I think he means the way in which it acts with regards to the handling is wrong.

Im no expert, but other people have stated that locked-diffs should jump and skip around alot and also be incredibly difficult to handle. However, LFS seems to make them perfectly smooth at least, although they do make the handling harder but more stable.

Quote from tristancliffe :

Axus - how can locked diffs be wrong? All you do (which LFS does) is ensure that the wheel speeds on that axle are the same at all times? I can understand it when people say the clutch pack is incomplete, but a locked diff seems one of the simplest things in the world to program...

(not being rude, I'm genuinely asking how you think a locked diff can be 'wrong').

Never said that they were - I said the clutch pack was incomplete, but during my argument with Kid, I ended up saying something that I didn't mean.

Fair enough. I think Bogey's point is valid too.

*re-reads own previous post*

Eeeeeh.. I'm not making much sense again. Tired and trying to code but it seems like I either need to re-write a huge chunk of code or stick with some ugly and annoying code.

Anyway, bogey's point is certainly worth looking into - I'm just thinking though... despite spinning at the same rate, each wheel doesn't exert the same amount of longitudinal force (too many other factors - load, temp, surface, whatnot). Surely the speed for each wheel for the next frame is not as easy as V_left = V_right then, but the force on the left wheel affects the speed on the right wheel and vice versa... I need to think about this whilst on a fresh head though - its probably really simple and I'm not thinking too clearly.

EDIT... and thinking about when they are turned, surely lateral force would come into the torque on the driveshaft too. Think about a car turning down a slope with a locked diff.

Quote from MAGGOT :

Won't that cause it to hop in corners?

all of the fastest rc cars use locked diffs so no

Quote from tristancliffe :

Axus - how can locked diffs be wrong? All you do (which LFS does) is ensure that the wheel speeds on that axle are the same at all times? I can understand it when people say the clutch pack is incomplete, but a locked diff seems one of the simplest things in the world to program...

(not being rude, I'm genuinely asking how you think a locked diff can be 'wrong').

depends on how accurately you want to simulate it
once you consider the way how the torque is transfered (via torsion of the driveshaft mainly) things get rather complicated
expecially since the drifeshaft will act a lot like a very stiff torsinal spring

Quote from Shotglass :

all of the fastest rc cars use locked diffs so no

No they don't... the last time we had this debate someone managed to find a hatchback that raced in Brazil apparantley with a locked diff, that was the only example of a R/C locked diff anybody could find. Also I think there were some people who were having a misconception that a solid rear axle was the same as a locked diff.

IRL not only would a locked diff bounce around, the load put on the driveshafts would cause them to break pretty quickly and the steering would be extremely heavy.

Quote from ajp71 :

No they don't... the last time we had this debate someone managed to find a hatchback that raced in Brazil apparantley with a locked diff, that was the only example of a R/C locked diff anybody could find.

rc cars are radio controlled cars for christs sake and all of them in the fastetst class have locked diffs front and back

Quote :

and the steering would be extremely heavy.

nonsense why would it be heavy ? the steering torque and the driving torque are pretty much orthorgonal

Quote from Shotglass :

rc cars are radio controlled cars for christs sake and all of them in the fastetst class have locked diffs front and back

I think a lot of people talk about R/C cars as being road course cars not remote control cars.

Quote :

nonsense why would it be heavy ? the steering torque and the driving torque are pretty much orthorgonal

Sorry I was thinking about LSDs then in FWD cars that can become very heavy in cars with short driveshafts. Racing Minis with LSDs are supposed to be very heavy cars.

Yup locked diffs have become the must have thing in R/C racing (1/10th touring cars). I still need to make the leap from the one way diff. Although I've never heard of anyone run them front and back.

The locked diffs in R/C cars seems to give very good acceleration out of corners but tend to be very hard on the drivetrain

Keiran

i dont think comparing locked diff R/C cars to real cars with locked diff is a good thing.. the R/C car is so light that a wheel turning too slow/fast to the other one will just make it slide a little, and for a real car with alot of weight on wheels, i do think like others said, that the car will tend to jump a little at least at low speeds, and have very heavy handling...

Quote from st0rm :

i dont think comparing locked diff R/C cars to real cars with locked diff is a good thing.. the R/C car is so light that a wheel turning too slow/fast to the other one will just make it slide a little, and for a real car with alot of weight on wheels, i do think like others said, that the car will tend to jump a little at least at low speeds, and have very heavy handling...

Agreed.

I think LFS does generate the heavy handling and understeer, but ATM these seem to be the only minor disadvantages which can be remedied in other areas of the setup. Thus there is no real penalty in adopting an unrealistic setup.

