Would like to post, but my dream vehicles are all customized machines, so I think it's better off leaving them a mystery to members of this forum. 
With lower profile tyres, one must shift platform and wheel tyre load control from using tyres like shock absorbers to using properly designed suspension instead of using no travel hacks. The worst example was the shark nose weirdo Williams BMW F-1 cars from a few years ago, with the nose design compromising suspension geometry to such a degree that the wheels don't get camber recovery with bump travel. In fact, camber grew more POSITIVE with compression! Explains all the uber understeer problems drivers complained about, especially as speed climbs and the suspension compresses further. Besides, which would you prefer to control the car, well tuned springs and dampers or the sidewall which has ever changing properties?
So, why is a lower profile (within reason of course) tyre grippier? Lower profiles allow stiffer sidewall contruction, allowing more stable contact patches. More contact patch stability is always good if ultimate grip is the aim. Of course, this would mean that the tyre works at smaller ranges of slip angles, but with F-1 cars as aero dependant as they are today, larger slip angles aren't too productive. Current F-1 wheels are what they are not because they're the ultimate in grip. They're the result of restrictive regulations.
Speaking of which, personally, I would prefer regulations that severely reduce downforce generated via wings BUT allow more freedom to improve tyre mechanical grip. Seriously reduces the aero induced anti-overtaking problems whilst keeping F-1 cars as the ultimate Formula cars both technologically and speed wise.
When the Bridgestone tyre engineers said they'll be undrivable, they meant they could be potentially so sticky that the human body just can't take the g's without help. A 15 inch wheel for current F-1 cars isn't excatly a rim and rubber band setup.
So, why is a lower profile (within reason of course) tyre grippier? Lower profiles allow stiffer sidewall contruction, allowing more stable contact patches. More contact patch stability is always good if ultimate grip is the aim. Of course, this would mean that the tyre works at smaller ranges of slip angles, but with F-1 cars as aero dependant as they are today, larger slip angles aren't too productive. Current F-1 wheels are what they are not because they're the ultimate in grip. They're the result of restrictive regulations.
Speaking of which, personally, I would prefer regulations that severely reduce downforce generated via wings BUT allow more freedom to improve tyre mechanical grip. Seriously reduces the aero induced anti-overtaking problems whilst keeping F-1 cars as the ultimate Formula cars both technologically and speed wise.
When the Bridgestone tyre engineers said they'll be undrivable, they meant they could be potentially so sticky that the human body just can't take the g's without help. A 15 inch wheel for current F-1 cars isn't excatly a rim and rubber band setup.
Last edited by Jamexing, .
Speaking of freedom, I wonder why people define as a animalistic, anarchist state of affairs. Well, guess most humans still run on caveman/woman psychology.
Freedom. What about freedom to access education to better oneself? Freedom to live happy and peaceful lives? Freedom to achieve prosperity without stepping on other people to make oneself taller? Freedom to achieve ones positive dreams without political and financial oppresion? The list could go on forever, but the point is that these basic freedoms that many peace loving and productive individuals desperately want remain remarkably neglected. And yes, true freedom (at least in my sense of the term) does mean responsibility. This does not go down very well with lawyers in litigious societies though.
If there's one good thing that's good about this thread is that people haven't tried to label me as pro/anti gun. Don't get me wrong, I'm a military enthusiast and I like everything from desert eagles to F-22 raptors, but I also don't believe that guns could solve a society's problems. They're good for suppresing violence to an extent, but when one responds to hate induced aggression with more reasons to perpetuate the hate, it's a dead end. Remember the Vietnam war?
Statistically the Americans were winning, if kill to loss ratios are of any indication. But years of brutality and atrocities commited by both sides didn't go down to well with many people around the world. It's a vicious cycle. You've got civillians that just want to be left alone to live peaceful lives, then the Vietcong show up and start forcefully drafting them to military service. America responds to this new threat by removing acres of forest and wiping out many civillians, their property and their homes. This feeds into the anti-American hatred, and this cycle of positive feedback goes on and on and on.....
The sad thing is that Americans went into this mess of a war knowing it was very likely to become a complete mess. The motive of stopping communist spread didn't quite add up if one understands how countries such as Malaysia, Thailand, Indonesia, etc operate. Let's face it, communist atheism won't go down well to countries with religious backbone. As i said by the art of war, "Know thy enemy, Know thyslef, Know when to Strike". The Americans simply didn't know their enemies too well.
I'm also glad that some here have actually understood one of my points about my Japanese comment. Yes, due to complicated cultural differences, what works in one place at the present time would fail miserably at another.
To see how bad racist stupidity and all the associated just could get, just search youtube for clips on the Virginia Tech Massacare. Just take a look at the majority of the comments posted on some obviously racist and hate-inciting videos and you'll all understand why I'm so genrally disgusted. One poor emotionally beat up boy is dead along with 32 others, and the last thing we need is to throw blame and labels around, wishing America to be free of Asians.
Hatred, believe it or not, goes far deeper than just simple differences. It's something that's complicated and havily intertwined into many facets of human experience, history and existance, so I won't try too hard to explain it in a forum. Yes, differences do cause misunderstandings and unintended quarrels. But in my experience, it takes much more than spilt milk to induce a cycle of hatred.
Another good thing is that at least quite few here have actually realised that the only real solution to a social problem is to address the root causes. As an ancient Chinese saying goes: "To permanantly remove grass, one must eliminate its roots".
