| makofoto | 01-11-2004 09:27 PM |
Instead of stiffer rear swy bar, softer front sway bar?
�
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I have pretty agressive 1 inch Hotchkis sway bars front and rear ... WRX Wgn with very mild Tein Wagon coilovers ... for AutoX'ing ... I'm wondering ... if instead of going to my stiffest rear sway bar setting ... should I leave it in the middle ... and go back to my oem front sway bar?
The Hotchkis bars are ... 88% stiffer then oem in the front ... and the rears can be set to about 70, 95 and 160% stiffer then stock ...
Or ... in the interest of flat cornering on a smooth AutoX course ... should I keep the Hotchkis in front ... and go totally stiff in back for more oversteer ... ?
The Hotchkis bars are ... 88% stiffer then oem in the front ... and the rears can be set to about 70, 95 and 160% stiffer then stock ...
Or ... in the interest of flat cornering on a smooth AutoX course ... should I keep the Hotchkis in front ... and go totally stiff in back for more oversteer ... ?
| Davenow | 01-11-2004 09:40 PM |
Smaller front bar will allow more roll in the front, which means more loss of camber in the front as the car leans. This will lead to MORE undesteer.
I ran stock front and 22mm rear for awhile, I added a 22mm front and had less understeer than with the stock front bar.
WHat are your alignment settings? What kind of tires?
Also, at least 60% of the understeer problem with the WRX is driver related.
I ran stock front and 22mm rear for awhile, I added a 22mm front and had less understeer than with the stock front bar.
WHat are your alignment settings? What kind of tires?
Also, at least 60% of the understeer problem with the WRX is driver related.
| makofoto | 01-11-2004 10:04 PM |
Boy, that seems to fly in the face of conventional wisdom ... doesn't it? I mean "traditionallly" we go to a stiffer/larger rear sway bar for more oversteer ...
Since the larger/stiffer rear sway bar produce oversteer by in effect reducing rear grip ... I thought that maybe I should do the opposite ... induce more oversteer by getting the front to stick better ... by reducing the front sway bar.
Subaru introduced more understeer by adding a larger front sway bar to the US STI ...
I only have -1 Camber all around ... with soft Tein Wagon CoilOvers and narrow 215/45/17 Toyo T1's on 17 X 7.5 SSR's.
This wasn't a bad combination at the last AutoX at CA Speedway ... where it RAINED. I came in 2nd behind a stock Evo8 ... in SM ... out of 27 cars.
Yes ... I know how to induce oversteer with throttle lift, flicks, etc.
Since the larger/stiffer rear sway bar produce oversteer by in effect reducing rear grip ... I thought that maybe I should do the opposite ... induce more oversteer by getting the front to stick better ... by reducing the front sway bar.
Subaru introduced more understeer by adding a larger front sway bar to the US STI ...
I only have -1 Camber all around ... with soft Tein Wagon CoilOvers and narrow 215/45/17 Toyo T1's on 17 X 7.5 SSR's.
This wasn't a bad combination at the last AutoX at CA Speedway ... where it RAINED. I came in 2nd behind a stock Evo8 ... in SM ... out of 27 cars.
Yes ... I know how to induce oversteer with throttle lift, flicks, etc.
| Davenow | 01-11-2004 10:16 PM |
it goes agains internet forum rumor logic, but not reality. EVERYONE that I have ever read about/talked to (I know a couple) that runs 22mm front and rear swears by it. SOme run 24 rear, but they all agree that the 22mm front is a great upgrade.
The front sway bar on the STI is 20mm:confused: IIRC anyway.
You need more negative camber up front. go to -1.5 up front and stickier tires.
The front end will stick better with a bigger front bar, because your alignment will not change as much mid turn due to body lean.
V6TurboTa and this kid Zac (cant spell his screen name from memory, but it starts with Zac) both run 22mm front and rear and LOVE it, and I know of a few others.
The front sway bar on the STI is 20mm:confused: IIRC anyway.
You need more negative camber up front. go to -1.5 up front and stickier tires.
The front end will stick better with a bigger front bar, because your alignment will not change as much mid turn due to body lean.
