Sway bar size resource for Honda and Acura vehicles.
#1
Live for the Twisties
Administrator
Thread Starter
Join Date: Jun 2010
Location: Langley, BC
Posts: 8,580
Likes: 0
Received 5 Likes
on
5 Posts
Rep Power: 260 Sway bar size resource for Honda and Acura vehicles.
Sway bar and subframe brace options for 7th Gen Civics
Rear sway bars and subframe braces are interchangeable between all DC5 sub-models and years, all EP3 sub-models and years and EM2, ES1, ES2 and ES3 models. Not all front sway bars are interchangeable between models due to clearance issues.
OEM
Front:
Rear:
DC5-R -22mm diameter a subframe brace may be required
DC5-S (05-06) - 21mm
DC5 (02-06) DC5-S (02-04) - 19mm
EP3 (05) - 17mm
EP3 (02-04) - 15mm
Reviews:
Notes:
Progress
Front:
27mm
Rear:
22mm non-adjustable
24mm adjustable
Reviews:
Notes:
Polyurathane bushings, endlinks and subframe brace included with rear sway bars.
Hotchkis
Front:
Competition - 25.4mm hollow - 2 position adjustable +59% and +71%
Rear:
Competition - 27mm hollow - 2 position adjustable +202% and +220%
Review:
Notes:
ASR
Front:
Rear:
32mm
Review:
Notes:
Largest sway bar currently made for our chassis.
Mugen
Front:
25.4mm x 3.5mm wall
25.4mm x 4.5mm wall
24.2mm x 3.0mm wall
Rear:
25mm
24mm
Review:
Notes:
Largest "street" sway bar available for our chassis.
Eibach
Front:
25mm
Rear:
DC5 Specification - 23mm
Review:
Notes:
Whiteline
Front:
24mm
Rear:
24mm Adjustable
Review:
Notes:
Tanabe
Front:
27.5mm
Rear:
22mm
Review:
Notes:
H&R
Front:
26mm adjustable
Rear:
20mm
Reviews:
Notes:
Toda
Front:
25mm
Rear:
Reviews:
Notes:
Swift
Front:
OEM Type-R diameter?
Rear:
OEM Type-R diameter?
Reviews:
Notes:
Available in 119% or 130% stiffer than stock
Cusco
Front:
26mm adjustable
Rear:
25mm
Reviews:
Notes:
Ultra Racing
Front:
25mm
Rear:
25mm
Reviews:
Notes:
Ultra Racing offers braces for every area of a DC5, including fender and side braces, how many of said braces could be used on a Civic is unknown. Most of them are likely useless, unless your very serious about racing and are looking to improve lap times by under a thousandth of a second.
http://www.ultraracing.com.my/Bars.asp?ID=4361
Ebay Brand
Front:
Rear:
22mm
Reviews:
Notes:
Cheap! Ebay brand, only $80 shipped for subframe brace and sway bar, but supposedly full chromemoly construction. Quality may be questionable as is the case with all ebay brand parts.
Sway Bar Related DIYs:
Rear Progress sway bar install w/ 01 LX mounting kit
https://www.civicforums.com/forums/4...nting-kit.html
Energy Suspension sway bar bushings
https://www.civicforums.com/forums/4...-bushings.html
General Sway Bar Information:
[/B]Removing front sway bar
https://www.civicforums.com/forums/4...pros-cons.html
What rear sway bar to choose discussion
https://www.civicforums.com/forums/2...sway-bars.html
Rear sway bars and subframe braces are interchangeable between all DC5 sub-models and years, all EP3 sub-models and years and EM2, ES1, ES2 and ES3 models. Not all front sway bars are interchangeable between models due to clearance issues.
OEM
Front:
Rear:
DC5-R -22mm diameter a subframe brace may be required
DC5-S (05-06) - 21mm
DC5 (02-06) DC5-S (02-04) - 19mm
EP3 (05) - 17mm
EP3 (02-04) - 15mm
Reviews:
Notes:
Progress
Front:
27mm
Rear:
22mm non-adjustable
24mm adjustable
Reviews:
Notes:
Polyurathane bushings, endlinks and subframe brace included with rear sway bars.
Hotchkis
Front:
Competition - 25.4mm hollow - 2 position adjustable +59% and +71%
Rear:
Competition - 27mm hollow - 2 position adjustable +202% and +220%
Review:
Notes:
ASR
Front:
Rear:
32mm
Review:
Notes:
Largest sway bar currently made for our chassis.
Mugen
Front:
25.4mm x 3.5mm wall
25.4mm x 4.5mm wall
24.2mm x 3.0mm wall
Rear:
25mm
24mm
Review:
Originally Posted by QKSLVER03@acuraworld
The difference is unreal. The car handles much better now, it corners like it's on rails dude.
Largest "street" sway bar available for our chassis.
