Quote from amp88 :

edit: Here's a clip from the Discovery Channel programme Command and Control which shows Williams testing the CVT box.

Great, been wanting to see and hear that for a long time. Judging by the video I reckon it was a good thing that they banned it. Really sounds awkward with the constant engine speed, just imagine a full grid of them.

Well the fact that LFS doesn't detect your GPU properly does indicate that something may be wrong with your installation. I would do driver cleaner --> GPU and Mainboard driver install --> directx install --> LFS fresh install

Why hasn't anyone mentioned driver cleaner yet?

Do any of these work?
http://www.lfsforum.net/attach ... id=29345&d=1177669474
http://www.lfsforum.net/attach ... id=29344&d=1177669349

If not then the only reason one of them temporarily worked is because the post preview window was still open in IE.

Last edited by J.B., Fri 27 Apr 2007, 10:54.

???

Quote from Bob Smith :

Or he could upload it with his licensed account, then link to the attachment with having to post using that account. I think.

http://www.lfsforum.net/attach ... id=29345&d=1177669474

Testing.

Nope. Link isn't valid. Probably needs to actually get posted before I can link to it.

Thx for the idea anyway, how could I not think of it myself? Next time I need to upload something I'll just add a post with my licensed name. Two other things I just noticed while using IE to log-in to my other account: the edit avatar and edit signature buttons sure are nice, *drool, and that IE is ridiculously fast compared to FF.

Last edited by J.B., Fri 27 Apr 2007, 10:37.

I for one welcome our new alien befriending overlord. :up:

Quote from Ball Bearing Turbo :

I think the joke is on you guys in this thread. Victor controls LFSW, and the forum as well to a large extent. He's a crafty and subtle fellow. You guys simply are not privy to his subconcious brainwashing efforts, and he finds it darkly amusing to outright unveil his disturbing intentions - and yet his malignant honesty is taken for jest.

Oh, the irony. The IRONY, my mislead forum friends. Wake up and smell the monster that IS, the Victor. Even the name carries the pungent odour of conspiracy, for he intends to be the very "victor" of the battle being fought for your very mind. And his last name - van Vlaardisomething - do you really think anyone these days has a last name that sounds like a vampire? It's so obvious!

Don't say I didn't warn you!

He's a musician, what do you expect?

I know this, because I am a musician as well. But I'm not trying to control your mind (right now). BTW, watch out for Kev, he's in cahoots with Victor.

:ices_rofl

Couldn't find it on the net but found it on my HD. And I can't remember ever reading it either.

EDIT: Hmm, can't upload it, probably because of my demo status.

EDIT2: Shame I have to go with rapidshare: http://rapidshare.com/files/27 ... mited_Slip_Diffs.pdf.html

Last edited by J.B., Thu 26 Apr 2007, 02:16.

OK, thought about it. I think you're right! The arrows are probably tractive force - friction resistance. So tractive force can still be equal to drive shaft force. I guess only Scawen can clear us up on this.

Of course this makes it all the more difficult to learn anything about diff operation by looking at the forces view. Not impossible, you could still find out things like what it takes to get a preloaded diff to start slipping or at what point the preload stops having an effect, but I think I'll leave it for now.

Holy posting speed, Batman. Can't keep up.

Quote from Bob Smith :

Tyre scrub is still going to affect the total force on each tyre though, thus the length of the lines. The tyre supporting the majority of the weight will have the greater rolling resistance and tyre scrub resistance, so the lines should be shorter. I just don't know if that would accout for the different in forces, it's hard to say how many times larger the force on one tyre is than the other (the left line goes off the top of the image, and I think both lines start from the centre of the tyre, so the bottom of each line is obscured by the tyre itself).

So what you're saying is that in steady state cornering the torque on the drive shaft does not equal the force that is pushing the car forward but the force pushing the car forward + the force needed to deal with friction in the tyre itself?

That does sounds very reasonable but I'll have to give it some thought. :up:

The forces are LR: 388 (N?) to RR: 298 N according to f1perfview.

Quote from Ball Bearing Turbo :

The colors are relative to the slip ratio, afaik.. At max green, the slip ratio is optimal and the tire is producing as much force as it can. Go beyond that, and the line decreases length, and turns red because you're past optimum longitudinal slip ratio.