V6TurboTa and this kid Zac (cant spell his screen name from memory, but it starts with Zac) both run 22mm front and rear and LOVE it, and I know of a few others.
| makofoto | 01-11-2004 10:33 PM |
Yah, I know about the alignment and tires ... hoping it rains one more time ... next weekend. :D
Then if the money is coming in ... better tires ... and hopefully another set of wheels ... :)
I also got corner balanced by Darren at WestSide ... and a tiny bit of toe out up front for a bit faster turn in ...
Then if the money is coming in ... better tires ... and hopefully another set of wheels ... :)
I also got corner balanced by Darren at WestSide ... and a tiny bit of toe out up front for a bit faster turn in ...
| Kostamojen | 01-11-2004 10:35 PM |
The suspension kit from the dealer/factory has a smaller front swaybar you can get, just to let you know.
| Davenow | 01-11-2004 10:54 PM |
[QUOTE][i]Originally posted by Kostamojen [/i]
[B]The suspension kit from the dealer/factory has a smaller front swaybar you can get, just to let you know. [/B][/QUOTE]
Yeah I just saw a website that has it separate too. I forget the URL though...
[B]The suspension kit from the dealer/factory has a smaller front swaybar you can get, just to let you know. [/B][/QUOTE]
Yeah I just saw a website that has it separate too. I forget the URL though...
| Porter | 01-11-2004 11:00 PM |
[QUOTE][i]Originally posted by makofoto [/i]
[B]Boy, that seems to fly in the face of conventional wisdom ... doesn't it? I mean "traditionallly" we go to a stiffer/larger rear sway bar for more oversteer ...
[/B][/QUOTE]
You can throw "conventional wisdom" out the window. It's a Subaru, not a Miata. The chassis dynamics are unique and change dramatically under braking or acceleration.
The finest handling Subaru I've ever driven had a 25mm front bar and a 24mm in the rear.
[B]Boy, that seems to fly in the face of conventional wisdom ... doesn't it? I mean "traditionallly" we go to a stiffer/larger rear sway bar for more oversteer ...
[/B][/QUOTE]
You can throw "conventional wisdom" out the window. It's a Subaru, not a Miata. The chassis dynamics are unique and change dramatically under braking or acceleration.
The finest handling Subaru I've ever driven had a 25mm front bar and a 24mm in the rear.
| ANZAC_1915 | 01-12-2004 03:33 AM |
How much roll you get depends also on your springs. A bigger front bar is not always better.
| exhacker | 01-12-2004 06:45 AM |
[QUOTE][i]Originally posted by Glenn Wallace [/i]
[B]How much roll you get depends also on your springs. A bigger front bar is not always better. [/B][/QUOTE]
Amen!
People should list all (or at least MORE) of their other suspension mods when talking about changing one part, IMO. I started reading this thread thinking I could learn something about autocross suspension secrets, and come to find that every other post is about changing the rear (not allowed in DS).
-x
Does *anyone* still compete in DS?
[B]How much roll you get depends also on your springs. A bigger front bar is not always better. [/B][/QUOTE]
Amen!
People should list all (or at least MORE) of their other suspension mods when talking about changing one part, IMO. I started reading this thread thinking I could learn something about autocross suspension secrets, and come to find that every other post is about changing the rear (not allowed in DS).
-x
Does *anyone* still compete in DS?
| Davenow | 01-12-2004 11:00 AM |
The couple stock class guys I know that drive WRX's use stock rear(have to) and the whiteline 22mm front along with Koni adjustables.
My suspension is
JIC FLT-A2 coilovers 8/6 rates a good alignment and 22mm front and rear sways.
Although I DID run teh 22mm front and rear on stock struts/springs and it works equally as well.
My suspension is
JIC FLT-A2 coilovers 8/6 rates a good alignment and 22mm front and rear sways.
Although I DID run teh 22mm front and rear on stock struts/springs and it works equally as well.
| Kostamojen | 01-12-2004 05:44 PM |
I think folks running larger front swaybars need to calculate their sustained highest speed in a corner vs. with smaller front swaybars. The larger front bar will make turn in faster, but will ultimatly decrease corner speed capacity (unless you start talking crazy alignments, with crazy suspensions and even crazier tires ala gary sheehan)
| makofoto | 01-12-2004 06:25 PM |
So for AutoX ... the larger front sway is good ... lots of changes in direction ... relatively low cornering speeds ... ? :D
| exhacker | 01-12-2004 07:10 PM |
[QUOTE][i]Originally posted by Davenow [/i]
[B]My suspension is
JIC FLT-A2 coilovers 8/6 rates a good alignment and 22mm front and rear sways.[/B][/QUOTE]
Is that the kg/mm measurement? That equates to 475/355 lb/in, which is relatively mild in the racing world. Sounds like something I could live with. That would definitely shift some of that 60/40 weight distribution. Have you corner-weighted? I'd love to see your specs (alignment, cross-weights, ride-height, etc).