Freedom. What about freedom to access education to better oneself? Freedom to live happy and peaceful lives? Freedom to achieve prosperity without stepping on other people to make oneself taller? Freedom to achieve ones positive dreams without political and financial oppresion? The list could go on forever, but the point is that these basic freedoms that many peace loving and productive individuals desperately want remain remarkably neglected. And yes, true freedom (at least in my sense of the term) does mean responsibility. This does not go down very well with lawyers in litigious societies though.
If there's one good thing that's good about this thread is that people haven't tried to label me as pro/anti gun.
Don't get me wrong, I'm a military enthusiast and I like everything from desert eagles to F-22 raptors, but I also don't believe that guns could solve a society's problems. They're good for suppresing violence to an extent, but when one responds to hate induced aggression with more reasons to perpetuate the hate, it's a dead end. Remember the Vietnam war? Statistically the Americans were winning, if kill to loss ratios are of any indication. But years of brutality and atrocities commited by both sides didn't go down to well with many people around the world. It's a vicious cycle. You've got civillians that just want to be left alone to live peaceful lives, then the Vietcong show up and start forcefully drafting them to military service. America responds to this new threat by removing acres of forest and wiping out many civillians, their property and their homes. This feeds into the anti-American hatred, and this cycle of positive feedback goes on and on and on.....
The sad thing is that Americans went into this mess of a war knowing it was very likely to become a complete mess. The motive of stopping communist spread didn't quite add up if one understands how countries such as Malaysia, Thailand, Indonesia, etc operate. Let's face it, communist atheism won't go down well to countries with religious backbone. As i said by the art of war, "Know thy enemy, Know thyslef, Know when to Strike". The Americans simply didn't know their enemies too well.
I'm also glad that some here have actually understood one of my points about my Japanese comment. Yes, due to complicated cultural differences, what works in one place at the present time would fail miserably at another.
To see how bad racist stupidity and all the associated just could get, just search youtube for clips on the Virginia Tech Massacare. Just take a look at the majority of the comments posted on some obviously racist and hate-inciting videos and you'll all understand why I'm so genrally disgusted. One poor emotionally beat up boy is dead along with 32 others, and the last thing we need is to throw blame and labels around, wishing America to be free of Asians.
Hatred, believe it or not, goes far deeper than just simple differences. It's something that's complicated and havily intertwined into many facets of human experience, history and existance, so I won't try too hard to explain it in a forum. Yes, differences do cause misunderstandings and unintended quarrels. But in my experience, it takes much more than spilt milk to induce a cycle of hatred.
Another good thing is that at least quite few here have actually realised that the only real solution to a social problem is to address the root causes. As an ancient Chinese saying goes: "To permanantly remove grass, one must eliminate its roots".
Last edited by Jamexing, .
That really depends on what exact dimensions, construction and compound the MRT uses. The only way to know how tyres used for the real MRT is to do tyre tests (aka long and expensive operation).
However, FYI, if F1 was allowed to use the low profile tyres and larger wheels, Their mechanical grip levels would get so high that coupled with current levels of downforce, no human (save the use of G-suits, etc) would be able to handle their phenomneal performance. I remember Bridgestone engineers once said that if you maintain the current overall dimensions of F-1 tyres whilst lowering the sidewall profile and increasing the wheelsize to 15 inches, they're practially undrivable.
And did I mention that kart tyres behave very similiarly to F-1 tyres? Or is it just that F-1 cars don't count as race cars?
However, FYI, if F1 was allowed to use the low profile tyres and larger wheels, Their mechanical grip levels would get so high that coupled with current levels of downforce, no human (save the use of G-suits, etc) would be able to handle their phenomneal performance. I remember Bridgestone engineers once said that if you maintain the current overall dimensions of F-1 tyres whilst lowering the sidewall profile and increasing the wheelsize to 15 inches, they're practially undrivable.
And did I mention that kart tyres behave very similiarly to F-1 tyres? Or is it just that F-1 cars don't count as race cars?
As for the sarin gas incident, guns wouldn't have helped. It wasn't a VIOLENT act of terrorism. It was a stealth attack with a weapon invisible to the naked eye. As they say, you can't shoot at what you can't see.
The problem as a personal protection device is that even if the one with it is a sane and reasonable person, it doesn't mean that he could use it effectively to save lives. These weapons are more a danger to yourself if you aren't familiar with their use and maintanece. A person who can't shoot straight could easily be more dangerous than someone who was trying to hit you.
Besides, it's one thing to do well in target practice. Most civillians simply do not have the experience, training and will to use firearms effectively against dangerous people.
Then there's the problem with escalation. Criminals have AK-47s, so we should arm ourselves with M16A3s? Then they come up with bazookas, so we should counter with stinger missles? What kind of neighbourhood is this? Is this just another scene from ROBOCOP 1/2/3? Oh man, we've got a war zone down here! And to get to this level shows how messed up and corrupt a society has become. Welcome to (insert a south american country)
And of course, social problems need to be addressed and seriously reduced if not elminated. Like it or not, people don't kill people randomly for absolutely o reason at all. And hatred doesn't come from thin air. People hate people because they're stepped on, feel so or been manipulated into believing the target of their hatred has done them harm in some way. I again stress that these are just some of the social problems that people around the world need to seriously address.
