Quote from [DUcK] :

yah, i know
it just seemed that the op thought that any car would lift-off-oversteer no matter what diff it had

Of course. Silly of me to think you wouldn't.

I just did some quick laps in the two road cars in the demo and they didn't really oversteer as much as I expected them to when I lifted, with the default sets. The XFG felt alright when the tires were cold but when they warmed up it seemed to go away. The XRG didn't really do it at all.

But like Duck said, not every car is supposed to spin if you lift in a sweeper!

My car has an open front diff and LSD center and rear, and it will turn in when off the throttle mid corner. When entering a corner off the throttle it will just plough straight.

In iRacing the Spec Racer Ford and the Skippy have open differentials, but I suspect the lift throttle oversteer is exaggerated, at least in the case of the SRF (Ian Lake's setup helps tame the SRF). The Radical (best car in the free trial), had some lift throttle oversteer, and responded well to steering induced understeer to compensate, making for some nice 4 wheel drifts:

http://jeffareid.net/ir/irssrad.wmv

Lift throttle oversteer is a rear wheel drive thing, related to engine braking. I know the Formula BMW is rear wheel drive, but the wings are usually set to be understeery at high speed, so the FBMW may only show lift throttle oversteer at slower speed. Are either of the other 2 demo cars rear wheel drive?

Quote from JeffR :

Are either of the other 2 demo cars rear wheel drive?

The XFG, the hatchback is FWD, and that's the one that oversteers for me. The XRG, the coupe, is RWD and that doesn't when off the throttle. At least with the default setups.

BTW, iRacing has a free trial now?

Wasnt the Scirocco postponed because of lacking physics.
I swear to god I read on this forum that Scawen had to rewrite something in the engine to make the Scirocco handle correctly (and if I recall properly it was the oversteer that was the issue).


Ill try to search for a quote...

Here:

Quote :

The Car traction (grip) on Tracks will be more better with less understeering. So the Scirrocco takes a long time of work on the engine because they needs to be updating the physikengine. This takes automaticlly a adjustment to the physiks of the other cars in lfs.

From here:
http://www.lfsforum.net/showthread.php?t=59665

OK, so you might have to take some of it with a grain of salt.

Quote from MadCat360 :

BTW, iRacing has a free trial now?

They've had one for six months or so.

Quote :

Lift throttle oversteer is a rear wheel drive thing, related to engine braking. I know the Formula BMW is rear wheel drive, but the wings are usually set to be understeery at high speed, so the FBMW may only show lift throttle oversteer at slower speed. Are either of the other 2 demo cars rear wheel drive?

It's not just a RWD thing although that could obviously make it worse, it's a weight transfer thing.

Quote from dumbass0 :

I swear to god I read on this forum that Scawen had to rewrite something in the engine to make the Scirocco handle correctly (and if I recall properly it was the UNDERsteer that was the issue).

Fixed

Correct you are.

Lets point out a few pointers here

1. You are demo user
2. You dont know weither Demo Cars are the same as GTR's

So really I havent even tried out Iracing so you know better than me or though if you want to post a improvement doit in the Improvement section mate that might help you abit.

edit: this was @ dumbass0

It's probably somewhat logical to presume that once that's fixed that there will be more "lift of oversteer" for a given setup.

Quote from (The Stig) :

Lets point out a few pointers here

1. You are demo user
2. You dont know weither Demo Cars are the same as GTR's

So really I havent even tried out Iracing so you know better than me or though if you want to post a improvement doit in the Improvement section mate that might help you abit.

If it's a (tire) physics issue it doesn't matter much what type of car it is. The fact that he's a demo user is completely irrelevant, as is the fact that he hasn't tried the GTR cars. He also wasn't posting a suggestion, but rather had a question which is perfectly valid in General.

Quote from MadCat360 :

The XFG, the hatchback is FWD, and that's the one that oversteers for me. The XRG, the coupe, is RWD and that doesn't when off the throttle. At least with the default setups

you always set FWD oversteery and RWD understeery (or less oversteery) due to driven axis position - FWD is prone to understeer on power and RWD to oversteer (even with locked or limited slip diff - both wheels with grip). I've never heard that wheels engage forces on wheels relative to chassis not to each other
I can't see why locked diff off-throttle would make car understeer?

Quote from dumbass0 :

Wasnt the Scirocco postponed because of lacking physics.
I swear to god I read on this forum that Scawen had to rewrite something in the engine to make the Scirocco handle correctly (and if I recall properly it was the oversteer that was the issue).
OK, so you might have to take some of it with a grain of salt.

Quote from Be2K :

[Victor] was on our Award Ceremony of the DRS League in Wuppertal last Weekend. So we had a talk with him (http://forum.digitalracingseri ... 4ad9222700b2a69fa8c14473d)
but he gave us only a little overview to the VW Scrirocco and about work in LFS. So they are working on a revision of the Physikengine to get a better car controle on all tracks. The Car traction (grip) on Tracks will be more better with less understeering. So the Scirrocco takes a long time of work on the engine because they needs to be updating the physikengine. This takes automaticlly a adjustment to the physiks of the other cars in lfs.

hard to believe literally because the physics engine is one for all the cars.

