ASR Adjustable Rear Swaybar

[PR_S14]

Searched and didn't see anything on this:

From King Motorsports:

"12.8.2007 Coming Soon! ASR Adjustable rear sway bar for 06-08 Civic Si
Available in mid January. This bolt on competition adjustable 32mm tubular rear sway bar will be available in .120" and .188' wall thickness. Perfect for autocross, road racing and DE events. Projected price is $499.00. To pre-order please call us at 262-522-7558.

Available exclusively from King Motorsports."

Link: King Motorsports Unlimited, Inc.


Overkill? How's the price?

[Firestrife]

I think thats way over priced for a sway bar.

[trickyazn]

imo from people who owned adjustable sway bars on other cars.. no one really changes the setting so yeah, pricing is WAY overkill.

[CanyonDriver]

32mm just sounds too thick. after a certain point doesnt seem like adding mm's would pose any benefit. my progress bar is 22mm and its fine. especially since it was $150 vs $500.

[Sirbelch]

But its adjustable and hollow (read lighter). That adjustability really helps when you auto x your DD.

[CanyonDriver]

Originally Posted by Sirbelch

But its adjustable and hollow (read lighter). That adjustability really helps when you auto x your DD.

i most definitly agree with that but still thats too hefty of a price tag for a sway bar. Unless someone is a serious autoXer who does national comps and such in their DD it really wouldnt be worth it.

[twistedframe]

wow, thats more than most adjustable sway bar KITS!

[aki]

Even for autocross, I don't see the point of adjusting. Why wouldn't an autocross setup be fine for daily driving? At most you'd probably need 21-22mm to dial out the understeer.

[Sirbelch]

Originally Posted by aki

Even for autocross, I don't see the point of adjusting. Why wouldn't an autocross setup be fine for daily driving? At most you'd probably need 21-22mm to dial out the understeer.

A good autocross set up should go beyond dialing out understeer and dialing in oversteer. At the speeds autocrosses are run at, there isn't a lot of force to get the back end to come around so they have to add stupid stiff rear springs, sway bars and add some toe out inorder to get the car to rotate freely. A car that rotates freely is not safe on the streets.

Although it doesn't say much about the bar, it might come with some bracing like the Comptech RSB for the RSX did. The Comptech was adjustable and had a brace and cost about 350. Its just a guess.

[PR_S14]

Originally Posted by Sirbelch

Although it doesn't say much about the bar, it might come with some bracing like the Comptech RSB for the RSX did. The Comptech was adjustable and had a brace and cost about 350. Its just a guess.

I was thinking the same thing. ASR makes subframes too. I was hoping it was a bar/subframe all in one. I think I'd definitely go this route if that were the case.

[aki]

Originally Posted by Sirbelch

A good autocross set up should go beyond dialing out understeer and dialing in oversteer. At the speeds autocrosses are run at, there isn't a lot of force to get the back end to come around so they have to add stupid stiff rear springs, sway bars and add some toe out inorder to get the car to rotate freely. A car that rotates freely is not safe on the streets.

The danger in rotation is more due to stiffer dampers/springs and toe, not the sway bar. Why? Because you can't have an excessively stiff rear sway on the track anyways, else it's robbing rear grip and preventing the suspension from doing its job. So an ideal sway bar size for the track shouldn't make regular driving dangerous. Plus, if the person ran those same stiff rear dampers/springs on the road it wouldn't be daily-driver friendly anyway. With a hardcore autocross setup that also doubles as a daily driver, they usually swap out or readjust the coilovers for track and road. Plus, if the person is a hardcore autocrosser, I'm sure they can even handle the extra rotation on a regular road.

[Highrev1]

[Sirbelch]

Originally Posted by aki

The danger in rotation is more due to stiffer dampers/springs and toe, not the sway bar. Why? Because you can't have an excessively stiff rear sway on the track anyways, else it's robbing rear grip and preventing the suspension from doing its job. So an ideal sway bar size for the track shouldn't make regular driving dangerous. Plus, if the person ran those same stiff rear dampers/springs on the road it wouldn't be daily-driver friendly anyway. With a hardcore autocross setup that also doubles as a daily driver, they usually swap out or readjust the coilovers for track and road. Plus, if the person is a hardcore autocrosser, I'm sure they can even handle the extra rotation on a regular road.

I was hoping you wouldn't think of that. I should have known better cause you are one of the smart ones. That kinda blows my hole statement out of the water

Hows the popcorn Revy?