I had 450/600 lb/in (7.5/10 kg/mm) Eibachs in a Civic race car, and that was a kidney-killer. I learned some of the Honda Challenge cars are running 750/900 lb/in (12.5/15 kg/mm) !!! whew... no thanks.
[B]My suspension is
JIC FLT-A2 coilovers 8/6 rates a good alignment and 22mm front and rear sways.[/B][/QUOTE]
Is that the kg/mm measurement? That equates to 475/355 lb/in, which is relatively mild in the racing world. Sounds like something I could live with. That would definitely shift some of that 60/40 weight distribution. Have you corner-weighted? I'd love to see your specs (alignment, cross-weights, ride-height, etc).
I had 450/600 lb/in (7.5/10 kg/mm) Eibachs in a Civic race car, and that was a kidney-killer. I learned some of the Honda Challenge cars are running 750/900 lb/in (12.5/15 kg/mm) !!! whew... no thanks.
| makofoto | 01-16-2004 11:22 AM |
bump
| zoomfactor | 01-16-2004 12:40 PM |
[QUOTE]The larger front bar will make turn in faster, but will ultimatly decrease corner speed capacity [/QUOTE] Kostamogen, why would you say this? Are you referring to a stock or semi-stock suspension with the larger front bar?
My personnal experience is that, if anything, corner speeds are up because you are able to apply throttle much earlier coming out. I don't get the open front diff spinning the inside wheel coming off a turn. Coilovers are probably helping, with the 22 mm front bar, but I have left the stock rear bar on (for the time being).
As far as crazy alignments, etc. - isn't the point to provide the optimal contact patch for your specific application whatever that entails?
- not flaming just curious;)
JD
[SIZE=1]edited for clarity[/SIZE]
My personnal experience is that, if anything, corner speeds are up because you are able to apply throttle much earlier coming out. I don't get the open front diff spinning the inside wheel coming off a turn. Coilovers are probably helping, with the 22 mm front bar, but I have left the stock rear bar on (for the time being).
As far as crazy alignments, etc. - isn't the point to provide the optimal contact patch for your specific application whatever that entails?
- not flaming just curious;)
JD
[SIZE=1]edited for clarity[/SIZE]
| Ru fan | 01-16-2004 02:49 PM |
I have found that disconnecting the front sway bar works really well. The down side is that the car transitioned much slower. With the stock sway bar, the nose of the car felt as if it was skipping along the pavement. With it off, the car would lean, and then bite into the pavement. To disconnect, just take one of the endlinks all the way off. Also note that a lot of race cars in more stock forms of racing will disconnect the front sway bar in the rain. My basic theory is that for auto-x where quick rotation is needed, a soft'ish, high grip front end is needed. The rear should be set to stiff with little camber. On the track, where steering angles are less, speeds are higher, and the front and rear are working about evenly, a more balanced suspension setup should be used.
Later,
Seth E.:alien:
Later,
Seth E.:alien:
| Kostamojen | 01-16-2004 08:57 PM |
[QUOTE][i]Originally posted by zoomfactor [/i]
[B]Kostamogen, why would you say this? Are you referring to a stock or semi-stock suspension with the larger front bar?
My personnal experience is that, if anything, corner speeds are up because you are able to apply throttle much earlier coming out. I don't get the open front diff spinning the inside wheel coming off a turn. Coilovers are probably helping, with the 22 mm front bar, but I have left the stock rear bar on (for the time being).
As far as crazy alignments, etc. - isn't the point to provide the optimal contact patch for your specific application whatever that entails?
