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Question about FWD oversteer
(16 posts, started )
Question about FWD oversteer
Pardon me if there is something similar but I couldn't find any.

So, given that LFS physics are probably still the most accurate out there, what about its FWD oversteer (especially when lifting off or braking while on turn)?

It occured to me that I never had problems with any FWD car drifting uncontrollably. Only chance is to have one of the rear wheels touch some grass or something.

Watch these:
@6m47s http://www.youtube.com/watch?v=ipqRXwfSLzU#t=6m47s
@1m20s http://www.youtube.com/watch?v=oSQ2ieyvaJ0#t=1m20s
the classic http://www.youtube.com/watch?v=2cW6WuhFH2k
http://www.youtube.com/watch?v=MbPdW1_ZMNQ

Nothing like this has ever happened in LFS. So, is it just the old physics waiting to be updated blah blah, or am I missing something?

edit: Well it's been asked again, but the question remains.
It really depends on steering input and throttle input, reason why FWD cars tend to oversteer 'uncontrollably' is normally either lack of heat in the rear tyres, or lack of throttle input at high speeds, which causes a decrease in front wheel speed and almost causing a braking effect, which removes some weight from the inside rear wheel causing the outside wheel to loose grip.

the usual reason is the resistance on the front wheels, and the normality of FWD cars being quite light in the front compared to rear.
Yeah but I couldn't reproduce that ingame. I tried with cold tires, braking on the turn or letting go the throttle etc but it would just slow down and/or go off-line.
I suspect that it's partly down to physics, and partly down to setup. You should be able to get a fair bit of lift-off oversteer in the XFG if you use enough ride height, soft enough ARBs, realistic (road car) camber, normals in the rear, an open differential etc. Trying it with loads of coast lock/preload, hybrids and and all that jazz is definitely going to make it difficult even if you're putting effort in it.
#5 - Nilex
1st link - sudden wheel turn under braking, going thru a corner
2nd - half throttle, speed decreasing, going thru a bumpy corner
3rd - rear wheels locked at turning point, front wheels turned wrong way
4th - braking hard on the apex, probably rear wheel locked
Not even going into setup differences, all these situations will produce same result in lfs, physics are already good enough to replicate those. Your best laptimes aren't yet fast enough to experience this on a regular basis. I dare to say it has happened to you before and you just forgot about it.
In XFG, put normal tires in the rear like those guys in the videos and experience oversteer extravaganza.
For lift off oversteer, I find it mostly relates to setup. The UF1000 and the FXO would the best to experience it. Download some setups from Setup grid etc, you will get plenty of oversteer in the FWDs with a lot of these setups.
Agreed, the setup can make a big difference to how easy it is to get lift-off oversteer.
I have a few FXO sets where, if you get the timing right, you can pretty easily get round mid-high speed corners with almost zero steering input.
Some other setups have so much understeer, you've almost got to give it a Scandinavian Flick to get round some corners.
It is all down to setup. In LFS we generally use locked differentials for fwd cars, whilst is actuality, open differentials are generally used in fwd road cars.

A locked differential causes a fwd car to understeer off power, and 'oversteer' on traction. This is because a locked diff causes both tyres to always spin at the same speed, but not to always receive the same amount of torque.

On corner entry (presuming 0% throttle so 0% input torque) this causes understeer because the inside wheel is spinning too fast for the radius of turn it is trying to do (or conversely, the outside wheel is spinning too slowly). On throttle this causes 'oversteer' because more force is produced at the outside tyre because it has more weight on it. (F=mu*N). In reality obviously this is limited by the max grip of the tyre.

In a normal road car, it will use an open differential. This means that the wheels are allowed to spin at different rates, but will always receive 50% of the torque. This means that, on entry, the outside wheel is allowed to spin faster than the inside wheel, causing the oversteer (it will spin faster because it is travelling farther). The car will then understeer on throttle because the inside tyre will spin faster due to there being less weight on it.

Feel free to tell me that I'm wrong or that I'm shit at explaining things.
All those videos you show are pretty much just result of bad driving inputs. Especially the Nordschleife one. Car actually starts to oversteer very gradually, there is lots of time to react but the driver fails to pretty much do anything. He countersteers when the car is pretty much spinned over already.

Make oversteery setup for XFG (comparatively tight rear and soft front) then drive provocatively and fail at correcting. You will spin.
test this in blackwood , i get lots of oversteer when playing with xfg with race setup
Thank you all for your inputs. I tested the XFG with your suggested setups (standard-ish) and it really oversteered, although I had to make it intentional (the race setups give me huge oversteer, but always controllable and, well, useful).

I still think that it's more forgiving than real life though. I struggled to make it >90º "by mistake", and when it did, it was because I provocatively braked hard (sometimes even blip) or lifted off, with some intentionally late correction. Or well, maybe the drivers in these videos are more clueless than I think (except for the onboard one which is because it can happen in racing, he goes very fast and he steers instantly when the co-driver shouts "cut, CUT").

Maybe it's indeed a setup thing. With my XFR (I drive it almost exclusively) I never get this behaviour even when top lapping and I am on the grip limit, even if it oversteers, I can correct it, unless I touch grass or hit a big bump/kerb which is often an instant 180.

Quote from JackDaMaster :..

I can't actually validate what you said, but it made a LOT of sense and explained a lot. Cheers.
In iracing, which apparanty has best fisix ever, the kia drifts more than a 70,s f1 car in first gear
Braking hard isn't going to give you lift-off oversteer, just understeer. Best result should come from applying just a tiny amount of brake while progressively lifting off (or just modulating) while turning into the entry of a corner.
Quote from Bmxtwins :In iracing, which apparanty has best fisix ever, the kia drifts more than a 70,s f1 car in first gear

The Kia has an open diff. You have to turn it off the throttle and go for a straight exit.
Quote from NotAnIllusion :Braking hard isn't going to give you lift-off oversteer, just understeer. Best result should come from applying just a tiny amount of brake while progressively lifting off (or just modulating) while turning into the entry of a corner.

Yeah consider it a mistake, although that's why I said blip in the parenthesis, touching the brake a little just gets the car out of traction.

Watching videos of crashes, I am surprised by the amount of FWD oversteer-caused ones.
I have a "drift" setup for the XFG which somebody sent me a while back. Quite tail-happy having knobblies for the rear wheels. Definitely doesn't truly drift though.
Attached files
XFG_drift.set - 132 B - 1124 views

Question about FWD oversteer
(16 posts, started )
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