w211 E55 VS CLK550 with exhaust
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CLS55 AMG
We shall see...
The flaw in your reading skills is that the author never says otherwise, only that the LSD, by virtue of transferring power away from the wheel into which spin had been induced by the axle twist, increased the available tractive force by 10%.
Read more carefully next time.
Also, you're saying that axle twist occurs in an IRS car? Document this, please. The axle is not a single piece any more, and the diff is mounted to the frame, which should alleviate the problem. So where's the data you've got coming from that indicates otherwise?
Let me explain something: I don't regard you as an expert on anything, chiefly because you haven't demonstrated any expertise on anything as of yet. So when you start throwing things out like "it is written", and "it is documented", it means squat to me unless you can provide the documentation providing proof of your claim. And frankly, given the total lack of reading comprehension you exhibit in your cursory, poor reading of the article I provided above, along with a purposely deceitful example of selectively editing text (more on that in a moment), I'd take it with a grain of salt even then.
Yes, and if we assume the moon is made of swiss cheese, then we can state with absolute certainty that a mouse can eat it. What a joke.
If you have anything at all which disproves the physics, formulae or the mathematics in that article, then please by all means present them. Otherwise, you're simply continuing to blow smoke up people's *****.
No. Wrong. If the adhesion is not identical, then the tires will not react identically, because their traction will be different. OK? What you're claiming is that you can apply the same force to two tires with different levels of traction, and yet have them react identically. This is quite frankly moronic. You're proving yourself to be more and more ignorant of physics, no to mention devoid of common sense: if all factors aren't equal, then the reaction will not be equal, and the more unequal they are, then the more unequal the response will be.
Further, since with an open diff the max amount of torque that can be delivered is dictated by the max amount the wheel with the least traction can handle, then prima facie the max amount of torque that can be delivered will be less than ideal when either of the driven wheels has less traction than the other.
Which is why pro drag racers all have open diffs on their cars...right? Oh no wait, they don't. Which is what you keep trying to skirt, but it's pretty well-established that one of the first things you get on a car is an LSD.
Can you name me ONE top-ranked NHRA driver who uses an open diff? Just one?
Further, nobody said that a car with an open diff could NOT drag race, so please stop with the straw-man tactics. The issue here is whether a car with a open diff gets equal traction to one with an open diff, and frankly, the article already established this. And the claims you're making to the contrary not only defy the physics, they also defy common sense.
How the hell does the miata.net link you provided help your case? It reiterates exactly what I've been saying, and NOBODY in there says that a torsen (LSD) diff won't help in anything other than absolutely perfect conditions, which don't exist most of the time.
Here's an example:
Gee, that sounds like exactly what I wrote in my previous post. 
Again, no contradiction whatsoever to anything I've said so far, and no support for your argument about LSD not providing more traction in drag racing. In fact, consider the following:
So, that's 2/3 articles you provided which actually support, not contradict, my arguments.
Thank you.
Continuing:
Let me ask you something seriously: did you ingest a bunch of peyote before you read the three articles you linked to here, or is it just that you think people (including me) aren't going to actually read them? I ask this because this article you linked, like the other two, actually supports my argument. Quoting:
Actually, all three of the articles you linked to explicitly state that an LSD helps, and none of them say it doesn't, save for one person on the Miata forum.
And we all know what torque monsters Miatas are, definitely comparable to a supercharged Benz in terms of getting a good launch.
Thank you.
Oh, really? You verified this on all of their sites?
And mileage? Wtf is this, a discussion on fuel economy all of a sudden?
An improvement is an improvement, and it was measured in both cases.
Again, nobody said that open-diff cars can't be raced, and the fact that a lame man can walk hardly proves he's the best runner. The LSD offers superior traction in most real-world cases, because, particularly on the street where the races we're discussing take place, in the real world the traction conditions cannot be guaranteed to be equivalent between both tires, and in all likelihood, WILL not be equivalent between both tires.
These are different cars, at different tracks. Again: do you have any data from anywhere showing that the same car, once an LSD was installed, did not demonstrate any gains?
Actually, what happens is this, from the howstuffworks.com link you thoughtfully provided:
So in any situation other than when both wheels have 100% identical traction available, i.e. in the real world, an LSD is the better choice.
How utterly dishonest of you. You quoted from two separate sentences and pasted the quotes together by sneaking an ellipsis in there and hoping nobody would notice. When one reads the fully written sentences, it's pretty obvious that you very carefully ommitted a very relevent portion of the text when you stuck that ellipsis in there :to hide the fact that this is only done on long ovals where one wheel is unlikely to break traction coming out of a turn.
Here is the page from the book you quoted which contains the sentences you quoted in their entirety, with the section you omitted via the ellipsis included, along with the sentence that immediately follows it, which you omitted and which is most illustrative:
And this was *after* they spent an entire paragraph explaining how beneficial an LSD is in racing applications, as anyone who clicks on the link can read for themselves.
You, sir, are a sneak and should be ashamed of yourself for pulling such an intellectually dishonest stunt like this. You claim to be a journalist? If so, you're a disgrace to the profession, as this violates every journalistic ethical standard for quoting material.
Which is exactly what I've been saying; thanks again for providing so much info to support my argument.
False. The launch doesn't dictate the traction, and the data you thoughtfully provided shows that unless you can guarantee that 100% of the time you will have 100% identical traction available at each wheel, i.e. in the real world, then an LSD is the way to go.
It works sometimes. I suppose that one could hunt quail with a BB gun, but most would agree that a shotgun is the way to go.
Read more carefully next time.
Also, you're saying that axle twist occurs in an IRS car? Document this, please. The axle is not a single piece any more, and the diff is mounted to the frame, which should alleviate the problem. So where's the data you've got coming from that indicates otherwise?
If you have anything at all which disproves the physics, formulae or the mathematics in that article, then please by all means present them. Otherwise, you're simply continuing to blow smoke up people's *****.
Further, since with an open diff the max amount of torque that can be delivered is dictated by the max amount the wheel with the least traction can handle, then prima facie the max amount of torque that can be delivered will be less than ideal when either of the driven wheels has less traction than the other.
Which is why pro drag racers all have open diffs on their cars...right? Oh no wait, they don't. Which is what you keep trying to skirt, but it's pretty well-established that one of the first things you get on a car is an LSD.
Can you name me ONE top-ranked NHRA driver who uses an open diff? Just one?
Further, nobody said that a car with an open diff could NOT drag race, so please stop with the straw-man tactics. The issue here is whether a car with a open diff gets equal traction to one with an open diff, and frankly, the article already established this. And the claims you're making to the contrary not only defy the physics, they also defy common sense.
I'm not the only one who knows this.
From the Miata.net forum: http://forum.miata.net/vb/showthread.php?t=309481
From the Miata.net forum: http://forum.miata.net/vb/showthread.php?t=309481
Here's an example:
Under ideal circumstances they will be the same off the line. The torsen (LSD) will only let loose when the limits of adhesion on both tires have been exceeded, whereas the open diff will let loose when the limit of either tire is exceeded regardless of the condition of the other tire. This means that under ideal conditions the difference between the limits will be zero and there will be no difference. Since the traction is never the same between the tires in real life, the torsen diff will have better grip in the real world. I can explain the physics of it if you would like.
As an example of how useless an open differential can be, say you're driving along and find a diner, and this diner has a clay parking lot, but currently everything is dry and you're hungry for some nice greasy diner food. You go inside, have a cup of coffee, eat your two day old pie, and as you go to walk back outside you notice it has started raining. The dirt you parked on is now mud which has become slick as grease. Before hopping in the car you notice the rear left wheel is on some nice grippy gravel, and the rear right wheel is sitting in a giant mud puddle. You figure, "Hey, one of my wheels is on gravel, I should be able to leave here fine right?". You crank the car, and as you ease onto the gas pedal the wheel in the mud sits there and spins mud all over your once clean car, getting you absolutely nowhere! You might try going in reverse, but this also gets you nowhere... This is where the term "one wheel drive" was coined. In drag racing situations, during the burnout, only one wheel will spin as well - during launch the maximum grip you will have will be governed to one wheel's torque limit as well.
Thank you.
Continuing:
No reduction:
http://www.ppi-ats.com/LSD/LSD_basics.html
http://www.ppi-ats.com/LSD/LSD_basics.html
LSD and open differential
LSD is an acronym for Limited Slip Differential. It is a gear mechanism which limits the rotational difference of the out-put shafts.
