Spring Rate Data

[jwernerny]

Originally Posted by shoestring

How about a spreadsheet for these? I love a spreadsheet.

This should work. Change the rear corner weight as appropriate, and specify the spring length and lb/in. Everything is in reference to the first one, which should be a Nivomat.

Mk I Spring Rate Calculator

[redblockpowered]

Some navel-gazing about stock rates here: http://forums.turbobricks.com/showth...85#post6064885

[mikep]

https://www.f1technical.net/forum/viewtopic.php?t=6371

[sloopy]

I was able to get some spring data from our friends at Lesjofors and they gave me permission to publish it :o)


Lesjofors {part number}
{description}
---
L: {length}
OD: {outer diameter}
WD: {wire diameter}
R: {spring rate}


################


Lesjofors 4095801
240 front
---
L: 452 mm
OD: 167 mm
WD: 13.5 mm
R: 15.3 N/mm (87.4 lbf/in)


Lesjofors 4095802
240 diesel front
---
L: 485 mm
OD: 166 mm
WD: 13.5 mm
R: 17.5 N/mm (100 lbf/in)


Lesjofors 4295801
240 sedan rear
---
L: 422 mm
OD: 127 mm
WD: 12 mm
R: 17.2 N/mm (98.3 lbf/in)


Lesjofors 4295803
240 wagon rear
---
L: 407 mm
OD: 134 mm
WD: 13 mm
R: 21.1 N/mm (121 lbf/in)


Lesjofors 4295816
240 ambulance rear
---
L: 410 mm
OD: 132 mm
WD: 14 mm
R: 30.0 N/mm (171 lbf/in)


Lesjofors 4595804
240 sedan sport kit (35 mm lower)
---
R front: 29 N/mm (166 lbf/in)
R rear: 26-35 N/mm (147-200 lbf/in)


Lesjofors 4595805
240 wagon sport kit (40 mm lower)
---
R front: 29 N/mm (166 lbf/in)
R rear:23-33 N/mm (131-188 lbf/in)


The sport kits have progressive rate in the rear. I also verified that the sport kit's rear rates are lower for the wagon.

[redblockpowered]

Who did you contact at Lesjofors for spring rates? That's very interesting. I wonder what they're willing to tell me for 740/940 springs.

[sloopy]

I talked to Jim at the Pennsylvania office. I can PM you his number.

[culberro]

Originally Posted by aharres

I was able to get some spring data from our friends at Lesjofors and they gave me permission to publish it :o)

Nice!!!

Any chance you can get the 240 diesel spring rate for the front? I had a pair that were a slight lift over stock and a go of bit stiffer.

[sloopy]

Yeah I'll give him a call on Monday.

Originally Posted by culberro

Nice!!!

Any chance you can get the 240 diesel spring rate for the front? I had a pair that were a slight lift over stock and a go of bit stiffer.

[sloopy]

I updated the table with data for the 240 diesel front spring.

[redblockpowered]

Jim says no rates for 740/940. They're kept by the applications engineers in Sweden. Now, they do publish wire diameters, along with diameter and length, and maybe they're made from the same material as the 240 springs...

[mikep]

The material used has almost no variation within the iron alloy family. But when measuring the spring, knowing the coating is important. Powdercoating can add a mm to the wire thickness, most paints 0.5ish mm.

[petercz]

Originally Posted by jwernerny

From an old post I wrote in 2008 (http://forums.turbobricks.com/showpo...0&postcount=26

IPD Nivomat Delete Rear Springs:

92.5 lbs/in. Free Length: 20". Compressed Length ~8" (1100 lb load on each spring)

Can anyone confirm, that they are really that soft? I read somewhere, there were two versions (old and actual).

[yamahapro]

Does anyone know the difference between a sedan and wagon HD overload springs from FCP/ IPD I have a pair here I am 99 percent sure are wagon springs.

[mikep]

Not me. Early on in this project i hoped to borrow lots of springs like that and measure them. I did borrow a few sets, like some of the lowering springs.

[tibboy12]

Hey everyone! I'm looking for some advice for my 81 245 on STS coilovers and lowering springs with an adjustable perch in the rear. The rear still feels like a pogo stick, thinking it might be too stiff after installing chevy S10 front shocks for my rear.

