As far as my limited experience allows me do sway bars and anti roll bars do a similar job i have read a few links on different forums and also here the only difference I see is that cars with higher horse power >500 seem to usually have anti roll bars.
Thanks
Royz
sway bar or anti roll bar
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Ed-vancedEngines
no no no.
Race Car language;
Sway Bar is to eliminate sway A car sways when it goes from side to side becuase rear end is not firmly held from swaying to one side and the other side. A sway bar locates the rear end from side to side and keeps it stable and straight under the car.
Examples of Drag Racing Sway Bars;
Panhard Bar
Diagonal link bar
X-Brace sway bar
Wishbone Sway bar
Watt's Linkage Sway Bars
Factory OEM language;
Sway Bar resists one side of car from rolling while in turns
Sawy Bars in rear do the same as sway bars in the front. They stiffen against the roll tendencies a car's suspension has while turning corners at speed.
Drag Racing Anti-Roll Bars ;
Mostly used with 4 link or 3 link cars to prevent the left rear side of car from rising at the same time of stabalising the right rear side of car from sinking down over the tires. Actually it helps prevent the right rear tire from climbing inside the fender and helps to keep the car more level in the rear when torque forces are pushnng the left rear tire down and the right rear tire up. Cars that had/have this tendency are said to *Roll or to Barrel Roll*. Anti-Roll helps control this.
Only with instances of Triangulated 4 link cars like Mustangs and Chevelles or G Body cars, that have no other meansto adjust pre-load except by changing spring tensions on right rear and left front, the Anti-Roll Bar can be used to help with rear suspensuon pre-laod on these cars.
If a car has the factroy rear sway bar it can be used as a drag racing anti-roll bar to some degree.
Ed
Race Car language;
Sway Bar is to eliminate sway A car sways when it goes from side to side becuase rear end is not firmly held from swaying to one side and the other side. A sway bar locates the rear end from side to side and keeps it stable and straight under the car.
Examples of Drag Racing Sway Bars;
Panhard Bar
Diagonal link bar
X-Brace sway bar
Wishbone Sway bar
Watt's Linkage Sway Bars
Factory OEM language;
Sway Bar resists one side of car from rolling while in turns
Sawy Bars in rear do the same as sway bars in the front. They stiffen against the roll tendencies a car's suspension has while turning corners at speed.
Drag Racing Anti-Roll Bars ;
Mostly used with 4 link or 3 link cars to prevent the left rear side of car from rising at the same time of stabalising the right rear side of car from sinking down over the tires. Actually it helps prevent the right rear tire from climbing inside the fender and helps to keep the car more level in the rear when torque forces are pushnng the left rear tire down and the right rear tire up. Cars that had/have this tendency are said to *Roll or to Barrel Roll*. Anti-Roll helps control this.
Only with instances of Triangulated 4 link cars like Mustangs and Chevelles or G Body cars, that have no other meansto adjust pre-load except by changing spring tensions on right rear and left front, the Anti-Roll Bar can be used to help with rear suspensuon pre-laod on these cars.
If a car has the factroy rear sway bar it can be used as a drag racing anti-roll bar to some degree.
Ed
The old sway bar / roll bar term. Who was to poet that said a rose is a rose, by any other name it would still be a rose. Well they are springs, more to the point they are straightened out springs sometimes called torsion bars. The tendency is to call the stiffer rate roll/sway bar a anti roll bar and the lower rated ones a sway bar. They all have a spring rate at the arm. Some don't look like they have an arm like the ones on the chev that uses the lower control arm, or some of the curvy kind you find in the front end, but they do. They all have a spring rate. Shorter and biger diameter is more spring rate, longer or thinner is less spring rate. the spring rate can then be increased or decreased by the length of the arm. Shorter arm = more effective spring rate and longer arm = less effective spring rate.
I like to call them the Robin Hood of springs. They rob from the rich and give to the poor. What this means if your suspension, (either end) compresses or separates the same on both sides the spring does nothing. If only one side compresses it loads the bar/spring with that many lbs, it in turn transmits that lbs to the other side, compressing it also. it tries to even out the differences in ride hight from side to side by taking the energy that is compressing one side and giving it to the other.