Eibach
Front:
25mm
Rear:
DC5 Specification - 23mm
Review:
Notes:
Whiteline
Front:
24mm
Rear:
24mm Adjustable
Review:
Notes:
Tanabe
Front:
27.5mm
Rear:
22mm
Review:
Notes:
Originally Posted by Tanabe
Unique to the Sustec Stabilizer is it's FULL CHROMEMOLY steel alloy construction. Chromemoly's strength is such that a small diameter chromemoly anti-swaybar is significantly stronger than the standard steel anti-swaybars that are larger in diameter.
Front:
26mm adjustable
Rear:
20mm
Reviews:
Notes:
Originally Posted by H&R
H&R Sport Sway Bars are crafted from a special (hf) 50CrV4 steel alloy%u2014the highest tensile strength available.
Front:
25mm
Rear:
Reviews:
Notes:
Originally Posted by Toda
The Toda 25mm front swaybar is available exclusively for the US RSX. This is the same swaybar developed for use with the Toda Racing RSX exhaust manifold. It features a large, exhaust manifold pass through opening, and is compatible with most JDM or non-JDM headers that rub against or make contact the stock sway bar. This unit can also be used as a performance swaybar upgrade. Sway bar bushings and brackets are included.
Swift
Front:
OEM Type-R diameter?
Rear:
OEM Type-R diameter?
Reviews:
Notes:
Available in 119% or 130% stiffer than stock
Cusco
Front:
26mm adjustable
Rear:
25mm
Reviews:
Notes:
Ultra Racing
Front:
25mm
Rear:
25mm
Reviews:
Notes:
Ultra Racing offers braces for every area of a DC5, including fender and side braces, how many of said braces could be used on a Civic is unknown. Most of them are likely useless, unless your very serious about racing and are looking to improve lap times by under a thousandth of a second.
http://www.ultraracing.com.my/Bars.asp?ID=4361
Ebay Brand
Front:
Rear:
22mm
Reviews:
Notes:
Cheap! Ebay brand, only $80 shipped for subframe brace and sway bar, but supposedly full chromemoly construction. Quality may be questionable as is the case with all ebay brand parts.
Function 7
Rear Progress sway bar install w/ 01 LX mounting kit
https://www.civicforums.com/forums/4...nting-kit.html
Energy Suspension sway bar bushings
https://www.civicforums.com/forums/4...-bushings.html
General Sway Bar Information:
[/B]Removing front sway bar
https://www.civicforums.com/forums/4...pros-cons.html
What rear sway bar to choose discussion
https://www.civicforums.com/forums/2...sway-bars.html
This is rough, please post up corrections and I will update accordingly.
Acura Vehicle
Model..................Years.........Front........ ....Rear
1.6EL...................97-00........24.0mm........14.0mm
1.7EL...................01.............25.4mm..... ...12.0mm
1.7EL...................02-04........23.0mm........13.0mm
1.7EL...................05.............25.4mm..... ...13.0mm
CL / TL.................02-03........27.2mm.......18.0mm
CL / TL Type S......02-03.........27.2mm.......19.0mm Swap the rear into 98-00 Accord
Integra GS-R.........94-01.........24.0mm......14.0mm
Integra Type R......94-01.........24.0mm.......22.0mm Swap the rear into 92-00 Civic/EL
MDX....................02-05.........23.0mm.......20.0mm
NSX.....................02-03.........28.6mm.......19.1mm
NSX.....................04-05..........18.3mm......19.1mm
RL.......................02-04..........30.0mm......21.0mm
RL.......................05...............29.0mm.. ....17.0mm
DC5 Type S..........02-04...........24.0mm......21.0mm Swap rear into 01-05 Civic/EL
DC5....................02-05...........23.0mm......19.0mm hollow Swap rear into 01-05 Civic/EL
TL......................04-05..........25.4mm.......17.0mm
TSX....................04-05...........25.4mm......15.0mm
Honda Vehicles
Model (Trim)........Years............Front...........Rea r
Accord (V6).........05................25.4mm.......13.0mm
Accord (I4)..........05................25.4mm.......14.0m m
EM2/ES1...................01-05...........15.9mm.......12.0mm
EM2/ES1 (EX/Si only)...........01-?.............25.4mm........
EP3.................03-04...........25.4mm.......15.0mm hollow
EP3.................05................25.4mm...... .17.0mm hollow
Civic (Si).............88-91...........18.0mm........15.0mm
Civic...................88-91...........17.0mm........13.0mm
Civic...................92-95...........21.0mm.........No rear bar.
Civic (Si/SiR)........92-95...........22.0mm.........No rear bar.
Civic...................96-00...........22.0mm.........No rear bar.
Civic (Si/SiR)........96-00...........26.0mm.........13.0mm
CR-V...................02-04...........27.2mm.........18.0mm
CR-V...................05...............27.2mm....... ..14.0mm
CR-V...................97-01...........26.0mm........13.0mm
Insight.................00-04...........17.3mm.........No rear bar.
