Ordered my ZOK/Clubsport Solstice today!

[SolsticeMan]

Well, I got some prelim info:

FE2 springs (front and rear) : 125 lbs/in and 175 lbs/in

FE3 springs (Z0K and GXP/RedLine) (front and rear) : 170 lbs/in and 225 lbs/in

This is close to the Eibach spring rates, IIRC.

The Z0K springs have a shorter free length, and lower the car by 1/2".

GMPP springs: 210 lbs/in and 285 lbs/in
These have a slightly shorter free length and load, so they lower the car a tiny bit.


Now, if you put the GMPP springs on your car, you're into street prepared autoX category... so keep that in mind.

[Mallard]

Great info. Thanks.

By the end of this summer my car would be classified as SM2, so I'm not too worried. I just need to get an idea of how different the suspensions are and how they compare to aftermarket spring rates.

[fastmike]

Originally Posted by Mallard Great info. Thanks. By the end of this summer my car would be classified as SM2, so I'm not too worried. I just need to get an idea of how different the suspensions are and how they compare to aftermarket spring rates.

I have a certain Nat champ that is wanting me to do the same...
I told him that I would have to wait until I see how the car does in CS.
FM

[LatinVenom]

Originally Posted by SolsticeMan Well, I got some prelim info: FE2 springs (front and rear) : 125 lbs/in and 175 lbs/in FE3 springs (Z0K and GXP/RedLine) (front and rear) : 170 lbs/in and 225 lbs/in This is close to the Eibach spring rates, IIRC. The Z0K springs have a shorter free length, and lower the car by 1/2". GMPP springs: 210 lbs/in and 285 lbs/in These have a slightly shorter free length and load, so they lower the car a tiny bit. Now, if you put the GMPP springs on your car, you're into street prepared autoX category... so keep that in mind.

So can I make a leap here and make a conclusion base on the above information, plus what you also said about the GMPP sway bars.
A reg Solstice like mine with the Eagles F1's GS-D3 and the GMPP suspension would out corner both the ZOK and the GXP, using the same speed for all three for a test run, YES......

[SolsticeMan]

Originally Posted by LatinVenom So can I make a leap here and make a conclusion base on the above information, plus what you also said about the GMPP sway bars. A reg Solstice like mine with the Eagles F1's GS-D3 and the GMPP suspension would out corner both the ZOK and the GXP, using the same speed for all three for a test run, YES......

A qualified yes, it appears.

It also depends on the surface. AutoX usually can tolerate higher spring rates and damping because the surfaces tend to be less bumpy. You CAN get too stiff, and it shows on road courses that have elevation changes, abrupt surface changes, or roughness. I'm thinking: Grattan Raceway, VIR, Nelson Ledges (rough), to some extend Mid-Ohio, all of which have elements that could throw a too-stiff car into a tizzy.

You could, however, conclude with near certainty, that a car equipped with GS-D3's will out-corner both a ZOK and GXP IF they are on stock tires. Outcornering a properly set-up Z0K? On Kuhmos or Hoosiers? No way. Skidpad grip is 70% tire capability. A stiff suspension with all season tires (i.e. tires with true all-season capability) will not outcorner a less stiff car with REALLY grippy tires.

You could also conclude with near certainty that the GMPP setup will have less body roll (higher spring rates, same as GXP/Z0K bars). That doesn't always translate into more cornering. It will definitely feel more like a go-kart.

[LatinVenom]

Thanks SolsticeMan, so then if the GMPP were to get Kuhmos or Hoosiers the advatange once again would go to the GMPP.....

[acrace]

I agree with SolsticeMan's comments.

If the GMPP springs were superior for road racing (SSB class trim, with a race alignment and Hoosiers, as tested by GM), then the assumption could be made that Z0K would have used them. Or maybe the plant folks didn't want more assembly complexity.

[LatinVenom]

My understanding is that the GMPP sway bars are either the same as the one in the FE3(ZOK,GXP) or slightly thicker than the FE3 sways.

[acrace]

Thanks for the catch. I meant springs. Would've thought that Z0K would've been released as the fastest possible combo, as SSB regs are very restrictive.

My info shows the Z0K as having the same P/N for bars as the 07 FE3 (turbo).

[LBJay]

Originally Posted by acrace Would've thought that Z0K would've been released as the fastest possible combo,

For who? At which track? Suspension tunning is a world of compromises, there is no "One" set-up that makes every driver happy and suits every track.

The fast drivers are those who get get the most out of what they have.

We had a guy in our region that could out PAX over half of a 100 car field... in an F Stock 92 Lincoln Town car. Totally stock with just R-compounds. A real ego buster.

