itsMikey

alright so ive been considering the Ground Control Weight Jacks for the Trans Am and was wondering...
1. installing them, do they have to be welded in? or how do they go in?
2. when determining how tall of a spring i want, what do i consider? i was thinking 8" springs at 1000lbs for the front and 9" at 600lbs for the back.
3. How hard is it to adjust them?
4. How much adjustment is there?

and if you have them, post some pics ive seen some others but would like to see more before i drop $500...

http://www.ground-control-store.com/...hp/II=20/CA=67


Mikey

//<86TA>\\

iTrader: (14)

front has about 3.5" maybe more of total adjustment. rear, 2.5? maybe 3

i didnt have to specify height of the springs when i ordered mine, they have it all figured out, just tell them what rate, of what you are doing and they will set you up.

no welding. Front adjuster sits on top of the spring, up in the k-member, rear setup sits in the stock rear axle spring perch.

front can be adjusted with a 1/2" ratchet and a extension up through the center of the a-arm. rear uses spanner wrenches. You should have some of the weight off the springs when you adjust them though.



my front adjusters were coated red, not sure why these ones are not.


unless the front you your car is stupid low, 1000 may be a bit much. With a small block, maybe try 850 or 900. rears, between 150 and 175 will get you stiffer than stock which is about 100. I have 250's in the rear of my 86, but i have a lower roll center in the rear. 600 for the rears is WAAAAAAAAAAAAAAAAYY too much unless you rear roll center is in the dirt, or underground

i have 1050's n the front, and they are too much, the car pushes. Im swapping to a 900 this summer sometime

karl's-92'-z28

iTrader: (5)

I bought a complete set of GC coilover brand new never used for $300, they came with SSS springs Suapension Spring Speacialists. Fronts are 800lbs 10" tall, rear are 150lbs 12" tall. This is the same setup CrazyHawaiian has. He has dropped spindles also, wichim gonna order also.

karl's-92'-z28

iTrader: (5)

Any pics of the front setup from underneath of the weight jacks
Mines came without instructions. Your Yellow bird looks sweet with the drop. For the fronts, do the springs sit on top the weight jacks?

//<86TA>\\

iTrader: (14)

reading ftw!

no pics. My 86 has the GC front jack setup, i put together the jack setup in my 92, that car has the nut plates welded in the spring pocket of the k-member and the bolts sticking up through the frame into the engine compartment, and the same in the rear.

karl's-92'-z28

iTrader: (5)

Duh...got it, it sits upsidedown in the K member....

Yahtzee

Im running weight jacks. 650lbs 8" in the front and 200lbs 9" rear. Here is a pic with the fronts adjusted all the way up, and the rears all the way down.....

itsMikey

that looks really good ^^

and thanks for answering all my questions guys appreciate it!!

i think ima do like..9" spring for the front at 900lbs and 10" rear at 300lbs

now, before anything else.

this IS going to be my daily as well as my auto-x'er..the roads around here arent TOO bad but i really dont care, i want it to handle more than i want it to be comfortable..thats what the impala is for

thanks again everyone..would love to see more pics of anyones cars with them installed with some specs about the springs

blyth18md

300lb rear springs are still damn stiff for autocross/daily duty assuming the rest of the rear suspension retains near stock geometry. You'll see more spring rates in that range on track cars. You see a lot more rear spring rates in the 150-200lb range.

What size rear bar? provisions to adjust rear roll center?

itsMikey

yeah, i want em to be stiff..maybe ill go a tad lower.

the rear suspension is gonna be solid..adjustable panhard with delsphere joints and LCA's with LCARBS and delspere joints..

and yeah, alot of other springs are at about 200lbs or so but there almost too soft. my BMR's were 150lbs and they seemed super spongy.

blyth18md

Honestly 200 range is likely a much safer bet. Especially assuming that you've already got the huge 24mm rear bar.

You've got to remember their is not a lot of weight in the rear of our cars and that even an increase of 50lbs/in is a huge % increase in stiffness.

itsMikey

yeah 36mm in the front and 24mm in the rear..

hmm...maybe 250 then?

87350IROC

iTrader: (2)

I'm running 850's in the front and 175s in the rear and have slight oversteer. 250+ is way to much for these cars. Start with a font/rear spring rate ratio of 5:1 and go from there. That will be close.

itsMikey

maybe 850 and 175 then for me..

hmm...

blyth18md

sounds like a good starting point.

itsMikey

alright...cuz like..i mean it IS gonna be my daily for a while but its performance i want.

you said it has a slight oversteer? how bad is it?

blyth18md

You should be in the ball park with those rates. You might want to keep your eyes open for smaller rear sway bar or bars to see if it suits your driving style better. The good news is so many people think the biggest bars are the best that the smaller (under 24mm) bars go cheap on the used market.

I think my rear bar is a 21mm, but they also put an 18 on these cars. See what you can find and see if they work better for you.

I also believe hellwig is still selling an adjustable rear bar, but I forget what the working rate range was on those bars, as you'll likely want to go with a less stiff bar after adding stiffness via spring to the rear.

//<86TA>\\

iTrader: (14)

i would say slight

IDK what rear bar he uses, but a smaller bar could help

87350IROC

iTrader: (2)

LOL, this thread isn't about me. Anyway my "slight" oversteer is noticeable on the track, but never on the street.

If it ever gets nice here in Seattle I plan to try playing with my Konis and trying a 36mm swaybar. My current sway bars are the stock 34/23mm.

AM91Camaro_RS

yeah, 175s should be good. anymore than that and you probably won't be able to hang on to it in a corner without other serious mods.

karl's-92'-z28

iTrader: (5)

My $500 setup Ground Control weight jacks 800lb 10" linear springs from Suspension Spring Specialists for the front, 150lb 12" linear springs for the rear, Hochtkis upper strut bar & stock Iroc wonder bar.

Jared57

On the ground control front weight jacks is there a thrust bearing? How is the jack bolt attached to the upper cup?

//<86TA>\\

iTrader: (14)

The jack bolt is tapped on one end for a 7/16 bolt. It's then bted to the cup with a hardened washer between to act as a 'bearing'. It works fine, you can adjust the springs under load