- not flaming just curious;)
JD
[SIZE=1]edited for clarity[/SIZE] [/B][/QUOTE]
The stiffer the swaybar, the more weight you are putting on the outside tire, and decreasing the traction of the inside tire. Unless you have huge sticky ass tires with crazy camber, this ultimatly leads to less traction on either the front or rear of the car. You want the front of the car to have ultimatly MORE traction or you end up with understeer. Camber, swaybars, etc. all help with this.
If your front however is too stiff, you get understeer. Yes, the initial reaction is faster, say entering a hairpin. But as you reach the apex, the weight that you put all on that one outside front tire starts to cause loss of traction, and you cant get on the throttle as much when exiting the corner (if you do get on the throttle, the car will push, and ultimatly not exit as fast causing slower lap times because that corner that you exited lead to a straight which you could have gone Xmph faster through by the next corner)
Maybe I have this all wrong, tell me if im wrong (im going by experience here so I hope not)
[B]Kostamogen, why would you say this? Are you referring to a stock or semi-stock suspension with the larger front bar?
My personnal experience is that, if anything, corner speeds are up because you are able to apply throttle much earlier coming out. I don't get the open front diff spinning the inside wheel coming off a turn. Coilovers are probably helping, with the 22 mm front bar, but I have left the stock rear bar on (for the time being).
As far as crazy alignments, etc. - isn't the point to provide the optimal contact patch for your specific application whatever that entails?
- not flaming just curious;)
JD
[SIZE=1]edited for clarity[/SIZE] [/B][/QUOTE]
The stiffer the swaybar, the more weight you are putting on the outside tire, and decreasing the traction of the inside tire. Unless you have huge sticky ass tires with crazy camber, this ultimatly leads to less traction on either the front or rear of the car. You want the front of the car to have ultimatly MORE traction or you end up with understeer. Camber, swaybars, etc. all help with this.
If your front however is too stiff, you get understeer. Yes, the initial reaction is faster, say entering a hairpin. But as you reach the apex, the weight that you put all on that one outside front tire starts to cause loss of traction, and you cant get on the throttle as much when exiting the corner (if you do get on the throttle, the car will push, and ultimatly not exit as fast causing slower lap times because that corner that you exited lead to a straight which you could have gone Xmph faster through by the next corner)
Maybe I have this all wrong, tell me if im wrong (im going by experience here so I hope not)
| NETWRX | 07-02-2004 03:52 PM |
It seems to me...
�
�
that the whole point of a sway bar is to redistribute more weight (actually down force) to the INSIDE wheel in hard cornering.
Without a sway bar, the car rolls to the outside and puts a lot of weight/force on the outside tire, lifting the inside wheel, reducing traction, and forcing the outside wheel to do a LOT more of the work turning the car. The sway bar's reason for being is to use that force to compress the suspension on the INSIDE tire (effectively moving some of the weight/force back onto the inside tire). Or, perhaps more accurately, it prevents some of that weight from being transferred to the outside wheel in the first place...?
In any case, it seems to me that a stiffer bar would keep more of the downforce on the inside wheel, allowing the two tires to more evenly share the work of turning the car. Short of getting the car to lean to the INSIDE of a corner, the stiffer the swaybar, the more evenly the weight/force is distributed between the two wheels.
Or, I could be completely wrong...
Am I?:huh:
Without a sway bar, the car rolls to the outside and puts a lot of weight/force on the outside tire, lifting the inside wheel, reducing traction, and forcing the outside wheel to do a LOT more of the work turning the car. The sway bar's reason for being is to use that force to compress the suspension on the INSIDE tire (effectively moving some of the weight/force back onto the inside tire). Or, perhaps more accurately, it prevents some of that weight from being transferred to the outside wheel in the first place...?
In any case, it seems to me that a stiffer bar would keep more of the downforce on the inside wheel, allowing the two tires to more evenly share the work of turning the car. Short of getting the car to lean to the INSIDE of a corner, the stiffer the swaybar, the more evenly the weight/force is distributed between the two wheels.
Or, I could be completely wrong...
Am I?:huh:
| makofoto | 07-02-2004 03:58 PM |
Sway bars on the WRX, especially in the front ... also help the car to maintain it's alignment ... that's why a thicker, stiffer front sway bar helps reduce understeer in a WRX ... helps it maintain camber
| Calamity Jesus | 07-02-2004 04:39 PM |
[QUOTE][i]Originally posted by NETWRX[/i]
[B][It seems to me...] that the whole point of a sway bar is to redistribute more weight (actually down force) to the INSIDE wheel in hard cornering.
