Leaf spring question for the road race guys...

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mopardude318

mopardude318

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Hi everybody. :)

I have TWO super stock leaf springs on my '68 barracuda that are the same part number, which is: P3412003. That part number is for the LEFT side. I bought these springs about 5 years ago and have only about 2 thousand miles on them. So they are relatively new. When I was ordering them, (I can't remember from who, West Oaks Dodge I think) the guy was telling me there is a left and a right for SS springs and that one side will sit lower. I told him I wasn't sure if I wanted the car sit lower on one side, so he sold me two left springs so the car will sit even.

Well, 5 years has passed and now I have a little more knowledge on leaf springs, and I'm building my car to handle and I've read that these spring aren't meant for a car to be road raced. They are on the car right now and they won't settle any more, and it's still too high for my liking, and it is pretty stiff! lol

So, should I remove one leaf on each side, or have them de-arched, or possibly trade someone who wants the stiffer springs for HD units? But I know SS springs come in a left and right, and since I have 2 lefts, it wouldn't be much use to someone who wanted SS springs....?? I guess ultimately what I wanted in the first place was HD springs, not SS springs. I wanted to replace the old sagging-in-the-rear springs that were on the car...

What are your thoughts about having two left SS springs on my car??
 
Having them de-arched sounds like a good plan.


At least you don't have two left feet!8)
 
SS springs are, by design, made for drag racing. SS stands for SuperStock.

If you de-arch a spring it gets longer and this can cause rear shackle interference problems.

Best bet……. XHD Springs or have some custom made.
 
If you have two left springs they are the less cambered of the two, and I believe have a somewhat lower wheel rate. For road handling this would be preferred over the typical SS installation with the biased springs. Even so, the issue with these springs is their relatively high camber. Spring camber raises the back end of the car which is bad for handling (elevated roll center, increased rear steer, forward weight bias).

The stock Mopar rear geometry had the springs nearly flat which is best for handling. So your best bet would be springs with a stock camber, but an increased wheel rate, such as HD or XHD springs. Next best would be to de-arch what you have now, but beware your shackle may bottom out limiting travel. Third best would be to flip your front hangers which will lower the back of the car, but does nothing to address the camber issue, and may cause grief with pinion angle.
 
Okay so would raising the front end just a little address the excess rear camber? I sort of did that right now, and turned the torsion bar adjusters one full turn to raise the front a hair, and here is how it sits now. What do you think of how it looks, too high altogether? to high in the front?

ff7by0.jpg


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Here is where the lower bump stop is from the frame. About a 1/4" of clearance...

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1968FormulaS340 said:
You are working against yourself by raising the ride height.
Click to expand...

Okay...Understood. I think I'm happy where it's at as of now I just raised it a touch to get it off of the bump stops...I haven't yet cut them in half, which I was planning on doing, so I could go a touch lower in the front, if I had to...I still have to solve my leaf spring dilemma...lol
 
mopardude318 said:
Okay...Understood. I think I'm happy where it's at as of now I just raised it a touch to get it off of the bump stops...I haven't yet cut them in half, which I was planning on doing, so I could go a touch lower in the front, if I had to...I still have to solve my leaf spring dilemma...lol
Click to expand...


Oh….. I wasn't paying attention again. Yup. You don't want it sitting on the snubbers.
 
mopardude318 said:
Hi everybody. :)

I have TWO super stock leaf springs on my '68 barracuda that are the same part number, which is: P3412003. That part number is for the LEFT side. I bought these springs about 5 years ago and have only about 2 thousand miles on them. So they are relatively new. When I was ordering them, (I can't remember from who, West Oaks Dodge I think) the guy was telling me there is a left and a right for SS springs and that one side will sit lower. I told him I wasn't sure if I wanted the car sit lower on one side, so he sold me two left springs so the car will sit even. ..
Click to expand...

You bought them through Troy when he worked at Westoaks. He is a fellow clubmember I've known for the past 20 years. I think I remember he saying he sold a few one side only sets. I faintly remember him asking me about selling them (one sides) to someone.

I wonder what the rate is of the short/weak side of the SS springs??? I wouldn't want more than 160-170.

I think right now it sits too high in the back. You could buy those drop front spring hangers from Dr Diff. But like was said that much rear arch is not great for handling. You get some "rear steer" when one side is compressed and the other is slightly extended when cornering hard.

Another way to go is the 1" or 0" arch MP circle track springs.
 
