Would I really benefit from a larger RSB?
 

I'm thinking ahead here but I'd still like to know...

Would I really benefit from an upgraded rear sway bar, such as the adjustable Whiteline 24mm bar, on a STi that has conservative suspension upgrades? Say just Prodrive springs, WL 26mm FSB and a better alignment.

I've read that a larger FSB does wonders for these cars much like a 20mm RSB does for older Imprezas but what about out back?

I'm not doing any sort of organized racing right now, just open track days and daily driving. The roads here in Germany aren't the smoothest and I don't want to stiffen up the suspension too much but improving overall grip is the goal. Thoughts?

If you are not going to a hard core setup customized for track usage, I would suggest a complete designed solution front and rear.

I personally like the hollow bars from Hotchkis and Cobb. Cobb also has matching spring packages.

And yes, a RSB in addition to the front should help.

Drive it with your springs and FSB and decide what it needs then. Don't just throw parts at it without clear goals.

Chances are you'll want a small upgrade to the RSB, but then again you may be perfectly happy with the stock 20mm.

Dean,

Why do your prefer hollow bars over solid bars?

Kevin,

Buying parts for the sake of buying parts is what I'm trying to avoid here :)

Dean likes hollow bars because they are lighter and generally not much more expensive.

And I know you aren't, that's why I suggested not buying one unless you decide "hmm, I could use a little more roll stiffness in the rear." :p

It was my impression that you had yet to buy anything. That is why I was recommending a complete designed and engineered solution.

As Kevin said, hollow is lighter per unit of stiffness. It also provides a larger surface area for the bushings to ride on and those brands also come with zerk lube fittings for the bushings, a big plus IMHO.

The Cobb also has an optional adjustable rear mount that also you to keep the end link geometry correct while moving between the different rear bar settings.

Dean,

You're correct, I haven't bought anything and I don't plan on buying anything until I've gotten used to the car on the track.

Why are the solid Whiteline adjustable bars so popular out of curiosity? They seem to be the recommended/standard over on IWSTI

Because they're cheap and high quality, I assume. I've got whiteline bars front and rear on my car... great bang for the buck.

Says the guy who put his car into a wall do to the fit or lack of lubrication of his rear bar. :)

I also don't understand why people think they are so "cheap"

Using GSTMotorsports as a reference, Whiteline bars depending on sizes for an '05 STI run $300-$345 for a set. That does not include grease fittings on the bushing clamps, or reinforced rear mounts.

Cobb on the other hand run $350 for the pair which are lighter, have grease fittings, and include upgraded rear mounts.

Hotchkis, who I believe actually manufacture the Cobb bars can be found for even less with the same features as well as either a street or competition setup starting right around $310 according to Froogle. The Competition setup with End links is about $480.

Bars are bars for the most part the only distinguishing factors are hollow vs. solid, and adjustability.

I like hollow bars personally.

The perception of Whiteline as cheap and quality dates back to a much more favorable exchange rate on the Aussie dollar.

are the hotchkis bars adjustable?

Rear only and two different rates as I mentioned before. Due to the geometry, I'm not convinced the Whiteline front adj. actually does anything, but it is the only "adj." front I am aware of. And it is pretty small.

Whiteline sells several different size front swaybars. A quick search found 22, 24 and 27mm adjustable bars for the WRX (at rallysport direct), and I also remember reading about a 32mm front bar a while ago.

The Whiteline bars used to be a whopping $100 each or so. Compared to twice that for the Cusco bar (paying for the name much?), Whiteline quickly got a reputation for a great affordable product. Plus, Whiteline has impeccable customer service: like when I was complaining on NASIOC (then i-Club) about my front bar clunking, I got an email from the president of WL telling me they had a redesigned bar for the GD and all he needed was my mailing address and he'd ship me one free of charge from Australia. Find me another company in this market that would do that!

Whiteline also has far more fitments and sizes than any of the other makers. Like Mike said, the Whiteline catalog has like 4 different sized bars for each of the Impreza platforms, including their "race" line of stuff which is ridiculously stiff.

Hotchkis is fairly recent to the Subaru scene, and it sounds like Cobb is leveraging their products... either way I don't know much about 'em other than they've got a great reputation for other makes. I certainly wouldn't say "stay away". In fact I might be willing to give 'em a shot myself due to the features that Dean listed... but only if the new Whiteline mounts don't have the same features. The mounts I've got are like 5 years old, and there's a new design out since then.

I've heard about the Cobb adjustable mounts and how they help you maintain proper geometry when adjusting the bar. The Whiteline mounts I bought from Pete don't adjust, but they seem to work just fine. Is the "bad" geometry really somthing that matters?

Cody,

I found this on Cobb's website:

In reference to their adjustable rear mounts, "As you use the stiffer sway bar settings, the rear endlink is placed at a compromised angle which reduces effectiveness and increases the chance of the endlink bending. Changing the sway bar design would only change what positions compromise the rear end link angle. With the COBB Adjustable Slider Mounts in place, you can now adjust the sway bar's position with relation to the end link. This allows you to keep the end link in the most effective position relative to its pickup point on the sway bar."

The only problem is... "Please note some clearance issues may exist if using the adjustable mounts with the stock STI muffler."

Interesting. I guess since my existing setup seems to work just fine (in all positions), I won't worry about it.