Sometimes it's just amazing how mean kids under 10 years old can be to their peers. They do an amazing job of sowing the seeds of hatred even from such a young age. And to bully someone else doesn't prove you're better then them. It just means you're a sorry excuse for a human that can't achieve happiness without inflicting pain on others. Basically an empty shell with no life worth mwntioning and living.
It's not a matter of armament. It's down to the effective function of society itself. Guns are the treatment of last resort when things do go horribly wrong. In the end prevention is >>> cure/treament.
The problem as a personal protection device is that even if the one with it is a sane and reasonable person, it doesn't mean that he could use it effectively to save lives. These weapons are more a danger to yourself if you aren't familiar with their use and maintanece. A person who can't shoot straight could easily be more dangerous than someone who was trying to hit you.
Besides, it's one thing to do well in target practice. Most civillians simply do not have the experience, training and will to use firearms effectively against dangerous people.
Then there's the problem with escalation. Criminals have AK-47s, so we should arm ourselves with M16A3s? Then they come up with bazookas, so we should counter with stinger missles? What kind of neighbourhood is this? Is this just another scene from ROBOCOP 1/2/3? Oh man, we've got a war zone down here! And to get to this level shows how messed up and corrupt a society has become. Welcome to (insert a south american country)
And of course, social problems need to be addressed and seriously reduced if not elminated. Like it or not, people don't kill people randomly for absolutely o reason at all. And hatred doesn't come from thin air. People hate people because they're stepped on, feel so or been manipulated into believing the target of their hatred has done them harm in some way. I again stress that these are just some of the social problems that people around the world need to seriously address.
Sometimes it's just amazing how mean kids under 10 years old can be to their peers. They do an amazing job of sowing the seeds of hatred even from such a young age. And to bully someone else doesn't prove you're better then them. It just means you're a sorry excuse for a human that can't achieve happiness without inflicting pain on others. Basically an empty shell with no life worth mwntioning and living.
It's not a matter of armament. It's down to the effective function of society itself. Guns are the treatment of last resort when things do go horribly wrong. In the end prevention is >>> cure/treament.
Last edited by Jamexing, .
Speaking of gun laws and gun ownership, there're quie a few observations I find rather interesting.
In many countries where guns are practically banned for most civiliians, gun crimes are...drum roll...VERY low.
Let's see, Japan. Almost no civillian guns and surprise surprise, VERY low gun crime rates. BTW, has anyone heard of school shootings in South East Asia? Bet not.
Isn't it possible that if heavy armament was required for peace, then the problem isn't the presesnce of guns or not? Isn't it possible that this is due to some deeper fundamental problem that strikes the people of that area to the core?
It is amazing that people have a remarkable ability to completely IGNORE root causes of problems. Like hyperactive kids. Oh, I know, lets just pump them up with PROZAC! Easy, cheap and very profitable. PERFECT!
Lonely autistic kid gets picked on in the cruellest and meanest possible ways all the time. I know let's pick on the easy target and have some sick and twisted fun! MUHAHAHA! The real solution is to of course get some true friends for this poor fellow, but NO, that's no good. Too "expensive" for the us cheap and nasty lots. Let's just squash him while we can and if he retaliates, just get rid of him! Or label him as a monster or moron, etc. EXCELLENT.
And bullying. There is simply no good excuse for picking fun on anyone that has not done you any intentional harm. It is amazing how so many people think bullying is acceptable. If it's "normal" then it must be correct, right? In some societies, "honour killing" is "normal" and actually encouraged. These 2 situtaions are in essence the same things.
Let's see, big and rich country bullies small and poor country. Poor country eventually gets on its last straw. Poor country wants revenge. Next thing we know it's WAR. Rich country simpy labels poor country as a terrorist nation, poor country cries out and lables rich country as "the almighty oppressor" or "the great satan" or whatever. Sound familiar?
If the fear of getting shot by a firearm is the thing that's keeping the peace, it doesn't mean that firearms are the solution to peace. It is in fact just another form terrorism and tyranny.
I wonder if most people remember what true freedom is anymore.
In many countries where guns are practically banned for most civiliians, gun crimes are...drum roll...VERY low.
Let's see, Japan. Almost no civillian guns and surprise surprise, VERY low gun crime rates. BTW, has anyone heard of school shootings in South East Asia? Bet not.
Isn't it possible that if heavy armament was required for peace, then the problem isn't the presesnce of guns or not? Isn't it possible that this is due to some deeper fundamental problem that strikes the people of that area to the core?
It is amazing that people have a remarkable ability to completely IGNORE root causes of problems. Like hyperactive kids. Oh, I know, lets just pump them up with PROZAC! Easy, cheap and very profitable. PERFECT!
Lonely autistic kid gets picked on in the cruellest and meanest possible ways all the time. I know let's pick on the easy target and have some sick and twisted fun! MUHAHAHA! The real solution is to of course get some true friends for this poor fellow, but NO, that's no good. Too "expensive" for the us cheap and nasty lots. Let's just squash him while we can and if he retaliates, just get rid of him! Or label him as a monster or moron, etc. EXCELLENT.
And bullying. There is simply no good excuse for picking fun on anyone that has not done you any intentional harm. It is amazing how so many people think bullying is acceptable. If it's "normal" then it must be correct, right? In some societies, "honour killing" is "normal" and actually encouraged. These 2 situtaions are in essence the same things.
