Rear Sway Bar Options

[Curt]

Are there any reasonable (quality-wise) alternatives betwen the Si rear sway bar and the one from Progress?

[gx4th]

CTE RSB Sway Bar - Rear (06-09 Civic Si)

That's an alternative. You can adjust for either 30% stiffer than stock SI or 60%

[tflo2000]

I just installed rear SI sway on my EX DD and anything is better than the coat hanger I took off!

[Xtreme Thunder]

Originally Posted by gx4th

CTE RSB Sway Bar - Rear (06-09 Civic Si)

That's an alternative. You can adjust for either 30% stiffer than stock SI or 60%

Eibach Adj. 19MM RSB is the same thing as the CT-E. Eibach produces them for CT-E. Eibach version is the same, adj and less money.

There is also a Blox 21MM, not sure of cost though.

[Curt]

I had been reading about the problem with the brackets that Progress was supplying not being right for the Si. Does the Eibach/CTE bar also have that problem?

[salviwill08]

Cusco has a 24mm sway bar! Saw it at aj racing and its like 248 not sure if its adjustable but this one seems much bigger

[J'sFA5]

Originally Posted by Curt

I had been reading about the problem with the brackets that Progress was supplying not being right for the Si. Does the Eibach/CTE bar also have that problem?

I have the eibach sway bar and it only comes with bushings no brackets, you are to use the stock ones. The only problem I had was it was a really tight fit, had to work the bracket around the bushing pretty hard before I could get the bolts on. Wish it would have come with new brackets but I havent had any problems once the install was done.

[Curt]

Looks like the Eiback/CTE has the advantage of two settings. Anyone with definitive feedback for how it works in conjunction with the HFP suspension setup? Seems to me that the Progress bar is a pretty big leap (in size), where the Eibach/CTE has an in-between setting.

[gx4th]

Curt, I'm also looking into an aftermarket rsb in the future (concentrating on ct stage 2 right now though).

One thing I'd point out is this Important info for all those with aftermarket sways!

Progress makes/includes reinforcement brackets now, but just wanted to point out the thread in case you haven't read it.

EDIT: currently i'm looking into the progress kit just cause it comes with those.

[J'sFA5]

Originally Posted by Curt

Looks like the Eiback/CTE has the advantage of two settings. Anyone with definitive feedback for how it works in conjunction with the HFP suspension setup? Seems to me that the Progress bar is a pretty big leap (in size), where the Eibach/CTE has an in-between setting.

Yes the eibach sway has two settings, I have it set to the stiffer one rite now. I also have it combined with the HFP suspension and I could not be happier, the drop is perfect for me since Im running 18's with 225/40/18. The handling is awesome, very tight in the turns and smooth on highways.

[gassser]

Originally Posted by Xtreme Thunder

Eibach Adj. 19MM RSB is the same thing as the CT-E. Eibach produces them for CT-E. Eibach version is the same, adj and less money.

There is also a Blox 21MM, not sure of cost though.

i went with the Blox 21mm, got it from inlineFour; claimed i saw this ad from advancespeedshop (see below); Brandon got close but didn't match the price. picked up an Injen CAI from Yip @ the advancedspeedshop.com location a few days later, so i'm sure i coulda got the rsb for $129.00!

Blox Racing Rear Sway Bar Kit 2006+ Honda Civic Si - P/N: BXSS-10103

[dminusbang]

I want a sway bar.. but im just a nubb... i just got my 09 si sedan and so far.. im getting tint and HID's this saturday.. i'm still very lost on other parts.. I know a sway bar is a BIG suspension upgrade.. the biggest one other then coils and tires right? ... I've heard of cusco, progressive, eibach, .. blox not really... I need someone, with a good heart, haha.. to maybe message me a product reference, the thicker the MM on the sway, the better? .. does 1 MM make a big difference? I just want to fix up my baby in the right way.. Thank you for your time and any information would be appreciated! ^^

[1358gencivic]

Okely,

Sway bar stiffness is based mostly on two things:
1) diameter of bar
2) the torque arm (some bars are adjustable)