I just installed 24mm adj.whiteline rear sway bars with kartboy endlinks. everything fit perfectly. it's on the stiffest setting. i drove around 20 miles and would hear a clunk sometimes when going over little dips and turning slowly. but it's not something i can reproduce all the time. i went home and tightened some nuts a little more and drove a couple more miles swerving left and right, and making hard U turns. i didn't hear any noise doing this. still only hear clunks, i think when one of my rear tires is higher than the other like slowly turning on a bump or dip. tomorrow i'll try lower settings. the below pictures were taken after driving. i went to nasioc about the clunking but the two main suggestions were to tighten stuff up a little more or reducing the stiffness. any others? oh, and i have sti pinks.

http://i88.photobucket.com/albums/k1...h_DSC01014.jpghttp://i88.photobucket.com/albums/k1...h_DSC01015.jpghttp://i88.photobucket.com/albums/k1...h_DSC01025.jpghttp://i88.photobucket.com/albums/k1...h_DSC01026.jpghttp://i88.photobucket.com/albums/k1...h_DSC01027.jpg
http://i88.photobucket.com/albums/k1...h_DSC01028.jpghttp://i88.photobucket.com/albums/k1...h_DSC01029.jpghttp://i88.photobucket.com/albums/k1...h_DSC01031.jpghttp://i88.photobucket.com/albums/k1...h_DSC01032.jpghttp://i88.photobucket.com/albums/k1...h_DSC01035.jpg

Have you checked clearance on your exhaust all the way along the line? Interference at the tranny cross member is fairly common.

Also, when the struts are at full droop, are the springs captive, ir loose? If the latter, that is likely your clunk. Spring shift.

There is a possibility that you could be having some issues with the rear struts. My rear struts made a clunking noise too when they went out. The new RSB could have just made it worse on the struts. Just an idea.

clearance between the cross member and exhaust is about 1/3 in. i can't stick my pinky between them. i lifted the rear end up so the tires were off the ground. it seems the springs are captive. if they were loose i'd be able to swivel the springs a little with the struts at a full droop, right? i adjusted the sway for the least stiffest setting and will test now. if i still hear clunks i'll probably inspect the struts some more. i'll try to find out if it's the exhaust for sure first. thanks.

The kartboy endlinks are too short unless you're running stiff coilovers. The sound you're hearing is the swaybar hitting the lateral link.

i tried to verify this by smearing a thick layer of grease on the part of the endlink where it would meet the lateral link if this was the case. drove around, heard a couple lunks, but no grease on the lateral link. while i was under the car, i looked closer at the U brace holding the bushing to the mount and saw an etching of something under all the tar-like stuff built up on the brace. i rubbed off the crap and saw it was "-> F". the arrow was pointing towards the back on both braces :lol: i'm pretty sure the noise was from the brace not being fit perfectly on mount.

http://i88.photobucket.com/albums/k1...h_DSC01037.jpghttp://i88.photobucket.com/albums/k1...h_DSC01040.jpg

i turned them around and drove a bit on the middle sway setting and so far all is good. i'll use the stiffest setting when i get new tires. thanks anyways for the input. to get back on topic with this thread, larger sways are super.

One quick word of advice, If this is you're first experience with suspension mods, and their effects on handling, be very alert to having you're bar set to the stiffest setting and normal street driving, The off throttle over steer could really put the fear of god in you. Not to mention on throttle. On ramps and off ramps can be especially hairy, with the car pottentially getting out of shape fast.

Mine has scared me a couple of times. Just thought I'd share.

+1

I had a friend roll his months old '01 2.5RS testing his new rear swaybar.

+2!!!

I just noticed it is in the stiffest setting. 24mm solid bar on full stiff on the street can get you in trouble quick. Be very careful.

i didn't like the stiffest setting too much. definitely don't need it for daily driving. i drove around a bit in the middle setting today to get used to it, going on/off ramps, dodging dead rabbits on the road and such. big difference from the stiffest and stock. i know what you mean about being careful, especially going fast on the highway and avoiding cars/obstacles in split second decisions.

if you went 24mm rsb on the stiffest setting then a 24mm non adjustable fsb would it still be as prone to oversteer?

the hotchkis bars are 25mm each :wow: if the 24 stiff is scary i dont want a 25mm bar.

Technically, yes it would be exactly as prone to oversteer. The added front grip from the FSB will make you less prone to washing-out over steer and more prone to snap oversteer, because you will be able to turn-in faster with the extra front grip. Basically, mod if you want but work your way up to the new limits slowly.

Also, hollow bars like the Hotchkis are not as stiff as a solid bar of the same outside diameter, unless that's an adjusted rating. Without looking at the chart I downloaded from Whiteline a long time ago, I'm guessing a 25mm hollow Hotchkiss is in the neighborhood of 21-22mm solid bar.

Hothchkis bars are hollow with different wall thicknesses depending on application.

For the rear, the 24mm solid bar is about equal to the 25.4mm street bar if I recall correctly. For more info on hollow vs. solid, look here:

http://www.hotchkistuning.com/bin/Mi...SwayTech-D.pdf

snap oversteer...like more abrupt like no oversteer to 180 in like .123124 seconds not like slow motion type oversteer?

Exactly. The rear of the car will be apt to simply swing around on you at a FANTASTIC rate!

That sounds like a load of fun!!!

On a serious note, since I now have a 32mm FSB, how would my car differ if at a later time I wanted to put in a RSB?

It would be more willing to rotate. Meaning, it would be easier to get a little bit of a slip angle going in the rear. But, if you ever decide to leave AS, just plan on coilovers or at least good springs first. Start with the important parts then add the accessorizing parts. Flavor to taste so to speak.

Adding a stiffer rear bar will decrease rear roll at the same time transferring weight to the outside. So depending on how the car handles with the FSB it is likely to stiffen the rear and assist in rotation.

If you aren't going to change springs/struts, sway bars are a good way to change handling characteristics.

Rear roll angle is the same as front roll angle, assuming you don't own a car as floppy as a '57 Eldorado vert. Stiffening a swaybar at either axle reduces overall chassis roll angle.