Thanks for the info steve. I don't know what the rate is, but they are pretty damn stiff, I can put all my weight on it and try to bounce it, but it don't move much. lol I think later, I will just get a set of the mopar HD units, or possibly the circle track springs like you mentioned. Right now the alignment guy is at my house, working on getting it all aligned for me. So, later I'll fix the leaf spring issue... He is almost dead on when it comes to the alignment specs, just a hair off on what I ultimately want. I'll let yall know how it comes out in a little bit...
 
I'm almost positive that Mopar Action's Green Brick used de-arched superstock springs. And that thing handled pretty darn good on the One lap tour. I'll have to dig through some back issues.


Wylde1.
 
I don't have any experience with ss springs.. But I am interested in seeing how all this goes..

To be honest My duster handles pretty awesome with just the big swaybar an alignment and poly front bushings. It is really predictable even breaking loose, though a little soft. It really depends on How "all out" you are planning on running. If you just want to drive it you could look into the drop hangers like autox said.
 
Wylde1 said:
I'm almost positive that Mopar Action's Green Brick used de-arched superstock springs. And that thing handled pretty darn good on the One lap tour. I'll have to dig through some back issues.


Wylde1.
Click to expand...

And I think they 2 left side SS springs as well.
 
I realized that I have these dropped front spring hangers left over from my street linx kit. So if I do use these to lower the car, from my understanding it still will not change the high camber of the ss springs, correct? And it would also possibly mess with pinion angle?

2qx2uyg.jpg
 
mopardude318 said:
I realized that I have these dropped front spring hangers left over from my street linx kit. So if I do use these to lower the car, from my understanding it still will not change the high camber of the ss springs, correct? And it would also possibly mess with pinion angle?
Click to expand...

What "camber" are you talking about? The leaf springs wont change camber.
The arch is what you should be concerned about...
Leaf springs not only support weight. but they also control axle location. So if the spring is arched at ride height a bump will change the axle location differently than a rebound which feels odd to the driver and can upset the car's grip. And you can use angle shims to fix pinion angle.
 
Sorry.. I forgot to mention that they should work fine. Use them and drive it.. if you don't like it THEN you could do something else. But I think you should try this since you have the stuff anyway.
 
Raising the front spring eye has an affect on a couple of things.
It will take out most of the built in steering that is designed in from factory, which is a good thing.
It will lower the effective spring rate slightly as the spring is more parallel to the ground, which is also a good thing.
but the pinion angle will be out so you will need angled shims under the spring perches.

I used 1" torsion bars in the front, std. sway bar on the front only and 6 leaf springs on the rear from a ute, lowered by turning the front bracket around and the car was very balanced.
 
scrappydoo said:
Raising the front spring eye has an affect on a couple of things.
It will take out most of the built in steering that is designed in from factory, which is a good thing.
Click to expand...

Very true... The factory designed the suspension to have roll understeer. Good for keeping grandmas on the road in the wet, bad for performance.
When you level out the spring it makes it more neutrally balanced. I am just using my stock ones, with lowering hangers and adjustable shackles.
 
You have several options. The front hangers with the extra eye bolt holes will allow you to lower the car. You can also de-arch the leaf springs which is what Eberg did with the Brick. Talk to the guys at Firm Feel and they can help you out. They have road race springs with a special front hanger or they can help you with your SS springs.
 
autoxcuda said:
You bought them through Troy when he worked at Westoaks. He is a fellow clubmember I've known for the past 20 years. I think I remember he saying he sold a few one side only sets. I faintly remember him asking me about selling them (one sides) to someone.

I wonder what the rate is of the short/weak side of the SS springs??? I wouldn't want more than 160-170.

I think right now it sits too high in the back. You could buy those drop front spring hangers from Dr Diff. But like was said that much rear arch is not great for handling. You get some "rear steer" when one side is compressed and the other is slightly extended when cornering hard.

Another way to go is the 1" or 0" arch MP circle track springs.
Click to expand...

i got my crate motor from Troy. where's he working now??
 
Based on my experience, with other cars, when your "on" the rubber compression limit stops, you loose "feel" in the front end,(spring of near infinate rate), especially when bottomed out and you hit even a small bump, front will push without notice. Dropped spindles with more compression travel ? Lowering blocks, at the rear are cheap to try, to dial-in the rear. You may like a small amout of "roll oversteer" at speed, usually more comfortable than "tight/push", in the front. Rear bar. ? Good Luck, ateam.
 
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