Or, I could be completely wrong...
Am I?:huh: [/B][/QUOTE]
Yes, we have no bananas (you are completely wrong)
Okay, so you're not [i]completely[/i] wrong. Body roll is minimized and a vehicle with a high center of gravity will benefit from less roll stiffness because it will be less likely to roll over so far as to tip the center of gravity (CG) beyond the outside tires (which would result in immediate roll-over). This is a problem with SUVs.. but not many passenger cars.
During a turn a swaybar is always trying to keep the wheels at the same position along their travel. If the right wheel is moving up into the fender, the swaybar will push up on the left wheel. If the right wheel drops down, the swaybar will push down on the left wheel. This allows the bar to keep the chassis on a plane more similar to that of the road that the wheels are travelling over.
During a left turn, the right wheels will travel up into the fenders as the weight transfers... because of this the swaybar will push up on the left wheel. Because the left wheel still wants to be down on the ground, the bar ends up transferring more force downward to the right wheel in it's effort to keep the chassis horizontal.
In effect, what has happened is that less pressure is on the left wheel (inside) and more on the right wheel (outside) than without the bar.
Because a Subaru has an engine that hangs out beyond the front axle, it is a very nose-heavy vehicle. Most of it's driving dynamics are similar to that of a FWD car because of the weight distribution... but because of the AWD, some concessions are made to keep traction more even front to rear than would be in a FWD car.
During acceleration out of a turn, a common broblem is the lifting of the inside front wheel. The car's CG is rocked back and to the side, away from that wheel. Having more roll stiffness on the rear axle (not neccesarily more than the front, just more) means that the outside rear wheel will have more force pressing it to the pavement. This will
a) Put more pressure on the outside rear contact patch, resulting in more rear-slip angle (more rear rotation)
&
b) Because of the dynamics of corner weights (and the fact that the front is doing less of the roll resistance), there will be more force placed upon the inside front wheel.
Since FWDers don't have to worry about traction on the inside rear wheel, the rear roll stiffness is usually greater than the front. This is why you see a lot of FWDers 'lifting legs' around road circuits and AutoX courses.
[B][It seems to me...] that the whole point of a sway bar is to redistribute more weight (actually down force) to the INSIDE wheel in hard cornering.
Or, I could be completely wrong...
Am I?:huh: [/B][/QUOTE]
Yes, we have no bananas (you are completely wrong)
Okay, so you're not [i]completely[/i] wrong. Body roll is minimized and a vehicle with a high center of gravity will benefit from less roll stiffness because it will be less likely to roll over so far as to tip the center of gravity (CG) beyond the outside tires (which would result in immediate roll-over). This is a problem with SUVs.. but not many passenger cars.
During a turn a swaybar is always trying to keep the wheels at the same position along their travel. If the right wheel is moving up into the fender, the swaybar will push up on the left wheel. If the right wheel drops down, the swaybar will push down on the left wheel. This allows the bar to keep the chassis on a plane more similar to that of the road that the wheels are travelling over.
During a left turn, the right wheels will travel up into the fenders as the weight transfers... because of this the swaybar will push up on the left wheel. Because the left wheel still wants to be down on the ground, the bar ends up transferring more force downward to the right wheel in it's effort to keep the chassis horizontal.
In effect, what has happened is that less pressure is on the left wheel (inside) and more on the right wheel (outside) than without the bar.
Because a Subaru has an engine that hangs out beyond the front axle, it is a very nose-heavy vehicle. Most of it's driving dynamics are similar to that of a FWD car because of the weight distribution... but because of the AWD, some concessions are made to keep traction more even front to rear than would be in a FWD car.
During acceleration out of a turn, a common broblem is the lifting of the inside front wheel. The car's CG is rocked back and to the side, away from that wheel. Having more roll stiffness on the rear axle (not neccesarily more than the front, just more) means that the outside rear wheel will have more force pressing it to the pavement. This will
a) Put more pressure on the outside rear contact patch, resulting in more rear-slip angle (more rear rotation)
&
b) Because of the dynamics of corner weights (and the fact that the front is doing less of the roll resistance), there will be more force placed upon the inside front wheel.
