customblackbird

iTrader: (15)

Been looking into weight jacks for my formula 350 which now has a 521 BBF and every suspension goodie you can imagine. The car has cut moog 5664s up front like 1 1/2 coils cut for a 2" drop but has a 900lb ish spring rate. The rears are new moog 5665s with about 1 3/4 coils cut for a 2" ish drop and about 150lbish spring rate i think. This is on my ford 8.8 out back.

My delema is that now I have 295/65r15 MT street drag radials and they are 30" tall... they FIT!!!! But my spring is alittle low for the drag radials so I put a 1/4" poly spacer above the spring and its ok with about 3/4" clearance around the whole tire. But when I put my 26" tall 315/35r17 tires on the rear wheel gap is not to my liking. This would mean i would have to drop the rear springs and remove the spacer everytime I switch from street tires to drag radials.

Ground control has a nice bolt on kit but they want 459$ plus shipping and they wont sell me just the rears. I would like to make my own rear weight jacks but I cant seem to find somethiing like the rear adjusters that ground control uses on there kits.

I dont need to mess with the fronts at all so buying the whole kit would be a waste. I would like to make the kit a bolt on and use 200lb springs.

ANY IDEAS!?

//<86TA>\\

iTrader: (14)

the rear is made from a short piece of coilover sleave for a typical 2.5" ID coilover spring with a metal tube with a shoulder wedged into the other end to seat intot eh axle, not really hard to make honestly. Most circle track shops will have everything you need

BlackenedBird

iTrader: (5)

Not sure who made these. Thought they were GC units, but after putting them next to real GC units, which are stamped Ground Control, I knew they weren't. I tried to buy just GV fronts to go with these but couldn't. Then I ended up finding a full set front & rear here on TGO & bought those.

In the pic, they are upside down & fit under the springs.

SCCAjunkie

Would these help?

http://www.speedwaymotors.com/AFCO-A...cer,23948.html

customblackbird

iTrader: (15)

ive been looking at speedway motors but i dont see the part that slips into the stock spring perch. Fabbing something isnt too hard but I would like to get something premade or close to what i need.

SCCAjunkie... that looks close but the adjuster looks wrong. that also doesnt have the specs of the hole DIA.

Honestly I would rather run something that can use a regular non pigtale spring bc they are cheaper and much more available.

Also the stock side of the rear coil spring is what? 2.5 ID at the pigtale side and 5.5" at the top? what about overall free spring height?

customblackbird

iTrader: (15)

SCCAjunkie... looking at that looks nice but the stock spring would have to get cut big time since that fits on the stop of the spring.

heres a pic showing it

What I need to find is a short spring like a 8" pigtale spring at 200lb rate for that work, and I would have to take the spring out to adjust it every time.

customblackbird

iTrader: (15)

I thought about this and I think this could work, using 5" x 8" springs lets just say (non pigtaled)

The bottom of the spring will rest on this plate. its a Top plate for a weight jack but If i weld it to a tube that fits in the stock Spring perch then I have a 5.5" steel 1/4" plate base. the spring will rest on this and use the above spring adjuster to adjust the height. This will allow the use of 5" springs and adjustable height.

what you guys think?

Pablo

iTrader: (1)

No need to get complicated with this.
Get some cheap airbags from airlift. This is exactly how I run 28 x 10.5 slicks on my Buick T type. I think I paid 50 dollars for them and the install took about 45 minutes. Takes a total of 2 minutes to change the height and tune the launch even with just a bicycle pump.
And in case you were wondering, I have run a 1.54 60 foot with them. I know of another Buick guy who has run 60 foots in the 1.2 range with them too.

Good luck.

customblackbird

iTrader: (15)

Not going to use airbags... Im not a huge fan of them. Plus I want this to last. My slicks are also 30" tall and not 28". if they were 28" i would have not needed to do any mods to the rear suspension. Thanks for the idea tho.

I measured my cut moog 5665s which are 13" tall free height.
Moog 5665 specs original
ID =4.3"
bAR DIA= 0.49"
install height= 10"
load rate= 580lbs
spring rate= 107lbin
Free height= 15.42"

So Ive dropped free height 2.5" and increased spring rate to what I can guess is around 160ish.

I think Im going to go with the above hidden spring adjuster/shim with a 5"x11" spring at 200lb. The adjuster will be installed at the bottom of the spring so Ill mod the spring pockets on the rear. The 11" height will be ok bc the adjuster has 2.5" of adjustment which will put me at 13.5" free height plus the thickness of the adjuster plates and poly spring isolator Im running. Effective adjustment of about 12-14.5" should be what i would get at free height. Since the rate is also higher it should have less drop even with the lower free height. I'll try 12.5" free height first and then adjust from there.

Now I gotta figure out how to adjust the jacks to fit the stock spring mounts on the rears.

Pablo

iTrader: (1)

.

