"sony1492" (sony1492)
08/22/2016 at 15:47 • Filed to: theory.vs.practice
0
16|
"sony1492" (sony1492)
08/22/2016 at 15:47 • Filed to: theory.vs.practice | 0
| 16 |
For simplicity Im going to be talking about suspension systems where all wheels are independant from one another.
Its also somewhat implied that the vehicle is on either coilovers or has some sports/race suspension bits on it.
Sway bars also known as anti-roll bars are essentially torsion bars thak connect the left and right suspension to each other. They control the overall bodyroll as one wheel is compressed it acts against the opposing sides spring (Which wants to push that side of the car as high as possible.) by pushing it back up however much the other sides compression has offset. When its function is in effect it bends allowing for independant movement of each side, but itll still be transfering force so independance is limited. All of this keeps the center of gravity low, Keeps the weight and thus contact patch differences on each tire to a minimum, and gives drivers more confidence as the car dosent sway leading to more predictable responses.
But its not all daiseys and rainbows swaybars have some downsides. First and foremost they keep suspensions from doing what their good at, following the contours of the road. When one sides loaded up and the other needs to fall into a dip it cant react as swiftly or in some cases at all, this leads to the tire momentairly losing a portion of its grip due to very little weight being on the tire. Secondly it can produce disturbances where one wheel encounters a bump and it forces the other side to experiance some of the bumps force aswell, this causes disturbances and can lead to a loss of control. Eventually itll reach a point where it is only a detriment to the unloaded sides wheel reaching the asphalt, and this point can approach sooner if the surface is imperfect, which they always are. There are certainly nessesary part to selling cars for mass consumption because peaple want it to feel like a plush go cart not a barge aswell as the fact that if a car wanted to spin out at the limit many many many peaple would.(mr2, s2000) So for a manufacturer its the only reasonable thing to do because after all understeer is alot less frightning to the unprepared as oversteer.
So you’ve gotten bored of your cars limit because at this point your just taking It to that on/off switch. Removing the swaybars or just one of them, can definately change the experiance (not always for the best depends on the suspension setup) you’ll immediately notice how the car dives and dips, although unsettling to drive at first it begins to feel alive allowing you to push it in different ways and offering up a large reward for hitting a corner just right. For the track sway bars offer large benefits but when the surface is imperfect their problems gleam, and thats when not having them can actually increase your speed. Plus at the end of the he day most of us dont track our cars but we do explore them on backroads, wouldnt you want to master the full potential of your car? Or in the least learn more about car control.
Im not completely talking out of my ass here Ive removed the swaybars on my personal car for a period of time, although it was originally out of necessity its now only running a front bar.
No this is not my car
crowmolly
> sony1492
08/22/2016 at 15:52 |
|
Not mentioned, but in drag racing a big rear bar on a coil spring car helps it launch a lot flatter, and removal of the front bar for weight transfer purposes is common.
|
sony1492
> crowmolly
08/22/2016 at 15:56 |
|
Solid point, I completely forgot about that.
Wrong Wheel Drive (41%)
> sony1492
08/22/2016 at 15:56 |
|
Well counterpoint is that are you ever really testing the limits of the car on a street environment? I know for me, the much stiffer and larger front sway bar that I added made a huge difference for my autox times. Street driving has not been negatively impacted since I definitely drive a bit less hard (more like 7/10 or 8/10 instead of 11/10). Even during my many tail of the dragon runs, I definitely enjoyed having the sway bar in there. Unless you are referring to mixed road/dirt driving? Maybe that would be different. I have been toying with the idea of a bigger rear sway bar since I don’t enjoy the occasional understeer I now get, but I may be able to just replace the end links and tinker with it to get a nice balance.
SidewaysOnDirt still misses Bowie
> sony1492
08/22/2016 at 15:58 |
|
There can be more outright grip without sway bars, but at the risk of it being easier to unsettle the car since the chassis will move more relative to the wheels and for the response to turn in being reduced because again the body moves more independently from the wheels. It’s mostly a feel/preference thing. Without the rear sway bar on my AW11, it pushed. There would also be less warning of the snap oversteer and it would be harder to control when it happened. Now I have tighter turn-in and less overall grip at the rear, but it doesn’t really matter because the back had too much relative to the front so would slow me down whereas now I can ride the balance with the throttle.