Let's see, big and rich country bullies small and poor country. Poor country eventually gets on its last straw. Poor country wants revenge. Next thing we know it's WAR. Rich country simpy labels poor country as a terrorist nation, poor country cries out and lables rich country as "the almighty oppressor" or "the great satan" or whatever. Sound familiar?
If the fear of getting shot by a firearm is the thing that's keeping the peace, it doesn't mean that firearms are the solution to peace. It is in fact just another form terrorism and tyranny.
I wonder if most people remember what true freedom is anymore.
Last edited by Jamexing, .
Well, ballast and intake restrictions ARE the cheapest and easiest ways to get cars balanced fast. Judging by what Scawen said, the current global handicaps are just arbitrarily set based on some logic that only he knows. Things should change quite a bit when physics issues get addressed (eventually).
One thing I find sickening here is that whenever a rally/rallycross enthusiast shows up, he's usually told to just buzz off to some other rally game.
WHEN WAS THE LAST TIME LFS WAS ADVERTIZED AS A TARMAC RALCING ONLY SIMULATOR?
Thanks guys, for turning away rally focussed customers. Exactly what the many players, would be customers and our devs DON'T need.
WHEN WAS THE LAST TIME LFS WAS ADVERTIZED AS A TARMAC RALCING ONLY SIMULATOR?
Thanks guys, for turning away rally focussed customers. Exactly what the many players, would be customers and our devs DON'T need.
Last edited by Jamexing, .
Here's one simple explaination to clutch diff preload:
With the new preload setting, we get to set the STATIC preload of the clutch diff. The % settings are how much locking force (aka preload) the diff gets whilst experiencing engine input shaft torque (both on and and off power(aka engine braking).
So, what is this preload variable? Well, it's simply how much difference of torque required to turn a clutch diff from a clutch friction locked state (aka locked diff) to a limited open diff set.
What does this mean for the grease monkey who's working on the car? Well, here's the somple way to understand preload:
First, get a car that has a clutch pack LSD (e.g. many pre-2000 Pajero models, etc). Jack the rear wheels up with a grarage jack and hold the rear tires off the ground, using axles stands, etc to ensure safety (as long as the wheels are free off the ground for you to spin as you please).
Now, hold any wheel from any side (let's just stick to the left wheel for this example) steady so that it can't spin at all. Then try to spin the wheel on the right side whilst the left wheel remains practically unspinable. You will discover that the right wheel requires a finite amount of torque to wrench it free and spin whilst the left wheel remains static. The torque required to overcome this differential locking force is the preload.
FYI, a properly working Pajero clutch diff has a static preload of of around 90-110Nm. These static preload settings are considered pretty tight in production cars. It is a 2-way 4 pinion clutch diff, and one of the best and tightest LSDs among production 4WDs. Another production 4WD known to have similarly effective rear LSDs is the Nissan Patrol(as much as I can rememeber for now). It's also a pinoin 2-way clutch pack diff. Some other vehicles have "LSDs" so horrible (aka cheap excuse of a thing chucked in just to make the catalogue features list look longer and more impresssive with all sorts of acronyms the average non-car guy isn't too familiar with) that they have only static preload, all from springs pushing on relatively few clutch packs. No extra locking under power or coast.
With the new preload setting, we get to set the STATIC preload of the clutch diff. The % settings are how much locking force (aka preload) the diff gets whilst experiencing engine input shaft torque (both on and and off power(aka engine braking).
So, what is this preload variable? Well, it's simply how much difference of torque required to turn a clutch diff from a clutch friction locked state (aka locked diff) to a limited open diff set.
What does this mean for the grease monkey who's working on the car? Well, here's the somple way to understand preload:
First, get a car that has a clutch pack LSD (e.g. many pre-2000 Pajero models, etc). Jack the rear wheels up with a grarage jack and hold the rear tires off the ground, using axles stands, etc to ensure safety (as long as the wheels are free off the ground for you to spin as you please).
Now, hold any wheel from any side (let's just stick to the left wheel for this example) steady so that it can't spin at all. Then try to spin the wheel on the right side whilst the left wheel remains practically unspinable. You will discover that the right wheel requires a finite amount of torque to wrench it free and spin whilst the left wheel remains static. The torque required to overcome this differential locking force is the preload.
FYI, a properly working Pajero clutch diff has a static preload of of around 90-110Nm. These static preload settings are considered pretty tight in production cars. It is a 2-way 4 pinion clutch diff, and one of the best and tightest LSDs among production 4WDs. Another production 4WD known to have similarly effective rear LSDs is the Nissan Patrol(as much as I can rememeber for now). It's also a pinoin 2-way clutch pack diff. Some other vehicles have "LSDs" so horrible (aka cheap excuse of a thing chucked in just to make the catalogue features list look longer and more impresssive with all sorts of acronyms the average non-car guy isn't too familiar with) that they have only static preload, all from springs pushing on relatively few clutch packs. No extra locking under power or coast.
Same problem here. It's quite reproducable. 1st gear on and you can move ever so slightly with no penalty. Hmmm, let's get a few inches on the competition...
Ah wait, they've all gained a few inches. 
Speaking of needing 20K tires to achieve F-1 like grip levels, I remember some tire tests done on go kart tires (aka tires commonmly used for karts, F-SAE, etc) revealed that their properties were remarkably similiar to full nlown F-1 tires. Both tyre types have similiarly high friction coefficients, with load sensitivity and slip angle charactersitics very similiar as well.
Wow, saw that quite a while ago. Brings back some good memories.