This sounds great so far, but remember it is a spring. It will transfer some and keep some. This kept energy is shown as twist in the bar, just like a coil spring would compress. How much it keeps depends on the rate of bar and length of arm. Fatter shorter with short arm the less it keeps as stored energy. Ah we say, We will just get a big fat short armed bar so there would never be enough energy to deflect it. Well we would be right, but it has it's own side effect. Being so stiff if we hit a little bump with one rear tire coming out of the blocks it would raise the other tire loosing contact. Plus ride like a Conestoga Wagon. If we make it soft enough to maintain tire compliance we don't equally load both tires. This is why you can not rely on a sway bar alone to get equal tire loading. You still need to preload one before you put the bar on and that makes the bar just a back up plan.
I like to call them the Robin Hood of springs. They rob from the rich and give to the poor. What this means if your suspension, (either end) compresses or separates the same on both sides the spring does nothing. If only one side compresses it loads the bar/spring with that many lbs, it in turn transmits that lbs to the other side, compressing it also. it tries to even out the differences in ride hight from side to side by taking the energy that is compressing one side and giving it to the other.
This sounds great so far, but remember it is a spring. It will transfer some and keep some. This kept energy is shown as twist in the bar, just like a coil spring would compress. How much it keeps depends on the rate of bar and length of arm. Fatter shorter with short arm the less it keeps as stored energy. Ah we say, We will just get a big fat short armed bar so there would never be enough energy to deflect it. Well we would be right, but it has it's own side effect. Being so stiff if we hit a little bump with one rear tire coming out of the blocks it would raise the other tire loosing contact. Plus ride like a Conestoga Wagon. If we make it soft enough to maintain tire compliance we don't equally load both tires. This is why you can not rely on a sway bar alone to get equal tire loading. You still need to preload one before you put the bar on and that makes the bar just a back up plan.
Older I get the less I know for sure
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BillyShope
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I'm afraid we have a real "Tower of Babel" situation here. This makes communication very difficult. I would suggest that we stick with the language spoken within the automotive industry.
An anti-sway bar (most working engineers shorten this to "swaybar") is used by the manufacturer to control the ratio of front to rear roll stiffness. Fifty years ago, manufacturers tried to avoid the added cost of swaybars. At times, a front swaybar was reluctantly added when a prototype evidenced steering characteristics close to neutral when the trunk was heavily loaded. Rear swaybars were almost never used.
Today, buyers demand better handling and are willing to sacrifice some ride quality to have it. The solution has been to rely on swaybars...both front and rear...to control body roll while relatively soft suspension springs provide an acceptable ride.
A swaybar acts as "bubstr" described. It is never confused, within the industry, with suspension links used to control component positions. A Panhard rod would never be called a swaybar. The OEM swaybar is also never adjustable. (At least, I've never heard of an example.)
Racers and aftermarket suppliers recognized the possibility of swaybar end adjustments to provide "tuning." It was also recognized that non-circular cross sections provided the possibility of swaybar rate changes through adjustment.
Then, more recently, the contribution of a very high rate rear swaybar to the improvement of dragstrip performance was recognized. (This applies only to rear wheel drive cars with beam rear axles.) The driveshaft torque tends to unload the right rear tire during forward acceleration. If there was no roll stiffness at the front of the car, the reaction to the driveshaft torque would act directly, through the rear springs, to totally cancel this tendency and retain equal rear tire loading. While front roll stiffness cannot be completely eliminated, its effects can be minimized by greatly increasing the rear roll stiffness.
One or more aftermarket manufacturers began to supply these very high rate rear swaybars, including adjustments which allow a static preloading of the right rear. The combination of high rate swaybar with preload adjustment allows the possibility of nearly equal rear tire loading.
I certainly can't fault these suppliers with not wanting their product to be confused with more conventional swaybars, so they called them "anti-roll bars." But, the general definition of "anti-sway bar" would still cover them.
