tuned Lsds seeing wheespin difference in excess of 60km/h (usually smoke occurs) and tuning that out to qhere I am now. So far found 20-30km/h on certain corners was all I could reduce it to without seriously hampering it in the turns and just getting slower hotlaps because of a more locked diff.
As for brakes I remember a few times I practiced trail braking, in certain cars I borrowed it was a success others difficult I'm sure the LSD decel value is responsible along with a bit of brake bias but I do not remeber what. Can someone explain this how to tune all rwd cars for trail braking technique?
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I missed the -, that's what forgot to add. it was always -0.16. That bold edit corrected everything even as minor as that. 