[LucasBlack]

since we're talking about serious auto-x'ers, let's think about the possible differences between them driving on the streets vs. running at events.

typically, most attendees that are more serious racers are running tires that they either don't run on the streets, or aren't even street legal. when running tires with different traction limits, there comes obviously the possibility to run very different settings as far as the suspension is concerened for the tires are able to accomodate for more extreme settings (as far as I can imagine). so this by itself can speak toward the possibility of running extremely tight rear setups when running semi-slicks or something of that nature. for, with tires of this sort, their limit at which they will begin to rotate is much higher, so to accomodate and take advantage of that, we can run stiffer rear suspensions and still have manageable traction while getting the rotation we desire as well.

and then, of course, when returning to street tires, the heightened stiffness of the rear suspension would be far too much for the street tires to try and keep up with, and the car would be hindered by that, and would actually be unsafe.


as far as adjusting "down" the dampers to be more street worthy as well, we all know that all suspension components work together to create the desired effect, so therefore, is it not possible that stiff dampers and thick RSB's are perfectly appropriate for the track, while softening the dampers and then reducing the bar stiffness would be more so appropriate for street tameness and safety?

[Moose]

Before I talk about sway bars we have to talk about springs ... in particular springs in a suspension ... because sway-bars are springs as well (torsion springs) and affect the suspension in a similar way to springs.


A spring resists movement ... as you compress it it resists and pushes the opposite direction ... When you apply a mass to the spring it compresses and "pushes back" in the opposite direction. Against the mass. So the spring is storing energy. When you compress the spring further it resists but ultimately compresses, equal to amount of mass applied. The amount of compression is based on the thickness of the spring wire, its metallic composition and the number or coils in the entire spring. The measure of spring compression (in length), caused by a particular mass is expressed as spring rate. Ie a 600lb/in spring requires 600# to compress the spring 1".

So lets say you have a EG civic weighing about 2200 lbs. It is riding on 550 lb/in springs. For simplicity sake we will assume that the car has perfect 50/50 weight distribution (Civics are more like 60-40 in reality). So each spring holds 550 lbs (2200 divided by 4) The car's mass applies 550 lbs of downward force on each of the springs, and the spring apply 550 lbs of upward force resisting the mass, BUT there is 1" of spring droop due to the mass applied. The Spring now has 550 lbs of potential energy stored in it waiting to be released.

Now lets say you are driving the car and you hit a bump ... this bump compresses the spring a further 1" ... therefore an additional 550 lbs of mass (energy) have been applied to the spring. When you come off the bump moveing forward the cars mass tends to keep it going in a forward direction for a little while (relative to the wheels) till gravity causes it to drop down towards the earth.

It that moment when the wheel was un-weighted there was 1100 lbs (550 lbs or car mass and 550 lbs of bump compressed mass) in the spring .. the spring then moves VERY quickly to rid itself of its energy so it unwinds ..as it has a fair bit of energy it moves past its rest position (its length when there is not weight applied) and expands until the slowly depleting energy is counteracted by the spring resisting being expanded.

So now you have a spring that is stretched with lets say for example with 800 lbs of force ..as some of the energy has been depleted in expanding the spring. Since it still has Energy in it .. it moves in the opposite direction past the neutral position and it then starts to compress the spring ... until the energy applied equals the resistance in the spring ... and so on and so on

Soo the spring yo-yo's back and forwards till all the energy is dissipated by the spring (converted to heat) and it returns to its rest position.

Since the car is attached to the spring and it supports its weight ... this yoyo motion of the spring exerts itself on the car and causes the car to yoyo as a result.



Soooo in a nutshell ... the spring supports the cars weight and resists suspension movement, the amount the spring resists movement is a function of the spring rate (stiffness) .

The Less the body rolls and the weight transfers, the more "centered" the car is over the contact patch (the tires) thus the more traction the car has. Remember the ONLY contact the car has with the ground is the tires ... so we must always maximize the tires contact patch.

From this we can say that if you increase the spring rate you can reduce body roll and weight transfer thus improving traction. Well this is true to a point. The suspension has to have compliance (movement) in it so that the suspension follows the bumps and dips in the pavement. If you have NO suspension travel (infinite spring rate) then the tires would come off the ground on every bump ... well this is not good if you are trying to get traction. Also as you increase the spring rate the stiffness goes up and the comfort level goes down


So you want to increase the spring rate to the maximum that you can deal with (street) or the maximum that still allows for enough suspension travel for the road / track conditions that you are designing the car for.

Ok, so you have increased the spring rate to limit of what you are designing the car for ... and you still have to much body-roll / weight transfer ... so what is a boy to do ?