Just checked in-game. Agree.

Quote from Ball Bearing Turbo :

If the weight is mostly on the outside wheel, and just a tiny bit of force is being applied to keep the car at steady speed, then the inside tire is probably slipping a bit and getting closer to it's optimal slip ratio which accounts for the colors/lines.

Looking at the raf data you are right that the inner slip ratio is higher than the outer. This would account for the colours but not for the length of the arrows. The way I understand the working of an open diff (equal torque to both wheels) the tyres should adjust their slip ratios to meet the equal torque requirement.

Quote from Bob Smith :

Or is that screenshot taken looking backwards?

Bingo.

Just to be sure we mean the same thing: With not accelerating I meant that the wheels had a constant speed, not that I was engine braking. In fact I was using a constant 40% throttle.

What I meant is that, from the perspectice of the wheel, if the torque coming from one side (from the driveshaft) is not exactly the same as the reactive torque coming from the other side (the tractive force between the tyre and the road) then the wheel wouldn't be able to maintain a constant speed. It would be forced to accelerate or deccelerate due to the non-zero torque sum.

Could you tell me more about tyre scrub?

Quote from Glenn67 :

Saying torque is the same is not the same as saying that tractive force at each wheel is the same...

Hmm, I thought it is. In the case that the tractive force is not the same as the drive shaft torque the wheel will be forced to accelerate, right? Newton's Laws basically. In the screenshot case the wheel wasn't accellerating.

Quote from csurdongulos :

aren't the yellow lines showing the weight distribution and the other coloured lines showing the amount of grip the tyres have? why would they show the drive shaft forces?

If they were the potential tyre grip/traction then they wouldn't be zero at standstill. They grow longer when you accelerate harder so I think they are actual forces not grip indicators.

Well, I think if the wheels are not accelerating but keeping a constant speed then the reactive forces at the tyres (the ones I think we're seeing in forces view) should be exactly the same as the forces coming from the driveshafts (Mechanical equilibrium).

I was just going to have a look at diff/tyre forces using forces view and raf data. I went to the skidpad, started out with an open diff and adjusted my driver inputs until I was keeping to a more or less constant, steady state circle.

I was expecting the longitudal tyre forces to be identical for both rear tyres in this case (fully open diff) yet the result can be seen in the attached screenshot.
Does anyone have an explanation? Is the assumption that in steady state an open diff delivers the same amount of torque to each wheel wrong? I can't find any disagreement via google.

-unlimited tracktime and consequenceless crashing make you approach to the limit very differently than in RL.

-on track behavior in league races is generally better than in RL, maybe also due to the immense tracktime LFS racers have, and because LFS racers are less desperate (bad positions don't ruin career etc.)

One thing he certainly wasn't is lucky. Qualifying to get into the final definately takes a lot of work and talent. The IRT travelled through Germany for over a year and if you wanted to be in the top ten to qualify for the final you had to be seriously quick. I gave it a try but even if would have put all my perfect splits together (3 laps of Aston Nat) I would still have been over a second slower than P10. And P1 to P10 were covered by a bit more than half a second. I have been watching the times over the past few months and some the fast guys must really have invested a lot of time into visiting all the quali events. But in the end it payed off big time for Husky. :up:

Quote from Tweaker :

I don't know why people are suggesting selling a car that goes 155mph (ulimited @ 200+ mph). It is a fast car. If you own a car faster than it already, yeah maybe you'd sell it... but hell, with the basic car I have now, I'd regret selling that thing.

Maybe something to do with the costs of running certain cars in Europe vs USA?

Another thing that'd be interesting is how much the M6 is still worth. Unless they brought it on a trailer to all the IRT events it will have quite a few km's on the clock.

Last edited by J.B., Sat 21 Apr 2007, 04:31.

Congrats! Would love to see some coverage or an mpr. Were Giga TV involved?

I'll be the first to admit that european HDTV is in an abysmal state. But how does this help your claim that there is such a thing as 768p HDTV?