S2000..................04-05..........26.5mm..........25.4mm
Models not available in USDM or CDM markets.
Model (Trim)........Year...............Front............ .Rear
Civic (Type R)......99-00.............22.0mm...........? Swap into USDM 92-00 Civic/EL
RacingIntegra (Type R)...05.................22.0mm...........? Swap into USDM 01+ Civic/EL & RSX
Acura Vehicle
Model..................Years.........Front........ ....Rear
1.6EL...................97-00........24.0mm........14.0mm
1.7EL...................01.............25.4mm..... ...12.0mm
1.7EL...................02-04........23.0mm........13.0mm
1.7EL...................05.............25.4mm..... ...13.0mm
CL / TL.................02-03........27.2mm.......18.0mm
CL / TL Type S......02-03.........27.2mm.......19.0mm Swap the rear into 98-00 Accord
Integra GS-R.........94-01.........24.0mm......14.0mm
Integra Type R......94-01.........24.0mm.......22.0mm Swap the rear into 92-00 Civic/EL
MDX....................02-05.........23.0mm.......20.0mm
NSX.....................02-03.........28.6mm.......19.1mm
NSX.....................04-05..........18.3mm......19.1mm
RL.......................02-04..........30.0mm......21.0mm
RL.......................05...............29.0mm.. ....17.0mm
DC5 Type S..........02-04...........24.0mm......21.0mm Swap rear into 01-05 Civic/EL
DC5....................02-05...........23.0mm......19.0mm hollow Swap rear into 01-05 Civic/EL
TL......................04-05..........25.4mm.......17.0mm
TSX....................04-05...........25.4mm......15.0mm
Honda Vehicles
Model (Trim)........Years............Front...........Rea r
Accord (V6).........05................25.4mm.......13.0mm
Accord (I4)..........05................25.4mm.......14.0m m
EM2/ES1...................01-05...........15.9mm.......12.0mm
EM2/ES1 (EX/Si only)...........01-?.............25.4mm........
EP3.................03-04...........25.4mm.......15.0mm hollow
EP3.................05................25.4mm...... .17.0mm hollow
Civic (Si).............88-91...........18.0mm........15.0mm
Civic...................88-91...........17.0mm........13.0mm
Civic...................92-95...........21.0mm.........No rear bar.
Civic (Si/SiR)........92-95...........22.0mm.........No rear bar.
Civic...................96-00...........22.0mm.........No rear bar.
Civic (Si/SiR)........96-00...........26.0mm.........13.0mm
CR-V...................02-04...........27.2mm.........18.0mm
CR-V...................05...............27.2mm....... ..14.0mm
CR-V...................97-01...........26.0mm........13.0mm
Insight.................00-04...........17.3mm.........No rear bar.
S2000..................04-05..........26.5mm..........25.4mm
Models not available in USDM or CDM markets.
Model (Trim)........Year...............Front............ .Rear
Civic (Type R)......99-00.............22.0mm...........? Swap into USDM 92-00 Civic/EL
RacingIntegra (Type R)...05.................22.0mm...........? Swap into USDM 01+ Civic/EL & RSX
Last edited by MindBomber; 03-05-2011 at 06:56 PM.
#3
Administrator
Hey! Look At Me!! I'm a Supporting Member!!
Administrator
iTrader: (22)
Join Date: Aug 2003
Location: Las Vegas, NV
Age: 39
Posts: 21,450
Received 1,144 Likes
on
799 Posts
Rep Power: 485 Re: Sway bar size resource for Honda and Acura vehicles.
Doesn't the RSX-S have a 22mm rear? Or only the RSX-R?
#4
Live for the Twisties
Administrator
Thread Starter
Join Date: Jun 2010
Location: Langley, BC
Posts: 8,580
Likes: 0
Received 5 Likes
on
5 Posts
Rep Power: 260 Re: Sway bar size resource for Honda and Acura vehicles.
I'm pretty sure only the RSX type-R has the 22mm rear, thats why it won't work on our civics..
#5
Administrator
Hey! Look At Me!! I'm a Supporting Member!!
Administrator
iTrader: (22)
Join Date: Aug 2003
Location: Las Vegas, NV
Age: 39
Posts: 21,450
Received 1,144 Likes
on
799 Posts
Rep Power: 485 Re: Sway bar size resource for Honda and Acura vehicles.
I thought I heard of people putting an rsx 22mm rear on the em2/es1
I'll look into that
edit: 05-06 RSX-S has a 21mm bar that works on the em2/es1
I'll look into that
edit: 05-06 RSX-S has a 21mm bar that works on the em2/es1
Last edited by xRiCeBoYx; 02-13-2011 at 12:36 AM.
#7
Banished to the Depths of Rice.
iTrader: (3)
Join Date: Jun 2005
Location: SoCal 714/909/626
Posts: 9,196
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 328 Re: Sway bar size resource for Honda and Acura vehicles.
so its a direct swap for the 19mm rsx?
do i need to replace those bushings or anything?
do i need to replace those bushings or anything?
