Topic: Swap Sway Bars?

[Bailey]

I have a 2006 Solstice NA...I have just installed DDM works pro-beam & Back bone (Love them...get additions) as well as Eibach Pro-kit Springs....I would to hear some options about swapping the stock sway bars (FE2) for the GMPP FE3...like on the GXP.  thoughts?

Thanks

Bailey

[snaponbob]

Do yourself a BIG favor and install the Z0K bars for the GXP. Note: these are about 20% stiffer than FE3 bars, and are different than Z0K bars for the 2.4 model (which are about the same as FE3 bars. You will be amazed at the difference. If you are just street driving, spend another few bucks and put the 2.4 Z0K alignment specs to the suspension (1.8 neg camber front, and 1.2 neg camber rear). I run about 2.8f/1.8r with little negative wear issues on the tires. Bad toe settings are what eats tires. With the stuff you have, some stiffer bars, and the alignment you might believe that someone switched cars on you!!!

[G8TR]

 
Listen to Bob, never gotten bad advice from anything he has said on the forums.

[opjohn]

Stop spending money Bailey :-) LOL

[jonymac]

Being a Sky Redline owner, I guess I have the FE3 bars?  Do the Z0K bars work on the Sky?

[lil goat]

Sure but they require a Sky hook, SOB has a Sky.

What colors do the sway bars come in , everyone knows red is faster.

[DeepBlueGXP]

I thought the GXP had the upgraded Z0K system, or that is what I head from the plant tour.  There is something better than the FE3?

[lil goat]

There is always some thing better, Jeff has the Sky Bar much better, then there is the Tiki Bar also very nice place to get stiff.

Blue is GXP Z0K bar notice thicker tubing wall.

[snaponbob]

Oh boy !!!!!!! Time to sort out the TWO different Z0K's !!!!!! And other stuff.

In no particular order;

There really are not a lot of choices of sway bars for the Kappa platform. It is reasonable to expect that there won't be either as the production run was low (probably under 100,000 in total) and as outfits such as Energy Suspension, Eibach, and Koni have discovered, demand has been rather low. Beyond the parts available from GM, it appears that only Eibach has the only after market bars. These bars were rolled out very early (before the GXP/RL was put on the market) and are upgrades from the FE2 bars. Nobody supplies bar rates but Eibach did say that they are about the same "rates" as the FE3 bars. Nobody except GM offers (other than custom) stiffer bars than the FE3 units.

Five (maybe six) different packages from GM for the Kappas (all developed for street or road race, and in typical GM fashion they all lean towards understeer);
1) FE2 - standard on the 2.4s. Compared to the FE3 set up, the springs and bars are about 18-20% softer, and the Bilstiens are valved to them. Bars are both hollow and (IIRC)  28mm front and 25mm rear.
2) FE3 - standard on GXP/RL. The front springs are 175 pounds per inch and rears are 220 pounds per inch. The bars are hollow and 33f/29r. Bilsteins valved to the springs and bars.
3) ZOK for the 2.4. Basically this is the FE3 with shorter springs.
4) Z0K for the GXP. Roughly 18-20% stiffer (and shorter) springs and bars, and not sure about how the Bilstiens are valved. Also, a beefed up rear chassis cross member.
5) GMPP handling package (early package for the 2.4). It is roughly the FE3 package for the 2.4s with marginally shorter springs. Absolutely not worth a dime if installed on a GXP/RL.
6) GMPP handling package for the 2.0. Some on the Solstice forum say this exists but may be nothing more than some of the GXP/Z0K stuff.

EVERYTHING bolts up to ANYTHING. It's all interchangeable. Koni offers over the counter single adjustable shocks for the Kappa. If you want ONE mod that will improve the way your Kappa feels, rides, and handles, this $600 set of shocks is simply the best money you can spend. In every way they are better than the Bilstiens. KW, BC, HKS, and maybe a couple other outfits offer replacement coil overs for the Kappas and offer different solutions from $1000 to $2000. For those with DEEPER pockets there are custom DA Konis, Penskes, Ohlins, AST, and some other shocks. Beyond bragging rights, these are geared towards racing. GM springs top out at about 210f/265r. There are infinite spring rate choices in 2.5"/65mm diameters. The Konis will need sleeves and upper spring adapters for this, and all the other above after market shocks use 2.5" springs. Currently I run 400f/450r (soon to change a bit) with SA Konis set rather firm and that may be the practical limit for daily use unless you like a really hard ride. The ProBeam and BackBone WORK, and with firm suspension the BackBone will reduce the cowl shake the stiffer stuff will increase. Kappas flex. Stiff suspension will make Kappas flex MORE. Some more negative will not really hurt the tires but sure will improve the response of the Kappa, not matter what is underneath it. As I have played with shocks, springs, bars, alignment, and other stuff over the past three years as I have tried to improve the handling for first SCCA Solo Stock class, and now Street Prepared, I marvel at how responsive the platform is to changes. Budget willing 2010 will see 18X9 or 10 wheels with 315/30X18 Hoosiers for racing and better shocks which should be incredible.

Depending on how you want your Kappa to ride, handle, and feel, with a switch to better shocks and some mix and match of the GM springs and bars you can make your Skystice be whatever you want, and for a lot less money than you might think. HTH.

[lil goat]

Great info Bob, so from what I read, if I have this right the GXP Z0K bar might be a worthwhile addition to my HKS's and the DDM goodies?