An “Open Differential” (as compared with LSD) allows the transfers of power to the wheel/s which are experiencing the least amount of resistance. This enables a car’s wheels with the least resistance to run at different speeds in a turn. As an example, when cornering, the inner wheel travels a shorter distance than the outer wheel. With an “Open Differential” you will experience easier handling during a turn. However, an “Open Differential” may not necessarily produce the best results for Racing, Drifting, and other Performance Driving.
Why does LSD improve your driving performance?
When cornering in competition or a racing situation, you will frequently experience body roll where one wheel of the car is lifted from the ground. This will cause the “Open Differential” to transfer all the torque to the wheel lifted rather than to the wheel that is on the ground. The results are a useless “wheel spin” where as the car loses its forward momentum. In order to eliminate the “spin”, your LSD will transfer the torque to both wheels which consequently improve your lapping time.
In Drifting, an “Open Differential” makes it very difficult to control vehicle’s slide with throttle actuation. LSD will allow the driver to steer the car with the throttle, allowing larger, more dramatic slide with plenty of forward movement.
In Drag Racing, the impact of an LSD is less dramatic. However, during sudden high-power starts and while up-shifting during acceleration, it is possible that either the left or right tire can frequently slip. A performance LSD will quickly detect the that condition and lock the differential so that you do not lose any time. Not even a few tenths of a second!
LSD is an acronym for Limited Slip Differential. It is a gear mechanism which limits the rotational difference of the out-put shafts.
An “Open Differential” (as compared with LSD) allows the transfers of power to the wheel/s which are experiencing the least amount of resistance. This enables a car’s wheels with the least resistance to run at different speeds in a turn. As an example, when cornering, the inner wheel travels a shorter distance than the outer wheel. With an “Open Differential” you will experience easier handling during a turn. However, an “Open Differential” may not necessarily produce the best results for Racing, Drifting, and other Performance Driving.
Why does LSD improve your driving performance?
When cornering in competition or a racing situation, you will frequently experience body roll where one wheel of the car is lifted from the ground. This will cause the “Open Differential” to transfer all the torque to the wheel lifted rather than to the wheel that is on the ground. The results are a useless “wheel spin” where as the car loses its forward momentum. In order to eliminate the “spin”, your LSD will transfer the torque to both wheels which consequently improve your lapping time.
In Drifting, an “Open Differential” makes it very difficult to control vehicle’s slide with throttle actuation. LSD will allow the driver to steer the car with the throttle, allowing larger, more dramatic slide with plenty of forward movement.
In Drag Racing, the impact of an LSD is less dramatic. However, during sudden high-power starts and while up-shifting during acceleration, it is possible that either the left or right tire can frequently slip. A performance LSD will quickly detect the that condition and lock the differential so that you do not lose any time. Not even a few tenths of a second!
And we all know what torque monsters Miatas are, definitely comparable to a supercharged Benz in terms of getting a good launch.
Thank you.
And mileage? Wtf is this, a discussion on fuel economy all of a sudden?
An ideal launch at the dragstrip has minimal to no slippage. The extensive use in drag racing with high horsepower cars and driveline shock eventually migrates to a Spool type LSD which is essentially a locked differential. Which does not transfer power back and forth and is for extreme power conditions. Again, the fact that Open Diff cars are able to drag race in itself points out how consistent traction can be on at the dragstrip.
The LSD offers superior traction in most real-world cases, because, particularly on the street where the races we're discussing take place, in the real world the traction conditions cannot be guaranteed to be equivalent between both tires, and in all likelihood, WILL not be equivalent between both tires.
Differentials and Traction
The open differential always applies the same amount of torque to each wheel. There are two factors that determine how much torque can be applied to the wheels: equipment and traction. In dry conditions, when there is plenty of traction, the amount of torque applied to the wheels is limited by the engine and gearing; in a low traction situation, such as when driving on ice, the amount of torque is limited to the greatest amount that will not cause a wheel to slip under those conditions. So, even though a car may be able to produce more torque, there needs to be enough traction to transmit that torque to the ground. If you give the car more gas after the wheels start to slip, the wheels will just spin faster.
On Thin Ice
If you've ever driven on ice, you may know of a trick that makes acceleration easier: If you start out in second gear, or even third gear, instead of first, because of the gearing in the transmission you will have less torque available to the wheels. This will make it easier to accelerate without spinning the wheels.
Now what happens if one of the drive wheels has good traction, and the other one is on ice? This is where the problem with open differentials comes in.
Remember that the open differential always applies the same torque to both wheels, and the maximum amount of torque is limited to the greatest amount that will not make the wheels slip. It doesn't take much torque to make a tire slip on ice. And when the wheel with good traction is only getting the very small amount of torque that can be applied to the wheel with less traction, your car isn't going to move very much.
The open differential always applies the same amount of torque to each wheel. There are two factors that determine how much torque can be applied to the wheels: equipment and traction. In dry conditions, when there is plenty of traction, the amount of torque applied to the wheels is limited by the engine and gearing; in a low traction situation, such as when driving on ice, the amount of torque is limited to the greatest amount that will not cause a wheel to slip under those conditions. So, even though a car may be able to produce more torque, there needs to be enough traction to transmit that torque to the ground. If you give the car more gas after the wheels start to slip, the wheels will just spin faster.
On Thin Ice
If you've ever driven on ice, you may know of a trick that makes acceleration easier: If you start out in second gear, or even third gear, instead of first, because of the gearing in the transmission you will have less torque available to the wheels. This will make it easier to accelerate without spinning the wheels.
Now what happens if one of the drive wheels has good traction, and the other one is on ice? This is where the problem with open differentials comes in.
Remember that the open differential always applies the same torque to both wheels, and the maximum amount of torque is limited to the greatest amount that will not make the wheels slip. It doesn't take much torque to make a tire slip on ice. And when the wheel with good traction is only getting the very small amount of torque that can be applied to the wheel with less traction, your car isn't going to move very much.
Here is the page from the book you quoted which contains the sentences you quoted in their entirety, with the section you omitted via the ellipsis included, along with the sentence that immediately follows it, which you omitted and which is most illustrative:
Many Indy Car race engineers use an open differential at the high-speed ovals because it "frees up the cars". Translated, this means that since the speeds are quite high and wheelspin is not a problem, the open diff is effective because it wastes less power. On shorter ovals, racers sometimes prefer a completely locked differential called a "spool".
You, sir, are a sneak and should be ashamed of yourself for pulling such an intellectually dishonest stunt like this. You claim to be a journalist? If so, you're a disgrace to the profession, as this violates every journalistic ethical standard for quoting material.
Other sources:
"In dry conditions, when there is plenty of traction, the amount of torque applied to the wheels is limited by the engine and gearing" and,
"So basically in drag racing terms a limited slip differential is only helpful when traction is an issue. If your tires are good and you setup is solid, you should be able to launch the car without much wheel spin, thus negating the need for a LSD. But if your power becomes to much and launching the car easily causes wheel spin, a LSD is a helpful way to control the spinning tire and apply the power more efficiently to the ground."
"In dry conditions, when there is plenty of traction, the amount of torque applied to the wheels is limited by the engine and gearing" and,
"So basically in drag racing terms a limited slip differential is only helpful when traction is an issue. If your tires are good and you setup is solid, you should be able to launch the car without much wheel spin, thus negating the need for a LSD. But if your power becomes to much and launching the car easily causes wheel spin, a LSD is a helpful way to control the spinning tire and apply the power more efficiently to the ground."
False. The launch doesn't dictate the traction, and the data you thoughtfully provided shows that unless you can guarantee that 100% of the time you will have 100% identical traction available at each wheel, i.e. in the real world, then an LSD is the way to go.
It works sometimes. I suppose that one could hunt quail with a BB gun, but most would agree that a shotgun is the way to go.
Last edited by Improviz; Dec 27, 2009 at 03:57 PM.
MBWorld Fanatic!
Joined: Sep 2002
Posts: 3,679
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CLS55 AMG
So you keep saying. But given your obvious lie about pulling an E90 M3 up past 130 mph by "drafting" it, you'll forgive me for not taking each and every claim you make as 100% factual.
How about this: I say there's been enough talk here. Let's see some action.
You say that that your car can pull an E90 M3 past 130 mph, and run a 4.6 second 5-60 run.
Fine.
So let's see you do both.
I am certain that, in your area, there are people who have available a VBox, which can very accurately measure 5-60 times.
So let's see if we can find someone to arrange a meet.
And we can also arrange for you to meet up with an E90 M3, and see if you can replicate this amazing feat as well.
This way we can guage for ourselves just how honest and accurate your claims have been up to this point.