Well, as you link says, it's just a pakaging advantage. The bad news is that external adjustability isn't possible, but in F-1 aero >>> fine suspension settings. Use of software such as Lapsim and all sorts of simulations also make adjustability rather redundant though. Removing weight from all the right places (like up high where the dampers are) helps too. Granted, it's all a matter of grams, but in F-1 where engineers work WAY overtime just to gain miliseconds of lap time, every bit helps.
Without all the space and mechanical monkey motion required to transform rotary motion back to linear motion, the weight savings are very substantial in F-1 terms.
In short, main advantage is all packaging. If you want something you could fine tune instantly on the track, forget it. They're bespoke and even more expensive then the already astronomically priced "normal" F-1 linear dampers.
McLaren has recently chose KONI as their damper supplier, and although their dampers don't offer this fancy packaging advantage (they're normal high pressure monotubes), they offer way superior mechanical performance. It's a revolutionary new technology for racing dampers, known as FSD (frequency selective damping). Basically changes damping force and velocity vs. force coefficient according to both velocity and frequency. It's as close to ideal as passive dampers can for now.
Last edited by Jamexing, .
Actually I do get the intention of global hansicaps, though honestly I have a hard time belieiving that extensive testing has already been done by the top regular LFS drivers for every track and car already in the limited time that patch W9 is out. If we had, all this could be nullified by the next significant physics upgrade, and it's all back to square one.
If things ran my way, we'll fix the turbo issues first before any serious balancing occurs.
Oh yeah, can't remember how many times in RB4/XFR, trying to exit the corner with a carefully exceuted full throttle blast in an attempt to gain maximum advantage from AWD traction, allowing one to exit as quickly as possible whilst drifting radially in a controlled fashion. Only to experience a major letdown thanks to ridiculous lag and even more ridiculous powerbands. For the RB4, we're better off making an exact numerical copy of the power/torqueband of a 90's 4G63 optimally tuned for 250 peak hp. Don't see how copyright would be an issue since the name "4G63" isn't used at all. Same for the XRT.
Or we could just plug in the engine from the RA into the RB4 and XRT, with some tweaks at the upper rev regions to get 250hp at 6500rpm instead of 245hp at around 5900rpm. Without the silly lag in turbo response, of course.
And when was the last time anyone saw a car like FXO (e.g. Honda Integra) with 250mm wide tires? No point trying to seriously balance the TBO class with this factor still within the equation. I'll rather have those tires reduced to say a more reasonable 235mm width before even considering serious attempts to balance the TBOs.
I'll like to leave the weight and intake restriction handicaps in, but will not force any of them on yet("global handicap"). The weight range adjustments seem fine, though the intake restrictions are frankly too ridiculous when adjusted to the greater levels. At 50% restriction (max), the TBOs manage to make just over 100hp. Tried that with the lowered gearing to suit and frankly there's no good reason to restrict them THAT far. What are we trying to do, race RB4s against XRs, XFs or even UF1s?
There's no way to assign appropriate numbers to ballasts and intake restriction until hotlaps and long distance tests are run extensively. And I find it hard to take balancing too seriosuly when some major physics issues like turbo modelling remain. Oh hail the RA, needs about 3 seconds just to fully spool its tiny low boost turbo!
Last edited by Jamexing, .
What perplexes me to this day is why LFS still insists on using identical sizes for both road AND rallycross.
If things go my way, we'll have one size for tarmac and another for hybird and knobblys. And the lack of proper gravel rally tracks is a glaring problem that has been neglected for as long as LFS existed. Some want multiple road sizes, but why bother when we have an entire category of specialized tires that've been so neglected for so long?
There are lots of things that'll simply take too long to explain in a proper manner, but here are some of my points.
Notice that I did not at any point say leaf springs are superior to coil sprung live axles. Notice I don't use the word "superior " to describe comparisons of leaves and coils at all. I just describe them as they really are.
And about torsion bars. They do aid packaging in the sense that they free up suspension arm design as there's only a need to contain a damper instead of the whole spring/shock assembly. The good thing with torsion bars is that it allows the springing element (the torsion bars) to be located in low, lowering center of gravity slightly. Just check the underside of a pre-2000 Pajero and you'll get it. Practically, their performance isn't too different from having linear coil springs, given all else is equal/very similar, of course. What limits their travel potential is the fact that they can't be twisted to too severe of an angle before they suffer permanent damage. Basically, it means that your suspension wishbone that the bar attaches to should never be rotated to too severe and angle. With coil springs, a properly selected coil in a coilover setup never need to worry about this. You could of course increase travel and overall performance (on and OFF road) by lengthening the wishbones so they travel much further for a given angle. This applies to all independant suspensions. Isuzu applied this principle to their isuzu troopers and compensated for the longer arms with thicker bars and frankly, it worked very well. Another great thing with torsion bar double wishbone suspension is the ease of adjustability of ride height. Just jack the car up and twist the adjuster screws and wallop, you could easily get some reasonable lift or correct for differences in corner weights. The only problem is that it is impossible to get progressive springing with the torsion bars alone. That would require special "bump stops" like those that porsches use. Anyway, no one has found an elegant way besides the use of special "bump stops" to achieve progressive springing.