#8
Administrator
Hey! Look At Me!! I'm a Supporting Member!!
Administrator
iTrader: (22)
Join Date: Aug 2003
Location: Las Vegas, NV
Age: 39
Posts: 21,450
Received 1,144 Likes
on
799 Posts
Rep Power: 485 Re: Sway bar size resource for Honda and Acura vehicles.
You need the brackets and rubber bushings to accommodate the larger diameter. Otherwise a direct swap.
#9
PITA Admin
Administrator
iTrader: (1)
Join Date: Dec 2008
Location: TN
Age: 52
Posts: 14,779
Received 1,440 Likes
on
1,196 Posts
Rep Power: 338
#12
Live for the Twisties
Administrator
Thread Starter
Join Date: Jun 2010
Location: Langley, BC
Posts: 8,580
Likes: 0
Received 5 Likes
on
5 Posts
Rep Power: 260 Re: Sway bar size resource for Honda and Acura vehicles.
^a junk yard, its just a solid piece of metal so there would be no benefit to buying a new one.
#14
Premium Member
Hey! Look At Me!! I'm a Supporting Member!!
iTrader: (95)
Join Date: Sep 2002
Location: NV
Age: 43
Posts: 51,241
Likes: 0
Received 18 Likes
on
13 Posts
Rep Power: 787 Re: Sway bar size resource for Honda and Acura vehicles.
lots of info missing for 01-05 civic. there are like 5 different sizes of swaybar depending on the year and also the model.
#15
Live for the Twisties
Administrator
Thread Starter
Join Date: Jun 2010
Location: Langley, BC
Posts: 8,580
Likes: 0
Received 5 Likes
on
5 Posts
Rep Power: 260 Re: Sway bar size resource for Honda and Acura vehicles.
^I noticed that there are some errors and omissions right away, but I haven't had time to research and make corrections. Feel free to edit my post with the any information you have Steve.
#19
Live for the Twisties
Administrator
Thread Starter
Join Date: Jun 2010
Location: Langley, BC
Posts: 8,580
Likes: 0
Received 5 Likes
on
5 Posts
Rep Power: 260 Re: Sway bar size resource for Honda and Acura vehicles.
Post up the corrections and myself or another Mod can make the changes, like I said, I stole this from another site and its far from perfect. I just don't have time to research correct it all myself at the moment.
#21
PITA Admin
Administrator
iTrader: (1)
Join Date: Dec 2008
Location: TN
Age: 52
Posts: 14,779
Received 1,440 Likes
on
1,196 Posts
Rep Power: 338 Re: Sway bar size resource for Honda and Acura vehicles.
Should we place the aftermarket ones here too?
Like eibach for 01-05
F/R 26/16, rear 2 hole adjustment, solid - Hx, Lx, Dx & Gx models require OEM Ex trailing arm, end links, bushing brackets and bolts for installing rear.
H&R
F/R 26/20, front adjustable, solid, same comments for non-EX models - balance F/R is better than the eibach
Like eibach for 01-05
F/R 26/16, rear 2 hole adjustment, solid - Hx, Lx, Dx & Gx models require OEM Ex trailing arm, end links, bushing brackets and bolts for installing rear.
H&R
F/R 26/20, front adjustable, solid, same comments for non-EX models - balance F/R is better than the eibach
Last edited by sdaidoji; 04-09-2011 at 09:54 AM.
#22
PITA Admin
Administrator
iTrader: (1)
Join Date: Dec 2008
Location: TN
Age: 52
Posts: 14,779
Received 1,440 Likes
on
1,196 Posts
Rep Power: 338 Re: Sway bar size resource for Honda and Acura vehicles.
I also came across this good theory
By anfrey clubcivic
note: i do not take credit for this. this information was posted elsewhere before.
S W A Y B A R F A Q
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
How do sway bars work, and how can you use them to tune your car’s suspension? Most performance people know that stiffer rear sway bars reduce the understeering tendencies of a vehicle, but if you ask them exactly why this is they generally draw a blank. Usually they know the results, but not the reasons behind chassis tuning. This article is intended to answer those questions as well as give readers a better understanding of what goes on in your suspension when you take a corner. First, let's get an understanding of what lateral weight transfer is, because this will help you understand exactly how sway bars work to tune the balance of the chassis.
Lateral weight transfer is a function of three things:
-overall weight of car
-height of the Cg (center of gravity)
-track width (this is the distance between the vertical centerlines of each tire on an axle, and many times track width is different on each axle)
So the first thing to notice here is that spring rate IS NOT a primary determinate in how much weight is transferred laterally on a car for a given amount of steering input. This is something many people have a hard time swallowing, but nevertheless it is true. All the springs primarily do is determine how much the suspension will compress or expand due to this weight transfer.