Because I think you're so full of ***** that you make the average garbage dump smell like Chanel #5.
So, how 'bout it, jon? Care to step up..for once?
Talk is cheap.
MBWorld Fanatic!
Joined: Sep 2002
Posts: 3,679
Likes: 0
CLS55 AMG
I'm working on a run with the CLK550 so hopefully by the end of this week we can get a couple of runs in and I will post it up with video. You guys can keep the debate on for the next couple of days or you guys can wait for the footage.
Till now I have settled the E55 vs M5 debate and the E55 vs C63 debate ( all stock form ).....Didn't expect this 1 but hey its all fun and games and we are all car enthusiats
.
Till now I have settled the E55 vs M5 debate and the E55 vs C63 debate ( all stock form ).....Didn't expect this 1 but hey its all fun and games and we are all car enthusiats
.
Senior Member
Joined: Dec 2002
Posts: 427
Likes: 29
From: BH, MI
C63S past: E90 M3 6M, w211 E55
Improviz, you are 100% correct on the LSD - real world, one tire will always break traction first over the other tire, as no two surfaces/tires are identical. once that lower traction tire breaks, so does your efficient launch.
in the real world, for consistent 0-60 launches, LSD is definitely useful. Just because an open diff can lay down two sets of rubber doesn't mean it lays down power equally - most likely due to the driveline shock of power that both tires lost traction, which isn't an efficient way of accelerating. If you are dancing on the limit of adhesion, one tire will most likely give before the other.
in the real world, for consistent 0-60 launches, LSD is definitely useful. Just because an open diff can lay down two sets of rubber doesn't mean it lays down power equally - most likely due to the driveline shock of power that both tires lost traction, which isn't an efficient way of accelerating. If you are dancing on the limit of adhesion, one tire will most likely give before the other.
MBWorld Fanatic!
Joined: Feb 2007
Posts: 3,443
Likes: 2
From: Desert
02 CLK 55 AMG,09 C63 loaded with P30
In a different car.
So you keep saying. But given your obvious lie about pulling an E90 M3 up past 130 mph by "drafting" it, you'll forgive me for not taking each and every claim you make as 100% factual.
About 50,000 times less dumb than you are on any given day.
How about this: I say there's been enough talk here. Let's see some action.
You say that that your car can pull an E90 M3 past 130 mph, and run a 4.6 second 5-60 run.
Fine.
So let's see you do both.
I am certain that, in your area, there are people who have available a VBox, which can very accurately measure 5-60 times.
So let's see if we can find someone to arrange a meet.
And we can also arrange for you to meet up with an E90 M3, and see if you can replicate this amazing feat as well.
This way we can guage for ourselves just how honest and accurate your claims have been up to this point.
Because I think you're so full of ***** that you make the average garbage dump smell like Chanel #5.
So, how 'bout it, jon? Care to step up..for once?
Talk is cheap.
So you keep saying. But given your obvious lie about pulling an E90 M3 up past 130 mph by "drafting" it, you'll forgive me for not taking each and every claim you make as 100% factual.
About 50,000 times less dumb than you are on any given day.
How about this: I say there's been enough talk here. Let's see some action.
You say that that your car can pull an E90 M3 past 130 mph, and run a 4.6 second 5-60 run.
Fine.
So let's see you do both.
I am certain that, in your area, there are people who have available a VBox, which can very accurately measure 5-60 times.
So let's see if we can find someone to arrange a meet.
And we can also arrange for you to meet up with an E90 M3, and see if you can replicate this amazing feat as well.
This way we can guage for ourselves just how honest and accurate your claims have been up to this point.
Because I think you're so full of ***** that you make the average garbage dump smell like Chanel #5.
So, how 'bout it, jon? Care to step up..for once?
Talk is cheap.
MBWorld Fanatic!
Joined: Sep 2002
Posts: 3,679
Likes: 0
CLS55 AMG
You made the claims, that 1)your car can run 5-60 in 4.6 seconds, the same as a supercharged AMG; 2) you pulled an E90 M3 up past 130 mph by "drafting" him.
Let me repeat: YOU made the claims.
One more time: YOU made the claims.
Therefore, the burden of proof is on YOU.
So I very generously offered to donate some of my time to give you the opportunity to prove your claims.
And you have, in response, ducked, dodged, weaved, evaded, and whined.
How rude of you.
I mean, really: I generously offer to assist you in showing everyone here that you can, in your car, pull E90 M3s by "drafting" them, and run a 4.6 second 5-60 run, and what do I get in response?
Insults.
Well, really, that hurts, man.
Where is the love?
Come on, I'm doing you a favor here, guy! Here is your big chance to actually prove me wrong, and show everyone here that I'm full of it, that your car *can* do a 4.6 sec. 5-60 run, that you *can* outrun an E90 M3 up past 130, that it *can* leap tall buildings in a single bound.
And we can get it all down on video, gold-standard proof, that you're not simply a chronic bull*****ter with a penchant for telling tall tales, but that, in fact, you've been telling us the truth all along here.
Sheesh, why the hostility?
MBWorld Fanatic!
Joined: Feb 2004
Posts: 5,475
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From: City with Tall buildings!
C43/55,2k11 Volvo S60 T6AWD,2k Audi B5 S4,95 Eagle Talon Tsi AWD 500+awhp
Jon, Jon....what are we going to do with you? We aren't talking theoretical here, we are talking actual. And you made a concrete claim about your car's performance capabilities. We ain't talking Car & Driver in a 209, baby, we're talking YOU. In YOUR car.
You made the claims, that 1)your car can run 5-60 in 4.6 seconds, the same as a supercharged AMG; 2) you pulled an E90 M3 up past 130 mph by "drafting" him.
Let me repeat: YOU made the claims.
One more time: YOU made the claims.
Therefore, the burden of proof is on YOU.
So I very generously offered to donate some of my time to give you the opportunity to prove your claims.
And you have, in response, ducked, dodged, weaved, evaded, and whined.
How rude of you.
I mean, really: I generously offer to assist you in showing everyone here that you can, in your car, pull E90 M3s by "drafting" them, and run a 4.6 second 5-60 run, and what do I get in response?
Insults.
Well, really, that hurts, man.
Where is the love?
Come on, I'm doing you a favor here, guy! Here is your big chance to actually prove me wrong, and show everyone here that I'm full of it, that your car *can* do a 4.6 sec. 5-60 run, that you *can* outrun an E90 M3 up past 130, that it *can* leap tall buildings in a single bound.
And we can get it all down on video, gold-standard proof, that you're not simply a chronic bull*****ter with a penchant for telling tall tales, but that, in fact, you've been telling us the truth all along here.
Sheesh, why the hostility?
You made the claims, that 1)your car can run 5-60 in 4.6 seconds, the same as a supercharged AMG; 2) you pulled an E90 M3 up past 130 mph by "drafting" him.
Let me repeat: YOU made the claims.
One more time: YOU made the claims.
Therefore, the burden of proof is on YOU.
So I very generously offered to donate some of my time to give you the opportunity to prove your claims.
And you have, in response, ducked, dodged, weaved, evaded, and whined.
How rude of you.
I mean, really: I generously offer to assist you in showing everyone here that you can, in your car, pull E90 M3s by "drafting" them, and run a 4.6 second 5-60 run, and what do I get in response?
Insults.
Well, really, that hurts, man.
Where is the love?
Come on, I'm doing you a favor here, guy! Here is your big chance to actually prove me wrong, and show everyone here that I'm full of it, that your car *can* do a 4.6 sec. 5-60 run, that you *can* outrun an E90 M3 up past 130, that it *can* leap tall buildings in a single bound.
And we can get it all down on video, gold-standard proof, that you're not simply a chronic bull*****ter with a penchant for telling tall tales, but that, in fact, you've been telling us the truth all along here.
Sheesh, why the hostility?
Super Member
Joined: Sep 2006
Posts: 537
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From: San Jose, CA
Charger SRT-8
Improviz,
It's obvious that debating you further is a complete waste of time and apparently others recognize this as well.
You completely ignored my statements and taken others out of context. You don't realize that uneven loading can occur with LSD cars with a SRA or IRS (IRS cars can break their axles with twising forces), that different adhesion coefficients does NOT mean the tire will automatically slip. There is no valid documentation that LSD improves ETs with a good launch where one tire doesn't slip more than the other which happens all the time in the real world. My knowledge of physics isn't the problem here.