And yes, it is EASIER to get long travel coils. That's one reason why they're favoured. A coil spring is in fact the same thing as a torsion bar, but packaged differently. They are both solid round bars of elastic material, and they both work on the principle of twisting the bars to generate force. What makes coil springs better overall for off-road racing in general, fast and slow, is the fact that getting a very precisely designed and controlled progressive behavior is so easy with coils. Just make coils with differing number of coils per spring length along its length, OR you could just stack more coils in series.
I'm quite aware of leaf destruction due to axle wrap under acceleration, etc. Frankly, I've not seen such and incident that's NOT caused by some silly leaf pack setup or even sillier driving. I'm quite aware that in the quest for ridiculous travel for a given length of leaf pack, people resort to ever fewer and ever THINNER leaves. As I've said leaves both provide springing AND axle location, and how on earth do you expect ridiculously thin main leaves to support your car properly let alone withstand axle warping torque? You can safely attain significantly more travel safely by using longer leaf packs, though obviously packaging issues don't allow one to go too far down that path. With coils though can somewhat get away with super soft coils by using 5-link or so to stabilize the axle somewhat. And of course, leaf packs aren't light nor compact, attributes coil spring provide easily. Composite leaf packs can provide all the benefits of progressive springing and severely reduce the weight issue, though unfortunately there aren't many the market yet. i know how leaf packs are changed. The good news is that they require less tools (no need for spring compressors, etc) and conceptually, they're easier to work with as the basic design is so simple. The bad news is of course it's more a case of needing more brute force to get it done.
The moral of the story? Don't resort to using ridiculously thin main leaves to gain travel and you'll do just fine. Remember, it does double duty, so keep it sufficiently strong. Instead, just use more and thinner leaves underneath to gain more travel via more progressive springing. The best plan would simply be to use the lockable articulated shackles that allow excellent cross axle articulation safely. This remove the anti twist problems and allows great improvements in travel without making the leaves ridiculously thin (aka WEAK). Provides excellent rock crawling travel at low speeds via the release of a few pins. For high speed runs, just keep it locked.
Note that the corvette application I mention uses TRANSVERSE leaf plates in independent double wishbone suspension, so leaf wrap issues don't really apply.
In short, weight, packaging and ease of axle/wheel control, etc, all lead to the domination of coil sprung live axles for slow off-roading and independent coil-over suspension for high speed off-road races.
Notice that I did not at any point say leaf springs are superior to coil sprung live axles. Notice I don't use the word "superior " to describe comparisons of leaves and coils at all. I just describe them as they really are.
And about torsion bars. They do aid packaging in the sense that they free up suspension arm design as there's only a need to contain a damper instead of the whole spring/shock assembly. The good thing with torsion bars is that it allows the springing element (the torsion bars) to be located in low, lowering center of gravity slightly. Just check the underside of a pre-2000 Pajero and you'll get it. Practically, their performance isn't too different from having linear coil springs, given all else is equal/very similar, of course. What limits their travel potential is the fact that they can't be twisted to too severe of an angle before they suffer permanent damage. Basically, it means that your suspension wishbone that the bar attaches to should never be rotated to too severe and angle. With coil springs, a properly selected coil in a coilover setup never need to worry about this. You could of course increase travel and overall performance (on and OFF road) by lengthening the wishbones so they travel much further for a given angle. This applies to all independant suspensions. Isuzu applied this principle to their isuzu troopers and compensated for the longer arms with thicker bars and frankly, it worked very well. Another great thing with torsion bar double wishbone suspension is the ease of adjustability of ride height. Just jack the car up and twist the adjuster screws and wallop, you could easily get some reasonable lift or correct for differences in corner weights. The only problem is that it is impossible to get progressive springing with the torsion bars alone. That would require special "bump stops" like those that porsches use. Anyway, no one has found an elegant way besides the use of special "bump stops" to achieve progressive springing.
And yes, it is EASIER to get long travel coils. That's one reason why they're favoured. A coil spring is in fact the same thing as a torsion bar, but packaged differently. They are both solid round bars of elastic material, and they both work on the principle of twisting the bars to generate force. What makes coil springs better overall for off-road racing in general, fast and slow, is the fact that getting a very precisely designed and controlled progressive behavior is so easy with coils. Just make coils with differing number of coils per spring length along its length, OR you could just stack more coils in series.
I'm quite aware of leaf destruction due to axle wrap under acceleration, etc. Frankly, I've not seen such and incident that's NOT caused by some silly leaf pack setup or even sillier driving. I'm quite aware that in the quest for ridiculous travel for a given length of leaf pack, people resort to ever fewer and ever THINNER leaves. As I've said leaves both provide springing AND axle location, and how on earth do you expect ridiculously thin main leaves to support your car properly let alone withstand axle warping torque? You can safely attain significantly more travel safely by using longer leaf packs, though obviously packaging issues don't allow one to go too far down that path. With coils though can somewhat get away with super soft coils by using 5-link or so to stabilize the axle somewhat. And of course, leaf packs aren't light nor compact, attributes coil spring provide easily. Composite leaf packs can provide all the benefits of progressive springing and severely reduce the weight issue, though unfortunately there aren't many the market yet. i know how leaf packs are changed. The good news is that they require less tools (no need for spring compressors, etc) and conceptually, they're easier to work with as the basic design is so simple. The bad news is of course it's more a case of needing more brute force to get it done.