[SolsticeMan]

Originally Posted by LBJay For who? At which track? Suspension tunning is a world of compromises, there is no "One" set-up that makes every driver happy and suits every track. The fast drivers are those who get get the most out of what they have. We had a guy in our region that could out PAX over half of a 100 car field... in an F Stock 92 Lincoln Town car. Totally stock with just R-compounds. A real ego buster.

[acrace]

I agree that the "best set up " is driver and track dependent (and also set up, including tires).

But, then again, given that the Z0K's purpose is to be competitive in SSB, the set up would be biased towards road racing (so autocrossing is irrelevant). Given that the "best" place to determine set up wasn't available during the Z0K's development (which is Heartland Park - "best" because that's where Runoffs will be this year and for the short term future, and "unavailable" because it was being resurfaced - I had the chance to check it out last September), I would assume that GM reverted to their usual suspect of tracks - VIR, Mid-Ohio, Grattan, and Gingerman. If the set up with the FE3 turbo springs is best, so be it, but if the GMPP springs would've yielded better lap times, then performance was left on the table. Don't forget, in SSB you can't swap springs.

Of course, this may be somewhat academic as the tires used for development won't be the hot set up this year


Al Chan
(Twenty-plus years of autocross experience; ten-plus years of FF/S2 set up experience)

[fastmike]

While Al is correct about track specific set ups, I think they did a pretty good job with the car set up.
How the car autox'es in the heat of battle should be somewhat answered, for me anyhow, this Memorial day weekend.
We have a full schedule that weekend.
Should be fun.
A big unknown but hey! that is exciting!
I am hoping for some wins.
Also, I have my fingers crossed that we get some good weather that weekend.
FM

[acrace]

FM:

I'll be watching your progress, and also hope to see the class run at HPT this September (I'll still be in Super Stock). I'll have a chance to see how dasto does this weekend in Cincy.

[fastmike]

Got on a set of scales today for a "quickie" weigh in.
Figured I had about 6.5 gallons of fuel in.(Next day edit: just filled up..probably only had 4 gallons when weighed)
Top down/no floor mats/stock everything/"spare tire" pump/goop thing in trunk(3 lbs?).
2799lbs.
WOOHOO!
Looking/hoping to get to 2740-50ish in race trim with 2 gallons of fuel in.
Race rubber + rims should save me 8-10lbs a corner. Exhaust could net me 10-15 lbs for a streetable system + we are building a "full race" system that should be VERY light.
http://www.burnsstainless.com/Ultral...temuffler.html

Scales were not "super level" where we were weighing. Front was higher than rear by 2 inches? and side to side scale level was not checked so take these #'s with that in mind.
With me in the drivers seat(185lbs), front side to side was under 20lbs off. Rear side to side was off more than I would like. Actually, way more than I would like. I am hoping it was the scale setup and also hoping that a level set of scales does not change the nice front to front balance..
Likely to be closer to perfect side to side for my 110lb codriver though.
51.5% front to 49.5% rear.
Exhaust and less fuel should lighten rear of car more than the front but maybe weighing on a totally level surface will push the balance back a hair???
I wasn't concerned too much right now with this stuff since lots of mods are happening next week like alignment/exhaust etc.
I bet that the SSB cars are ending up with a decent weight balance after cage etc with some fuel in the tank.
Good job GM!
If I get really picky, there is some stock legal things I can do to "even" stuff up like bushing preload etc. Little stuff like that is probably more for a "mental" advantage than a real performance advantage from what I have witnessed over the years for solo especially if you don't know the course direction etc. beforehand..

Hp and TQ to weight should be able to get VERY close to the 99 Miata with both in race trim if my fat butt was driving both.
That is assuming the exhaust I put in bumps up my car some. If not, the advantage might go the Miata.
I am hoping for TQ across the band and a few HP would be nice too...
Gearing is guessed at 57mph in second for my car. 99 Miata's vary on second gear revlimiter depending on tire choice.

Car's width has been noticeable when I have been "threading" the needle between "botz dots" and similar things.
Stuff I didn't even notice in the Miata is VERY noticeable in the Solstice.
It is looking like I will need to make more grip than the Miata's to make up for the width penalty.
I actually said "whoa" out load today while trying to do a tight entrance to a lane change/offset.

Next step...exhaust...we are making 3 prototypes next Thursday.
Friday is alignment and Sat/Sun is the maiden voyage.

FM

PS: I am serious enough about this years competition that I am getting fit and losing weight down to my 175lb clothed target weight.