BODY ROLL
So why is body roll bad? Two reasons:
#1- it screws up the camber angle of the tires to the road, plus throws off other suspension settings
#2- it unsettles the driver
Next, you need to know that the principle way you control body roll is through spring rates. And here's where we encounter the problem of not being able to change the static spring rates between cornering maneuvers and just going straight. To show a quick example of this:
- Say the amount of body roll during a corner is 10 degrees for a spring rate of 500 lbs. If you wanted to halve this amount of roll, you would need to roughly double the spring rate to accomplish it. Now we already know that limiting body roll can improve handling (depending on circumstances and suspension setup), but running a spring that stiff will cause the car to be so bouncy that the tire will rarely be in good contact with the ground, unless the road is perfectly smooth. So how can we selectively increase spring rates only under cornering so that our straight line stability & tire to road contact is not compromised by really stiff springs? The sway bar is the answer.
Now it should be stated here what sway bars essentially do, even though I know you may already know this. What a sway bar does is counteract the action of body roll during cornering by transferring spring rate from the inside wheel to the outside wheel in a corner. This means that you don't actually get any added spring rate; you just subtract it from one side and add it to the other. This has the ultimate effect of transferring load from the inside tire to the outside, which has the visual effect of compressing the suspension on the inside of the turn and expanding the suspension on the outside of the turn (thus limiting body roll). This is good mainly because it smoothes the speed of weight transfer during quick transitions and also limits the camber change experienced at the corners of the car through suspension travel. And of course, using this concept one can dial in the amount of total loading on the outside tire by varying the effectiveness of the sway bar (stiffer bars equal more transfer). And the beauty of all this is that it mostly only occurs during cornering, so our straight line spring rates are not affected. The other thing Ok, so hopefully now you all understand this concept. This is the most important part though, so if anything is still fuzzy read this again until you get it. Also, here's an example of how this works:
-For this example we will use a sway bar with a roll stiffness of 250 lbs.
Left front static load: 1000lbs
Right front static load: 1000lbs
-lateral weight transfer in a right hand turn
Left front: + 500lbs
Right front: - 500lbs
Total weight transfer: 1000lbs
-load transfer of sway bar(which is 250 lbs):
Left front: +250lbs
Right front: -250lbs
Total weight transfer: 1000lbs
-total effective cornering load for this example:
Left front: 1000 + 750= 1750lbs
Right front: 1000 - 750= 250lbs
-without sway bar
Left front: 1000 + 500= 1500lbs
Right front: 1000 - 500= 500lbs
----------------------------------------------------------
Alright, now we are coming into the home stretch of this learning curve. You need to know that although you cannot control the total amount of lateral weight transfer during cornering (as I stated earlier), you CAN have some control over how it is distributed on each axle. Looking at the above example, you see that with or without the sway bar involved, total weight transfer change is always 1000 lbs. You can't change this amount, but you can re-distribute it along the axle. And this is a function of spring rates entirely, which we now know is best controlled during cornering through the use of sway bars.
So how does one control the balance of a car when armed with this knowledge? It's actually very simple at this point, if you understand that increasing tire loading adds to the total amount of traction available from it, but this relationship is NOT linear. The more load on the tire, the more traction available, but the amount of traction gained diminishes as load increases. So at first it's almost a direct "you add 250lbs of load, you get 250lbs of extra traction", but at 1000lbs of load, you might only get 800lbs of extra traction. Knowing this, look at the example I gave of the sway bar at work. Since it transfers load away from the inside tire, you lose traction there. Although it transfers this load to the outside tire, it is already quite loaded and therefore the 250lbs of load will not increase overall traction by 250lbs. More like maybe 150lbs. Now the inside tire, being much less loaded, could have gained more like 220lbs or traction from the 250lbs of load. So look at what we have in the end: although the outside tires already do most of the work, adding a sway bar actually lowers the total amount of traction available at this end of the car by increasing the difference in load distribution. And the stiffer that sway bar is, the more it will limit the total traction available at that end.
So, to make a really long post short (again, sorry), what we end up with is the knowledge that weight transfer ultimately lowers the total amount of traction available at each end of the car. This is why the more we can limit total weight transfer (by increasing track, lowering the Cg height, or lowering overall vehicle weight) the more total traction will be available. But for the purposes of this post, we are explaining how sway bar sizing (which directly reflects it's roll stiffness amount) cures an unbalanced car. If a car is understeering, it's because the rear end has more total traction than the front. If you put a big sway bar on the rear suspension to limit the total amount of traction available there (by maximizing the amount of load transfer to the outside wheel), you can dial it in to match the front suspension's total available traction. And when we get really smart, we start to match the front & rear bars to one another to achieve the best balance through the largest possible range of suspension movement.