1) Changing the diameter only will increase the the stiffness by the diff. of the two bars to the 4th power. So, the stock rear bar on a '09 Civic Si sedan is 17mm. Increasing it to 18mm will get you a 25% increase in stiffness. BTW, go with solid when ever possible, it might be heavier, but when you go with hollow, you have to calculate a solid bar with the OD, a solid bar with the ID, and subtract the ID bar from the OD bar. So it is lighter by a few lbs. but you are losing out all that stiffness.
Roll bar stiffness (in %) for increase in diameter only:
Tantiswaybar
Usually replacing the anti-roll bar will get you a diff shape/size/etc. than stock. If it is going to bolt up to all the same points, etc. then you might want to consider it the same bar, just a larger diameter. So, lets say you buy that Blox bar, 21mm, do the calcs, you get a 133% increase in stiffness.

2) If the bar is a diff shape enough where you want to calculate it, use the equations at the site below.
Sway Bar Rate Calculator | Build A Faster Car
I dropped the info in a spread sheet, makes it easier to do.
In the diagram on the webpage, the torque arm is -A-. For some anti-sway bars the mounting point is fixed, for some, it is adjustable. In the equation, A is squared, and it is on the bottom of the equation for stiffness. So, if A is a small number, when you square it, you get a smaller number, and then you divide by it, which increases the answer. In math terms; the stiffness rate decreases by 1/r^2. So, the smaller r is, the better. For example is the mounting point is 3 inches away from the bend in the bar (the torque arm = 3"), you will be dividing by 9 in the equation. If you move your mounting point to 2 inches away (torque arm = 2"), you are now only dividing by 4.

Confused? Sweet. No really, simplify it as much as possible. Assume the bars are the same (they can't be that far off if they are mounting in all the same locations), and calc the % increase in stiffness (the first calc.). If you want to some adjustability, get an adjustable bar, you can change the stiffness if you want.
More rules to follow:
-anti sway bars cut down on body roll, but basically do not change ride quality.
-stiffer shocks cut down on body roll, and changes the ride quality (usually not too bad).
-stiffer springs cuts down body roll and lowers your center of gravity, but will change the ride quality, usually to the point of verily harsh.

Cheers!

Jim
'09 Civic Si 4 door

[dminusbang]

DUDE!!!.. JIM!!!.. you're the man!..
thank you so much for that confusing yet simple explanation of suspension
and sway bar calculations. hahaha.. believe it or not, it really did help a lot!
and we got the same car!.. what color is yours? mines in that dark gray with navi!!
hehe.. ^^ would it be alright if i asked you some other things along the way?
thanks again Jim, appreciate your help!

[cros]

anymore insight on the Blox 21mm bar? also, where can you buy the reinforcement brackets for the endlinks? I know I saw a site that sells them separately, but I cant remember what it was.

[cros]

bump for answer!

[trickyazn]

I have multiple sway bars for sale in the FS section.

your options are all there!

[1358gencivic]

Originally Posted by J'sFA5

The only problem I had was it was a really tight fit, had to work the bracket around the bushing pretty hard before I could get the bolts on. Wish it would have come with new brackets but I havent had any problems once the install was done.

Was the car up on jacks or not? That could make the difference. I couldn't get my Otto fstb on my Maxima until I jacked it up.

Cheers!

Jim

[Curt]

Since first starting this thread I've gone from the original setup on the 08 FA5 I recently purchased (stock suspension with H&R springs), put in the HFP dampers and springs plus the Eibach rear sway bar on the softer of the two settings. Huge improvement. Just today I put the rear sway bar to the stiffer of the two settings, and like the handling a bunch better.
So here's the question: Discounting all of the analytical discussion about the sway bar diameters, configuration and moment arms, in a relative sense where does the Eibach (in each of its 2 settings) stand in terms of stiffness compared to the stock Si bar, the Progress bar and other rear sway bar options? More specifically for my curiosity, is the Progress stiffer than the Eibach (on its stiffer setting), and if so, by about what percentage.

[bluecreature]

Bump for update on previous question! Is the Progress stiffer than the Eibach on its stiffest settings?