Well this is where sway-bars come in ... remember they are springs as well, BUT with a difference. Springs on a car are always "on' i.e. they are always affecting the car. Sway-bars differ from springs in one key area ... they have a variable effect on the suspension !!!!! This is the KEY part of the beauty of sway-bars.

So let's talk about sway-bars and how they work. A sway bar is a steel rod made of spring steel typically. The wall thickness, the overall diameter and the length of the "return" arms affect its resistance to twisting and thus its spring rate.

The sway-bar "rod" is attached to the chassis of the car, parallel to the lower control arms (LCA's) . It is attached with d-brackets and bushings allowing the bar to rotate easily and to slide a bit from left to right. There are two "arms" that come out at right angles to the bar, thus perpendicular to the bar and LCA's. There are end-links attaching the ends of the arms to the LCA's. Thus both sides of the suspension via the LCA's are connected together. So as one side of the suspension moves up ..it pulls the other side up as well. The Design of the swaybar dictates its spring rate and thus how much force it can exert on the opposite side of the suspension.

Under cornering, the car is leaning over, with one side of the suspension being pushed up while the other is drooping down. Because the two sides of the suspension are attached to one another via the sway-bay the sway-bar resists this difference in movement, pushing down the high-side and lifting up the low side. Since the sway-bar is attached to the car via the d-brackets on the chassis, the sway-bar twists the car and the suspension more level. Sooo the sway-bar ADDS to the over-all spring rate of the car ... under cornering ONLY !!!!!. The MORE the car leans over, the MORE the swaybar resists this movement.

If both arms move up at the same time, ie over a bump that both hit ... then the sway-bar has NO effect on the overall spring rate of the system.

This is the beauty of sway-bars, they allow you to minimize the amount of spring rate you require while maximizing the amount of resistance to body-roll and weight transfer while cornering.


Tuning

Ok, so now let's talk about tuning with sway-bars. We know the sway-bar is a torsion (twisting) spring. The spring rate of the sway-bar is determined by a couple of things.
1-The wall thickness of the sway-bar
2-The Diameter of the sway-bar
3-The metallic composition of the sway-bar
4-The length of the "return" arms.

1,2,and 3 make sense ... the beefier the bar is the stiffer the bar is ... thus has a higher spring rate. But number 4 ... WTF?

Well ... The "return" arm coming off the sway-bar is a lever. The longer the lever, the more the LCA has to travel to exert the same amount of twist. So you can change the effective spring rate of a sway-bar by moving the pickup point for the end-links up and down the sway-bar returns. Adjustable swaybars have a variety of holes along the lenth of the return to alow for adjusting the relative swaybar rate

Is bigger always better ... well it is if you are a porn star ... but nessessarily for suspension

Sway-bars can be bad though when not matched to the overall spring rate of the suspension. If the suspensions spring rate is very low, and you have added a big bar to minimize body-roll, the swaybar has to work VERY hard to control the body roll, since the springs are not doing much. Because you are twisting the sway-bar a lot to control the body-roll the twisting is being transmitted into the chassis, putting a lot of stress on the chassis. This is what causes the ITR sway-bars to tear out of the rear sub-frame on many Civics.

The other issue with swaybars is that they increase the overall spring rate of the suspension under cornering ... Because the swaybar ONLY effects the suspension when both sides are loaded unevenly how do you choose an appropriate valving for your shocks ??? If you valve the shocks for the springs alone ... when the sway bar is effecting the suspension ... you are under damped, if you valve the shocks correcting for hte effect the swaybar has on the springs .. you are over damped when the sway bar is at rest. This can cause problems and unstability when the suspension is movement. So you want to pick a swaybar that complements or is with in the same rate range as your suspension.

When a big swaybar "overpowers" the valving of a shock, it can and will cause snap oversteer.


So the trick is to maximize the suspensions spring rate to get the handling characteristics you want, and then use the sway bar to tune the transitional characteristics you need. This way the shocks damping is the most effective it can be.


So at the end of the day an adjustable 32mm swaybar "MAY" not be overkill depending of the spring rates being used, and WHAT "rate" setting the swaybar is set to. In reality this particular bar is probably better suited for a track car based on the potential spring rate the swaybar represents.

You can go too big ... For example, on my old track car (EG Civic) when I was running f350#/r450# springs with Adj Koni's and a 22mm Rear bar the car was twitchy and had a tendancy to lift throttle oversteer (snap oversteer) as the bar was "too big" for that particular setup. When I moved upto f450#/r650# spring rates the car became much more balanced with the 22mm rear bar ... the rates between the springs and the swarbar were better matched to one another and to the valving of the dampers.


As a final note ... I have realy over simplified what is actually going on in a suspension system to make it easier to explain what is going on within a particular part.