Not that I dont use it sometimes

Just to put my tuppence in - I think the locked diffs behave as they should.

Locked diffs are very hard on the driven tyres. Can't be ideal for endurance.

The locked diff definitely works as it should. The involved math isn't that complicated. However, in my opinion, the tyres don't work as they should and don't penalize setups with a locked diff correctly.

Vain

Quote from Bob Smith :

Locked diffs are very hard on the driven tyres. Can't be ideal for endurance.

but easier on the inside tyre I'd say as it won't spin up as easily. But then who cares about the inside tyre

Quote from Gentlefoot :

but easier on the inside tyre I'd say as it won't spin up as easily. But then who cares about the inside tyre

Everyone except oval-junkies.

Vain

Quote from keiran :

Yup locked diffs have become the must have thing in R/C racing (1/10th touring cars). I still need to make the leap from the one way diff. Although I've never heard of anyone run them front and back.

the 1/8 nitros and 1/10 nitros ar running on locked diffs front and back even since (at least ever since the excel and impact which probably came out at the time when those series became popular)

Quote from st0rm :

i dont think comparing locked diff R/C cars to real cars with locked diff is a good thing.. the R/C car is so light that a wheel turning too slow/fast to the other one will just make it slide a little, and for a real car with alot of weight on wheels, i do think like others said, that the car will tend to jump a little at least at low speeds, and have very heavy handling...

think again ... rc car tyres generally have a lot of grip ... and probably more grip then a comparable "real" tyre if you take the scale into account
and they run a lot faster then "real" cars as well
those 2 facts combined with the lightness of the car should if anything exaggerate the jumping and skipping you think would happen in a real car

Quote from Vain :

Everyone except oval-junkies.

Vain

doesn't matter if you are turning left or right, the inside tyre does very little.

Whilst it seems loads of people here can tell me that LFS is perfect and the locked diff is right can someone explain to me why no body uses them? Make it simple why do WTCC use LSDs?

Quote from Gentlefoot :

doesn't matter if you are turning left or right, the inside tyre does very little.

But the inside tyre of this turn will be the outside tyre of the next turn, so don't scrub it off completely or overheat it.

That's my train of thought.

Vain

Nascar's use locked diffs. THey run two road circuits a year and I've never known lsd's to be mentioned(am I right on this?).
I have herd of setups(at an oval) with the rear end jackup and the front softer. Just like several lfs setups i've seen for the xrr with a locked diff.


This rids the setup of the horrible understeer but I personally could never weed out the massive oversteer on power.
Most drivers like this power oversteer which could explain why locked diffs are so popular.

are lsd's allways faster than locked diffs in real life?
If not then lfs is doing it right(mostly)

Quote from ajp71 :

Whilst it seems loads of people here can tell me that LFS is perfect and the locked diff is right can someone explain to me why no body uses them? Make it simple why do WTCC use LSDs?

People do use them in LFS and IRL. I personally know racers who weld there open diffs up!

Quote from Vain :

But the inside tyre of this turn will be the outside tyre of the next turn, so don't scrub it off completely or overheat it.

That's my train of thought.

Vain

I know m8 - I was just being flippant - but some corners are more important than others so that's was why I made the point. And usually there are more left turns than right on an anticlockwise track and vice-versa.

Quote from ajp71 :

Whilst it seems loads of people here can tell me that LFS is perfect and the locked diff is right can someone explain to me why no body uses them? Make it simple why do WTCC use LSDs?

because
a) as youve said irl a locked diff puts quite a lot of strain on the driveshaft which lfs doesnt simulate as of yet (see tiff snapping his driveshaft during the drift competition on a car that has either a locked diff or one very close to locking)
b) real clutch packs are preloaded whereas lfs´s arent which makes them extremely unstable during shifts

Quote from -wes- :

Nascar's use locked diffs. THey run two road circuits a year and I've never known lsd's to be mentioned(am I right on this?).
I have herd of setups(at an oval) with the rear end jackup and the front softer. Just like several lfs setups i've seen for the xrr with a locked diff.

The lockers used on ovals are designed for going left and left again: http://www.detroitlocker.com/DLctr.htm

When Nascars run on r/c tracks they run with a different chassis and I'd guess an LSD or open diff. I'm not saying a locked diff doesn't have potential in usome applications ie. drag racing, oval racing, ice racing and maybe some loose surface rallying but it seems to me so wrong in a FWD car on a fixed surface racing track, I just can't believe that a permanatley fully locked diff should either be faster of possible on a FWD car given that no one can give a link to a credible source saying they are being used IRL. As some people have said they do put a lot of strain of the driveshafts which LFS doesn't simulate but they still argue nothing is wrong?