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How Do I Tell What My Spring Rates Are?


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Mine squeek during low speed in and out of driveways and that sort of thing.

When the car's off the ground, you can wiggle the springs with your hands, but not when on teh ground.

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Thats funny.. i'm not expert on shocks & springs but is it you setup the ride height to be so low so that when the car is off ground, the distance between the lower spring seat and the top mount is so huge that the spring is literally not compressed anymore? But yours is R34, mine's R33 so I dunno...

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My problem was that with the standard circlip groove on the Koni's and King springs, the front was too low and the rear too high.

So, I bought and installed the Whiteline springs, and still, too low at the front and too high at the rear. So then we machined new grooves (the Koni dealer in Vermont) in both front and rear shocks and refitted. So the fronts were higher, there fore pre load on the springs, and the rear was lower, so no preload on the springs.

the heights though, are spot on. 345 front and 350 odd at the rear.

The squeeking sounds to be soming through the top of the shock, but that could just be the tranmitting of the sound through the steel.....

Stoopid cars.

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Pete, sounds like the bush might be binding and squeaking on bumps. Is it front or rear? The rear of 34's is a yoke at the bottom right? Hard to say that they would be the culprit but I had my old ones do it at the front.

Do you have after market anti roll bars? Often the urethane bush can squeak with them.

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SK,

Does this method of working out spring rates still hold true for progressive rate springs?

Cheers.

Yep, it's a bit more complex to calculate and I would need to know the coil spacing. I will post up a picture on how to do it over the weekend.

:P

PS. most so called "progressive rate" springs actually are simply designed to remain trapped at full droop. The soft rate is totally soaked up by the weight of the car, so there is no progression in the rate once the spring is installed and compressed.

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Yeah, I've got the same problem, my front is too low till it can scrape the tyre on hard cornering... I dunno why but most ppl with Whiteline kit would have this "dive in" stance with the cars. I think I'm gonna ask my front ones to be re-adjust like yours, make it a bit higher so the car's sitting horizontal again...

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Yeah, I've got the same problem, my front is too low till it can scrape the tyre on hard cornering... I dunno why but most ppl with Whiteline kit would have this "dive in" stance with the cars. I think I'm gonna ask my front ones to be re-adjust like yours, make it a bit higher so the car's sitting horizontal again...

I have seen this a few times lately, mostly due to people using GTR front shocks in GTST's. They are shorter. Or placing the lower spring seat in the wrong circlip groove.:(

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Found an online calculator, it gets obtains values pretty close to what ur estimating SK.

http://www.proshocks.com/calcs/coilsprate.htm

Its from the website below, it has some good stuff on it...

http://www.martindalecenter.com/Calculator...rs1_3_Auto.html

Im going to measure my shocks tomorrow, their Trust coilovers, so no doubt the are going to be pretty stiff. Cant find any info about them on the internet, I dont think Trust make suspension anymore.

Rhett

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Yup, hit me with it, SK. :P

These are King springs, lows, which I just got today. $250 for the 4, brand new from Repco, ordered yesterday. Most happy. :rofl: Replacing shitarse Pedders SportsRyder... which are saggy, imho.

Fronts: KDFL-101

ID Upper: 96mm

Lower: 85mm.

WD: 12mm

# Coils: 7.1

Rears: KDRL-61SP

ID Upper: 100mm

Lower: 90mm.

WD: 13mm.

# Coils 9.

Will put up the specs for the pedders when they come out tomorrow.

Edit: Tried that american calculator - roughly converted to inches, and got 244lb for the fronts and 164lb rears... which seems a little strange to me. Most setups have lower spring rate in the rear, but 80lb is a third of the fronts spring rate.

Oh well, shall take SK's calcs as canon, rather than my dodgy guesstimating.

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  • 2 months later...

I don't suppose somebody could meaure a set of stock S13 Silvia springs for me? I am just currious to know what the stock rating is. I am about 15000miles from my car at the moment and can't seem to see the springs :)

Thanks guys!

Adrian

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Oi Gary....

question for you :) what about these tien jobbies with the little cushion spring ? effect? or not...

They are called tender or helper springs, usually they are between 75 lbs per inch and 125 lbs per inch. They are mainly there to keep the main spring captive at full droop. They also give a modicum of inside wheel contact at places like the dipper. They totally collapse when the weight of the car is placed on the spring stack, that's why they are made of flat wire, so they neatly stack on top of each other.

You can live without them and simply limit the travel of the shock, so the main spring stays captive. But (there is always a but) that sometimes means there is not enough droop to get the wheels off when you jack the car up. Saw that happen on a Nissan SuperTourer, they limited the shock travel to save buying tender springs. Then they couldn't get the rear wheels on. :lol: :lol: :lol:

:) cheers :P

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Yup, hit me with it, SK. :)

These are King springs, lows, which I just got today. $250 for the 4, brand new from Repco, ordered yesterday. Most happy. :P Replacing shitarse Pedders SportsRyder... which are saggy, imho.

Fronts: KDFL-101

ID Upper: 96mm

    Lower: 85mm.

WD:        12mm

# Coils: 7.1

Rears: KDRL-61SP

ID Upper: 100mm

    Lower: 90mm.

WD: 13mm.

# Coils 9.

Will put up the specs for the pedders when they come out tomorrow.

Edit: Tried that american calculator - roughly converted to inches, and got 244lb for the fronts and 164lb rears... which seems a little strange to me. Most setups have lower spring rate in the rear, but 80lb is a third of the fronts spring rate.

Oh well, shall take SK's calcs as canon, rather than my dodgy guesstimating.

Sorry I missed this post.

96/85 - 12 - 7.1 = 205 lbs per inch

100/90 - 13 - 9 = 175 lbs per inch

:) cheers ;)

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SK would you mind calculating these please:

Top ID: 88mm

Bottom ID: 76mm

Thickness: 12mm

# turns: 10.125

Top ID: 98mm

Bottom ID: 66mm (yes it's a big difference!)

Thickness: 12mm

# turns: 7.0

Nismo springs for R32GTR

Thanks!

Mark

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This is roughly my fronts - hard to do with them on the car. Not sure if its right

Coil OD = 70mm Bottom /95mm Top

Wire OD = 12.5 mm

# of Coils = 7.25 turns

Not sure about the Coil OD, i used string to go around the circumference(outside) then measured the string, then used:

Diam = Circum / pi to get the diam of the outside, then minus 25mm (2 x wire OD).

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SK would you mind calculating these please:

Top ID: 88mm

Bottom ID: 76mm

Thickness: 12mm

# turns: 10.125

Top ID: 98mm

Bottom ID: 66mm (yes it's a big difference!)

Thickness: 12mm

# turns: 7.0

Nismo springs for R32GTR

Thanks!

Mark

Hi Mark; results as follows;

88/76 X 12 X 10.125 = 170 lbs per inch

98/66 X 12 X 7 = 270 lbs per inch

:) Cheers :)

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This is roughly my fronts - hard to do with them on the car. Not sure if its right

Coil OD = 70mm Bottom /95mm Top

Wire OD = 12.5 mm

# of Coils = 7.25 turns

Not sure about the Coil OD, i used string to go around the circumference(outside) then measured the string, then used:

Diam = Circum / pi to get the diam of the outside, then minus 25mm (2 x wire OD).

That means the 70mm/95mm is ID not OD?

No coil plant I know of makes 12.5mm spring steel wire, are you sure it's not 12 mm or 13 mm?

If it is 95 and 70 ID and 12.5 mm then;

95/70 X 12.5 X 7.25 = 300lbs per inch

:) cheers :)

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