InfernalVortex

iTrader: (4)

This is from some research I was doing on FRRAX. Definitely read through this thread for information. More than enough to figure it out, but it's just a lot.

Ground Control weight jacks have their own design problems... The pigtail springs and the tall spring perch can, occasionally, do this:



http://www.frrax.com/rrforum/index.php?&showtopic=183

These are the allstar weight jacks:

http://pitstopusa.com/i-5066715-alls...uster-nut.html

Comparison





Only problem is finding a good spring. What we need is kind of between sizes. You can always trim a spring down though. For the Allstar jacks use a standard width spring (no pigtails on the bottom). The other problem with the allstars is that they are steel, which is fine, but they will rust if not prepped. You can try wd40 or clearcoat or whatever, but if you want to maintain some adjustability, you'll want to do something to make sure they dont rust, because once they do they wont be so adjustable anymore.

http://pitstopusa.com/c-131813-sprin...l-springs.html

Im sure a lot of this information was already mentioned, but I just wanted to point out that it HAS been done, successfully, and there are compelling reasons for and against the allstar design, and reasons for and against going for the ground control setup. There's not a clearcut advantage for GC beyond just having a kit sent to you that you dont have to do any work to put together.



BIG_MODS actually made his own front weight jacks, but that's a lot trickier. He's got a thread about that on FRRAX, and he was able to make a set, but it required a lot of fabrication to make new spring cups to sit in the factory spring pockets, and some modification to the k-member.

robertfrank

iTrader: (27)

My weight jack on the passenger rear does this same thing, almost like it wants to always sit crooked and not fully in the spring pocket of the rear of the car. I've fiddled with it many times and it always seems to return to this position. I've gave up on it honestly.

customblackbird

iTrader: (15)

good post. ill have to read about it when i got the time.

However I had already thought about that and basically purchased it and installed it about 4 days ago. Turned out pretty good.

I got speedways hidden adjustment shim with 2.5" of adjustment. Then I got 11"tall by 5" AFCO 200lb springs. I used a 1/2" poly spacer/isolator at the top of the spring. Basically made my own weight jacks. Worked out fine so far. The springs altho much shorter than stock still give me a good bit of wheel gap (perfect for the drag radials) however I adjusted them all the way down and they are close to where my cut moog 5665s are. If i remove the top isolator I could gain 1/2" to lower my ride. I could have gotten away with a cheaper 10.5"x5" "truecoil" spring at about 46$ each.

Cost was about 160$ to my door and I could have saved alil by going with a different brand but they were about 52$ each.

heres a few pics.

articwhiteZ

iTrader: (56)

last year i call GC. and asked to buy just the Rear WT Jacks.
talked to the Head Guy.

asked for just the rear Wt Jacks, with a set of springs that would Keep The car at the Stock Ht.with the Wt Jacks on. so i could go up or Down.

from My MT ET streets 12.5 x 28 15 or back to the Mt sportsmen 12.5 x 29.5 15

cost was $220 shipped to my door... Just ask for the Boss, cut out the small fry!
springs are 10" tall , 175lbs, shocks 50/50


using coil overs in front, and Wt jacks out Back.
my 92 z28 has the Ground FX on the car that keeps me from going to a 30" tall DR tire. till the car is back halfed. im running the MT Sportsmen 29.12.5.15

articwhiteZ

iTrader: (56)

check into zink plating..silver or gold zink. about $10 and rust proof forever!

customblackbird

iTrader: (15)

I called them and they said they werent selling half kits anymore. Due to not being able to warrenty the product/setup since ppl can do what they want with the half kit.

I measured my stock cut moog 5665 and got about 13.5-14" (this was after removing like 1 3/4 coils already. I thought the 11" spring would be fine but I dnt think i can get it as low as i wanted. I could have gotten away with a 10.5 -10" spring. I should be able to stuff a 30" tall tire without issues now.

articwhiteZ

iTrader: (56)

Due to not being able to warrenty the product/setup since ppl can do what they want with the half kit.

THATS SORTA SOUNDS Bone Head to me!

we are going to do what we want with there parts anyway

but NOW we know we can get the parts to make a work alike Wt jack from speedway.and for less money..

83 Crossfire TA

iTrader: (2)

Huh, looks good, but do the GC jacks have a means for locking them when you have them adjusted where you want them?

BlackenedBird

iTrader: (5)

Yes. A set screw in the side of the adjuster ring. You can see it in the pic I posted above in Post #3 on the left WJ. The "odd hole" that seems out of sequence spacing with the rest of the holes.