**NOTE**: This is a primer on the vehicle dynamics governing roll stiffness and it’s effects on cornering balance, NOT a purely scientific explanation of this. Some forces at work have been left out for simplicity, the point with these posts is to gain a basic understanding of what’s going on when you enter a corner, not be able to design your own suspension system
__________________
By special ED clubcivic
Here is another good article that explains all the basics about sway bars -
http://www.grmotorsports.com/swaybars.html
The only missing sidetopic is the effect of lost bar rate/degraded feedback feel from swaybar pivot bushing and endlink bushing deflection/squish. Basically, if the rubber bushings that provide the pivot points for the bar or the rubber cushioning endlink bushings are too soft or damaged, you will not get as much force as the bar could be applying because it is being absorbed by movement or deflection at those mounting points. A solution that eliminates endlink play and bar deflection are Heim joints and spherical bearings rather than soft bushings, at a sacrifice of the desired NVH control of course.
Also, with soft bar mounts, the driver will possibly sense that the car is "softer" than it actually is, which usually causes loss of confidence in the car's cornering capabilities. This is important because in competitive driving, either on the autocross course or on the track, the mental aspect is significant. If the driver has the confidence in the vehicle, he will tend to push harder (and go faster) than if the car feels squishy or is bodyrolling more than desired.
By anfrey clubcivic
note: i do not take credit for this. this information was posted elsewhere before.
S W A Y B A R F A Q
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
How do sway bars work, and how can you use them to tune your car’s suspension? Most performance people know that stiffer rear sway bars reduce the understeering tendencies of a vehicle, but if you ask them exactly why this is they generally draw a blank. Usually they know the results, but not the reasons behind chassis tuning. This article is intended to answer those questions as well as give readers a better understanding of what goes on in your suspension when you take a corner. First, let's get an understanding of what lateral weight transfer is, because this will help you understand exactly how sway bars work to tune the balance of the chassis.
Lateral weight transfer is a function of three things:
-overall weight of car
-height of the Cg (center of gravity)
-track width (this is the distance between the vertical centerlines of each tire on an axle, and many times track width is different on each axle)
So the first thing to notice here is that spring rate IS NOT a primary determinate in how much weight is transferred laterally on a car for a given amount of steering input. This is something many people have a hard time swallowing, but nevertheless it is true. All the springs primarily do is determine how much the suspension will compress or expand due to this weight transfer.
BODY ROLL
So why is body roll bad? Two reasons:
#1- it screws up the camber angle of the tires to the road, plus throws off other suspension settings
#2- it unsettles the driver
Next, you need to know that the principle way you control body roll is through spring rates. And here's where we encounter the problem of not being able to change the static spring rates between cornering maneuvers and just going straight. To show a quick example of this:
- Say the amount of body roll during a corner is 10 degrees for a spring rate of 500 lbs. If you wanted to halve this amount of roll, you would need to roughly double the spring rate to accomplish it. Now we already know that limiting body roll can improve handling (depending on circumstances and suspension setup), but running a spring that stiff will cause the car to be so bouncy that the tire will rarely be in good contact with the ground, unless the road is perfectly smooth. So how can we selectively increase spring rates only under cornering so that our straight line stability & tire to road contact is not compromised by really stiff springs? The sway bar is the answer.
Now it should be stated here what sway bars essentially do, even though I know you may already know this. What a sway bar does is counteract the action of body roll during cornering by transferring spring rate from the inside wheel to the outside wheel in a corner. This means that you don't actually get any added spring rate; you just subtract it from one side and add it to the other. This has the ultimate effect of transferring load from the inside tire to the outside, which has the visual effect of compressing the suspension on the inside of the turn and expanding the suspension on the outside of the turn (thus limiting body roll). This is good mainly because it smoothes the speed of weight transfer during quick transitions and also limits the camber change experienced at the corners of the car through suspension travel. And of course, using this concept one can dial in the amount of total loading on the outside tire by varying the effectiveness of the sway bar (stiffer bars equal more transfer). And the beauty of all this is that it mostly only occurs during cornering, so our straight line spring rates are not affected. The other thing Ok, so hopefully now you all understand this concept. This is the most important part though, so if anything is still fuzzy read this again until you get it. Also, here's an example of how this works:
-For this example we will use a sway bar with a roll stiffness of 250 lbs.
Left front static load: 1000lbs
Right front static load: 1000lbs
-lateral weight transfer in a right hand turn
Left front: + 500lbs
Right front: - 500lbs
Total weight transfer: 1000lbs
-load transfer of sway bar(which is 250 lbs):
Left front: +250lbs
Right front: -250lbs
Total weight transfer: 1000lbs
-total effective cornering load for this example:
Left front: 1000 + 750= 1750lbs
Right front: 1000 - 750= 250lbs
-without sway bar
Left front: 1000 + 500= 1500lbs
Right front: 1000 - 500= 500lbs
----------------------------------------------------------
Alright, now we are coming into the home stretch of this learning curve. You need to know that although you cannot control the total amount of lateral weight transfer during cornering (as I stated earlier), you CAN have some control over how it is distributed on each axle. Looking at the above example, you see that with or without the sway bar involved, total weight transfer change is always 1000 lbs. You can't change this amount, but you can re-distribute it along the axle. And this is a function of spring rates entirely, which we now know is best controlled during cornering through the use of sway bars.
