SPRING RATE OF REAR SPRINGS?

[BLUESMAN]

I plan on installing a pair of 52" rear springs in the front.Anyone have the specs on the rear spring rates?I know that I will have to move the front hanger 3 1/2" forward to move the diff 1" forward,just wondering how soft the springs are.Thanks Mike

 

[BadDog]

I think Twiztid is running 52s in front...

 

[BLUESMAN]

Thanks Russ,I PM'd him.Mike

 

[Twiz]

I used the main-leaf of a 4" lift, 52" long rear spring as my main, the other leafs are from the rear of a S10.
The last leaf is off a my '67 camaro.

I'm not much help on the spring rate.
I just fiddled around with the spring pack until I got something I liked.
Thats the great thing about leafs, you can just about do anything you want with 'em. Increase/decrease the overall spring rate - raise it/lower it - make 'em smoother, or get them to hit at some point.
Try to get that amount of adjustability with a set of coils, without going broke.

A word of advise;
- Grab every spring pack you can get you hands on for free, check out Body-shops, Junk-yards, other rides you might have sitting around the house, and don't forget about your knuckle-draggin buddys. You never know where "that perfect leaf" might be found.
- If I was to do it over, I might have just stuck with the S10 spring pack and worked it over from there.
- The core support mount will/might need to be relocated, as it is part of the front spring mount.
- There is not a doubt in my mind that longer front springs are needed. The stock (or A.M. lift) springs are too short.
- On the same note. The key to getting any-kind of travel from the front springs, is all-about correcting the crappy shackle angle you get when useing A.M. lifted springs, or anyother spring pack, for that matter.

 

[Donovan]

At ride height, what angle is your shackle at Twiztid?

 

[BLUESMAN]

Thanks Twiztid,I plan on making a new much stronger front spring hanger 3 1/2" forward of the stock hanger.That will give a little better angle at the rear for the shackle and move the diff 1" forward.At this point I'm going with stock rear springs and remove the overload leaf.then see where I stand.It's gotta be better than the Rouch Country springs i have now(already removed one leaf from them).The rear shackle are actually angles forward,sure that does'nt help the ride.I'm just hoping that the stock springs are strong enuff to carry the front end.So you started with 4" lifted rear springs?Thanks,yet another project to get started......Does it ever end??

 

[Ryan Melton]

I've got 52's in the front of mine. They give about 3-3 1/2 inches of lift in a front applicaiton. Stephen Watson told me the factory 4+1 GM rears are supposed to be about 270#/in.

Ryan

 

[BLUESMAN]

That includes the overload leaf?Are you running with the overload?I was'nt plannimg on installing it.Thanks.

 

[Twiz]

</font><blockquote><font class="small">In reply to:</font><hr />
At ride height, what angle is your shackle at Twiztid?

[/ QUOTE ]

I don't recall off hand, something around 45 degrees, it's laid back pretty far. (The front suspension is out of it right now, so I can't measure it)
The shackle is just long enough to clear the frame (5.25", center to center)
The arc of the shackle follows the spring, and really made the spring pack super-soft. That is one of the reassons for the 4" lift main-leaf I used, the S10 pack has a pretty mean free-arch to it too. From there I just mixed and matched untill I got it to where I liked it.

I'am convinced, to get the front suspension to move, it has to have the shackle angle corrected. Longer spring help too, but not as much as the shackle angle.

 

[Triaged]

Try playing around with this
http://home.earthlink.net/~triaged/LeafSprings.xls
That is a Excel spreadsheet I made to calculate the spring rate. The front spring info I just made up to make it match the spring rates in the CK5 tech info page...but the rear springs I measured.