The moral of the story? Don't resort to using ridiculously thin main leaves to gain travel and you'll do just fine. Remember, it does double duty, so keep it sufficiently strong. Instead, just use more and thinner leaves underneath to gain more travel via more progressive springing. The best plan would simply be to use the lockable articulated shackles that allow excellent cross axle articulation safely. This remove the anti twist problems and allows great improvements in travel without making the leaves ridiculously thin (aka WEAK). Provides excellent rock crawling travel at low speeds via the release of a few pins. For high speed runs, just keep it locked.
Note that the corvette application I mention uses TRANSVERSE leaf plates in independent double wishbone suspension, so leaf wrap issues don't really apply.
In short, weight, packaging and ease of axle/wheel control, etc, all lead to the domination of coil sprung live axles for slow off-roading and independent coil-over suspension for high speed off-road races.
Last edited by Jamexing, .
There are many reasons why leaf springs aren't favoured at the top echelons of off-road racing. Since there are many reasons to this, shall only explain a few of them.
One reason is simple packaging. Corvettes run single plate leaf springs in double wishbone suspensions enjoy many of the benefits of the system, such as the fact that the spring element is situated low in the vehicle (lowered center of gravity) and also the fact that it is lighter than a coilover setup.
However, for long travel systems needed for racing, there are many severe issues. As off-road racing and rallying advanced, the benefits and overall superiority of independant suspension grew. For instance, one of the reasons Pajero Evolutions form both the 90's and the current Pajero EVOs run independant rear suspension is fue to the fact that live axles tend to bend and get out of shape as high speed off-road mile accumulate. The worst part is that unlike independant suspension, which can be adjusted via toelinks to correct misalignment as long as the major suspesion components aren't severely damaged, if they're bent, it's a major pain to fix if it's still fixable. One can also easily see that packing leaves into independant suspension that provides reasonable travel for high speed off-roading is practically impossible, not without very silly, bulky, heavy and underperforming designs. For off road independant suspensions, torsion bars and coil springs are optimum given the packaging constraints. In fact, coilover springs and dampers are ideal for independant double wishbone suspensions, since they allow tight and efficient packaging of springs and dampers whilst allowing all the setup flexibility and adjustability one can do with passive suspension.
In short, leaf springs and independant suspensions with good travel don't mix.
So, what about live axles? Well, as I've mentioned before, multileaf setups offer nice and progessive spring rates, but do experience interleaf friction as a result. This adversely affects their ability to oscillate quickly, a trait required for high speed off-road performance. Of course, I've also mentioned that this is already quite markedly reduced with innovations such as teflon, etc interleaf inserts that severely reduce his problem. But in the end, they still can't oscillate as freely as coil springs of equivalnet stiffness. With coils, one can do conduct the majority of axle oscillation control via dampers alone, allowing easier and more precise fine tuning of the suspension.
These are just some reasons why coil springs are preferred for off-road racing. Other reasons include more predictable axle location. Since leaf springs act as both spring and trailing and leading links, their kinematics are more complex than the relatively more rigid links used for coil sprung live axles.
Too much to mention in one thread/post, but this should answer at least a portion of your question.
Please read my post about military wraps. Explains how they can limp home even WITH broken leaves.
If ANY component goes wrong (from those coils/dampers to those axle location links) on a coil sprung vehicle, THEN you're REALLY doomed. A car that rests on its axle is effectively immobillized.
Articulation? You've obviously not heard of many leaf spring related innovations currently on the market. The chief problem of articulation with leaf springs is that since the springs are flat metal plates, they're very resistant to twist. This does have the positive effect of offering enough roll stiffness to NOT need rollbars. With coil sprung live axles, no rollbar = sway out of control unless your springs are STIFF.
The secret to extreme leaf spring articulation? No, it's NOT a simple manner of just using fewer and/or thinner leaves. The secret is in the shackles that hold the springs.
Your average shackle is rigid on the roll plane, disallowing the leaf to rotate freely, causing the leaves to experience torsion, something the leaves resist very well. With shackes that allow the driver to unlock and allow roll axis articulation, the leaves are allowed to twist freely. This results in a practically ideal system that allows excellent articulation off road whilst in the unlocked mode and excellent handling at high speeds in the normal locked mode. Lockable articulated shackles!
Last edited by Jamexing, .
Actually, there are lots of classes of cars that LFS still currently lacks. Cars such as 300-350hp WRC style rallycars, mid-engined supercars, mid-engined (LFS style) GTR class cars, etc.
Actually, lateral acceleration figures of LFS levels whilst cornering (somewhere in the neighbourhood of just over 1g to just under 1.3g peak) we see on the road super's isn't really unattainable with road legal tires that can deal with rain. Tires
Skidpad numbers are one thing as they only show average lateral acceleration steady state cornering. Peak lateral acceleration whilst cornering at race speeds always exceed them. Note that these are very short intervals of time whilst cornering.
Very sticky road tires say, WIDE BFG KDs mounted to relatively lightweight cars actually generate skidpad lateral acceleration figures like 1.02-1.05 quite easily. This assumes of course that the car is well setup in the first place.
For tires such as those Hoosiers I mentioned just now, average lateral gs for skidpads can actually exceed 1.2g even with stock suspenion, which unsurprisingly struggled to cope with the weight transfer caused by such extreme cornering loads. With properly tuned springs/dampers/rollbars...
Skidpad numbers are one thing as they only show average lateral acceleration steady state cornering. Peak lateral acceleration whilst cornering at race speeds always exceed them. Note that these are very short intervals of time whilst cornering.