So how does one control the balance of a car when armed with this knowledge? It's actually very simple at this point, if you understand that increasing tire loading adds to the total amount of traction available from it, but this relationship is NOT linear. The more load on the tire, the more traction available, but the amount of traction gained diminishes as load increases. So at first it's almost a direct "you add 250lbs of load, you get 250lbs of extra traction", but at 1000lbs of load, you might only get 800lbs of extra traction. Knowing this, look at the example I gave of the sway bar at work. Since it transfers load away from the inside tire, you lose traction there. Although it transfers this load to the outside tire, it is already quite loaded and therefore the 250lbs of load will not increase overall traction by 250lbs. More like maybe 150lbs. Now the inside tire, being much less loaded, could have gained more like 220lbs or traction from the 250lbs of load. So look at what we have in the end: although the outside tires already do most of the work, adding a sway bar actually lowers the total amount of traction available at this end of the car by increasing the difference in load distribution. And the stiffer that sway bar is, the more it will limit the total traction available at that end.
So, to make a really long post short (again, sorry), what we end up with is the knowledge that weight transfer ultimately lowers the total amount of traction available at each end of the car. This is why the more we can limit total weight transfer (by increasing track, lowering the Cg height, or lowering overall vehicle weight) the more total traction will be available. But for the purposes of this post, we are explaining how sway bar sizing (which directly reflects it's roll stiffness amount) cures an unbalanced car. If a car is understeering, it's because the rear end has more total traction than the front. If you put a big sway bar on the rear suspension to limit the total amount of traction available there (by maximizing the amount of load transfer to the outside wheel), you can dial it in to match the front suspension's total available traction. And when we get really smart, we start to match the front & rear bars to one another to achieve the best balance through the largest possible range of suspension movement.
**NOTE**: This is a primer on the vehicle dynamics governing roll stiffness and it’s effects on cornering balance, NOT a purely scientific explanation of this. Some forces at work have been left out for simplicity, the point with these posts is to gain a basic understanding of what’s going on when you enter a corner, not be able to design your own suspension system
__________________
By special ED clubcivic
Here is another good article that explains all the basics about sway bars -
http://www.grmotorsports.com/swaybars.html
The only missing sidetopic is the effect of lost bar rate/degraded feedback feel from swaybar pivot bushing and endlink bushing deflection/squish. Basically, if the rubber bushings that provide the pivot points for the bar or the rubber cushioning endlink bushings are too soft or damaged, you will not get as much force as the bar could be applying because it is being absorbed by movement or deflection at those mounting points. A solution that eliminates endlink play and bar deflection are Heim joints and spherical bearings rather than soft bushings, at a sacrifice of the desired NVH control of course.
Also, with soft bar mounts, the driver will possibly sense that the car is "softer" than it actually is, which usually causes loss of confidence in the car's cornering capabilities. This is important because in competitive driving, either on the autocross course or on the track, the mental aspect is significant. If the driver has the confidence in the vehicle, he will tend to push harder (and go faster) than if the car feels squishy or is bodyrolling more than desired.
#23
Autocross Padawan
iTrader: (2)
Join Date: Aug 2009
Location: CT
Posts: 601
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 186 Re: Sway bar size resource for Honda and Acura vehicles.
JDM Universe also has an excellent thread on this -- It's complete with pictures and a compatibility list:
http://www.jdmuniverse.com/forums/ho...formation.html
Front Lower Control Arm compatibility:
Civic EX and HX front LCAs should be used when adding or upgrading to:
- 1992-1995 Civic Si
- 1992-2000 Civic EX
- 1994-1997 del Sol DOHC
- 1996-2000 Civic HX
- 1994-2001 Integra LS
- 1994-2001 Intagra GSR
- 1996-2001 Integra Type R
Civic Si front LCAs* should be used when adding or upgrading to:
- 1999-2000 Civic Si
- 1997-2000 Civic Type R
If you already have an EX/HX LCA and would like to upgrade to the Civic Si or Civic Type R front bar, you can do so using Integra Type R endlinks documented below.
*Civic Si front shock forks need to be used as well when upgrading to the Civic Si/Civic Type R front lower control arms.
Front Endlink compaibilty:
Please note, aftermarket bushing kits should be purchased for the following endlink kits given the sway being added/upgraded to.
Civic EX and HX sway bar endlinks should be used when adding:
- 1992-1995 Civic Si
- 1992-2000 Civic EX
- 1994-1997 del Sol DOHC
- 1996-2000 Civic HX
- 1994-2001 Integra LS
- 1994-2001 Integra GSR
The EX and HX endlinks are vertical bolts with bushings that come straight down through the sway bar and then through the LCA. The holes for both go horizontally, parallel to the ground.