[projectprelude]

insane price.... rofl

[PR_S14]

Wow. HUGE thanks for this info. It couldn't possibly make more sense.

[Moose]

If it is like the rest of their 32mm Kits like they have for the EP3, RSX, Teg EG EK etc it will be a complete kit with a full width brace, reinforcing backing plates, spherical endlinks, bushings, and all hardware.

So for the money it is actually not to bad ... considering what you get

I have used ASR products and they are top notch ... they have been installed them on a couple of friends Track ITR's

For more info ...
ASR - online

Moose

[PR_S14]

Lol, I was just going to mention this. I found a link comparing the price to the earlier civic kits which include the the additional brace and what not.

Pit Crew Motorsports

[Holland]

Originally Posted by Moose

Before I talk about sway bars we have to talk about springs ... in particular springs in a suspension ... because sway-bars are springs as well (torsion springs) and affect the suspension in a similar way to springs.


A spring resists movement ... as you compress it it resists and pushes the opposite direction ... When you apply a mass to the spring it compresses and "pushes back" in the opposite direction. Against the mass. So the spring is storing energy. When you compress the spring further it resists but ultimately compresses, equal to amount of mass applied. The amount of compression is based on the thickness of the spring wire, its metallic composition and the number or coils in the entire spring. The measure of spring compression (in length), caused by a particular mass is expressed as spring rate. Ie a 600lb/in spring requires 600# to compress the spring 1".




Well said...... But its JDM so it has to be better ... RIGHT????
Sway bars are a helping fix a larger problem.. too soft of a spring rate... that being said the progress bar is a great upgrade to hepl bring the car netrual.... but I would queston the need for a adj bar ... you can do the same with tire psi and preload...

So lets say you have a EG civic weighing about 2200 lbs. It is riding on 550 lb/in springs. For simplicity sake we will assume that the car has perfect 50/50 weight distribution (Civics are more like 60-40 in reality). So each spring holds 550 lbs (2200 divided by 4) The car's mass applies 550 lbs of downward force on each of the springs, and the spring apply 550 lbs of upward force resisting the mass, BUT there is 1" of spring droop due to the mass applied. The Spring now has 550 lbs of potential energy stored in it waiting to be released.

Now lets say you are driving the car and you hit a bump ... this bump compresses the spring a further 1" ... therefore an additional 550 lbs of mass (energy) have been applied to the spring. When you come off the bump moveing forward the cars mass tends to keep it going in a forward direction for a little while (relative to the wheels) till gravity causes it to drop down towards the earth.

It that moment when the wheel was un-weighted there was 1100 lbs (550 lbs or car mass and 550 lbs of bump compressed mass) in the spring .. the spring then moves VERY quickly to rid itself of its energy so it unwinds ..as it has a fair bit of energy it moves past its rest position (its length when there is not weight applied) and expands until the slowly depleting energy is counteracted by the spring resisting being expanded.

So now you have a spring that is stretched with lets say for example with 800 lbs of force ..as some of the energy has been depleted in expanding the spring. Since it still has Energy in it .. it moves in the opposite direction past the neutral position and it then starts to compress the spring ... until the energy applied equals the resistance in the spring ... and so on and so on

Soo the spring yo-yo's back and forwards till all the energy is dissipated by the spring (converted to heat) and it returns to its rest position.

Since the car is attached to the spring and it supports its weight ... this yoyo motion of the spring exerts itself on the car and causes the car to yoyo as a result.



Soooo in a nutshell ... the spring supports the cars weight and resists suspension movement, the amount the spring resists movement is a function of the spring rate (stiffness) .

The Less the body rolls and the weight transfers, the more "centered" the car is over the contact patch (the tires) thus the more traction the car has. Remember the ONLY contact the car has with the ground is the tires ... so we must always maximize the tires contact patch.

From this we can say that if you increase the spring rate you can reduce body roll and weight transfer thus improving traction. Well this is true to a point. The suspension has to have compliance (movement) in it so that the suspension follows the bumps and dips in the pavement. If you have NO suspension travel (infinite spring rate) then the tires would come off the ground on every bump ... well this is not good if you are trying to get traction. Also as you increase the spring rate the stiffness goes up and the comfort level goes down


So you want to increase the spring rate to the maximum that you can deal with (street) or the maximum that still allows for enough suspension travel for the road / track conditions that you are designing the car for.

Ok, so you have increased the spring rate to limit of what you are designing the car for ... and you still have to much body-roll / weight transfer ... so what is a boy to do ?