Very sticky road tires say, WIDE BFG KDs mounted to relatively lightweight cars actually generate skidpad lateral acceleration figures like 1.02-1.05 quite easily. This assumes of course that the car is well setup in the first place.
For tires such as those Hoosiers I mentioned just now, average lateral gs for skidpads can actually exceed 1.2g even with stock suspenion, which unsurprisingly struggled to cope with the weight transfer caused by such extreme cornering loads. With properly tuned springs/dampers/rollbars...
Why not just get these:
http://www.tirerack.com/tires/ ... =Hoosier&tireModel=R6
or these:
http://www.tirerack.com/tires/ ... &tireModel=Radial+Wet
Cornering POWERRRR!!!!!
Leaf springs, depsite of their old age, are some of the most versatile suspension components of all time. It is unfortunate that people these days overlook all the serious advantages they offer.
Increasing/decreasing stiffness of a leaf spring packs is a simple manner of increasing individula leaf stiffness and/or increasing the number of leaves. You could also manipulate stiffness via the arch angle too. With multileaf packs, progressive springing is VERY easy to achieve. In fact, leaf springs have been quite commonly progressive before the idea of progressive coil springsa ever came to be. This ease of achieving progressive spring allows excellent load capability without seriously affecting traction in low load conditions. For a little real life test, just swap the rear leaf packs of your average OEM hilux with a leaf pack that uses thinner but more numerous leaves whilst maintaing or improving load capacity. You'll be amazed with the improvements in comfort and incidentally, traction over less than ideally flat surfaces.
In the old days, interleaf friction was a desirable trait as dampers of the day were quite franky, absolutely rubbish. These days, interleaf friciton is easily reduced significantly with interleaf teflon/etc inserts. This significantly improves their ability to oscillate quickly and deal with rougher terrain at higher speeds.
Another serious advantage often overlooked is their ability to locate axles effectively without any extra trailing/leading arms or panhard rods, etc. This somewhat negates their greater weight over coil sprung live axles. With current high quality leaf springs, military wraps are used to support the vehicle in the extremly unlikely case that they actually break. BTW, leaf springs are STILL the most durable springs since the metal experiences less stress and strain over their normal working ranges than coil springs. Basically, they take longer to reach metal fatigue.
The moral of this? Don't write leaf sprung live axle suspensions off as inferior to coil springs. Like many things in life, things simple aren't THAT simple.
Increasing/decreasing stiffness of a leaf spring packs is a simple manner of increasing individula leaf stiffness and/or increasing the number of leaves. You could also manipulate stiffness via the arch angle too. With multileaf packs, progressive springing is VERY easy to achieve. In fact, leaf springs have been quite commonly progressive before the idea of progressive coil springsa ever came to be. This ease of achieving progressive spring allows excellent load capability without seriously affecting traction in low load conditions. For a little real life test, just swap the rear leaf packs of your average OEM hilux with a leaf pack that uses thinner but more numerous leaves whilst maintaing or improving load capacity. You'll be amazed with the improvements in comfort and incidentally, traction over less than ideally flat surfaces.
In the old days, interleaf friction was a desirable trait as dampers of the day were quite franky, absolutely rubbish. These days, interleaf friciton is easily reduced significantly with interleaf teflon/etc inserts. This significantly improves their ability to oscillate quickly and deal with rougher terrain at higher speeds.
Another serious advantage often overlooked is their ability to locate axles effectively without any extra trailing/leading arms or panhard rods, etc. This somewhat negates their greater weight over coil sprung live axles. With current high quality leaf springs, military wraps are used to support the vehicle in the extremly unlikely case that they actually break. BTW, leaf springs are STILL the most durable springs since the metal experiences less stress and strain over their normal working ranges than coil springs. Basically, they take longer to reach metal fatigue.
The moral of this? Don't write leaf sprung live axle suspensions off as inferior to coil springs. Like many things in life, things simple aren't THAT simple.
Some of us have better things to do than scanning a thesaurus for superlatives. EBesides, what's wrong with calling real life legends legendary?
Well, people could be more specific when they generallize entire brands of cars to be superior/inferior in some way.
Last edited by Jamexing, .
What kind of jeep are you talking about? The legendary willys? The modern hard core off-roading legends known as the Wrangler Rubicons with Dana 44 (aka extra-extra beefy) axles? Or the sick joke known as the Jeep commander that runs on 1$ shocks?
Which kind of Land rover? The legendary Range Rovers? The super high tech range Rover Sport that actually works OFF-road? Or the legendary defenders of old with their legendary appetite for drive belts?
Just in case every here is wondering who Mickey Thompson is, check this:
http://en.wikipedia.org/wiki/Mickey_Thompson
This man was a legendary racer AND land speed record breaker. He did everything from help developing off road racing tires to absolutely dominate off-road racing to
FYI, you can all take a look at Mickey Thompson tires here:
http://www.mickeythompsontires.com/
Note: Only REAL men with nerves of CARBON NANOTUBES and balls of TITANIUM need apply.
http://en.wikipedia.org/wiki/Mickey_Thompson
This man was a legendary racer AND land speed record breaker. He did everything from help developing off road racing tires to absolutely dominate off-road racing to
FYI, you can all take a look at Mickey Thompson tires here:
http://www.mickeythompsontires.com/
Note: Only REAL men with nerves of CARBON NANOTUBES and balls of TITANIUM need apply.
FGED GREDG RDFGDR GSFDG