[Critterman]

Bob you make my head spin but thanks for the input.  DDM gave me a little more negative Camber in the rear, when they installed my HKS coilovers.  Front and rear are both around 2 degree now.   Car handles totally different now, it is (hard to describe the ride) a stiffer ride not harsh.   I have not noticed any dip in a hard turn, but then again I don't autocross.  So if I am going to get serious about handleing I need to look at sway bars next.   What do you suggest?  I am currently running the stock N/A sway's

[Critterman]

goat posted while I was typing, but Jim if you upgrade to the GXP ZOK bars,  I will take your GXP bars to the dump for you

[lil goat]

If I can find a part number for the GXP Z0K sway bar that works, I am sure that we can just put them in the dumpster at Chandlers  . I can find part numbers for the sway bar for the Sport package, but not the Club Sport (Z0K) The bars are not that expensive so I wouldn't mind getting one.

[snaponbob]

A couple responses.
1) Two degrees negative camber in back is just too much for street use, and really too much for racing !! With 2 degrees negative in front something around 1.3 to 1.5 in the rear would be better.
2) Since the Kappas all understeer, if one wants to make the handling more neutral on an FE3 car (GXP/RL) install the GZP/Z0K bar on the rear. Leave the FE3 bar on the front. This was, and still is, the hot set up for GXP's in Solo Stock. The car will not be tail happy, just more responsive. Same if one puts an FE3 rear bar on a 2.4 with FE2 suspension.
3) Critter's assessment of "stiifer but not harsh" is exactly right. If the shock/spring package is well matched, it's magic. Example: A racing buddy has a 1988 E30 M3 BMW (rare piece). He had 500-600 pound springs on Konis which he liked. Now the car has AST dampers and springs are about 800-900 pounds. Guess what? Handles better and rides better !!! Why? Vorshlag custom valves the ASTs to the springs to the individual car and driver's needs.

[lil goat]

OK now I just have to find a GXP Z0K sway bar, then I can will my sway bar to Critter and the world will be a better place.  GXP/Z0K Part Number? Bueller, Bueller, Frye, Frye, anyone?

[Uranium-238]

I'm trying to track down the part number at the moment, will post it if I find it.

[Uranium-238]

OK, this appears to list the GXP ZOK suspension components:

http://sccaforums.com/forums/permalink/344775/344802/ShowThread.aspx#344802

Since I know better that to trust a single forum post, I'm trying to confirm these are in fact the GXP ZOK bars. Don't want to order them and find out they're something else. Inputting this in to GM parts direct or a similar sight just says it's a "shaft," no specifics.

[lil goat]

I saw that one and the numbers didn't work on GM Parts Direct. Might work at a dealership, I am going to check tonight going by anyway.

[Ben L]

I'm not sure I'm qualified to weigh in here, but I can report that the combination of the Race Backbone, Pro Beam, and BC coilovers, with the spring rates biased toward the rear (8k/mm in the rear and 7k/mm in the front), with the stock bars, has eliminated my GXP's understeering tendencies. 

I am running the BCs' damping at 7 clicks in the front and 15 in the rear.  The car is now extremely neutral.  Although I had some trouble finding the course Sunday at FedEx, the car was performing very well . . . .

I have no need to muck with the sway bars at this time.  Point is, a lot can be done with decent quality entry level single adjustable coilovers and springs. 

Saturday is a 1.6 mile autox circuit at the Cumberland Historics.  Its usually like a mini road race course with a couple of slaloms in the straights.  I can't wait!   

[Bailey]

Thanks for all the information..."food for thought"!  Excellent dialogue

PS...OPJohn....wait until I ask about the supercharger!!

[Uranium-238]

I saw that one and the numbers didn't work on GM Parts Direct. Might work at a dealership, I am going to check tonight going by anyway.

Odd, plugging 25855622 into GM parts direct yields :

http://www.gmpartsdepartment.com/partlocator/index.cfm?action=searchCatalogOEM&siteid=214533

It was working earlier...
 

Let me know what you find out at the dealer though. Sounds like a great way to loosen up the car a little bit.

[snaponbob]

Here is the list copied over from the link;

25849163     Front Spring                             2
25835621     Front Stabilizer                     1
25855626     Rear Spring                             2
25855622     Rear Stabilizer Shaft                     1
25855623     Rear Stabilizer Shaft Insulator     2
25855624     Rear Stabilizer Shaft Insulator Clamp     2
25877302     Rear Suspension Support Crossmember     1

[jonymac]

On that other thread there seemed to be some back and forth on whcih ones were the right PN#s.  So Bob, for a Sky RL, would you need all the parts on that list?  On that other thread you also mentioned keeping the FE3 front while upgrading the the rear to Z0K - that still hold true for street driving?

GMpartsdirect:

GM PART # 25855622
CATEGORY: All
PACK QTY: 1
CORE CHARGE: $0.00
GM LIST: $369.98
OUR PRICE: $219.33

      
DESCRIPTION: SHAFT

[snaponbob]

BTW, not all sites are equal. Try this one as it seems to be a bit better. http://www.gm-auto-parts.com/ifrm_browse.php Some of the items come up, but the rear frame rail may be one that the dealer has to generate a SPAC order (they'll know what that is). As an SCCA member I can get the parts at 10% true cost from a local Chevy dealership. PM me if you want some of these bits.

[snaponbob]

On that other thread there seemed to be some back and forth on whcih ones were the right PN#s.  So Bob, for a Sky RL, would you need all the parts on that list?  On that other thread you also mentioned keeping the FE3 front while upgrading the the rear to Z0K - that still hold true for street driving?

GMpartsdirect:

GM PART # 25855622
CATEGORY: All
PACK QTY: 1
CORE CHARGE: $0.00
GM LIST: $369.98
OUR PRICE: $219.33

      
DESCRIPTION: SHAFT

Be REAL careful about prices from some of the sites. Some whore out the part and them jam you on the S&H. If people do some searching on the Solstice forum the part numbers are there. Here is what needs to happen; decide what you want to do to your car, throw out the answer and we can all find the right part numbers.