Well this is where sway-bars come in ... remember they are springs as well, BUT with a difference. Springs on a car are always "on' i.e. they are always affecting the car. Sway-bars differ from springs in one key area ... they have a variable effect on the suspension !!!!! This is the KEY part of the beauty of sway-bars.

So let's talk about sway-bars and how they work. A sway bar is a steel rod made of spring steel typically. The wall thickness, the overall diameter and the length of the "return" arms affect its resistance to twisting and thus its spring rate.

The sway-bar "rod" is attached to the chassis of the car, parallel to the lower control arms (LCA's) . It is attached with d-brackets and bushings allowing the bar to rotate easily and to slide a bit from left to right. There are two "arms" that come out at right angles to the bar, thus perpendicular to the bar and LCA's. There are end-links attaching the ends of the arms to the LCA's. Thus both sides of the suspension via the LCA's are connected together. So as one side of the suspension moves up ..it pulls the other side up as well. The Design of the swaybar dictates its spring rate and thus how much force it can exert on the opposite side of the suspension.

Under cornering, the car is leaning over, with one side of the suspension being pushed up while the other is drooping down. Because the two sides of the suspension are attached to one another via the sway-bay the sway-bar resists this difference in movement, pushing down the high-side and lifting up the low side. Since the sway-bar is attached to the car via the d-brackets on the chassis, the sway-bar twists the car and the suspension more level. Sooo the sway-bar ADDS to the over-all spring rate of the car ... under cornering ONLY !!!!!. The MORE the car leans over, the MORE the swaybar resists this movement.

If both arms move up at the same time, ie over a bump that both hit ... then the sway-bar has NO effect on the overall spring rate of the system.

This is the beauty of sway-bars, they allow you to minimize the amount of spring rate you require while maximizing the amount of resistance to body-roll and weight transfer while cornering.


Tuning

Ok, so now let's talk about tuning with sway-bars. We know the sway-bar is a torsion (twisting) spring. The spring rate of the sway-bar is determined by a couple of things.
1-The wall thickness of the sway-bar
2-The Diameter of the sway-bar
3-The metallic composition of the sway-bar
4-The length of the "return" arms.

1,2,and 3 make sense ... the beefier the bar is the stiffer the bar is ... thus has a higher spring rate. But number 4 ... WTF?

Well ... The "return" arm coming off the sway-bar is a lever. The longer the lever, the more the LCA has to travel to exert the same amount of twist. So you can change the effective spring rate of a sway-bar by moving the pickup point for the end-links up and down the sway-bar returns. Adjustable swaybars have a variety of holes along the lenth of the return to alow for adjusting the relative swaybar rate

Is bigger always better ... well it is if you are a porn star ... but nessessarily for suspension

Sway-bars can be bad though when not matched to the overall spring rate of the suspension. If the suspensions spring rate is very low, and you have added a big bar to minimize body-roll, the swaybar has to work VERY hard to control the body roll, since the springs are not doing much. Because you are twisting the sway-bar a lot to control the body-roll the twisting is being transmitted into the chassis, putting a lot of stress on the chassis. This is what causes the ITR sway-bars to tear out of the rear sub-frame on many Civics.

The other issue with swaybars is that they increase the overall spring rate of the suspension under cornering ... Because the swaybar ONLY effects the suspension when both sides are loaded unevenly how do you choose an appropriate valving for your shocks ??? If you valve the shocks for the springs alone ... when the sway bar is effecting the suspension ... you are under damped, if you valve the shocks correcting for hte effect the swaybar has on the springs .. you are over damped when the sway bar is at rest. This can cause problems and unstability when the suspension is movement. So you want to pick a swaybar that complements or is with in the same rate range as your suspension.

When a big swaybar "overpowers" the valving of a shock, it can and will cause snap oversteer.


So the trick is to maximize the suspensions spring rate to get the handling characteristics you want, and then use the sway bar to tune the transitional characteristics you need. This way the shocks damping is the most effective it can be.


So at the end of the day an adjustable 32mm swaybar "MAY" not be overkill depending of the spring rates being used, and WHAT "rate" setting the swaybar is set to. In reality this particular bar is probably better suited for a track car based on the potential spring rate the swaybar represents.

You can go too big ... For example, on my old track car (EG Civic) when I was running f350#/r450# springs with Adj Koni's and a 22mm Rear bar the car was twitchy and had a tendancy to lift throttle oversteer (snap oversteer) as the bar was "too big" for that particular setup. When I moved upto f450#/r650# spring rates the car became much more balanced with the 22mm rear bar ... the rates between the springs and the swarbar were better matched to one another and to the valving of the dampers.


As a final note ... I have realy over simplified what is actually going on in a suspension system to make it easier to explain what is going on within a particular part.