customblackbird

iTrader: (15)

What are you guys running for spring heights and rates on front and rear weight jacks? Im upgrading to a moly front K-member and want to absorb more of the ground through the springs than the car/k-member.

I currently run a 5"x11" 200lb rear spring with handmade weight jack and my fronts are cut moog 5664's if I remember correctly for a massive drop and about 900ish lb/in.

Im looking to soften it up a bit and thinking weight jacks in the front, I think I want to step the rear down to 150lb and perhaps a 800lb front spring ( have a BBF up front, which weighs about as much as an all iron SBC). I don't want it to be mush but not as harsh as it is now. But most important is the front spring heights… 9" or 12" or ??" at what rate?

SlickTrackGod

I had a light weight V6 (about 250lbs lighter on the nose then the V8 cars)
I ran 800lb springs with a free height of 12" I had a very low 24 3/4" front fender lip

Considering the extra weight of your BBF (which you say weights about the same as the SBC) I would say the weight jack takes up about 2 1/2", so if you ran a 9" spring with your weight and spring rate you should be fine in the 25" to 26.5" fender height range of adjustment.

Important added info: I should also note this is without any front isolator bushing on top of the spring.

customblackbird

iTrader: (15)

Well I'm not going with the ground control weight jack setup. Looking at piecing together my own AFCO lightweight bucket which doesn't take up any spring space. So you think a 12" spring at 80 lb is sufficent?

How long of a bolt do you use? 5 3/4", 8" or 11".

Also looking at the GC setup there is no part that is welded to the frame or spring bucket?

My BBF has aluminum heads (weigh as much as iron SBC heads, aluminum intake, aluminum waterpump etc... weight is close if not a smidge more than a SBC.

SlickTrackGod

i would never use a setup like GC, I was not talking about that. I am talking using jack bolts, welded plates and swivel cups. This subtracts about 2 1/2" from the overall spring pocket.

6 to 8" jack bolts are sufficient. I would use 6 personally so there is not header interference issues and such. So what it the head of the jack bolt is down into the frame cavity hole if the car is jacked that high with the jack bolt, but it shouldn't be. 6" should be adequate

SlickTrackGod

Here's a post you can reference where TEDSgrad (Brian) used 9.5" springs and swivel jack cups WITH 2" drop racecraft spindles and he was about 26" ride height. I was telling him he could probably go 11" springs because the fact he has drop spindles.

Keep in mind you wan to leave room up top for the spring cup to swivel. If you do not have room then the top side of the cup will swicel and knock into the adjuster plate. This is why I say it takes up aprox 2 1/2" space.

https://www.thirdgen.org/forums/susp...g-vetruck.html

customblackbird

iTrader: (15)

So what do you think of something like this? Light weight cup, swivel on the tip of the cup, no jam nut and uses a SS ball to lock the bolt in place. But I don't really see how it takes up 2 1/2" of space at the top of the spring in the spring bucket. Also my Kmember is now going to be a RaceCraft Moly K-member with spring perches, so do I need to weld the spring perches to the WG frame plate?

heres the road race version of the K-member thats on its way to me… spring perch is the same.


This is the WG setup Im looking at.


Thinking of a 5.5x9.5" 800-850lb spring.

SlickTrackGod

A couple of points I want to address about what you just wrote-

1) it is not safe to mix CM and mild steel together.
2) with that Kmember (not being the stock one I am refering to) you will probably plan to cut off the bottom spring retention ring and weld the jack plate to the flat underneath of the upper spring seat ring- that will take out strength also to get the more clearence you are assuming you'll gain. I would not weld that to the top (especially mixing CM and mild steel. I would suggest just attaching it to the underneath leaving the retention ring IF you plan to mix metals in the first place.

3) what you are not calculating is room for adjustment as well as swivel room. You want a longer spring that will put you maxed out to get the desired ride height you seek? or do you want a happy medium in adjustment range? this leaves some room plus thickness of the swivel jack. Figure about 1" or better room for play adjustment and swivel- this is what you are leaving out in your build assumption.

customblackbird

iTrader: (15)

1/2) Never said I was going to "mix" the materials… wasn't sure how I was going to attach the upper frame plate But I also did Not want to cut the brand new Kmember up. Figured you could add to the frame plate and make your own "cup" and then just do a couple of welds on the outer perimeter edge to keep it from moving/sliding back and forth. I also need to contact race craft and verify that the spring cups/motor mounts are moly and not mild steel.

3) I have no idea by picturing it in my head what clearances are what and how I need to compensate for anything. I would like a happy medium range, I don't want it "slammed" as the car is mostly street driven and I want function over looks. My plan is to get the car at or around its current ride height but with the use of weight jacks or coil overs but with a slightly softer spring rate/ride. I basically just need a base spring free height/rate that will get me in the ball park and adjust my height accordingly.

TEDSgrad

iTrader: (4)

Here's a pic of all the stuff I put in. Weight jacks are front and center. Springs are 9.5" and when I spin the bolt all the way up, I can pull out the springs by hand - a little tug, if I go 11" I would need a spring compressor (but I am contemplating it).


There is no problem hitting the can with the swivel. Suspension is hanging in this pic, but you can see how much spring coil and where the swivel cup is:


Here is the bolt up top at approx ride height. I did the suspension & brakes went to the track, and came back and took out the 215k L98 for a LS2.


After the LS swap, here's the driver's side, just a slight and gentle moving of the brake lines for the bolt.

TEDSgrad

iTrader: (4)

And my ride height.

customblackbird

iTrader: (15)

you still had to weld the frame plate right?

customblackbird

iTrader: (15)

And it looks like you have drop spindles and spohn caster/camber plates.

TEDSgrad

iTrader: (4)

Correct.
Here's where the plate goes in (pic is unmolested spring cup).


I cut out the raised center, then increment cut around the rind (it's uneven because of how you have to cut it). The increment cutting helps in welding and I hammered them even. It worked out well. The swivel cup weight jacks are great! This takes a bit of work, and with no lift, I'm on my back welding up in the cup. Once I pull the motor, I cleaned up top so you can't tell. You can see that I drilled a small centering hole to make sure I was not hitting anything up top, and it served as a centering hole for the hole saw I used to cut through the frame rail, then welded in the plate.


I also used Spohn's under fender plates (even though they're for coil-overs) for added strength on the strut tower/fender (similar to what he offer for the real coil-overs to strengthen that area - upper shock area). Front lower left of the pic of the parts.

tvc 15

Here's a pic with the K member out of the car.