Statements like this further point that you're a waste of time:
it means squat to me unless you can provide the documentation providing proof of your claim. And frankly, given the total lack of reading comprehension you exhibit in your cursory, poor reading of the article I provided above, along with a purposely deceitful example of selectively editing text
Which is why pro drag racers all have open diffs on their cars...right? Oh no wait, they don't. Which is what you keep trying to skirt, but it's pretty well-established that one of the first things you get on a car is an LSD.
Can you name me ONE top-ranked NHRA driver who uses an open diff? Just one?
Let me ask you something seriously: did you ingest a bunch of peyote before you read the three articles you linked to here, or is it just that you think people (including me) aren't going to actually read them? .
How utterly dishonest of you. You quoted from two separate sentences and pasted the quotes together by sneaking an
You, sir, are a sneak and should be ashamed of yourself for pulling such an intellectually dishonest stunt like this. You claim to be a journalist? If so, you're a disgrace to the profession, as this violates every journalistic ethical standard for quoting material.
Any further contributions by me are simply repeats of my previous posts and unnecessary.
It's obvious that debating you further is a complete waste of time and apparently others recognize this as well.
You completely ignored my statements and taken others out of context. You don't realize that uneven loading can occur with LSD cars with a SRA or IRS (IRS cars can break their axles with twising forces), that different adhesion coefficients does NOT mean the tire will automatically slip. There is no valid documentation that LSD improves ETs with a good launch where one tire doesn't slip more than the other which happens all the time in the real world. My knowledge of physics isn't the problem here.
Statements like this further point that you're a waste of time:
it means squat to me unless you can provide the documentation providing proof of your claim. And frankly, given the total lack of reading comprehension you exhibit in your cursory, poor reading of the article I provided above, along with a purposely deceitful example of selectively editing text
Which is why pro drag racers all have open diffs on their cars...right? Oh no wait, they don't. Which is what you keep trying to skirt, but it's pretty well-established that one of the first things you get on a car is an LSD.
Can you name me ONE top-ranked NHRA driver who uses an open diff? Just one?
Let me ask you something seriously: did you ingest a bunch of peyote before you read the three articles you linked to here, or is it just that you think people (including me) aren't going to actually read them? .
How utterly dishonest of you. You quoted from two separate sentences and pasted the quotes together by sneaking an
You, sir, are a sneak and should be ashamed of yourself for pulling such an intellectually dishonest stunt like this. You claim to be a journalist? If so, you're a disgrace to the profession, as this violates every journalistic ethical standard for quoting material.
Last edited by Deuuuce; Dec 28, 2009 at 02:06 AM.
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CLS55 AMG
Another lie. I quoted the source material you provided directly, and unlike you didn't "selectively edit" it to make it appear as though it supported my argument when it did not; there was no need for me to do this, because even the material you provided supported my argument.
Ergo, whether or not the wheels have the same traction coefficient, axle twist alone can introduce lower traction on one wheel than on the other. Thus your ignorant statement that LSDs only help when one wheel has less traction than the other was rendered null and void, but the physics used in the article obviously flew so far above your head that you couldn't even hear the wings flap, resoundingly demonstrated when you responded to something that the article hadn't even said, just as you diagnosed skratch77's traction issues by claiming things he'd never said had happened had happened.
Oh, and then there was the material I provided from LSD manufacturers, who presumably know something about their product, which explicitly stated that they provide improved traction in drag racing situations....but why listen to them, what could they possibly hope to know about their product?
No, it's your lack of knowledge of physics that's the problem here.
That is perhaps the most charitable usage of the word "contribution" that I've ever heard.
Last edited by Improviz; Dec 28, 2009 at 02:27 AM.
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Charger SRT-8
Go back and re-read my posts. Carefully. Understand a valid test vs. an invalid one.
The insults are beneath me, btw. Realize the same open diff car that cut a 2.5 60ft can also cut a 1.9 properly launched. It won't be any quicker with and LSD. Properly launched with good traction (common), swapping an LSD for an Open Diff will have no benefit.
I'll repeat some key words for you that I used: Consistency, reliability, Spool. See if you can find the instances I used them.
The insults are beneath me, btw. Realize the same open diff car that cut a 2.5 60ft can also cut a 1.9 properly launched. It won't be any quicker with and LSD. Properly launched with good traction (common), swapping an LSD for an Open Diff will have no benefit.
I'll repeat some key words for you that I used: Consistency, reliability, Spool. See if you can find the instances I used them.
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...says the guy who argued with something that an article didn't even say, and claimed skratch77
s traction problems were the result of things he never said had occured.
"Invalid test" being defined as "one which presents data with which deuuuuuuuuuuuce disagrees."
And the physics are above you.
Unfortunately, even the articles you provided don't lend support to this idiotic claim, and even more unfortunately, there really aren't many people here dumb enough to be swayed by repeating an unsubstantiated statement ad infinitum.
Unsubstantiated claim, undercut by every piece of data you provided, and by the physics presented in the hot rod article, which you haven't the knowledge to even attempt to refute.
And it begs a question: why do pro drag racers invariably use LSDs of one form or another on their vehicles if open diffs are so great? Never answered that one, did you? Nor did you list any top drag racer who uses an open diff.
Why is that?
Arrogant. Just because I disagree with (and disproved) your swill doesn't mean I didn't read it. Remember: I'm the one who caught you dishonestly modifying a quote to make it seem as though it said something it hadn't, so don't go acting like you've got clean hands here. You were caught red-handed in a lie, and that alone should be sufficient to demonstrate your lack of credibility to anyone here.
Hell, even SOAKOnline, the magazine you list in your signature, has an article about limited slip differentials, and flat-out states that they're beneficial in drag strip situations, and it also states that the reason Chrysler added LSDs to the SRT8s (your car) for 2009 was due to "owner complaints" about the lack of them. Here's a quote from the article:
You lose.
s traction problems were the result of things he never said had occured.
"Invalid test" being defined as "one which presents data with which deuuuuuuuuuuuce disagrees."
And the physics are above you.
And it begs a question: why do pro drag racers invariably use LSDs of one form or another on their vehicles if open diffs are so great? Never answered that one, did you? Nor did you list any top drag racer who uses an open diff.
Why is that?
Hell, even SOAKOnline, the magazine you list in your signature, has an article about limited slip differentials, and flat-out states that they're beneficial in drag strip situations, and it also states that the reason Chrysler added LSDs to the SRT8s (your car) for 2009 was due to "owner complaints" about the lack of them. Here's a quote from the article:
With an "open" differential, both wheels apply engine power to the ground and even can lay down twin black strips of rubber when there is a loss of adhesion or overpowering of the tires. However, when one becomes "unloaded" due to less traction and starts to spin, the power isn't transferred to the other wheel which means the rate of acceleration doesn't increase. This can be a problem on the street, the racetrack and the dragstrip.
Last edited by Improviz; Dec 28, 2009 at 02:55 AM.
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Hell, even SOAKOnline, the magazine you list in your signature, has an article about limited slip differentials, and flat-out states that they're beneficial in drag strip situations, and it also states that the reason Chrysler added LSDs to the SRT8s (your car) for 2009 was due to "owner complaints" about the lack of them. Here's a quote from the article:
You lose.
You lose.
Last edited by Deuuuce; Dec 28, 2009 at 03:17 AM.
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CLS55 AMG
Hell, even SOAKOnline, the magazine you list in your signature, has an article about limited slip differentials, and flat-out states that they're beneficial in drag strip situations, and it also states that the reason Chrysler added LSDs to the SRT8s (your car) for 2009 was due to "owner complaints" about the lack of them. Here's a quote from the article:
With an "open" differential, both wheels apply engine power to the ground and even can lay down twin black strips of rubber when there is a loss of adhesion or overpowering of the tires. However, when one becomes "unloaded" due to less traction and starts to spin, the power isn't transferred to the other wheel which means the rate of acceleration doesn't increase. This can be a problem on the street, the racetrack and the dragstrip.
Also, why did you write the following post in the Dodge Charger forum:
http://www.chargerforums.com/forums/...26&postcount=4
I think a Quaiffe limited-slip differential would be a far better investment for the street, strip and track.
Ladder bars (or traction bars) they were made for leaf spring cars right?
If you did do that, your handling would go away, far away, into the dumps.
Ladder bars (or traction bars) they were made for leaf spring cars right?
If you did do that, your handling would go away, far away, into the dumps.
Oh, and while we're on the subject of journalism: why did you purposefully misquote that indycar reference, deuuuce?
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Classic, as in you just got pwned....if an LSD is of no benefit at a drag strip, then why, prey tell, did you write, in your magazine, that it is?