Here's the run down of what I've installed onto my wagon.
1. STS coilovers, 325lb fronts and 275lb rears, bilstein touring struts in the front and Chevy S10 front shocks for the rear -> I'm thinking this is my problem, too stiff for the wagon? I'm fairly low in the front, so it feels perfect with my BBS RC090. I can barely fit my pinky inside from top of the tire and fender.
2. Rear end is where my concerns at. I've completely taken out both bump stomps and the one by the diff, but I believe I'm still hitting the rear crossmember.
3. kaplhenke panhard bar, IPD torque rods and poly trailing arm bushings.

Any help would be much appreciated!

[mikep]

You can start a new thread in performance, but the main thing i see is you have not factored in the rear control arm motion ratio (squared).
Multiply the rear spring rate by 1.5 and that is what the vertical rate is.
The front loses a little bit (5%) due to the angle.
Also, s10 shocks only work with 11” springs or shorter.

[tibboy12]

Originally Posted by mikep

You can start a new thread in performance, but the main thing i see is you have not factored in the rear control arm motion ratio (squared).
Multiply the rear spring rate by 1.5 and that is what the vertical rate is.
The front loses a little bit (5%) due to the angle.
Also, s10 shocks only work with 11” springs or shorter.

Sorry about that! I should have posted there first, but thank you for the advice about the squared factor. I will give that a shot and see what numbers I get!

[rearwheelpeel]

1974 164:
Front springs
Wire diameter - USA - 16.7 mm = .657”………Other - 16.4mm = .646”
Outer diameter - USA - 126.7mm = 4.99”……..Other - 126.mm = 4.97”
Springing coils - 8.4
Load - USA - 7239-7730 N…….Other - 6429-6920 N
Length fully compressed - USA - 135.3mm = 5.33”…
….Other - 132.3mm = 5.21”
Spring Length - USA - 202.4 = 7.968”………Other - 199.5mm - 7.854”

Rear springs
Wire diameter - 12mm = 0.472”
Outer diameter - 128mm = 5.04”
Springing coils - 8
Load - 2070-2207 N = 464-495 lb
Length fully compressed - 112mm = 4.41”
Spring length - 287mm - 11.3”

[mikep]

Excellent. Thanks.

[Marvelous3]

This might need its own topic, but let’s say you were going from a completely stock suspension to a bne coil over set up on a 240 wagon. Koni yellow shocks/struts. What spring rate would you want to run and what length? Let’s say we’re setting the car up to autox and/or do some laps around road Atlanta.

[OldCarNewTricks]

Originally Posted by Marvelous3

This might need its own topic, but let’s say you were going from a completely stock suspension to a bne coil over set up on a 240 wagon. Koni yellow shocks/struts. What spring rate would you want to run and what length? Let’s say we’re setting the car up to autox and/or do some laps around road Atlanta.

Ben helped me choose spring rate for the rear of my 242. I bet he could help you choose a good setup, too!

[mikep]

When Towery started with the stock car spring idea, he went with 11# tall by 5" dia 200# in rear. I inherited those springs, and went from there. This was when we were treating the rear like most other cars with the spring on the axle or on a strut.
After learning about motion ratios, and going all over in rates, I have found that 13" 225# in the rear of a sedan (337.5# vert, less in roll), with 9" tall 5.5" pigtails, 350# in front (close to the rear number in vert due to the strut inclination) was very good. Not too stiff, very good handling with 23mm front, 19mm rear bars. 1" or so lower than stock.
In my current wagon I have 13" 275# rear (412.5# in vert) with suburban Gabriel Ultras and 425# in front with very stiff bilsteins. This will be for rallycross and autocross. In my first wagon I originally ran the 275s in rear with the 350s in front, and it was awkward on concrete and bridges.

[mikep]

The Koni yellows handled the 350# springs well in front.

I think the reason that some suburban shocks (1" shorter than stock at the shock, but even shorter at the spring) don't work well on the rear of a 240 is that the stroke is really slowed down at the shock. The gabriel ultras are not know for finesse, which works better at the slower stroke rate when installed in a 240.
The bilstein shocks that came stock on the front of the 88(?)s10 4x4 did very well with a 3"-4" drop and very stiff springs. I still have the set I used on the rallycross 244.