Source: jdmuniverse.com
http://www.jdmuniverse.com/forums/ho...formation.html
Front Lower Control Arm compatibility:
Civic EX and HX front LCAs should be used when adding or upgrading to:
- 1992-1995 Civic Si
- 1992-2000 Civic EX
- 1994-1997 del Sol DOHC
- 1996-2000 Civic HX
- 1994-2001 Integra LS
- 1994-2001 Intagra GSR
- 1996-2001 Integra Type R
Civic Si front LCAs* should be used when adding or upgrading to:
- 1999-2000 Civic Si
- 1997-2000 Civic Type R
If you already have an EX/HX LCA and would like to upgrade to the Civic Si or Civic Type R front bar, you can do so using Integra Type R endlinks documented below.
*Civic Si front shock forks need to be used as well when upgrading to the Civic Si/Civic Type R front lower control arms.
Front Endlink compaibilty:
Please note, aftermarket bushing kits should be purchased for the following endlink kits given the sway being added/upgraded to.
Civic EX and HX sway bar endlinks should be used when adding:
- 1992-1995 Civic Si
- 1992-2000 Civic EX
- 1994-1997 del Sol DOHC
- 1996-2000 Civic HX
- 1994-2001 Integra LS
- 1994-2001 Integra GSR
The EX and HX endlinks are vertical bolts with bushings that come straight down through the sway bar and then through the LCA. The holes for both go horizontally, parallel to the ground.
Source: jdmuniverse.com
#24
Re: Sway bar size resource for Honda and Acura vehicles.
i noticed looking up at the top with your models and years and listings that you have the si and sir together. isn't the sir the Canadian ex?
#25
Re: Sway bar size resource for Honda and Acura vehicles.
i have a 97 ex so that means my front is 22mm right? also when looking for an upgrade most of the ones that i come across are about 24mm, do i go off of how thick they are or what their roll stiffness is. and if you have any good suggestions of a front and rear bar for mine i'm all ears!
#26
PITA Admin
Administrator
iTrader: (1)
Join Date: Dec 2008
Location: TN
Age: 52
Posts: 14,779
Received 1,440 Likes
on
1,196 Posts
Rep Power: 338 Re: Sway bar size resource for Honda and Acura vehicles.
I re-read the thread and realize that this important piece of info is actually missing here...
Our cars, FWD, will benefit a lot from REAR sway bar. installing a beefier FRONT sway bar will just make your front tires squeal understeer and squeal like a pig. Squeeee, squeeeee, squueeeeeee! and screw the balance of the car, unlsee you have very specific spring rates front/rear (as in very high rear sprin rate and normal to mild front spring rate like the progress springs).
Our cars, FWD, will benefit a lot from REAR sway bar. installing a beefier FRONT sway bar will just make your front tires squeal understeer and squeal like a pig. Squeeee, squeeeee, squueeeeeee! and screw the balance of the car, unlsee you have very specific spring rates front/rear (as in very high rear sprin rate and normal to mild front spring rate like the progress springs).
#27
PITA Admin
Administrator
iTrader: (1)
Join Date: Dec 2008
Location: TN
Age: 52
Posts: 14,779
Received 1,440 Likes
on
1,196 Posts
Rep Power: 338 Re: Sway bar size resource for Honda and Acura vehicles.
if you see the EX, you will notice that it is EX/Si, so the listings are US/CAN. But this is a good point, they could get confusing.
#28
Re: Sway bar size resource for Honda and Acura vehicles.
ya i realize that now haha. Squeal piggy squeal! haha. but i think for now im just going to leave the front alone but definitely add a rear with a subframe brace. it seems like anything between 18 and 22 will do just fine. i was also doing a bit more research and it seems that i will also need new bushings and end links. are the endlinks just where the bar attaches to the lca's? and if so do i need to find some from an 99-00 si or are there aftermarket ones i can get. i also was reading in another thread that the 01-05 endlinks will also work, any feedback on that?
#29
PITA Admin
Administrator
iTrader: (1)
Join Date: Dec 2008
Location: TN
Age: 52
Posts: 14,779
Received 1,440 Likes
on
1,196 Posts
Rep Power: 338 Re: Sway bar size resource for Honda and Acura vehicles.
look in the progress technologies - they make the best sways, comes with the reinforcements - i believe the 6th gen as well. skunk2 had the endlink adder kit?
#30
Live for the Twisties
Administrator
Thread Starter
Join Date: Jun 2010
Location: Langley, BC
Posts: 8,580
Likes: 0
Received 5 Likes
on
5 Posts
Rep Power: 260 Re: Sway bar size resource for Honda and Acura vehicles.
Hotchkis and ASR also make excellent sway bars. The subframe brace is essential, because the stock one will rip clean off the car on hard cornering conditions, but a lower tie bar isn't major essential. Make sure you get good aftermartket endlinks, the stock ones will snap with a big sway bar.