Little Black Coupe Turned Silver
> sony1492
08/22/2016 at 16:10 |
|
I added a 1.5" rear bar to my car, and it’s sorta amazing now. It might 3-wheel if I push it hard enough, but at least I can get the stupid car to turn in now.
|
sony1492
> Wrong Wheel Drive (41%)
08/22/2016 at 16:10 |
|
All of this is down to the driver preferance personally I drive too fast and all the roads around me are suited for it (also the roads are very lumpy because its earthquake country) so the tires spend a substantial amount of time near the limit, where just a little more speed would cause some form of sliding. But if a sway bar feels better to the driver theyll definately drive faster with one. Im pointing out that theres a possibility for a larger gray area between holding the road and sliding without one.
ChooChooMotherFudger
> sony1492
08/22/2016 at 16:15 |
|
!!! UNKNOWN CONTENT TYPE !!!
I amma stop you right there.
If by that you mean that the weight transfer is reduced, you are wrong.
Also it can only lower the CG by adding weight down low.
Textured Soy Protein
> sony1492
08/22/2016 at 16:16 |
|
I lowered my E92 335xi on B&G springs and Koni FSD shocks. But I was looking to decrease body roll more than just the shocks and springs would accomplish, and also shift the balance of more roll stiffness in the rear to help the car rotate more. So I swapped out the 15 mm rear sway bar for a 24 mm one from an M3 convertible. I also added poly bushings to the stock front sway bar, and adjustable end links to both bars. Very happy with the overall balance of the car.
|
Wrong Wheel Drive (41%)
> sony1492
08/22/2016 at 16:20 |
|
Yeah I see where you are coming from. I guess I just don’t get much opportunity to try it out. I am always way too worried about sliding around when I cant really see whats coming from oncoming traffic. So it ends up being impossible to really test the limits. I think I do get what you are saying though, I bet I would rather be missing the sway bar for street driving but only because the limits would end up lower and I am not concerned with "lap times".
DC3 LS, will be perpetually replacing cars until the end of time
> sony1492
08/22/2016 at 16:23 |
|
I prefer roll bars on the street. I just upgraded from a 92 Civic (stock gasp!) with no roll bars to an Integra (same chassis for those that don’t know) with bars front and rear. At first I planned to take off the front bar to reduce understeer, but I love it because it makes the steering so responsive and precise. Sure it lowers the actual grip, but I’m firmly in the camp having a car you can have fun in without doing go to jail speeds.
Although to caveat it the Civic rode like a goddamn Cadillac with IRS and no bars. Same can’t be said for the Integra, but it’s by no means bad.
|
sony1492
> ChooChooMotherFudger
08/22/2016 at 16:29 |
|
Im saying the center of gravity would be lower with sway bars because without them the chassis is higher due to the inside wheel pushing the body up then the center of gravity is higher slightly. Im not claiming to be correct but I assumed the contact patchs were related to the weight over them.
just-a-scratch
> sony1492
08/22/2016 at 16:53 |
|
If the inside suspension is extended, what is the outside doing? In a corner, the load transfer to the outside will compress that suspension. The effect is roll. It doesn’t necessarily have an effect on the height of the center of mass.
tromoly
> sony1492
08/22/2016 at 17:02 |
|
Still incorrect, CG rises significantly only if the outside suspension doesn’t compress, if the CG is high enough to cause that there’s more fundamental issues than running a swaybar.
|
sony1492
> just-a-scratch
08/22/2016 at 17:04 |
|
Im poor at explaining things on top of being flat wrong, this is a poor combination. Ill edit the title to reflect this.
DynamicWeight
> sony1492
08/22/2016 at 17:51 |
|
I recently got a pretty good lesson in removing sway bars. I took my RC car to the track the other day and part way through my front sway came loose. I just could not understand why the car was not performing the way I knew it could. It was like suddenly I had to take turns at 3/4 the speed and couldn’t figure out what was wrong. It wasn’t until the end of the day when I was cleaning up that I saw it had come off. Then it all made sense.
|
ChooChooMotherFudger
> ChooChooMotherFudger
08/22/2016 at 21:14 |
|
Contact patch is related to the weight over them, but the sway bar is not related to the weight on the wheels during the corner.
Its a common misconception that the stiffer a car is to roll (during corners) the less weight is transferred from the inside wheel to the outside wheel, resulting in it going faster.
As for the CG I would guess that is negligible.
That said I like the rest of what you wrote; it is a good point and something I never would have thought of.