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View Full Version : what would you preffer, being on top or on the bottom



Tig
10-22-2009, 06:13 PM
Curious.
Would I get the same handling characteristics with a drop leaf and shackle combo as I would with a flip kit?


This info is for my 99 2dr 2wd Tahoe.
Thanks

Tig
11-07-2009, 09:35 AM
Anyone :hmm:

Van B
11-07-2009, 10:51 AM
I don't know, but I find it hard to believe your title only made 104 people curious enough to look inside.

Twentyover
11-07-2009, 11:12 AM
Flip it. The more arc in the spring, the easier it is to control & modify rate

Tig
11-07-2009, 06:33 PM
I don't know, but I find it hard to believe your title only made 104 people curious enough to look inside.

I was thinkin the same thing. Thought it was a catchy title, enough to peak someones interest to respond. I thought wrong, lol.


Twentyover
Flip it. The more arc in the spring, the easier it is to control & modify rate

How can you control and modify rate?
I didnt know it was possible to modify spring rate.

Quick question.
What does 1950lb load equal out in spring rate?
Thanks

Rhino
11-07-2009, 06:48 PM
I was thinkin the same thing. Thought it was a catchy title, enough to peak someones interest to respond. I thought wrong, lol.



How can you control and modify rate?
I didnt know it was possible to modify spring rate.

Quick question.
What does 1950lb load equal out in spring rate?
Thanks

I don't know a way to modify a spring load accurately. The main components of spring rate are metallurgy and material thickness. Neither of which are easy to modify after the spring is manufactured.

To answer your question about rate, we would need to know more details. spring rate is usually measured in in/lbs. If you place 500 lbs on a spring, and it settles 1 inch, it's said to have a rate of 500 in/lbs.
If you knew how much the springs settled with that 1950 lb load, you would be able to calculate it's rate.

Tig
11-07-2009, 07:12 PM
I don't know a way to modify a spring load accurately. The main components of spring rate are metallurgy and material thickness. Neither of which are easy to modify after the spring is manufactured.

To answer your question about rate, we would need to know more details. spring rate is usually measured in in/lbs. If you place 500 lbs on a spring, and it settles 1 inch, it's said to have a rate of 500 in/lbs.
If you knew how much the springs settled with that 1950 lb load, you would be able to calculate it's rate.

I wasnt too sure either. Honestly I didnt know it was possible to modify the rate.

What type of details/info would you need?
I'll have to get in touch with Eaton to get more info. I've asked on several ocassions with no such luck and no answer about the 1950lb load.

Thanks for the info, I appreciate it.

Twentyover
11-07-2009, 09:49 PM
How can you control and modify rate?
I didnt know it was possible to modify spring rate.

Quick question.
What does 1950lb load equal out in spring rate?
Thanks


Rate is cntrolled by spring length, leaf thickness, leaf length, leaf width, & # of leafs. On the little green race car, we de-arched, removed a leaf, and shortened a leaf to soften the rear suspension. Metallurgy, assuming we're talking steel here, is irrelevent to rate, but is important to prevent the springs from sacking

(In the interst of full disclosure- this is an MGB, weight is removed from the car, and a rear bar has been added to restore roll stiffness. De-arching was done at a blacksmith shop, leaf modifications were executed in the back yard. A non-adjustable bar had us overseering when installed, and understeering when a leg was removed. It was replaced by an adjustable bar.)

This stuff isn't rocket science, knowing how to make a leaf spring has been around for years.

What is 1950? unladen weight? What is maximum laden weight? What travel do you need? What is the function of the vehicle using the spring? I'm sure if think about it when it's not 1 in the morning and the beer wears off I could probably come up with a couple more questions. Think you want to start with ride frequency.

Rhino
11-08-2009, 07:25 AM
I wasn't really thinking in terms of a leaf when thinking about material thickness. By removing a leaf, you're effectively thinning the spring material.

I guess by metallurgy I was thinking more of it's modulus of elasticity.

Twentyover
11-08-2009, 08:31 AM
Shear Modulus, about 11.5 million psi for almost all steels. Also, if it was dependent on MoE, that's pretty much 30 million psi for all steels.

My approach is to figure each leaf independent of the others and stack rates of each leaf. In addition to removing a leaf, you can taper or uniformly thin the width of a leaf (except for the primary one) modifying it's rate. Also technically possible, but more difficult, would be to thin the thickness of a leaf. If one were to try that, maybe easier to look at another application w/ thinner material for base stock.

Tig
11-15-2009, 05:43 PM
I didnt realize there was so much involved or some of the terms used. My last truck, I was able to call Hotchkis and a week later I was pretty much track ready. The function is a DD "street truck". Wish it was that easy with my Tahoe, the odd size leaf is prooving to be rather difficult. I did find a site with more info in regards to the leaf springs I'm interested in.

I asked about the spring rate of the leafs and he responded back saying "it has a 1950lb load".

mrn2obelvedere
11-19-2009, 07:15 AM
Curious.
Would I get the same handling characteristics with a drop leaf and shackle combo as I would with a flip kit?


This info is for my 99 2dr 2wd Tahoe.
Thanks


I think the cornering characteristics might be similar, but the squat/anti-squat characteristics will probably be drastically different.

Tig
11-22-2009, 06:39 AM
For now I'm going with replacement leafs and flip kit. I have the flip and need new leafs anyway.
We'll see how it handles after that, may make some trac bars to.

silver69camaro
11-23-2009, 05:23 AM
I think everybody is looking too deep into this. The only difference you may notice is a difference in roll center height, which will affect roll rate. Thats it, really. I can't imagine this this a track car...

mc84_zz4
11-23-2009, 10:23 AM
I like to be on top.

Tig
11-23-2009, 03:20 PM
silver,
Thanks, I agree. Way too much thought went into this, lol. Its for my truck which is a DD. My end goal is for a great handling street truck. I am hoping to try some auto-x in the near future as well.

mc,
too funny dude.