//<86TA>\\

iTrader: (14)

in the last pic of the GC piece, you can see that the collar (gold) is split, there is a pinch bolt in there that when tightened pulls the threads of the collar tight into the threads of the sleeve and locks it in place.

with the weight of the car on them, they should not move even without a locking means

articwhiteZ

iTrader: (56)

SilverLT1vert

I'm so glad I found this thread! I've been thinking about doing something like this for a while now. Right now I am running Eibach sportlines, but I'd like to go a lot lower (I plan on doing 3/4" extended ball joints up front). I'm not sure exactly how much they lowered the car ('85 Iroc) because I didn't measure, but it actually wasn't much. The front sat a lot lower than the rear which I didn't like, so recently for a car show I removed all the isolators, and the car sits perfect for now. My main problem with the car is how soft the rear is. Just loaded with luggage and no passengers the car will easily squat 1-1.5" and hit the bumpstops with ease on the highway. I always thought 200lb springs in the rear would be perfect and I would actually be able to carry passengers again! My question for you is, do you think 200lb rear springs were enough of an increase in spring rate (even over your cut springs) to be noticeable and enough to carry passengers without totally ruining the ride when solo? I was considering 225lb springs as well, but nothing more than that. The plan in my head was to follow your lead almost to a T, except I thought about running 9.5" tall 5" diameter 200lb springs with fourth gen isolators (1/2" or so). I'd like sit about at the ride height I am now (1.5-2") with the adjuster about 3/4 of the way up. Basically so that I can go down another 2" if necessary, or .5" up along with a higher rate spring. Any thoughts or suggestions would be greatly appreciated! Cheers!

customblackbird

iTrader: (15)

The 200lb AFCO springs im running seem to be perfect as far as harshness goes. The car is much more stiff in the rear compared to the stock cut moog 5665s. The springs are so stiff that the 11" spring is too tall, with the 200lb rate the spring doesnt compress all that much and as ive stated before I would have rather found a 10" spring so i can adjust the spring low enough for my stock 26" tall street tire. At the lowest point on the weight jacks the 11" spring without an isolator (it feels better without the poly isolator) sits about the same height as my cut moog 5665s which Im alittle annoyed about. But it allows me enough adjustment to fit my 30" tall drag radial under there no problem! I had the car out to the track 2 weeks ago and it ran consistent 1.8s 60's... which isnt great but much better than the street tires 2.3s 60'. The car still isnt dead hooking as I can still get them to spin if I mash them at the light or foot break the 521s massive tq.

I dnt run any passengers, rear seats have been removed and i have a 8pt mild steel roll bar installed which is 120lbs all the time added to the car. The 200s compress when I push down on the rear quarters with my body weight (im about 200lbs of muscle) and I prob wouldnt go with 225lb springs. Since I dnt have alot of weight in the rear of the car, if your planning to load it up then 225 might not be a bad choice. Just remember you want the rear and front to be balanced otherwise it will prob handle worse. If i were to do it again I would get the same 200lb spring but in a 9.5-10" height. A 225 rear spring would have to have like a 1000lb front spring roughly which would be one hell of a stiff ride. my cut moog 5664s have about 900lb rate and its not too bad.

Get rid of the sportlines, those things are junk. I had them and sold them to cut up some new moog springs.

SilverLT1vert

Thank you for the quick response! Sounds like the 9.5" 200lb springs might be the way to go. My car isn't very heavy, and I rarely carry passengers or luggage, but I like to know that I can if necessary. Sounds like I might have to swap out my front springs for the Moog 5664's. I'm going to install 3/4" extended ball joints and bump steer kit, then trim the spring, keeping it as long as possible for my desired ride height.

I'd really like to know the spring rate of the front sportlines. My car is super stiff! I mean unusually stiff... My brother has a 91 Z28 convertible, bone stock, and to me his rides almost too soft, but good. He also had a 91 RS bone stock that rode about the same. We put the pro-kit and kyb's on it and it barely lowered it at all. And it still rode super smooth. It was probably one of the best handling/riding 3rd gens I've ever been in. My car will literally jar the hell out of you even on small bumps, and the rear will squat and hit the bump stops! I did trim the front bump stops down about halfway, since I only had about 1/4" clearance after lowering which helped a lot. So far I haven't hit the bearing plate with the shock, but I'll install shock mounted bumpstops before I go any lower.

paul_huryk

I have the GC weight jacks in my Camaro - ride decent but occasionally get a "clunk" going over certain types of pavement at certain speeds. Not super happy with them.

customblackbird

iTrader: (15)

Front sportlines are about 704lbin rate. The rears are very soft at like 100 at ride height and 130lb compressed since the rears are a progressive rate. The prokits are 714lbin front and have a 130-160lb rear progressive spring. The stiffness your prob feeling is that the car is riding on the bump stops most of the time lol. seriously get rid of those springs.

to help with the front bearing plate issue, u really need to regain the decrease of spring/strut travel that you've lost by lowering the car. basically you making the susupension travel/operate in a state at which it was never designed to operate in. Struts/shocks are compressed more than they should be all the time.

