Some Shit ive been working on-
Spring Rates-
Factory 6 cyl AT XJ Coil
Wire dia: .5"
Total Coils: 9 Active: ~8
Coil OD: 5.0"
Calc Spring Rate: 120 lb/in
Tested Spring Rate: 125 lb/in
Unloaded Height: 18.0"
Old man EMU
OEM Old man EMU XJ is supposedly 142-147 lb/in rate. 17" length 5.25" diameter
OEM ZJ with 4.0 is supposedly 190 lb/in rate front and rear.
OME 930 coils: 160 lb. spring rate. 1.75" of lift on XJ
OME 934 coils: 180 lb. spring rate.The 934 spring is 35 mm (1.37") longer than the 930 spring.
The 930 is listed as a XJ or ZJ I-6 spring and the 934 is listed as a
ZJ V-8 spring but is also used on the XJ. the 934 should give about 2.5in lift.
OEM is supposedly 147 lb/in rate. OME coils give 2.25" - 2.5" of lift and have a 148 lb/in rate
PORC
XJ 6.5" 185 lbs/in (22.5" long)
Pro-Comp
-Front Coils-
TJ 2" 170 lbs/in
TJ 4" 175 lbs/in
XJ 3" 230 lbs/in
XJ 4" 150-155 lb/in (19" Long) O.D. is 5.1" or 5.25"
ZJ 3" 220 lbs/in
RockKrawler
XJ 3"
XJ 4.5"
XJ 6.5" are 165 lbs/in
Rubicon Express
ZJ 4.5in coils are 240 lb/in. (22" tall long)
(RE 5.5XJ coils are 4.5ZJ coils.)
From Rubicon Express customer service email to T.N. (November 2004):
The 3.5" TJ fronts are approximately 240 pounds per inch. Uncompressed free length is 19"
The 4.5" TJ fronts are approximately 219 pounds per inch. Uncompressed free length is 19.75"
Rustys
XJ 3" 150 lb/in rate.
XJ 4.5" 150 lb/in rate, 22" tall unloaded
XJ 6.5" 150 lb/in (22" long), 12 wraps of 5/16" stock
XJ 8.5-9" 180 lb/in
Rusty's says "Most of our spring are built to 180lbs. Our 4.5" leaves are built to
150lbs. as are our 300 coils. The 305 coil is set to 180lbs."
Sky Jacker
ZJ 3" coils 218 lbs/in
Tera Flex
XJ 3" TJ coils have a 170 lb/in rate
XJ 4" TJ coils have a 200 lb/in rate , 20.25" tall unloaded
From TeraFlex customer service email to T.N. (June 2004):
TJ springs
SR3T- Free length= 15" Spring rate= 190
SR4T- Free length= 15.38" Spring rate= 210
SF3T- Free length= 19.5" Spring rate= 170
SF4T- Free length= 20.25" Spring rate= 200
Links-
From
http://www.pirate4x4.com/forum/showthread.php?t=111316
From
http://www.pirate4x4.com/forum/showthread.php?s=&threadid=87811
http://www.patricksnorton.com/bronco/lifttech.html
http://www.naxja.org/forum/showthread.php?t=14157
http://therangerstation.com/tech_library/coilspringrate.htm
http://www.cswnet.com/~carother/coil_spring_calculator.htm
http://www.proshocks.com/calcs/coilsprate.htm
OTHER USEFUL SHIT-
Tracker Sidekick 2dr Convertable
452.8 PPI Front 156.5 PPI Rear
Tracker Sidekick 4-dr
508.7PPI Front 177.9 PPI Rear
Ford Ranger 4wd front coils (Rangerstation.com) 500 PPI
Here are some facts about coil springs.
What is Spring Rate?
====================
Spring rate refers to the amount of weight needed to compress a spring
an inch (Example:500# per inch) To understand and properly check a
spring for rate you need to know the factors that determine the rate of the
spring. Fortunately, there are only three things that affect spring
rate, so there's not that much to remember!
1. Wire diameter. This affects rate since greater diameter wire is
stronger than lesser diameter wire. So, when wire diameter is increased,
spring rate increases.
2. Mean diameter of spring. Mean diameter is the overall outside
diameter of the spring less one wire diameter. When mean diameter increases,
the spring rate decreases.
3. Active coils. Determination of the number of active coils varies
according to spring design. Count the total coils minus two for springs
with both ends closed (includes all AFCOILS). Count the total coils minus
one for springs with one end closed and one end open. As the number of
active coils increases, the spring rate decreases.
If a spring's rate is linear (most racing springs have linear rates)
its rate is not affected by the load put onto the spring. For example, a
linear rate spring rated at 500#/inch will compress 1" when a 500#
weight is placed onto the spring. If another 500 pound weight is put onto
the spring the spring will compress another inch. At this point the load
on the spring has increased to 1000 pounds. The rate of the spring,
however, remains constant at 500#/inch.
If the load put onto a spring increases the rate of the spring, the
spring is said to have a progressive rate. Progressive rate springs are
sometimes used on torque arms to absorb engine torque. Keep in mind that
the load (or preload) put onto a progressive rate spring can greatly
increase the rate of the spring.
Typically, progressive rate springs are made by varying the spacing
between the springs' active coils. During compression the close coils
bottom out and deaden. This reduces the amount of active coils and spring
rate increases as a result.
Springs that are designed to include coils of different diameter or are
wound using a tapered wire will also produce a progressive rate.
Most coil springs are actually progressive to some degree
The front springs on a IFS Suzki (used in a A-arm aplication) are under
twice the load of those used in a solid axle configuration. In Short
most solid axle type coils will collapse under the leverage weighted
load on the front of a Suzuki IFS vehicle.
Pictured below are Cherokee fronts on a 4-dr Kick...
These springs are fully colapsed / bottomed out. They will not support
the weight of my Kick due to the IFS A-arm leverage.
Here is a formula to find the PPI measurment of Coil springs....
http://therangerstation.com/tech_library/coilspringrate.htm
Coil Spring Rate Formula:
11,250,000 - Torsional Modules For Steel (Constant)
CSPWD - Coil Spring Wire Diameter (How thick is the wire?)
8 - Constant
NOAC - Number Of Active Coils (Coils that are free to move. Not coils
seated. It may be that 1/2 of the top and bottom coil is seated
causing a spring with 8 coils to have the distance of 7 free.)
CMD - Coil Mean Diameter (The diameter from center to center of the
coil. Measure the diameter of the coil from wire center to wire center. If
you know the coil is .5 inches thick and the outside diameter of the
coil spring is 3 inches, then the Coil Mean Diameter would be 2.5
inches)
(11,250,000 x (CSWD x 4)) {Divided by} (8 x NOAC x (CMD x 3))
All Measurements in inches - Enter as decimal
For Inch Fractions To Decimal Chart, Click HERE
http://therangerstation.com/tech_library/fractionstodecimals.htm
Those Ford Ranger Guys at therangerstation.com have certinly done their
home work and have a very nice site.