Also, why did you write the following post in the Dodge Charger forum:
http://www.chargerforums.com/forums/...26&postcount=4
How would it be better at the strip, deuuuce, given that you've spent the better part of three pages here arguing that it would make no difference? Why would you want one for your car, deuuuce, given that it won't help your ET? Wouldn't be for street-racing, you've advocated against that...so why do you want one?
Oh, and while we're on the subject of journalism: why did you purposefully misquote that indycar reference, deuuuce?
Also, why did you write the following post in the Dodge Charger forum:
http://www.chargerforums.com/forums/...26&postcount=4
How would it be better at the strip, deuuuce, given that you've spent the better part of three pages here arguing that it would make no difference? Why would you want one for your car, deuuuce, given that it won't help your ET? Wouldn't be for street-racing, you've advocated against that...so why do you want one?
Oh, and while we're on the subject of journalism: why did you purposefully misquote that indycar reference, deuuuce?
The Indy Car reference: to show that an LSD could actually hurt. That's all.
Here is an interesting excerpt, unedited, answered by a team of actual engineers:
Originally Posted by budoboy
Thanks for taking the time to talk to us. I love my Charger SRT8 and appreciate that so much performance was made available for such a reasonable price.
Do you see an advantage to getting a Quaife LSD for drag racing? I have ported heads/cam/2800 stall converter and have just bought drag radials. I'll be upgrading my halfshafts and wonder if I should bother with the Quaife if I'm only going to be drag racing.
Do you have any recommendation on best bang for the buck weight savings at the track. I want to be stock appearing so I was wondering if there are any boat anchors underneath the car that I can live without :-)
I love showing up Mustangs and Corvettes at the track with my 4-dr beast.
No. The Quaife will bias while going straight due to slight variations in surface and tire diameter and cause drag, hurting you all the way down the track. The indepenent suspension at the rear means the right does not unload and the left loading under power like a live axle car. Make sure the rear tires have equal corner weights and you should not need the limited slip.
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CLS55 AMG
You wrote the following, quoting a book:
Many Indy Car race engineers use an open differential at the high-speed ovals because it "frees up the cars". Translated, this means that since the speeds are quite high and wheelspin is not a problem, the open diff is effective because it wastes less power. On shorter ovals, racers sometimes prefer a completely locked differential called a "spool".
The only problem is that:
1) the preceeding paragraph in the article, which you did not quote, discusses how open diffs are poor for racing because they have traction issues;
2) the portions of the two sentences you omitted hurts your case;
3) the portions you glued together to form one sentence are from two different sentences.
No matter how you slice it, that's extremely dishonest, and absolutely taken out of the context of the original article.
Here is an interesting excerpt, unedited, answered by a team of actual engineers:
Originally Posted by budoboy
Thanks for taking the time to talk to us. I love my Charger SRT8 and appreciate that so much performance was made available for such a reasonable price.
Do you see an advantage to getting a Quaife LSD for drag racing? I have ported heads/cam/2800 stall converter and have just bought drag radials. I'll be upgrading my halfshafts and wonder if I should bother with the Quaife if I'm only going to be drag racing.
Do you have any recommendation on best bang for the buck weight savings at the track. I want to be stock appearing so I was wondering if there are any boat anchors underneath the car that I can live without :-)
I love showing up Mustangs and Corvettes at the track with my 4-dr beast.
No. The Quaife will bias while going straight due to slight variations in surface and tire diameter and cause drag, hurting you all the way down the track. The indepenent suspension at the rear means the right does not unload and the left loading under power like a live axle car. Make sure the rear tires have equal corner weights and you should not need the limited slip.
Originally Posted by budoboy
Thanks for taking the time to talk to us. I love my Charger SRT8 and appreciate that so much performance was made available for such a reasonable price.
Do you see an advantage to getting a Quaife LSD for drag racing? I have ported heads/cam/2800 stall converter and have just bought drag radials. I'll be upgrading my halfshafts and wonder if I should bother with the Quaife if I'm only going to be drag racing.
Do you have any recommendation on best bang for the buck weight savings at the track. I want to be stock appearing so I was wondering if there are any boat anchors underneath the car that I can live without :-)
I love showing up Mustangs and Corvettes at the track with my 4-dr beast.
No. The Quaife will bias while going straight due to slight variations in surface and tire diameter and cause drag, hurting you all the way down the track. The indepenent suspension at the rear means the right does not unload and the left loading under power like a live axle car. Make sure the rear tires have equal corner weights and you should not need the limited slip.
Now, back to your post. If the poster in question was actually a Chrysler engineer, he was basically toeing the (then-) company line, saying the same stuff as the Mercedes engineers, who assured us all that the edl braking was superior to an LSD, no need for an LSD, move along folks, nothing to see here....but of course we all found out the story on that one. I also notice that the post you quoted was from 2008. Interesting that shortly after it was written, Chrysler turned around and added an G648 Rear Axle with Limited Slip to the Challenger, 300C, and Charger SRT8 models in 2009, isn't it? I suppose they did that because they don't do any good, right?
We can verify that they think it does no good at the track by reading this blurb they put out:
New for the 2009 Dodge Challenger SRT8 is a limited-slip differential, resulting in even more on-track performance for the ultimate American muscle coupe.
Carbon clutch packs are built into each side of the differential. When torque is transmitted through the differential, the clutch packs engage to prevent wheel slip. The greater the torque going to the wheels, the greater the “locking effect,” sending torque to the side that is needed. The limited-slip differential is a more efficient transmittal of torque because it senses the torque and transfers it quicker, before wheel slip occurs. The result is a better handling vehicle on the track.
The limited-slip differential housing is a lightweight aluminum die casting offering improved thermal and weight savings advantages. The final drive ratio is 3.91.
Carbon clutch packs are built into each side of the differential. When torque is transmitted through the differential, the clutch packs engage to prevent wheel slip. The greater the torque going to the wheels, the greater the “locking effect,” sending torque to the side that is needed. The limited-slip differential is a more efficient transmittal of torque because it senses the torque and transfers it quicker, before wheel slip occurs. The result is a better handling vehicle on the track.
The limited-slip differential housing is a lightweight aluminum die casting offering improved thermal and weight savings advantages. The final drive ratio is 3.91.
And yes, I agree: in such a perfect world, an open diff would work just fine. But as you (talking out of the other side of your mouth) pointed out, the real world ain't perfect.
As to engineers, the engineers at quaife, as I pointed out previously, state that the Quaife DOES help straight-line acceleration by improving traction...and heck, even laypersons get this stuff sometimes: this guy named Deuuuce (no relation, I'm sure), over on the Dodge Charger forum, also weighed in on the subject:
http://www.chargerforums.com/forums/showpost.php?p=1851851&postcount=17
Originally Posted by ironside
thought the SRT engineers were all about the BLD's (brake-lock diff, using abs as a poor man's traction control), saying they were better than an LSD (at least that was what they said about the Caliber)
Are 2009 SuperBees included in this 'lucky' bunch of cars with LSD's and tougher half shafts?
How can you confirm if you have this stuff or not?
Are 2009 SuperBees included in this 'lucky' bunch of cars with LSD's and tougher half shafts?
How can you confirm if you have this stuff or not?
Originally Posted by deuuuce
Yes, they used to. They said it was better probably because.....it was cheaper.
SuperBees are just appearance packages, otherwise mechanically identical to the same model year car.
The LSD IS helpful in a straightline if you have uneven surface or compromised traction on one side vs. the other. Sometimes at the dragstrip that can be handy.
The SRT Engineers DID say it could slow you down a little overall as the torque keeps transferring back and forth between the wheels, FWIW.
SuperBees are just appearance packages, otherwise mechanically identical to the same model year car.
The LSD IS helpful in a straightline if you have uneven surface or compromised traction on one side vs. the other. Sometimes at the dragstrip that can be handy.
The SRT Engineers DID say it could slow you down a little overall as the torque keeps transferring back and forth between the wheels, FWIW.
http://www.chargerforums.com/forums/...4&postcount=46
Originally Posted by PickardvilleSRT8
A limited slip slowing the car down............I have never heard something like that on any vehicle, traction is not a bad thing. There are guys on here pulling excellent 60 foots with the stock open diff but I don't see how a limited slip that only aids in traction could really slow you down. The Quiafe is not the style however I would personally want as its torque biasing crap is useless to me. A regular old clutch pack limited slip would be fine, or an Auburn ECTED......that would be just awesome. Limited slip and spool, all in one.
If that's the case the Challengers should be slower because they all have limited slips in them( SRT's and 6 speed R/T's). From the quater mile times posted they most certainly not. And if a lmited slip is not useful to the SRT boys, why would the Challenger have one in the first place...........