You need to get the Hotpart or UMI or J&M type of adjustable caster camber plates. When I got my hotpart versions they were 250$ and have a lifetime gaurentee. I see that UMI and other versions are only 159$ now... you will get more performance from getting rid of the $hitty stock strut tower bearing things. They have an increased 1" for bearing height which puts ur struts back in the operating range.

hellz_wings

iTrader: (2)

I'm in definite need of stiffer rears and want to lower the rear slightly. I was considering weight jacks and now I'm sold. They're cheap and effective. I was also looking into the AFCO springs (I like the yellow color actually) but wasn't sure which model would fit.. Customblackbird used an 11x5 spring @ 200lbs but it seemed to high for him, I think going with a shorter (cheaper and lighter) spring would work better. My car sits at about 27" in the front and the rears now are about 28" so I don't need to lower that much, although I want to get front WJ and a bit stiffer springs later on too, so I'm doing this as a long term investment.

Speedway jacks + AFCO 150lbs springs would be a good combo for me (my rear PHB is lowered so I need stiffer rear springs.. I found this out the hard way last night when at on the way to the track i experienced, what may be the first time, very scary understeer close to a wall.. Very scary lol. (hence the reason I'll lower the front about 0.5" in the near future MAYBE to lower roll center and CG so the front grips more an understeers less.. but it depends on how it does after installing the 150lbs in the rear).

customblackbird

iTrader: (15)

At the 200lb rate i would have gone with the 9.5-10" 200lb spring rate. If you lower the rate the the springs height doesnt have to change much. A 150lb spring will compress more than the 200lb spring at the same weight put on them. So say that 150lb spring will drop like 1/4-1/2" more if I were to swap them onto my car right now. The reason I like the 200lb spring at the moment too is that It allows me to fit the 30" tall drag radial with just barely increasing the weight jacks... roughly 1" on the driver side and 1.5" on the pass side. what i dont want to do is run the weight jack all the way to the top of the adjuster... that way if the spring wanted to walk out/fall out/ or spin out it could since there would be nothing in the middle to stop it. The setup is pretty good for me, the ride height i would have liked maybe 1" more drop MAX... but AFCO doesnt make a 10.5" spring or a 10" I believe.

I went with AFCO bc they are a big name in the racing business and there $hit is LEGIT! Not to mention they guarantee the springs rate/height for the life of the spring that means you got some good $hit! The yellow is not my favorite but the stock new moog spring coating is good for maybe 10days and then it starts to rust and look like $hit.

Front weight jacks would be nice. Not a fan or drilling holes in my front engine Sub frames... or doing all that mambo jambo. my moog 5664s got the perfect height for road handling and i wouldnt want to keep messing with stuff when i got to the track. Sure I might be giving up alittle at the track but its prob not that much. I cant see stiff front springs being a good thing either for the track, hell even a 150lb rear spring prob isnt that good.

91banditt2

iTrader: (1)

Customblackbird can you give a long term review of these coil spring adjusters? I'm using this same arrangement on my 91 Firebird with a 9.5" 200lb Eibach spring, any issues or concerns with the adjuster ring move around?

customblackbird

iTrader: (15)

yup, no issues! I haven’t messed with the ride height in a few years and have put over 5k miles and they haven’t moved. In order to move them you basically need to jack up the car and remove all
weight on the springs and even then they are kinda tough to adjust. I thought about adding notches and making a tool to help (like a spanner wrench) with that but like I said I haven’t messed with the ride height in years.

91banditt2

iTrader: (1)

Thats good to know, so mods to the original spring “cups” on the rear end? I’ve got the same spring adjusters and they are a super loose fit on my 9 bolt, I cut some rubber hose to fill in the gap to get the spring adjust centered.

customblackbird

iTrader: (15)

nope, I originally made a taller lip with exhaust tubing maybe 1” or so as I was worried too. But found out it wasn’t needed and removed them. Once you get weight on them they don’t move. You don’t want to do anything that will cause removal to be harder either. I have a 8.8 but used the stock brackets off my 9 bolt it’s going to look weird on the pass side but you’ll be fine.

customblackbird

iTrader: (15)

I also made my own front weight jacks from speedway but it took some welding and fabrication. Overall not too bad and I’ve played with the front adjustment quite a bit. I run trucoil 800 or 850lb springs and they adjust through the bottom of my UMI lower Aarms with a 1/2” socket wrench. I just jack up the front and put a wrench on it and count how many turns then adjust the other side. Real easy to fine tune the height. I also have a racecraft moly kmember and didn’t need to make any mods to anything. I think I have less than $250-300 invested in the whole setup front and back. Ride on the street is firm and not harsh with the Koni yellow struts and double adjustable Viking rear shocks.

91banditt2

iTrader: (1)

I don't know if your remember but we've had conversations about the fronts I've made my own based on some of your advice through PM and email