The online racing simulator
Sincere question re:oversteer
(13 posts, started )
Sincere question re:oversteer
Like I posted in my "I'm back" thread, I'm very glad to be back in LFS land. One thing that I cannot figure out is a certain behaviour I experience with most cars. I will try to describe it as best as I can and hopefully someone can tell me what's up and what's causing it.

I'm driving along at moderate speed aproaching a medium corner. Yhe car does something strange in the middle of the corner. At least it's strange to me becuase I cant seem to duplicate this behaviour in ISI sims. Anyway, please correct me if I'm wrong, but if i tried to take a corner at decent speed without fear and my setup was crap, I should just push into the outside wall right? What happens in game is that the car seems to just loose all grip in this scenario and the backend swings around in towards the outside of the turn. Like I said, I would expect to be on the outside wall becuase I'm either going too fast and loosing grip or my setup isn't set up for good turn in. Anyway something happens and my car acts like I just applied the handbrake and swings my ass around. What is this called and why does it happen. I haven't tried this in real life so I'm not sure if it's normal or the flaw some people mention with LFS physics. All i want is an explanation so I can just get back to enjoying my time with LFS instead of figuring out how to correct it. Everything else is top notch.

Thanks
#2 - axus
LFS is only noticably unrealistic at low speeds. The way the car behaves in such a violent maneuvre is down to its suspension settings, wheel alignment, road surface (bumpy, inclined, flat, whatever), center of gravity, tyre pressures, brakes and throttle posiotions when beginning to steer, how violently you steer, etc etc.

http://www.miata.net/sport/Physics/01-Weight-Transfer.html

A replay and a setup would be a nice place to start when posting such a thread because we really cannot guess what all these things are without knowing what car it is, and what sort of setup it is (you can easily make a car understeer when steered violently with the vast array of settings available to you in LFS). Without knowing this we cannot tell you what causes the spin.
Here's the replay. All the way at the very end. Prolly not the best example. But this happens to me alot. Maybe it's just me. I'll try and get a better example, but this is a start. Is there a way to make the speedo give me MPH instead of KPH? I hate not being able to tell how fast I'm really going.

Thanks
Attached files
LostIt.raf - 1.1 MB - 110 views
#4 - axus
Unit settings are under Options -> Player
This is telematry data from your replay, not your actual replay. The replay will be in the spr folder. The setup will be in the settings folder.
#5 - Gunn
When you say "no cars", which cars in particular do you mean?
You say you expect the car to run wide off the track if you push too hard? Make the setup very understeery and I assure you the same thing will happen in LFS.

Also try to remember you should really be comparing LFS to real life rather than another sim (which is also unlikely to be perfect), particularly one using the ever-so-popular ISI engine.
Did you try increasing the rear ride height a little at a time to see if it reduces the tendancy to snap oversteer?
You might be bottoming out.

Sometimes, you can hear the car scraping, but sometimes you don't and jacking up the rear a bit can make a car more predictable.
You can also bottom out on the bumpstops which could make the rear rebound a little, making it lighter, therefore losing traction.

I've had this happen at times myself and i think it's also related to the unpredictable reaction when riding a curb's edge (sometimes
violently sending the car on 2 wheels). I suspect a peak in the 'absorbtion' part of the suspension. Probably both in the bumpstop
and the tires, which could explain why the tires sometimes display weird behaviors before these 'bugs' (hey tire deformation can
also be a debug tool ! hehe). Once the absorbtion is saturated (i'm trying to vulgarize here), the reaction is the same in most, if not
all collision bugs in LFS, large and rapid rebound. In more simple terms, things seem to rebound much more once you reach a certain
force.

Of course it could also be that once you bottom out, there is no more suspension so it's sure not to help traction once you hit the
smallest road irregularity
You would be surprised how real cars can sometimes react in uncertain ways . . . The Audi TT had to be recalled because it had a tendancy to swap ends whilst cruising down the motorway. Although it was more a design flaw that didn't get caught than an actual handling 'bug'.

Watch some indi or any racing for that matter and you will notice that alot of race cars 'snap' and not always in the direction you would think.

Alot of fast setups are designed to have an 'edge' to them, it whats makes them fast. Some drivers like that and can control them,, some drivers prefer a more stable but potentially slower setup. Horses for course and in LFS you can set the car to make it more realiable for you in corners. But then where would all the fun be?

Work on a setup mate and you will find the car comes to you.
Whoops, sorry, clicked reply in the wrong thread. That's what stinks about dialup. I go to new posts and right click them all and "open in new window" so I don't have to sit waiting for them to load. I can read the first loaded, while the others are still loading. Sorry again :-)
Quote from Bob Smith :You say you expect the car to run wide off the track if you push too hard? Make the setup very understeery and I assure you the same thing will happen in LFS.

Also try to remember you should really be comparing LFS to real life rather than another sim (which is also unlikely to be perfect), particularly one using the ever-so-popular ISI engine.

I hear ya Bob. I should be comparing to real life cars but all I do is sim race :-) Basically I was using the default setup on the XRG or XRT, not sure which. Not sure if that setup is really oversteery or not. But when I take a corner too hard, it's almost as if the rears loose grip completely and swing around. Just seemed odd to me. If this is working as designed and I have a flawed setup I'm kewl with that. i guess I need to do some setup tweaking.

Thanks
Almost all real cars are designed to understeer. It is a safer condition for unskilled drivers to handle understeer than oversteer. When you understeer, lifting off the gas and some braking will usually resolve the situation. When you car starts to oversteer because of lateral loads, adding a touch of gas is what needs to happen. Most drivers IRL will not react this way so they will lose control.
So, in LFS, we generally setup cars to be a bit on the oversteer (or loose) side. It is faster because you can turn in better and the car will continue to turn through the corner. However, you do have to learn how to balance the car on the throttle. Small power applications at the right time is the key.
The other oversteer condition is when the rear tires lose grip because of too much power applied for the conditions. This condition is fixed by lifting off the loud pedal, but be ready for a nasty snap back.
Yeah, ISI sims generally seem to be set up by default with major plough on understeer, even in RWD race cars.
The stock setups I found straight away to be really bad. I assume it was just my driving style etc, I mean that in no way to be a knock at the Devs or whomever put the sets together. Having played around with sets myself and used some 'imports' there are far better setups out there that give the cars much better neutrality. Often in ways that you wouldn't have intitially looked at (Nose high running for instance, although I assume with the introduction of new physics that will change. And the roll bar settings is something that I can never work out properly. You read the manuals and the actual settings needed for certain tracks and the fastest times are completly counter intuitive . . .but hey ho. Thats what makes it fun.)

Just ask around, collect a few setups from people. Try and work out a few yourself (It's quite hard to do I found, but it is great for learing about how it all works) you'll soon find that your car settles down to your driving style and visa versa.

The thing that I do actually enjoy about LFS is that it does reward good driving. If you show good car control and are sympathetic to RW handling principles the in game world responds to you in a very positive way. You can't go hairing around corners at break neck speeds, just like you can't in RL. There are definite and clear limits to the physics, just like there is the Real World. If you get to close to someone, there is gunna be tears at bed time unless you are both very compitent drivers. Downforce plays a major factor. So many things effect the way the cars handle and you drive. I like that, it makes sense. But then so many things don't make sense either. Maybe that reflects RL too.

Sincere question re:oversteer
(13 posts, started )
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