too stiff sway bars?
09-22-2006, 07:28 PM
#2
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If it has too stiff of a front sway bar then you will understeer and it will negativley effect your launch. If its too stiff of a rear sway bar you will oversteer more.
09-22-2006, 08:00 PM
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Yah thats what Im talking about. If you go too stiff all around thats whats gonna happen. And you will feel like your out driving your tires all time when your cornering even if its not that fast. Heres a scenario for you to understand more. I was driving my buddys SS and it has a front sway bar thats enormous. I was coming into a right hand turn that was a right angle turn and I was only going maybe 20 mph and the front end plowed forward and I wasnt on the breaks at all! I was in 2nd gear and held the gas down a bit when it happend. I backed off the throttle and it some what corrected. This is the same turn that I've taken at atleast 30 mph with my car with stock suspension and the same exact tires as my friends car. Now lets say that the car had the same size rear sway bar then the if I backed off the throttle or gave too much or did any thing to disrupt the way the wieght was transfering then the car would have oversteerd when I tryd too correct it. Or if it didnt understeer and I was trying to exit the corner too fast with too much throttle it would over steer. And if you would exit the corner with a smaller then enourmas rear sway bar and used the same amount of throttle then it would either stick harder or not over steer as much. I hope this helps.
09-22-2006, 08:22 PM
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From a performance/street perspective, a 35mm front/21mm rear setup is pretty good. Most aftermarket front rear swaybar combos usually have too stiff of a rear swaybar, or too weak of a front swaybar.
09-22-2006, 10:34 PM
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Lateral Load Transfer Distribution is the 'technical term' your looking for. Esentially its how the load transfer is controlled between the front and rear on a steady state turn.
First off let me state by saying that independant of the stiffness, your load transfer from one side to the other will be the same. Load transfer is a function of CG location, track width, and lateral acceleration.
By adding stiffness, your trying to minimize chassis roll and the main reason you want to do this is to control your tire camber change. lots of body roll typically changes your tire contact patch in a bad way. (i.e. positive camber) this kills your maximum lateral acceleration you can achieve.
Another reason your doing it is for transient response, this response time is typically the more drastic effect felt by drivers after they increase stiffness. this can also be changed by moving roll centers of the suspension.. but i'll save that for a more in depth discussion.. A downside to increasd response time is the ease at which the tires limits can be exceeded, quick inputs will put you in the ditch alot faster than with a softer suspension.
Now being too stiff is not a point that can be determined easily and its all dependant of the conditoins your driving. if you have rougher surfaces, you may actually be decreasing your lateral accel by stifening your suspension and not making it compliant, therefore will not allow the contact patch to be optimally planted the entire way around. on a smooth surface you can get away with much stiffer settings and be much more in the range of 'calculated' maximum lat. accel.
Also, roll stiffness is a combination of roll bars AND your shocks+springs. Vehicles are typically designed with a roll stiffness gradient in mind (degrees of roll per lateral g of accel). This can be accomplished through really stiff springs or softer springs and big sway bar, each way has its tradeoffs and needs to be analyzed for how you plan on using the vehicle and even the road course your racing at..
First off let me state by saying that independant of the stiffness, your load transfer from one side to the other will be the same. Load transfer is a function of CG location, track width, and lateral acceleration.
By adding stiffness, your trying to minimize chassis roll and the main reason you want to do this is to control your tire camber change. lots of body roll typically changes your tire contact patch in a bad way. (i.e. positive camber) this kills your maximum lateral acceleration you can achieve.
Another reason your doing it is for transient response, this response time is typically the more drastic effect felt by drivers after they increase stiffness. this can also be changed by moving roll centers of the suspension.. but i'll save that for a more in depth discussion.. A downside to increasd response time is the ease at which the tires limits can be exceeded, quick inputs will put you in the ditch alot faster than with a softer suspension.
Now being too stiff is not a point that can be determined easily and its all dependant of the conditoins your driving. if you have rougher surfaces, you may actually be decreasing your lateral accel by stifening your suspension and not making it compliant, therefore will not allow the contact patch to be optimally planted the entire way around. on a smooth surface you can get away with much stiffer settings and be much more in the range of 'calculated' maximum lat. accel.
Also, roll stiffness is a combination of roll bars AND your shocks+springs. Vehicles are typically designed with a roll stiffness gradient in mind (degrees of roll per lateral g of accel). This can be accomplished through really stiff springs or softer springs and big sway bar, each way has its tradeoffs and needs to be analyzed for how you plan on using the vehicle and even the road course your racing at..
Last edited by DanO; 09-22-2006 at 10:41 PM.
09-23-2006, 05:18 PM
#7
Originally Posted by DanO
Lateral Load Transfer Distribution is the 'technical term' your looking for. Esentially its how the load transfer is controlled between the front and rear on a steady state turn.
First off let me state by saying that independant of the stiffness, your load transfer from one side to the other will be the same. Load transfer is a function of CG location, track width, and lateral acceleration.
By adding stiffness, your trying to minimize chassis roll and the main reason you want to do this is to control your tire camber change. lots of body roll typically changes your tire contact patch in a bad way. (i.e. positive camber) this kills your maximum lateral acceleration you can achieve.
Another reason your doing it is for transient response, this response time is typically the more drastic effect felt by drivers after they increase stiffness. this can also be changed by moving roll centers of the suspension.. but i'll save that for a more in depth discussion.. A downside to increasd response time is the ease at which the tires limits can be exceeded, quick inputs will put you in the ditch alot faster than with a softer suspension.