Mind you the SRT guys (the engineers quoted by Deuuuce--improviz) say that the SRT8's are optimally tuned( which they are not) have no need for catchcans( look how many of us prove that otherwise) amongst who knows what else. They seem to just find they have to justify the shortfalls of these cars no matter how ridiculous the answers are. An open diff may help your mile per hour from spinning but that in no way aids the ET. If you hook, you hook, and that's the best it can be. If not, it's all comprimise anyhow.
If that's the case the Challengers should be slower because they all have limited slips in them( SRT's and 6 speed R/T's). From the quater mile times posted they most certainly not. And if a lmited slip is not useful to the SRT boys, why would the Challenger have one in the first place...........
Mind you the SRT guys (the engineers quoted by Deuuuce--improviz) say that the SRT8's are optimally tuned( which they are not) have no need for catchcans( look how many of us prove that otherwise) amongst who knows what else. They seem to just find they have to justify the shortfalls of these cars no matter how ridiculous the answers are. An open diff may help your mile per hour from spinning but that in no way aids the ET. If you hook, you hook, and that's the best it can be. If not, it's all comprimise anyhow.
Originally Posted by deuuuce
I agree, and I can only speculate.
We all want the LSD due to the deficiencies of the open diff.
What they were talking about was the continuous torque biasing, I believe. So any detrimental effect would be rather small. Also, higher hp cars could only benefit due to traction being an issue even when rolling. Hence no open diffs in those eithers.
We all want the LSD due to the deficiencies of the open diff.
What they were talking about was the continuous torque biasing, I believe. So any detrimental effect would be rather small. Also, higher hp cars could only benefit due to traction being an issue even when rolling. Hence no open diffs in those eithers.
For Fantasy Land, there's open diff...for everywhere else, there's LSD.
Last edited by Improviz; Dec 28, 2009 at 02:12 PM.
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guys its not rocket science here folks,an lsd in the REAL WORLD will help traction(I thought everyone knew that).Forget about perfect conditions ect,our cars are making to much torque and need to put it down threw 2 wheels.
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CLS55 AMG
He's even said as much in several of his posts (mostly ones that weren't done here), so frankly I'm wondering what the hell he's even arguing about.
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Give me a break. Your first entry in the thread was that LSDs do not help on the same car, unless the driver botches his launch, which in deuuuuce-speak means "launches his car on any surface which is not perfect". Now you're saying they do. That is a flip-flop, no matter how you slice it.
That's a lie. Let's examine this again, as you seem to be trying to waste space here by generating some distance between it and the latest posts, so here I'll present it in its entirety.
You wrote the following, quoting a book:
Here is the page from the book you quoted which contains the sentences you quoted in their entirety, with the section you omitted via the ellipsis included, along with the sentence that immediately follows it, which you omitted and which is most illustrative:
So you omit all of the sections showing that it helps, obviously to give a false impression that the article stated that LSDs are not beneficial, which is why indycar drivers use them.
The only problem is that:
1) the preceeding paragraph in the article, which you did not quote, discusses how open diffs are poor for racing because they have traction issues;
2) the portions of the two sentences you omitted hurts your case;
3) the portions you glued together to form one sentence are from two different sentences.
No matter how you slice it, that's extremely dishonest, and absolutely taken out of the context of the original article.
You wrote the following, quoting a book:
Here is the page from the book you quoted which contains the sentences you quoted in their entirety, with the section you omitted via the ellipsis included, along with the sentence that immediately follows it, which you omitted and which is most illustrative:
So you omit all of the sections showing that it helps, obviously to give a false impression that the article stated that LSDs are not beneficial, which is why indycar drivers use them.
The only problem is that:
1) the preceeding paragraph in the article, which you did not quote, discusses how open diffs are poor for racing because they have traction issues;
2) the portions of the two sentences you omitted hurts your case;
3) the portions you glued together to form one sentence are from two different sentences.
No matter how you slice it, that's extremely dishonest, and absolutely taken out of the context of the original article.
And I avoided using the part because in modern nomenclature a "Spool" is essentially a locked Open Diff and is basically only used for non-handling applications such as drag racing. Btw, it doesn't transfer power back and forth. Also, you're using alledged "misquote" to illustrate a non-dragstrip benefit. That isn't the topic.
Before proceeding, I'd like to point out that the Chrysler engineers you just cited illustrated another error in your previous post:
Nope. They stated explicitly that there is no unloading/loading under power, which is caused by twist, in an IRS car, exactly what I said yesterday and what the article in question stated. Moving on...
Nope. They stated explicitly that there is no unloading/loading under power, which is caused by twist, in an IRS car, exactly what I said yesterday and what the article in question stated. Moving on...
Now, back to your post. If the poster in question was actually a Chrysler engineer, he was basically toeing the (then-) company line, saying the same stuff as the Mercedes engineers, who assured us all that the edl braking was superior to an LSD, no need for an LSD, move along folks, nothing to see here....but of course we all found out the story on that one. I also notice that the post you quoted was from 2008. Interesting that shortly after it was written, Chrysler turned around and added an G648 Rear Axle with Limited Slip to the Challenger, 300C, and Charger SRT8 models in 2009, isn't it? I suppose they did that because they don't do any good, right? We can verify that they think it does no good at the track by reading this blurb they put out:
Aside from not being tuned in to what other engineers were obviously telling his marketing department, it sounds like the engineer who wrote that post you cited is living in the same world as you are: a world where everything is perfect, where there are no traction variations between tires, no debris on the track, perfectly level track with no surface variations, irregularities, or slick spots all the way up the 1/4 mile, where the burnout lane is perfect, perfectly level, and where it is impossible for one tire to ever break loose.
And yes, I agree: in such a perfect world, an open diff would work just fine. But as you (talking out of the other side of your mouth) pointed out, the real world ain't perfect.
We can verify that they think it does no good at the track by reading this blurb they put out:Aside from not being tuned in to what other engineers were obviously telling his marketing department, it sounds like the engineer who wrote that post you cited is living in the same world as you are: a world where everything is perfect, where there are no traction variations between tires, no debris on the track, perfectly level track with no surface variations, irregularities, or slick spots all the way up the 1/4 mile, where the burnout lane is perfect, perfectly level, and where it is impossible for one tire to ever break loose.
And yes, I agree: in such a perfect world, an open diff would work just fine. But as you (talking out of the other side of your mouth) pointed out, the real world ain't perfect.
Hmm, sounds like you didn't exactly view the statement by the Chrysler engineers as The Word of God there, deuuuce, and in fact a) you were quite skeptical about their claims, agreed with the other poster that they basically say that the car was perfect despite its known shortcomings; b) you agreed with what I, my sources, and your sources have been saying, just as you did in the article you wrote....I guess it depends upon which side of your mouth you are talking out of at any given moment.
For Fantasy Land, there's open diff...for everywhere else, there's LSD.
For Fantasy Land, there's open diff...for everywhere else, there's LSD.
Last edited by Deuuuce; Dec 28, 2009 at 03:06 PM.
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CLS55 AMG
Deuuuce, rather than address your spin, obfuscation, and lies point by point, I'm simply going to illustrate what a hypocrite and a liar you are by simply using your own words. The only thing I will say is that I invite any and all readers to examine what Deuuuce did when he quoted the text on IndyCars, to read the text itself for which I provided the link, and draw their own conclusions about Deuuuce's honesty, integrity, or lack thereof.
I also invite them to read the following and see how Deuuuce will argue one thing in one forum, then turn around and take a counter-position here, and cite a source here (Chrysler engineers) as Gospel, while in another forum he calls their integrity and the accuracy of their statements, as well as their motivations, into question.
So, firstly, you write an article entitled "Design flaw in the new McLaren MP4-12C", wherein you argue that the new McLaren has a design flaw: the omission of an LSD:
http://www.soakmag.com/soakworld/article.asp?c=Autos&t=Design+flaw+in+the+new+McLar en+MP4-12C%3F&aid=1154
So there you argue, not once, but twice, that LSD ***IS BENEFICIAL AT THE DRAG STRIP***. Then you come over here and argue that it isn't.
Nice.
Then there are these two nuggets from chargerforums.com:
http://www.chargerforums.com/forums/showpost.php?p=1851851&postcount=17
Great, so there, you argue that the LSD is helpful at a drag strip, but then you come over here and argue that it isn't.
Nice.
And then there was this:
http://www.chargerforums.com/forums/showpost.php?p=1607914&postcount=46
OK, so there you're saying that you think that LSD helps, that if it hurts it would be negligible, that a high horsepower car can have traction issues even when rolling, and that the Chrysler engineers are basically saying that the car is perfect despite its known flaws.