An anti-sway bar (most working engineers shorten this to "swaybar") is used by the manufacturer to control the ratio of front to rear roll stiffness. Fifty years ago, manufacturers tried to avoid the added cost of swaybars. At times, a front swaybar was reluctantly added when a prototype evidenced steering characteristics close to neutral when the trunk was heavily loaded. Rear swaybars were almost never used.
Today, buyers demand better handling and are willing to sacrifice some ride quality to have it. The solution has been to rely on swaybars...both front and rear...to control body roll while relatively soft suspension springs provide an acceptable ride.
A swaybar acts as "bubstr" described. It is never confused, within the industry, with suspension links used to control component positions. A Panhard rod would never be called a swaybar. The OEM swaybar is also never adjustable. (At least, I've never heard of an example.)
Racers and aftermarket suppliers recognized the possibility of swaybar end adjustments to provide "tuning." It was also recognized that non-circular cross sections provided the possibility of swaybar rate changes through adjustment.
Then, more recently, the contribution of a very high rate rear swaybar to the improvement of dragstrip performance was recognized. (This applies only to rear wheel drive cars with beam rear axles.) The driveshaft torque tends to unload the right rear tire during forward acceleration. If there was no roll stiffness at the front of the car, the reaction to the driveshaft torque would act directly, through the rear springs, to totally cancel this tendency and retain equal rear tire loading. While front roll stiffness cannot be completely eliminated, its effects can be minimized by greatly increasing the rear roll stiffness.
One or more aftermarket manufacturers began to supply these very high rate rear swaybars, including adjustments which allow a static preloading of the right rear. The combination of high rate swaybar with preload adjustment allows the possibility of nearly equal rear tire loading.
I certainly can't fault these suppliers with not wanting their product to be confused with more conventional swaybars, so they called them "anti-roll bars." But, the general definition of "anti-sway bar" would still cover them.
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BillyShope
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Agree with the above posters, an anti roll bar and and an anti sway bar are exactly the same thing but known by two very different names.
Same thing as with dampers and shock absorbers, exactly same thing, different name. Other similar confused terms are rebound and jounce, bonnet and hood, and the list goes on and on.
I believe Ed was referring to lateral location devices, which can sometimes also alter the roll center height, and that may modify the weight transfer characteristics in roll.
Both an anti roll bar, and an anti sway bar are generally accepted as being a transverse torsion bar, fitted with cranked ends that is arranged to twist and supply a resisting force to body roll.
Same thing as with dampers and shock absorbers, exactly same thing, different name. Other similar confused terms are rebound and jounce, bonnet and hood, and the list goes on and on.
I believe Ed was referring to lateral location devices, which can sometimes also alter the roll center height, and that may modify the weight transfer characteristics in roll.
Both an anti roll bar, and an anti sway bar are generally accepted as being a transverse torsion bar, fitted with cranked ends that is arranged to twist and supply a resisting force to body roll.
Cheers, Tony.
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Ed-vancedEngines
let's try again to expalin this a little differently.
Way before the adjsutable sway bar was re-invented and the idea adapted to be used on the rear suspension, the adjustable sway bar was already being used in other forms of racing on the front of the car. ON the front of the car it greatly aided the car's cornering ability and when used in cars turning only one direction it also at times was used to not only keep the front of the car from having as much body roll, it was also sued in those situations on circle track cars to pre-load one side of the car in the front.
The adjustabele bar was also used in other forms of racing to resist body roll in the rear of the car to give additional corner handling ability.
In factory cars whether it was used as a one piece bar of spring steel to work in a torsion spring application to aid in cornering and in handling. If it was used in the front or the rear it was called a sway bar.
In aftermarket uses and in other forms of rcing the adjustable torsion spring bar with arms connected by adjustable links was still called an adjustable sway bar.