Now being too stiff is not a point that can be determined easily and its all dependant of the conditoins your driving. if you have rougher surfaces, you may actually be decreasing your lateral accel by stifening your suspension and not making it compliant, therefore will not allow the contact patch to be optimally planted the entire way around. on a smooth surface you can get away with much stiffer settings and be much more in the range of 'calculated' maximum lat. accel.
Also, roll stiffness is a combination of roll bars AND your shocks+springs. Vehicles are typically designed with a roll stiffness gradient in mind (degrees of roll per lateral g of accel). This can be accomplished through really stiff springs or softer springs and big sway bar, each way has its tradeoffs and needs to be analyzed for how you plan on using the vehicle and even the road course your racing at..
First off let me state by saying that independant of the stiffness, your load transfer from one side to the other will be the same. Load transfer is a function of CG location, track width, and lateral acceleration.
By adding stiffness, your trying to minimize chassis roll and the main reason you want to do this is to control your tire camber change. lots of body roll typically changes your tire contact patch in a bad way. (i.e. positive camber) this kills your maximum lateral acceleration you can achieve.
Another reason your doing it is for transient response, this response time is typically the more drastic effect felt by drivers after they increase stiffness. this can also be changed by moving roll centers of the suspension.. but i'll save that for a more in depth discussion.. A downside to increasd response time is the ease at which the tires limits can be exceeded, quick inputs will put you in the ditch alot faster than with a softer suspension.
Now being too stiff is not a point that can be determined easily and its all dependant of the conditoins your driving. if you have rougher surfaces, you may actually be decreasing your lateral accel by stifening your suspension and not making it compliant, therefore will not allow the contact patch to be optimally planted the entire way around. on a smooth surface you can get away with much stiffer settings and be much more in the range of 'calculated' maximum lat. accel.
Also, roll stiffness is a combination of roll bars AND your shocks+springs. Vehicles are typically designed with a roll stiffness gradient in mind (degrees of roll per lateral g of accel). This can be accomplished through really stiff springs or softer springs and big sway bar, each way has its tradeoffs and needs to be analyzed for how you plan on using the vehicle and even the road course your racing at..
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09-26-2006, 12:30 AM
#8
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I've had 4 front swaybars and 4 rear swaybars on my Z28 so maybe I can give you more of a "real world" answer.
A very stiff front bar (35 solid) makes the steering feel sort of "dead" at slow speeds. The car becomes very sensitive to uneven pavement. At higher speeds the steering response is very nice and the car corners very flat. With good tires, I did not find understeer to be an issue.
A very stiff rear bar (25 solid) makes the rear easy to slide around corners at lower speeds which is fun but not real effective for going quickly. At high speeds it makes the car corner really flat which is very confidence inspiring.
A very stiff front bar (35 solid) makes the steering feel sort of "dead" at slow speeds. The car becomes very sensitive to uneven pavement. At higher speeds the steering response is very nice and the car corners very flat. With good tires, I did not find understeer to be an issue.
A very stiff rear bar (25 solid) makes the rear easy to slide around corners at lower speeds which is fun but not real effective for going quickly. At high speeds it makes the car corner really flat which is very confidence inspiring.
09-26-2006, 08:44 AM
#9
Bars, springs and shocks all have to work in harmony for handling.
Need enough front spring to keep the nose from plowing the dirt under heavy braking and enogh front bar to keep the front suspension geometry doing it job to mainitain tire contact patch. (turn in)
Need enough shock to keep the rebound from the front loading pivoting the car's weight to the rear and/or the loaded side. Also need enogh rear rear spring to keep the car's transition even. (mid-corner)
Need a soft enough spring in the rear to get good weight transfer and load the rear tires for a corner exit launch.
So, it's the package and is all subjectively based upon driver preference.
Need enough front spring to keep the nose from plowing the dirt under heavy braking and enogh front bar to keep the front suspension geometry doing it job to mainitain tire contact patch. (turn in)
Need enough shock to keep the rebound from the front loading pivoting the car's weight to the rear and/or the loaded side. Also need enogh rear rear spring to keep the car's transition even. (mid-corner)
Need a soft enough spring in the rear to get good weight transfer and load the rear tires for a corner exit launch.
So, it's the package and is all subjectively based upon driver preference.
Last edited by mitchntx; 09-26-2006 at 09:16 AM.
09-26-2006, 09:20 AM
#10
i think i understand it now. i bought a set of ground control coilovers with koni shocks and eibach springs. i'm gonna give the strano bars a shot with this setup cause that seems to be the most "neutral" setup of bars. thanks for the thoughts guys, i'm lookin forward to it
09-26-2006, 11:18 AM
#11
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my understanding is to stay with the stock rear sway bar and just swap in poly bushings since these cars come from the factory with a well sized rear sway already unless your gonna use the car on a road course.
i had a 35mm solid on my camaro that i swapped onto my dd TA because for around town driving it wasnt to aggressive but really made a difference at higher speed like on the freeway and ended up with a hollow strano bar on the front of the camaro since that car is a weakend warrior toy and i like the results.
i had a 35mm solid on my camaro that i swapped onto my dd TA because for around town driving it wasnt to aggressive but really made a difference at higher speed like on the freeway and ended up with a hollow strano bar on the front of the camaro since that car is a weakend warrior toy and i like the results.