Yet you come over here and, on each and every one of those points, take a contrary position.
Nice.
Add to these fine examples of hypocrisy your selective editing of a text you quoted to try and make it look as though it supported the argument you're making (here, as opposed to the arguments you've made elsewhere), and it quickly becomes apparent that your true motiviation here is NOT the accurate dissemination of information, but rather to simply try and spin, twist, and lie your way out of agreeing with points you've made elsewhere, simply because you're too obstinate to admit what not only the data you've provided in this very thread states plainly, but also what you, yourself, have argued both in other forums and in the article you wrote, quoted above.
This is pathetic.
So fine, keep trying to dig your way out of what you've said, about LSDs themselves, their benefits both on and off of a drag strip from a dig and roll, the reliability of what the Chrysler engineers have written, etc. etc. etc...but you're fooling no one with this weak little ruse.
I also invite them to read the following and see how Deuuuce will argue one thing in one forum, then turn around and take a counter-position here, and cite a source here (Chrysler engineers) as Gospel, while in another forum he calls their integrity and the accuracy of their statements, as well as their motivations, into question.
So, firstly, you write an article entitled "Design flaw in the new McLaren MP4-12C", wherein you argue that the new McLaren has a design flaw: the omission of an LSD:
http://www.soakmag.com/soakworld/article.asp?c=Autos&t=Design+flaw+in+the+new+McLar en+MP4-12C%3F&aid=1154
There is a disturbing trend in the automotive world of eliminating the limited slip differential (LSD). Manufacturers are promoting alternatives with fancy names, but none of them do what an LSD can do and this can be a problem. If you're spinning, you're not accelerating. This can be a big, big problem on the street and on the track for reasons I'll explain.
According to the Road & Track Magazine, Nov. 2009 issue, the upcoming McLaren MP4-12C doesn't have one! This car has every ingredient to make it one of the greatest sports cars on the road except for the potential penalty of lacking an LSD. This could be a major compromise from a company that is renowned worldwide for it's engineering expertise and racing pedigree. Their best known accomplishments are multiple championships in Formula 1 and the world's fastest production car for seven years.
With an "open" differential, both wheels apply engine power to the ground and even can lay down twin black strips of rubber when there is a loss of adhesion or overpowering of the tires. However, when one becomes "unloaded" due to less traction and starts to spin, the power isn't transferred to the other wheel which means the rate of acceleration doesn't increase. This can be a problem on the street, the racetrack and the dragstrip.
Most annoyingly, daily driving can be compromised. After pulling out onto an uneven surface, begin accelerating and if aggressively programmed, the engine power could be reduced in addition to the rear brake being applied. A real pain in the ***. A little extra brake wear over time and now you're maintaining your speed or slowing down when you should be accelerating. Try it when a vehicle is headed your way and you "thought" you had enough time... That is why many drive with Traction Control partially off. I'll control my own throttle, thank you very much.
How about in rain and snow? Drive over or start on a slippery patch and you just sit and spin, the wheel with traction never getting the available power transferred. Apply more gas and you spin faster. Great. At the dragstrip it's the same thing. Get "out of the groove" with one tire and the other doesn't pick up the slack. For those that run higher traction tires such as drag radials at the dragstrip, the uneven distribution of the power from one side vs. the other can break a rear differential or half-shaft at some point.
The reason many manufacturers leave out a limited slip differential is for of cost savings, pure and simple. Less mechanical parts means less cost. If it was a size and packaging issue that meant raising the center of gravity, extending the wheelbase, or something else radical, will it mean the McLaren, while wildly fast and capable, will be left behind by the competition?
According to the Road & Track Magazine, Nov. 2009 issue, the upcoming McLaren MP4-12C doesn't have one! This car has every ingredient to make it one of the greatest sports cars on the road except for the potential penalty of lacking an LSD. This could be a major compromise from a company that is renowned worldwide for it's engineering expertise and racing pedigree. Their best known accomplishments are multiple championships in Formula 1 and the world's fastest production car for seven years.
With an "open" differential, both wheels apply engine power to the ground and even can lay down twin black strips of rubber when there is a loss of adhesion or overpowering of the tires. However, when one becomes "unloaded" due to less traction and starts to spin, the power isn't transferred to the other wheel which means the rate of acceleration doesn't increase. This can be a problem on the street, the racetrack and the dragstrip.
Most annoyingly, daily driving can be compromised. After pulling out onto an uneven surface, begin accelerating and if aggressively programmed, the engine power could be reduced in addition to the rear brake being applied. A real pain in the ***. A little extra brake wear over time and now you're maintaining your speed or slowing down when you should be accelerating. Try it when a vehicle is headed your way and you "thought" you had enough time... That is why many drive with Traction Control partially off. I'll control my own throttle, thank you very much.
How about in rain and snow? Drive over or start on a slippery patch and you just sit and spin, the wheel with traction never getting the available power transferred. Apply more gas and you spin faster. Great. At the dragstrip it's the same thing. Get "out of the groove" with one tire and the other doesn't pick up the slack. For those that run higher traction tires such as drag radials at the dragstrip, the uneven distribution of the power from one side vs. the other can break a rear differential or half-shaft at some point.
The reason many manufacturers leave out a limited slip differential is for of cost savings, pure and simple. Less mechanical parts means less cost. If it was a size and packaging issue that meant raising the center of gravity, extending the wheelbase, or something else radical, will it mean the McLaren, while wildly fast and capable, will be left behind by the competition?
Nice.
Then there are these two nuggets from chargerforums.com:
http://www.chargerforums.com/forums/showpost.php?p=1851851&postcount=17
Originally Posted by ironside
thought the SRT engineers were all about the BLD's (brake-lock diff, using abs as a poor man's traction control), saying they were better than an LSD (at least that was what they said about the Caliber)
Are 2009 SuperBees included in this 'lucky' bunch of cars with LSD's and tougher half shafts?
How can you confirm if you have this stuff or not?
Are 2009 SuperBees included in this 'lucky' bunch of cars with LSD's and tougher half shafts?
How can you confirm if you have this stuff or not?
Originally Posted by deuuuce
Yes, they used to. They said it was better probably because.....it was cheaper.
SuperBees are just appearance packages, otherwise mechanically identical to the same model year car.
The LSD IS helpful in a straightline if you have uneven surface or compromised traction on one side vs. the other. Sometimes at the dragstrip that can be handy.
The SRT Engineers DID say it could slow you down a little overall as the torque keeps transferring back and forth between the wheels, FWIW.
SuperBees are just appearance packages, otherwise mechanically identical to the same model year car.
The LSD IS helpful in a straightline if you have uneven surface or compromised traction on one side vs. the other. Sometimes at the dragstrip that can be handy.
The SRT Engineers DID say it could slow you down a little overall as the torque keeps transferring back and forth between the wheels, FWIW.
Nice.
And then there was this:
http://www.chargerforums.com/forums/showpost.php?p=1607914&postcount=46
Originally Posted by PickardvilleSRT8
A limited slip slowing the car down............I have never heard something like that on any vehicle, traction is not a bad thing. There are guys on here pulling excellent 60 foots with the stock open diff but I don't see how a limited slip that only aids in traction could really slow you down. The Quiafe is not the style however I would personally want as its torque biasing crap is useless to me. A regular old clutch pack limited slip would be fine, or an Auburn ECTED......that would be just awesome. Limited slip and spool, all in one.
If that's the case the Challengers should be slower because they all have limited slips in them( SRT's and 6 speed R/T's). From the quater mile times posted they most certainly not. And if a lmited slip is not useful to the SRT boys, why would the Challenger have one in the first place...........
Mind you the SRT guys (the engineers quoted by Deuuuce--improviz) say that the SRT8's are optimally tuned( which they are not) have no need for catchcans( look how many of us prove that otherwise) amongst who knows what else. They seem to just find they have to justify the shortfalls of these cars no matter how ridiculous the answers are. An open diff may help your mile per hour from spinning but that in no way aids the ET. If you hook, you hook, and that's the best it can be. If not, it's all comprimise anyhow.
If that's the case the Challengers should be slower because they all have limited slips in them( SRT's and 6 speed R/T's). From the quater mile times posted they most certainly not. And if a lmited slip is not useful to the SRT boys, why would the Challenger have one in the first place...........