Quote from jtw62074 :

Much of the confusion comes about due to the desire to visualize the engine input torque creating the locking torque in the diff, then wanting to know how that torque is then fed to the wheels. In reality, at least mathematically speaking, the engine torque input is not really a variable to be looking at here.

What do you mean by this? As far as I can tell the input torque from the engine is in fact the variable that tells the diff what to do, assuming it is not in the locked or preload state of operation. Just like the wheelspeed difference is the controling variable for a viscous diff. In fact clutch pack LSD's are also known as "torque sensing" differentials.

Another thing I notice is that you state a diff running at a torque bias of, say, 2 (how to covert locking factor to torque bias) limits one wheel to a maximum of double the torque that is on the other wheel. The way I see it, it not only limits it, it actually makes sure that the torque on one wheel is exactly double the torque of the other wheel (as long as the clutch plates are slipping). After all if the clutch plates are slipping then the torque they are transfering from one wheel to the other is a fixed percentage of total torque. Add to this that the total torque at the wheels has to equal the torque coming from the engine (Newtons 3rd Law) then the tyres have no choice but to adapt their slip ratios to the torque and normal loads they are getting. Am I disagreeing with you here or simply misunderstanding something?

@Vain:

Just try to imagine the concept of preload with a linear coil spring. Say you have a spring that is 100mm long and needs 10N to be compressed by 10mm. To preload it you install it in such a manner that it can't fully expand and is compressed to 90mm length. Think something like this with limited travel. The mechanism that is holding the spring in this position will have to deal with 10N force that the spring is exerting. Now if you press down on the device, for the first 10N of force you apply, the spring will not actually compress further, you will only be taking the load off the preload device and moving it your thumb. Only when you get over 10N of force will the precompressed spring beginn to compress further than the 90mm it was compressed to by the preload.

How exactly this is implemented in an LSD I don't know as pictures seem to be very rare.

Quote from Shotglass :

rubbish

I actually asked a guy at Media Markt once why all the so called HDTV's have the wrong resolution and he told me it was because 720p was outdated. LOL.

I see.
*runs, ashamed by revealing coding n00bishness

Quote from Shotglass :

hehe i didnt want to imply that all stupidity falls back on you in case my graph is wrong it was just to make clear i didnt research the formulae at all

Well now all stupidity falls back to Pat Symonds (and others).

Last edited by J.B., Thu 19 Apr 2007, 19:28.

I pretty much agree with the graph, not sure about the pseudo code though. Shouldn't it be something like this?


Also the term "transfered through diff" can be confusing as it's not clear if the torque is being transfered from wheel to wheel or from gearbox to wheels. I would rename "Max_Torque_transfered_through_Diff " to "torque_fifference_between wheels".

Generally I think I can see this discussion converging to a common understanding so that's a good thing.

Quote from wheel4hummer :

Wouldn't any clutch preload setting greater then the torque outputed by the transmission just make it a locked differential?

Too much preload could permanently lock the diff, yes, but I don't think the transmission torque is the relevant factor. Probably more to do with tyre slip ratios and longitudal forces etc.

Quote from Vain :

Let's put it straight:
The car with LSDifferential with preload drives down a straight. The driver leaves throttle and brakes alone and starts turning in left.
The front wheels start turning the car, which causes forces on the rear tyres. The front wheels try to make the left rear wheel slower than the right rear wheel.
These forces mean that there is a torque at the differential.
If this torque is smaller than what you set preload to the differential resists the torque and acts like a locked diff.
If this torque is bigger than what you set preload to the differential starts slipping. The torque it exerts is exactly what you set preload to. f.e. 100 Nm if you set preload to 100 Nm. Regardless of how much the driver turns the steering wheel, the diff won't exert more torque than that, 100Nm and no more.
If the driver starts accelerating now the differential is loaded and exerts additional torque from the power-lock setting, and pretty soon preload is neglectible.

That is my current position. No warranty though.

Vain

I agree. Still some minor issues that would have to be worked out though. For example if the preload is the amount of tourque the clutch plates can take before slipping then once they start slipping the torque transfered should be a bit smaller than the preload value as dynamic friction coefficient is < static friction coefficient.

About the two formulas I used in this thread: I didn't come up with them myself, one was taken from here (page 10) and one from here.