Not so hard to beleive. It just means that there's things in the tire model (which is universal in LFS) that make all cars prone to more understeer than is perhaps realistic. Thus the changes they're making to better the VW will affect every single car's handling.

Quote from AndRand :

I can't see why locked diff off-throttle would make car understeer?

What car turns in easier one with an open diff or a locked one?

Quote from AndRand :

I can't see why locked diff off-throttle would make car understeer?

Because the wheels are making different radius turns, they can't spin at the same rate. The outside drags, the inside is pushed, and it creates a rotational force around the center of mass that pushes the nose of the car to the outside, creating understeer.

Quote from Ball Bearing Turbo :

Not so hard to beleive. It just means that there's things in the tire model (which is universal in LFS) that make all cars prone to more understeer than is perhaps realistic. Thus the changes they're making to better the VW will affect every single car's handling.

But it doesnt imply all the cars would need to be changed. Opposite to setups.

Quote :

What car turns in easier one with an open diff or a locked one?

right... but does easier turning in means oversteer? When you put both antiroll-bars stiffer the car turns easier but that doesnt mean it is more oversteery. Doesnt locking rear wheels evenly on brake means that inner, faster wheel brakes harder therefore turning rear even more?

Quote from AndRand :

But it doesnt imply all the cars would need to be changed. Opposite to setups.

If they change the tire physics the handling of all cars will inherantly change - which is what you already said so I'm getting confused as to what you're trying to say...

Quote :

Doesnt locking rear wheels evenly on brake means that inner, faster wheel brakes harder therefore turning rear even more?

I'm afraid you've lost me again... Bottom line is that the wheels need to be able to turn at different speeds. If they can't (locked diff), the car will resist rotation hence a tendancy toward understeer all other things being equal.

Quote from Ball Bearing Turbo :

If they change the tire physics the handling of all cars will inherantly change - which is what you already said so I'm getting confused as to what you're trying to say...

that you dont have to change all the cars when you change physics for all the cars (if the changes would imply only some setups tweak)

Quote :

I'm afraid you've lost me again... Bottom line is that the wheels need to be able to turn at different speeds. If they can't (locked diff), the car will resist rotation hence a tendancy toward understeer all other things being equal.

sorry, I am a bit mechanicly illiterate and have to figure it out - when you brake one rear wheel the car will rotate in that direction, so when you turn and brake wheels evenly... it will be easier to loose grip on inside wheel I am wondering about that because it is against my experience - with diff highly locking on throttle-off (over run) you release throttle and the car is not straightening up but loosing rear grip and spinning.

Quote from Liff :

They've had one for six months or so.

Sorry this is completly off topic, but I've been all over iRacing's site and found nothing about any free trial.

Hey,

Guys this is off-topic suggested to be closed I suppose ?

Quote from ultrataco :

Sorry this is completly off topic, but I've been all over iRacing's site and found nothing about any free trial.

Try me

@andrand - locked diff means both wheels spin identical revolutions, therefore it is acting as a solid and pushing the car straight ahead while the car is coasting (no throttle or brake)

Quote from MadCat360 :

BTW, iRacing has a free trial now?

Yes, one month. The promo code is PR-RADICAL-ONE-MONTH .

Quote from [DUcK] :

@andrand - locked diff means both wheels spin identical revolutions, therefore it is acting as a solid and pushing the car straight ahead while the car is coasting (no throttle or brake)

Precisely. And the same happens when pulling away as well.

I found this out for myself not so long ago when my mate asked me to jump in his granada and drive it upto the pitlane ready for his next race at a banger meeting as he was sorting his overalls out.

It was RWD, had a 2.8 engine and a locked diff, was on mud, and was parked behind another banger, so i jumped in, started it, turned the steering right (bloody hard to steer when parked because the power steering pump and fluid are removed for racing) selected 1st gear and tried to turn normally, as i would drive a regular car on the road.

Nope, not a chance! All it would do was push in a perfectly straight line, i ended up having to reverse back about 15 or so feet (just to make sure) rev it harder and drop the clutch to kick the back of the car sideways in the direction i wanted to go in.

Quote from danthebangerboy :

Nope, not a chance! All it would do was push in a perfectly straight line, i ended up having to reverse back about 15 or so feet (just to make sure) rev it harder and drop the clutch to kick the back of the car sideways in the direction i wanted to go in.

That's the other thing I was wondering about in LFS, putting a locked diff on the cars doesn't have as adverse an effect on handling as I thought it should. They seem to turn just as well, and sometimes even better than they do with a lsd

My hope is the physics update that has delayed VW will be enough to kill locked diffs as the popular physics exploit it is.

If after a while we see slip diffs instead of locked in WR we know the changes are good