I do not know of this bar device either adjustable or non-adjustable being called an anti-roll bar until a Darg Race Chassis Builder named Willie Reils adapted and re-invented the use of it to be used to help take body roll or in this case it was called Barrel Roll out of the rear suspension in the 1986 Silver coloured Oldsmobile Firenza belonging to Warren Johnson. The it was called an Anti-Roll bar becuase it's sole first purpose was to take Body Roll or Barrel Roll from the rear of that 3 Link Barrel Rolling car.
Further adding to the confusion was when rear end side to side locater bars were put into use and for some reason the names departed from what was comonally used. The new rear end locator bars were also called sway bars. I.E. Wishbone sway bar. After Chris Alston came up with the idea of the Diagonal Link it was also called a sway bar but it was called a diagonal sway bar.
Now let's get even more confused;
All bars called sway bars and all bars called anti-roll bars do in essence serve the same basic purpose but for different applications and for different reasons in the different forms of racing and even in street usage. It is all to assist in equalizing the lateral body position right to left.
(my opinions)
Ed
Way before the adjsutable sway bar was re-invented and the idea adapted to be used on the rear suspension, the adjustable sway bar was already being used in other forms of racing on the front of the car. ON the front of the car it greatly aided the car's cornering ability and when used in cars turning only one direction it also at times was used to not only keep the front of the car from having as much body roll, it was also sued in those situations on circle track cars to pre-load one side of the car in the front.
The adjustabele bar was also used in other forms of racing to resist body roll in the rear of the car to give additional corner handling ability.
In factory cars whether it was used as a one piece bar of spring steel to work in a torsion spring application to aid in cornering and in handling. If it was used in the front or the rear it was called a sway bar.
In aftermarket uses and in other forms of rcing the adjustable torsion spring bar with arms connected by adjustable links was still called an adjustable sway bar.
I do not know of this bar device either adjustable or non-adjustable being called an anti-roll bar until a Darg Race Chassis Builder named Willie Reils adapted and re-invented the use of it to be used to help take body roll or in this case it was called Barrel Roll out of the rear suspension in the 1986 Silver coloured Oldsmobile Firenza belonging to Warren Johnson. The it was called an Anti-Roll bar becuase it's sole first purpose was to take Body Roll or Barrel Roll from the rear of that 3 Link Barrel Rolling car.
Further adding to the confusion was when rear end side to side locater bars were put into use and for some reason the names departed from what was comonally used. The new rear end locator bars were also called sway bars. I.E. Wishbone sway bar. After Chris Alston came up with the idea of the Diagonal Link it was also called a sway bar but it was called a diagonal sway bar.
Now let's get even more confused;
All bars called sway bars and all bars called anti-roll bars do in essence serve the same basic purpose but for different applications and for different reasons in the different forms of racing and even in street usage. It is all to assist in equalizing the lateral body position right to left.
(my opinions)
Ed
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BillyShope
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This reminds me of when I was a toddler and my parents gave me the opportunity to name the new family dog. That poor dog lived the remainder of its life answering to "Kee-Kee" because I thought it was a kitten.
The following doesn't surprise me:
And, the following is never used...in the automotive industry...to describe the function of the swaybar:
Now, do you suppose we could eliminate the confusion when referring to rear gears? When I refer to a low rear end, I'm thinking of a high numerical axle ratio. On this one, we can't refer to common usage in the automotive industry, for I found I always had to be careful to explain exactly which I meant.
The following doesn't surprise me:
But, again, there will be less confusion if we stick with the terminology used in the automotive industry. This is not because it's necessarily "better," but simply because it's relatively unchanging and can be referenced with a quick Google.Ed-vancedEngines wrote: The new rear end locator bars were also called sway bars.
And, the following is never used...in the automotive industry...to describe the function of the swaybar:
The anti-sway bar contributes to the total roll stiffness of the car. It must, of necessity, be added to either the front or rear suspension. For this reason, it affects the distribution of the roll couple when cornering and also affects the distribution, fore and aft, of the driveshaft reaction torque (in a RWD beam rear axle car) during forward acceleration.Ed-vancedEngines wrote:It is all to assist in equalizing the lateral body position right to left.
