Topic: Which Z0K suspension to use ? Base Z0K or GXP Z0K

[Acadian]

?????? wich z0k suspension springs and bars to pick for my upgrade.



My solstice is a no option 2006 (at all.....)lightweight base model that i would like to upgrade to zok specification.

zok base and zok gxp seems to share the FE3 dampers but have different part number for springs and different part # for sway bars.

if the car was stock, i would easily choose the zok package for the ssb (2.4l na ).

but since my car is now ddmworks supercharged should i go with the zok pkg for the ssb(base 2.4l) or the T2 class zok package for the gxp ?

does the addition of the ddmworks pkg (supercharger,intercooler,header
and hiflow cat ) bring more weight to the front that my car's balance is closer to a gxp. or the weight difference is minor due to the removal of the cast iron manifold and the fact that my car has no option at all...

all in all , should i buy zok gxp springs and sway bar or should i buy
the zok (base 2.4l) springs and sway bars ?

i really do not know if the zok gxp package was a setup made for the difference in the 4 corner weight balance of the slightly heavier gxp or more geared for the higher cornering speed of the turbo version in race trim.

any input or suggestion welcome.

thanks

acadian
stage 2 supercharged

i do not want a pkg that look cool (read in da weeds low) but doesn't work. i want to drive the car hard on country road with confidence but without spending big $$$ for coil overs that i will probably fight to death to tune properly on public roads.

is the gmpp pkg a better option or is it mainly geared for autocross and too stiff and not as nicely tuned for road racing.

all in all, not too much concerned by comfort level, but really concerned about having the best grip on curved, bumpy and cracked public roads. with occasionnal track days at a couple of very nice racetrack around here.

looking to add the  ddm backbone brace to the combo but still undecided as for the ddm brace or zok crossmember.

since i also need dampers , i am afraid to use the koni instead of the fe3 bilstein because i have heard that the car will sit roughly 1.0-1.5" lower than the stock zok ride height because of the way the bilstein are pressurized. is this true ?

[snaponbob]

You have covered a lot of territory in one post. So --

I am pretty sure I had the first set of single adjustable Konis. They DID drop the car about 1.5" f&r. However, others have e-mailed me to say they only saw about .5 - .75" drop. Lee Grimes @ Koni N.A. does not understand why my shocks have done this even after having them apart at the 2008 Solo Nationals to re-valve them. (BTW, they ARE properly assembled with all factory parts.) If you are concerned about ride height you can buy FE3 Bilstein take offs (they pop up from time to time) with stiffer springs, or pop for the KW V3 shock/spring package and adjust the ride height and shock valving the way you want. Once you have the shock/spring issue resolved obtain the FE3 front sway bar, brackets, and bushings, as well as the GXP Z0K rear sway bar, brackets, and bushings. This will give you very balanced front/rear roll resistance and thus less understeer.

A lot of people get all knotted up about the Z0K packages. They are quite different for the 2.4 and 2.0 Sols. The Z0K for the 2.4 has the 2.0's FE3 spec shocks and springs (with about 1.5" shorter springs) as well as FE3 sway bars and hardware, along with ABD and LSD. The Z0K for the 2.0 has 18-20% stiffer springs, shocks, and bars than the FE3 alond with a a replacement rear frame channel. For your purposes you can mix and match to your needs.

HTH. Let the questions flow.

[Acadian]

i  was thinking of using the fe3 front sway bar in combination with the zok rear bar.
what is crazy here, is that even the front and rear bars are different on a zok na vs a zok gxp !

front fe3 bar is almost a done deal.
wich bar to choose for the rear ? so many variable...(zok na vs zok gxp )

anyone know the weight difference between a na and a gxp ?

the weight distribution front and rear between a na and a gxp ?

significant or minor ?

enough to make a real difference or something to consider in my choice of springs ?

i tought that the 18-20% stiffer than gxp springs were the one from gmpp.i was probably wrong but could not verify.

thanks snaponbob for writing lots of very informative post concerning the handling of our cars, i've read most of them.

[snaponbob]

Springs are used primarily for holding the car up! Secondary they are used to control "ride frequency" from soft to stiff as well as the main handling characteristics. The weight at each end and type of suspension help determine those rates as well. Then the sway bars are added to help the handling as sort of a final tuning touch. That said;

i  was thinking of using the fe3 front sway bar in combination with the zok rear bar.  what is crazy here, is that even the front and rear bars are different on a zok na vs a zok gxp ! 
front fe3 bar is almost a done deal.
wich bar to choose for the rear ? so many variable...(zok na vs zok gxp )

Remember that I cautioned about how people get crazy about the differences in the NA, NA/Z0K, GXP/RL, and GXP/Z0K components. You just fell into that "trap". There are three front bars (FE2, FE3, and GXP/Z0K) and three different rear bars (ditto). The sway bars can only control sway (roll) beyond what the springs can do. The basic set up of the NA 9FE2) and GXP (FE3) is understeer. If you want less sway and the sway understeer simply install the FE3 bars (brackets and bushings as well). If you want the rear end to be more "lively" install the GXP/Z0K rear bar. But some serious cautions here because of your next questions!!