Since FWDers don't have to worry about traction on the inside rear wheel, the rear roll stiffness is usually greater than the front. This is why you see a lot of FWDers 'lifting legs' around road circuits and AutoX courses.
| afpdl | 07-02-2004 06:28 PM |
If swaybars put more downward force on the inside wheel they would be
A. magic swaybars
B. make the car roll more.
I mean this as a rear swaybar doesnt transmit downward force to the inside rear wheel. It will help keep the inside front wheel down because the car will roll less not by applying downward force.
A. magic swaybars
B. make the car roll more.
I mean this as a rear swaybar doesnt transmit downward force to the inside rear wheel. It will help keep the inside front wheel down because the car will roll less not by applying downward force.
| DrBiggly | 07-02-2004 06:47 PM |
Interesting on the 22mm bar upgrade. I went from a 21mm in the front to a 22mm in the front and noticed less understeer.
Spring rates are 7k front, 8k rear. 22mm rear sway. I intend to try a 24mm front sway shortly to see what kind of results I get.
Anyone with significant suspensions and large front bars want to comment? Tom? KC?
Spring rates are 7k front, 8k rear. 22mm rear sway. I intend to try a 24mm front sway shortly to see what kind of results I get.
Anyone with significant suspensions and large front bars want to comment? Tom? KC?
| nhluhr | 07-02-2004 07:38 PM |
[QUOTE][i]Originally posted by Porter[/i]
[B] You can throw "conventional wisdom" out the window. It's a Subaru, not a Miata. The chassis dynamics are unique and change dramatically under braking or acceleration.
[/B][/QUOTE]
it's still totally bound by the laws of physics.
Total roll stiffness is goverened by the combination of the front and rear roll couples.
The 02+ Imprezas are very stiff in torsion so for the most part, if your current setup has you cornering at a roll amount that you think is good but you want to tune steer characteristics, the CORRECT thing to do is change BOTH swaybars. Make one softer and the other stiffer.
The bar that is made softer will mean less weight transfer on that end of the car and a resulting increase in tire grip.
The bar that is made stiffer will mean more weight transfer on that end of the car and thus less grip at the tires.
Many people fail to understand that higher roll stiffness means more weight transfer due to body roll, but it is physical fact and a failure to grasp this concept leads to a lot of shooting in the dark about chassis tuning.
If you are currently rolling MORE than optimal for whatever surface you're racing on, meaning you are needing to dial in more static negative camber to keep the tire flat under hard roll, then you would surely benefit from increasing the total roll stiffness of the car. In this case, you will see an increase in grip by getting thicker bars at either end or both, but not softer bars.
[B] You can throw "conventional wisdom" out the window. It's a Subaru, not a Miata. The chassis dynamics are unique and change dramatically under braking or acceleration.
[/B][/QUOTE]
it's still totally bound by the laws of physics.
Total roll stiffness is goverened by the combination of the front and rear roll couples.
The 02+ Imprezas are very stiff in torsion so for the most part, if your current setup has you cornering at a roll amount that you think is good but you want to tune steer characteristics, the CORRECT thing to do is change BOTH swaybars. Make one softer and the other stiffer.
The bar that is made softer will mean less weight transfer on that end of the car and a resulting increase in tire grip.
The bar that is made stiffer will mean more weight transfer on that end of the car and thus less grip at the tires.
Many people fail to understand that higher roll stiffness means more weight transfer due to body roll, but it is physical fact and a failure to grasp this concept leads to a lot of shooting in the dark about chassis tuning.
If you are currently rolling MORE than optimal for whatever surface you're racing on, meaning you are needing to dial in more static negative camber to keep the tire flat under hard roll, then you would surely benefit from increasing the total roll stiffness of the car. In this case, you will see an increase in grip by getting thicker bars at either end or both, but not softer bars.
| nhluhr | 07-02-2004 07:53 PM |
[QUOTE][i]Originally posted by Kostamojen[/i]
[B] The stiffer the swaybar, the more weight you are putting on the outside tire, and decreasing the traction of the inside tire. [/B][/QUOTE]
This is true, but the increased roll stiffness also allows the tire to see less positive camber on hard cornering which MORE THAN CANCELS the effect of increased weight transfer by putting the tires much flatter on the ground.