Now, do you suppose we could eliminate the confusion when referring to rear gears? When I refer to a low rear end, I'm thinking of a high numerical axle ratio. On this one, we can't refer to common usage in the automotive industry, for I found I always had to be careful to explain exactly which I meant.
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I have to agree that the terms are different for different types of motor sports. Even with in the same one. Some of them that come to mind are the low gear some call them short or tall gears, high and low. Then there is anti squat, in certain places this is called getting on the bar, or getting off. sometimes stagger is called split. And a while back I heard another name for king pin inclination, that I can't remember. The argument was you don't have a king pin you can't have king pin inclination.
Although lateral links can and do effect roll, most of them do it by raising or lowering the roll center, with the exception of the wishbone, diagonal link, X brace, truck bar and even the ladder bar rear suspension, which do work on the sway bar principle. You just have to look harder for the bar and arms. They use the rear end housing as the bar. And I wouldn't say these are the only exceptions, because someone will come up with an old trick and put a new name on it tomorrow.
Although lateral links can and do effect roll, most of them do it by raising or lowering the roll center, with the exception of the wishbone, diagonal link, X brace, truck bar and even the ladder bar rear suspension, which do work on the sway bar principle. You just have to look harder for the bar and arms. They use the rear end housing as the bar. And I wouldn't say these are the only exceptions, because someone will come up with an old trick and put a new name on it tomorrow.
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BillyShope
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That's a very good point! A 4link...when the upper and lower links are not parallel...and a ladder bar have the same problem: They put the suspension into bind while cornering and the rear axle housing becomes a big torsion bar. And, the manufacturers have done this sort of thing! With front wheel drive vehicles having a simple tubular beam rear axle, that rear axle has deliberately been put into bind for extra rear roll stiffness. But, to my knowledge, this has never been done with a RWD beam axle car. (And, the result is still not called a swaybar.)Bubstr wrote:They use the rear end housing as the bar.
For that matter, a rear swaybar of a RWD car with beam rear axle could be designed to locate the axle assembly laterally. Since the bean counters are always interested in anything that might save a penny or two, I'm certain designs have been pursued, but, again, to my knowledge, nothing has ever been built.
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Would the truck arm rear suspension be an example of this? The rear suspension used on Nascar Nextel cup cars. Basically it was an early Chevy truck rear suspension. It was bolted solidly to the rear tube and to vary the roll stiffness they would shave the I beam to let it twist, and had several hight adjustments in the front, and the use of blocks at the rear of the bar for squat. This is not a state of the art suspension and not very forgiving on a rough track, but is mandated in the Nextel cup.BillyShope wrote:That's a very good point! A 4link...when the upper and lower links are not parallel...and a ladder bar have the same problem: They put the suspension into bind while cornering and the rear axle housing becomes a big torsion bar. And, the manufacturers have done this sort of thing! With front wheel drive vehicles having a simple tubular beam rear axle, that rear axle has deliberately been put into bind for extra rear roll stiffness. But, to my knowledge, this has never been done with a RWD beam axle car. (And, the result is still not called a swaybar.)Bubstr wrote:They use the rear end housing as the bar.
For that matter, a rear swaybar of a RWD car with beam rear axle could be designed to locate the axle assembly laterally. Since the bean counters are always interested in anything that might save a penny or two, I'm certain designs have been pursued, but, again, to my knowledge, nothing has ever been built.
What them guys do with it is amazing. Shows you can make a silk purse out of a sows ear.
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BillyShope
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[quote="Bubstr]Shows you can make a silk purse out of a sows ear.[/quote]
Truer words were never spoken! I think this suspension was first used on the Conestoga wagons. It would be interesting if NASCAR freed them from these restrictions. This is one of the reasons why I prefer a local short track to a NASCAR race.
Truer words were never spoken! I think this suspension was first used on the Conestoga wagons. It would be interesting if NASCAR freed them from these restrictions. This is one of the reasons why I prefer a local short track to a NASCAR race.
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