Mind you the SRT guys (the engineers quoted by Deuuuce--improviz) say that the SRT8's are optimally tuned( which they are not) have no need for catchcans( look how many of us prove that otherwise) amongst who knows what else. They seem to just find they have to justify the shortfalls of these cars no matter how ridiculous the answers are. An open diff may help your mile per hour from spinning but that in no way aids the ET. If you hook, you hook, and that's the best it can be. If not, it's all comprimise anyhow.
Originally Posted by deuuuce
I agree, and I can only speculate.
We all want the LSD due to the deficiencies of the open diff.
What they were talking about was the continuous torque biasing, I believe. So any detrimental effect would be rather small. Also, higher hp cars could only benefit due to traction being an issue even when rolling. Hence no open diffs in those eithers.
We all want the LSD due to the deficiencies of the open diff.
What they were talking about was the continuous torque biasing, I believe. So any detrimental effect would be rather small. Also, higher hp cars could only benefit due to traction being an issue even when rolling. Hence no open diffs in those eithers.
Yet you come over here and, on each and every one of those points, take a contrary position.
Nice.
Add to these fine examples of hypocrisy your selective editing of a text you quoted to try and make it look as though it supported the argument you're making (here, as opposed to the arguments you've made elsewhere), and it quickly becomes apparent that your true motiviation here is NOT the accurate dissemination of information, but rather to simply try and spin, twist, and lie your way out of agreeing with points you've made elsewhere, simply because you're too obstinate to admit what not only the data you've provided in this very thread states plainly, but also what you, yourself, have argued both in other forums and in the article you wrote, quoted above.
This is pathetic.
So fine, keep trying to dig your way out of what you've said, about LSDs themselves, their benefits both on and off of a drag strip from a dig and roll, the reliability of what the Chrysler engineers have written, etc. etc. etc...but you're fooling no one with this weak little ruse.
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Charger SRT-8
But simply replacing an Open Diff with an LSD on a sticky track doesn't make the car quicker. Funny how you used my quote where I stated "sometimes". Not all the time, right? lol.
And a higher horsepower car is more likely to overpower the track, but not always. Oh, maybe I should repeat another word and re-phrase it, "Sometimes a higher horsepower car WON'T over power the track". Can you comprehend the difference?
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Consistency implies that it provides better ETs on average than an open diff. So if it gives you better ETs on average, then it's kind of bizarre to argue that it doesn't make the car any quicker...and yet, here you go again:
Here's an example:
Under ideal circumstances they will be the same off the line. The torsen (LSD) will only let loose when the limits of adhesion on both tires have been exceeded, whereas the open diff will let loose when the limit of either tire is exceeded regardless of the condition of the other tire. This means that under ideal conditions the difference between the limits will be zero and there will be no difference. Since the traction is never the same between the tires in real life, the torsen diff will have better grip in the real world. I can explain the physics of it if you would like.
As an example of how useless an open differential can be, say you're driving along and find a diner, and this diner has a clay parking lot, but currently everything is dry and you're hungry for some nice greasy diner food. You go inside, have a cup of coffee, eat your two day old pie, and as you go to walk back outside you notice it has started raining. The dirt you parked on is now mud which has become slick as grease. Before hopping in the car you notice the rear left wheel is on some nice grippy gravel, and the rear right wheel is sitting in a giant mud puddle. You figure, "Hey, one of my wheels is on gravel, I should be able to leave here fine right?". You crank the car, and as you ease onto the gas pedal the wheel in the mud sits there and spins mud all over your once clean car, getting you absolutely nowhere! You might try going in reverse, but this also gets you nowhere... This is where the term "one wheel drive" was coined. In drag racing situations, during the burnout, only one wheel will spin as well - during launch the maximum grip you will have will be governed to one wheel's torque limit as well.
No reduction:
http://www.ppi-ats.com/LSD/LSD_basics.html
http://www.ppi-ats.com/LSD/LSD_basics.html
LSD and open differential
In Drag Racing, the impact of an LSD is less dramatic. However, during sudden high-power starts and while up-shifting during acceleration, it is possible that either the left or right tire can frequently slip. A performance LSD will quickly detect the that condition and lock the differential so that you do not lose any time. Not even a few tenths of a second!
In Drag Racing, the impact of an LSD is less dramatic. However, during sudden high-power starts and while up-shifting during acceleration, it is possible that either the left or right tire can frequently slip. A performance LSD will quickly detect the that condition and lock the differential so that you do not lose any time. Not even a few tenths of a second!
Power to weight and gearing would point to the capability of the higher trap speeds. Regarding the LSD, on street cars with street tires, it helps with uneven traction, but it will not decrease the 60ft time of an identical non-LSD car unless excess slippage occurs. IF that happens, the launch is effectively "blown" vs. what the car is capable of. This applies to a decently prepped surface.
And of course, you don't think that that benefit is going to be helpful, except when it is, and that it won't lower 60' times, except in the case where loss of traction by an open diff will hurt 60' times, where the LSD will help.
Wow, what a brilliant deduction. I'm impressed that you managed to figure that out all by yourself.
I can comprehend that you're an idiot who thinks he's fooling people with extra-careful word parsing, selective quoting, obfuscation, and spin. So let's just use verbiage and state that you're fooling the people who don't actually read what you're writing.
Last edited by Improviz; Dec 28, 2009 at 05:43 PM.
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Go back and re-read my posts. Carefully. Understand a valid test vs. an invalid one.
The insults are beneath me, btw. Realize the same open diff car that cut a 2.5 60ft can also cut a 1.9 properly launched. It won't be any quicker with and LSD. Properly launched with good traction (common), swapping an LSD for an Open Diff will have no benefit.
I'll repeat some key words for you that I used: Consistency, reliability, Spool. See if you can find the instances I used them.
The insults are beneath me, btw. Realize the same open diff car that cut a 2.5 60ft can also cut a 1.9 properly launched. It won't be any quicker with and LSD. Properly launched with good traction (common), swapping an LSD for an Open Diff will have no benefit.
I'll repeat some key words for you that I used: Consistency, reliability, Spool. See if you can find the instances I used them.
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02 CLK 55 AMG,09 C63 loaded with P30
Jon, Jon....what are we going to do with you? We aren't talking theoretical here, we are talking actual. And you made a concrete claim about your car's performance capabilities. We ain't talking Car & Driver in a 209, baby, we're talking YOU. In YOUR car.
You made the claims, that 1)your car can run 5-60 in 4.6 seconds, the same as a supercharged AMG; 2) you pulled an E90 M3 up past 130 mph by "drafting" him.
Let me repeat: YOU made the claims.
One more time: YOU made the claims.
Therefore, the burden of proof is on YOU.
So I very generously offered to donate some of my time to give you the opportunity to prove your claims.
And you have, in response, ducked, dodged, weaved, evaded, and whined.
How rude of you.
I mean, really: I generously offer to assist you in showing everyone here that you can, in your car, pull E90 M3s by "drafting" them, and run a 4.6 second 5-60 run, and what do I get in response?
Insults.
Well, really, that hurts, man.
Where is the love?
Come on, I'm doing you a favor here, guy! Here is your big chance to actually prove me wrong, and show everyone here that I'm full of it, that your car *can* do a 4.6 sec. 5-60 run, that you *can* outrun an E90 M3 up past 130, that it *can* leap tall buildings in a single bound.
And we can get it all down on video, gold-standard proof, that you're not simply a chronic bull*****ter with a penchant for telling tall tales, but that, in fact, you've been telling us the truth all along here.
Sheesh, why the hostility?
You made the claims, that 1)your car can run 5-60 in 4.6 seconds, the same as a supercharged AMG; 2) you pulled an E90 M3 up past 130 mph by "drafting" him.
Let me repeat: YOU made the claims.
One more time: YOU made the claims.
Therefore, the burden of proof is on YOU.
So I very generously offered to donate some of my time to give you the opportunity to prove your claims.
And you have, in response, ducked, dodged, weaved, evaded, and whined.
How rude of you.
I mean, really: I generously offer to assist you in showing everyone here that you can, in your car, pull E90 M3s by "drafting" them, and run a 4.6 second 5-60 run, and what do I get in response?
Insults.
Well, really, that hurts, man.
Where is the love?
Come on, I'm doing you a favor here, guy! Here is your big chance to actually prove me wrong, and show everyone here that I'm full of it, that your car *can* do a 4.6 sec. 5-60 run, that you *can* outrun an E90 M3 up past 130, that it *can* leap tall buildings in a single bound.
And we can get it all down on video, gold-standard proof, that you're not simply a chronic bull*****ter with a penchant for telling tall tales, but that, in fact, you've been telling us the truth all along here.
Sheesh, why the hostility?
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