[B] The stiffer the swaybar, the more weight you are putting on the outside tire, and decreasing the traction of the inside tire. [/B][/QUOTE]
This is true, but the increased roll stiffness also allows the tire to see less positive camber on hard cornering which MORE THAN CANCELS the effect of increased weight transfer by putting the tires much flatter on the ground.
| nhluhr | 07-02-2004 07:56 PM |
[QUOTE][i]Originally posted by NETWRX[/i]
[B] that the whole point of a sway bar is to redistribute more weight (actually down force) to the INSIDE wheel in hard cornering.
Without a sway bar, the car rolls to the outside and puts a lot of weight/force on the outside tire, lifting the inside wheel, reducing traction, and forcing the outside wheel to do a LOT more of the work turning the car. [/B][/QUOTE]
It doesn't work like that. The more body roll you have, the less weight transfer there is. Hard to fathom, I know, but imagine a car hitting the bump stops, when the roll stiffness suddenly goes to "infinite" for a moment. You basically lose all traction on that outside wheel because far more weight is transferred to it.
Stiffer swaybars mean more weight transfer and less grip until you factor in their effect on camber.
[B] that the whole point of a sway bar is to redistribute more weight (actually down force) to the INSIDE wheel in hard cornering.
Without a sway bar, the car rolls to the outside and puts a lot of weight/force on the outside tire, lifting the inside wheel, reducing traction, and forcing the outside wheel to do a LOT more of the work turning the car. [/B][/QUOTE]
It doesn't work like that. The more body roll you have, the less weight transfer there is. Hard to fathom, I know, but imagine a car hitting the bump stops, when the roll stiffness suddenly goes to "infinite" for a moment. You basically lose all traction on that outside wheel because far more weight is transferred to it.
Stiffer swaybars mean more weight transfer and less grip until you factor in their effect on camber.
| BIGSKYWRX | 07-03-2004 12:31 AM |
I've ran bigger sway bars f/r, but went to a smaller front (19mm RA swaybar) and prefer it over the former setup. My car is not dedicated autox car though. it does see a lot of autox action, but rallyx and track days as well. I get the same handling characteristics I got w/ the bigger bars, but handles the rougher surfaces much better. I do run a fair amount of camber (-2.0) and a fair amount of caster (5.0) which also helps maintan a good contact patch.
There are lots of variables and your end use(s) are going to have a large influence on how you choose your sway bars.
Big Sky
There are lots of variables and your end use(s) are going to have a large influence on how you choose your sway bars.
Big Sky
| AlpineFD | 07-03-2004 03:40 AM |
Sway bar increases weight transfer to the outside tire, tire load sensitivity, at a certain point increasing load on the tire results in increase in traction but at a decreasing rate, so you end up with less over all grip on that end of the car.
| nhluhr | 07-03-2004 03:44 AM |
[QUOTE][i]Originally posted by AlpineFD[/i]
[B] Sway bar increases weight transfer to the outside tire, tire load sensitivity, at a certain point increasing load on the tire results in increase in traction but at a decreasing rate, so you end up with less over all grip on that end of the car. [/B][/QUOTE]
Yep, grip is a ratio of weight to lateral cornering force generated.
Traction is essentially that lateral cornering force.
Increasing weight on a tire DOES increase its traction, but you are reducing grip of that tire... meaning the tire IS indeed sticking harder but it is giving less lateral force in proportion to its vertical loading.
The problem is that the extra weight transfer is removing more weight from the inside wheel and you're losing more traction than you're gaining so you end up with a net loss overall from the increased weight transfer.
[B] Sway bar increases weight transfer to the outside tire, tire load sensitivity, at a certain point increasing load on the tire results in increase in traction but at a decreasing rate, so you end up with less over all grip on that end of the car. [/B][/QUOTE]
Yep, grip is a ratio of weight to lateral cornering force generated.
Traction is essentially that lateral cornering force.
Increasing weight on a tire DOES increase its traction, but you are reducing grip of that tire... meaning the tire IS indeed sticking harder but it is giving less lateral force in proportion to its vertical loading.
The problem is that the extra weight transfer is removing more weight from the inside wheel and you're losing more traction than you're gaining so you end up with a net loss overall from the increased weight transfer.
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