anyone know the weight difference between a na and a gxp ? The Kappas (Sky and Solstice) can weigh as little as about 2700 and as much as 3100 pounds. NAs without A/C are the lightest up to the A/C equipped GXP/Redline.
the weight distribution front and rear between a na and a gxp ? Non A/C NA almost 50/50. Add A/C and that changes about a point, and the A/C equipped GXP/RL is a bit more than 52/48.
significant or minor ? In day to day driving it's very minor. In racing it makes a big difference. In autocross a Sol 2.4 Z0K will out-handle a stock GXP!!!! Going back to some serious cautions if you install the FE3 or GXP/Z0K (maybe overkill) on a 2.4 it will be quite balanced. If you use the FE3 front bar and GXP/Z0K rear bar the car could possibly go from balanced to a car that could be skittish in the back. GREAT for drifting (!!) but not real user friendly on the street. Yet that same sway combo is great on a GXP/RL. (There is that f/r weight issue.)
enough to make a real difference or something to consider in my choice of springs ? If you want to have a better handling car for daily use use the GXP springs if you want stock ride height. Both Z0K spring sets WILL lower your car. The GXP/Z0K will stiffen the car about 40% over the stock 2.4 springs. Whatever springs you choose do NOT mix and match. (The results would take an even longer post!! )

i tought that the 18-20% stiffer than gxp springs were the one from gmpp.i was probably wrong but could not verify. The GMPP package is not much more than the GXP stuff for the NA. They retail for about $1200 but pop up all the time on e-bay for about half of that and is the cheapest way to do you upgrade. However, the springs are NOT the shorter springs like the Z0K's, but the same as the GXP/RL FE3.

Do not forget, EITHER set of springs from the Z0Ks WILL lower your car enough to make parking lot speed bumps, getting on and off shop lifts, even enterring and exiting some driveways some real challenges. Whatever you do, when you are finished with the changes remember to get an alignment because things can/may change. (Are you having fun yet?)

[Acadian]

wow!!! thanks a lot snaponbob.

it answers a lot of question...

i don't mind the lowered ride height as long as the combo works (looks with performance).

guess the final thing i need to digest this amount of info is how much additional weight in the front my ddmworks stage 2 supercharger kit added. and figured out if my ratio is still at 50/50 or closer to the gxp's 52/48.

[Acadian]

quote: (Are you having fun yet?)


Actually i do, this the part of modding that i like the most, the brainstorming part of it makes me looking for the very best possible way of doing things.

thats just me,

[snaponbob]

wow!!! thanks a lot snaponbob.

it answers a lot of question...

i don't mind the lowered ride height as long as the combo works (looks with performance).

guess the final thing i need to digest this amount of info is how much additional weight in the front my ddmworks stage 2 supercharger kit added. and figured out if my ratio is still at 50/50 or closer to the gxp's 52/48.

Safe to assume 52/48 with the huffer. Ride height will make a minor difference in street handling, so looks would be a major factor there. But this will make a fairly low car a LOW car. Suggestion would be FE3 front bar, GXP/Z0K rear bar, FE3 springs for standard ride height and 2.4 Z0K springs for the FE3 spring rate and lower stance, and either FE3 or GXP/Z0K Bilsteins (good) or Konis single abjustables (better).

[Acadian]

thanks for the suggestion, will strongly consider that one

[snaponbob]

calling snaponbob ... 

Yeeeeeeessssssssssssss !!!  Wassaaaap?

[lil goat]

Sounds like you will be building a nice handling car, and Bob is certainly the man to ask all I can add is don't forget the after market, lots of very nice coilover setups out there and now they are down as low as $1000 complete, then just add sway bars see above. Don't forget to upgrade your wheels and tires, seems the most over looked mod on the Solstice, lighter wheels male a HUGE difference as well as good tires.

[Brad Kenny]

Here is what I have been looking for for almost a month... recommend making a sticky for NA users to look at... not everyone is a GXP... HAHAHA!!!

Safe to assume 52/48 with the huffer. Ride height will make a minor difference in street handling, so looks would be a major factor there. But this will make a fairly low car a LOW car. Suggestion would be FE3 front bar, GXP/Z0K rear bar, FE3 springs for standard ride height and 2.4 Z0K springs for the FE3 spring rate and lower stance, and either FE3 or GXP/Z0K Bilsteins (good) or Konis single abjustables (better).

[Critterman]

All you had to do was ask Susan   

Here is what I have:
Stock front bar
FE3 rear bar
HKS coil overs, set as high as they go (about an 1.5" lower than stock)
DDM corner balanced with semi-aggressive alignment 
Shock are set fairly soft for street use, and then I harden them for track time.

[Acadian]

What i  ended up doing was to install
 
a complete gxp z0k  set up on my NA.  
(fe3 shocks, 4 gxp zok springs mounted with one spring perch, gxp z0k bars front and rear)

Very happy with the results , would not change a thing.

 Funny thing is that before the conversion, my stock fe2 na was lower in the front compared to my mom's stock gxp !

After the gxp zok conversion , my car is now very level compared to what it was before( stock 2006 fe2 was front end low,rear up in the air !),now lower than before in the rear and a little bit higher up front than the original fe2 but lower than the stock gxp.Stance is now  very level.

Still a lot of ground clearance to play with. i think ground clearance is greatly diminished only when one use low pressure shocks like koni's with the zok package. another thing that probably helped me is the fact that my solstice is a bare bone lightweight car with no options.

Is the gxp zok too stiff for an na solstice used daily ?

I do not think so, car is still comfortable. The only exception would be when i drive in the city over rough roads filled with potholes at slow speed. Otherwise it is perfect.

The car now handles likes it's on rails !  i FREAKIN LOVE IT !:devil:

[LatinVenom]

Does any one know what are the Alignment specs from the factory for
the Z0K suspension on a GXP.
This is what I have found but I do not believe is what comes standard from the factory.
Camber Front -1.75 +/- .75 Deg.
           Rear   -1.5 +/- .75 Deg.

Caster Front 7.75 +/- .5 Deg.
          Rear -4.0 +/- .5 Deg.

Toe Front .10 +/- .2 Deg
      Rear   .10 +/- .2 Deg

Thanks in advance.