Sway Bars
#16
There are so many contradicting theories in this post... A sway bar or amti roll bar does just that, it limits body roll. It does so by applying downard pressure to the opposite side of the car that due to G-forces if being pushed up. There are times when you want the ar to have some roll which is why you can tune a sway bar by using different thickness bars. The thicked the bar, the hard it is to deflect and the more it will push down on the A-arm. A sway bar is itself a torsion bar spring... The reason why you will lose traction on that end is not so much the sway bad but the forces upon it... The unfortunate side effect of pussing the side of the car down that's rolling into the turn is it'll life the outside wheel up... When cornering, it's the outside wheels that have the majority of traction, the inside wheels are pretty much skimming the surface. What you want is a combination of springs, dampening and sway bar that will work together. You don't want such a heavy sway bar that will actually lift the outside wheels off the ground, causing the car to spin out... IMO the best setup would be the heaviest springs for the surface you are running on and the lightest bar that will help overcome the additional G-forces encountered in cornering...
#17
Well I have tons of front end traction, but my rear end seems to be a tad loose. I am going to try and move my rear toe-in to -2 instead of -1, and try removing my rear sway bar.
#18
holycow,
The reason that you may have thought that you were gaining traction was perhaps due to the fact that your car was doing the opposite of traction rolling, which is just plain pushing. If the transfer of weight exceeds the limits of the tire, this will happen. As vtl mentioned, in connecting a sway bar, the force being passed through the sway bar to lift the opposite arm and keep the chassis level is indeed transferring some of the load being placed on the outside tire. By doing this, you may get keep the load within the limits of the tire, and more traction up front is the result... I hope that makes more sense for you.
vtl,
The typical sway bar that's used in RC cars doesn't really "push down" the outside wheel. The bar absorbs the load by way of torsion, until the inside arm starts to lift. The thicker the bar, the less torsion that is required on the bar to start lifting the inside arm, thus, thicker bars give you less roll. When you think about it, if you wre already pushing, and you added a sway bar, you would push even more, but sometimes, this isn't the case.
The reason that you may have thought that you were gaining traction was perhaps due to the fact that your car was doing the opposite of traction rolling, which is just plain pushing. If the transfer of weight exceeds the limits of the tire, this will happen. As vtl mentioned, in connecting a sway bar, the force being passed through the sway bar to lift the opposite arm and keep the chassis level is indeed transferring some of the load being placed on the outside tire. By doing this, you may get keep the load within the limits of the tire, and more traction up front is the result... I hope that makes more sense for you.
vtl,
The typical sway bar that's used in RC cars doesn't really "push down" the outside wheel. The bar absorbs the load by way of torsion, until the inside arm starts to lift. The thicker the bar, the less torsion that is required on the bar to start lifting the inside arm, thus, thicker bars give you less roll. When you think about it, if you wre already pushing, and you added a sway bar, you would push even more, but sometimes, this isn't the case.
#19
R/C Tech Elite Member
iTrader: (47)
Originally posted by holycow
I have always thought the opposite. Thats usually why the higher performing, faster, high-traction race cars have little or no roll at all. According to your logic, you would think racecars would be 12 inches from the gound and would be leaning all over the place going around corners... but they dont.(obviously a huge exaguration ) They are usually very stiff, with no roll at all.
I know in my real car, reducing the amount of roll has greatly increased my traction. are RC cars different?
I have always thought the opposite. Thats usually why the higher performing, faster, high-traction race cars have little or no roll at all. According to your logic, you would think racecars would be 12 inches from the gound and would be leaning all over the place going around corners... but they dont.(obviously a huge exaguration ) They are usually very stiff, with no roll at all.
I know in my real car, reducing the amount of roll has greatly increased my traction. are RC cars different?
The challenge is to get the car to where everything comes together, and in the turns you have all of your traction, and dont do any traction rolls.
#20
Originally posted by TurnNBurn
in connecting a sway bar, the force being passed through the sway bar to lift the opposite arm and keep the chassis level is indeed transferring some of the load being placed on the outside tire. By doing this, you may get keep the load within the limits of the tire, and more traction up front is the result..
in connecting a sway bar, the force being passed through the sway bar to lift the opposite arm and keep the chassis level is indeed transferring some of the load being placed on the outside tire. By doing this, you may get keep the load within the limits of the tire, and more traction up front is the result..
If the car is rolling just enough to put all the weight to the outside two tires, making them bite just right, then adding the sway bar would reduce traction because it would put more weight on the inside tires that arent going to be doing as much for the car as the outside two tires.
BUT.. if the car is rolling just so, and the turn is exceeding the bite capablitlies of the outside tires, making the car push... then adding a sway bar would reduce the weight going to the outside tires, making it bite properly, and transfering the wasted traction to the inside tires?
THIS makes sense to me... is this right?
#21
holycow,
Yeah, you pretty much get the point... although one thing that just occurred to me that you have to also consider (which hasn't been mentioned before) is that if the car is pushing because it's rolling too much, it just might be pushing real bad because the roll is causing the tire to ride on the outside edge instead of the whole contact patch. By adding the sway bar you a) transfer some weight to the inside, and b) allow the tire to continue riding on its entire surface, instead of the outside edge. This results in improved traction.
Yeah, you pretty much get the point... although one thing that just occurred to me that you have to also consider (which hasn't been mentioned before) is that if the car is pushing because it's rolling too much, it just might be pushing real bad because the roll is causing the tire to ride on the outside edge instead of the whole contact patch. By adding the sway bar you a) transfer some weight to the inside, and b) allow the tire to continue riding on its entire surface, instead of the outside edge. This results in improved traction.
#22
Gocha... I actually wear all my tires right on the inside line, right next to the sidewall, with just -1 camber all around...
I am using
pre-glued takeoff 27s
100 weight oil, 2 hole piston
red springs all around
think I need to reduce my caster perhaps?
I am using
pre-glued takeoff 27s
100 weight oil, 2 hole piston
red springs all around
think I need to reduce my caster perhaps?
#23
I think you need to lighten the oil a bit....
#24
Even with the two whole piston position? maybe try 70 or 80?
#25
yea I'm having that problem of some major push. Currently running front sway/no rear. I'm going to try and remove the front, and run a rear sway bar...
I would think that would make the rear comeout and drift...would it be better to run nothing...
this is for an indoor/hi traction/tight turns/medium speed track...
I would think that would make the rear comeout and drift...would it be better to run nothing...
this is for an indoor/hi traction/tight turns/medium speed track...
#26
I had the same problem.. installed the front one-way diff,,, and now the car turns like no tomorrow... so much in fact, I almost have a bit of OVER steer now! I actually dropped my steering DR down about 15-20% just to compensate, and boy does she come around the corners well now!
#27
Originally posted by holycow
I had the same problem.. installed the front one-way diff,,, and now the car turns like no tomorrow... so much in fact, I almost have a bit of OVER steer now! I actually dropped my steering DR down about 15-20% just to compensate, and boy does she come around the corners well now!
I had the same problem.. installed the front one-way diff,,, and now the car turns like no tomorrow... so much in fact, I almost have a bit of OVER steer now! I actually dropped my steering DR down about 15-20% just to compensate, and boy does she come around the corners well now!
are you running w/ the front sway-bar only w/ the 1-way diff? thanks!
#28
I am running the oneway with BOTH sway bars... but my back end seems a tad squirly.. I think i am going to add a degree of rear toe-in, and remove the rear sway.
Last edited by holycow; 09-08-2003 at 04:27 PM.
#30
yeah yeah! typo