Front coil spring stiffness
05-06-2011, 10:42 AM
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Year: 2001
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Front coil spring stiffness
I tried searching the forum but I couldn't really get any results on what the best manufacturer for front coil springs is. Basically, I'm looking for front springs that will give me 3" of lift without being really stiff, since it is my DD and I drive on highways a lot.
Following the recommendation of a thread on this forum, I bought and installed Rusty's 3" HD 180lb front springs. They say these springs wont sag over time like the regular 3" springs and since I have a brush guard on the front I figure HD would be better for the extra weight. But these springs are stiff. Driving on concrete highways that have the seams every few feet is horrible. Even my bastard pack leaf springs feel softer than these coils.
I don't think it's a shock problem since I shelled out $$ for Bilsteins, front and rear (they are awesome by the way, the rear feels so much nicer compared to stock when going over speedbumps, etc). Everything else is stock though. Could the different control arm angle cause the suspension to feel stiffer up front? Or are the Rusty's coils just stiff?
I hear old man emu is the best, but they only offer coils that will lift an XJ about 1.5", unless I go with the higher spring rate ZJ coils which will give closer to 3" of lift. I'm afraid of going with the 3" coils because I don't want to buy stiff springs, again. Should I go with the OME XJ 1.5" coils and add a spacer? Does anyone know how the OME ZJ 3" coils feel compared to stock? Should I go with a totally different manufacturer? I love the height my XJ is sitting at with the 3" Rusty's coils but I hate how stiff the drive is.
Thanks for your help in advance.
Following the recommendation of a thread on this forum, I bought and installed Rusty's 3" HD 180lb front springs. They say these springs wont sag over time like the regular 3" springs and since I have a brush guard on the front I figure HD would be better for the extra weight. But these springs are stiff. Driving on concrete highways that have the seams every few feet is horrible. Even my bastard pack leaf springs feel softer than these coils.
I don't think it's a shock problem since I shelled out $$ for Bilsteins, front and rear (they are awesome by the way, the rear feels so much nicer compared to stock when going over speedbumps, etc). Everything else is stock though. Could the different control arm angle cause the suspension to feel stiffer up front? Or are the Rusty's coils just stiff?
I hear old man emu is the best, but they only offer coils that will lift an XJ about 1.5", unless I go with the higher spring rate ZJ coils which will give closer to 3" of lift. I'm afraid of going with the 3" coils because I don't want to buy stiff springs, again. Should I go with the OME XJ 1.5" coils and add a spacer? Does anyone know how the OME ZJ 3" coils feel compared to stock? Should I go with a totally different manufacturer? I love the height my XJ is sitting at with the 3" Rusty's coils but I hate how stiff the drive is.
Thanks for your help in advance.
05-06-2011, 10:55 AM
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You think rustys HD 3" feel nice? Maybe my standards are too high.. but I've been in lifted XJ's that ride smoothly and the setup i have now is definitely stiffer. I don't even think I can get used to it. I'm seriously considering the OME 1.5 with spacers even though I hate the idea of having spacers instead of a taller spring.
05-06-2011, 11:19 AM
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You won't find much softer than the regular Rusty's coils. I think the issue might be more of your control arm angles than the springs. I was running the 8" Rusty's LA lift (180lb rate springs) and the Jeep drove way better than stock. I haven't run the OME springs but after running the Rusty's coils, I'm sticking with them from now on.
05-06-2011, 11:24 AM
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You won't find much softer than the regular Rusty's coils. I think the issue might be more of your control arm angles than the springs. I was running the 8" Rusty's LA lift (180lb rate springs) and the Jeep drove way better than stock. I haven't run the OME springs but after running the Rusty's coils, I'm sticking with them from now on.
I'm pretty sure that the OME coils will ride even better than rusty's.
05-06-2011, 12:03 PM
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Coil Spring Technical Data:
Compiled from various sources.
From http://www.pirate4x4.com/forum/showthread.php?t=259408
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.
Tera 4" TJ coils have a 200 lb/in rate , 20.25" tall unloaded
Tera 3" TJ coils have a 170 lb/in rate
RE Rubicon Express 4.5in ZJ coils are 240 lb/in. give 5.5" ish of lift on an XJ 22" tall unloaded
RE 5.5XJ coils are 4.5ZJ coils.
Rusty's 6.5" 22" long, 12 wraps of 5/16" stock
Rusty's 4.5" coils give 5" of lift and have a 150 lb/in rate, 22" tall unloaded
Rustys 3" coils give 3" and have 150 lb/in rate.
Rancho 3" coils, at least the old coils give about 2 1/4" of lift on an XJ and have a very high 235 lb/in rate.
Rockkrawler 6.5" are 165 lbs/in
SJ Sky Jacker 3" ZJ coils 218 lbs/in
SJ 6in XJ RR coil is 13 coils and same height and thickness as the RE ZJ4.5in XJ5.5in coil.
From http://www.pirate4x4.com/forum/showthread.php?t=111316
Pro-Comp 4" coils:
uncompressed length=19"
Spring Rate=150-155 lb/in
I think the O.D. was 5.1" or 5.25"
From http://www.pirate4x4.com/forum/showt...threadid=87811
XJ front springs
OEM is supposedly 147 lb/in rate.
Tera 4" TJ coils give 4.5" of lift on an XJ and have a 200 lb/in rate , 20.25" tall unloaded
Tera 3" TJ coils give 3.5" of lift on an XJ and have a 170 lb/in rate
Rusty's 4.5" coils give 5" of lift and have a 150 lb/in rate, 22" tall unloaded
RE's 4.5" ZJ coils give 6"-6.25" of lift on an XJ and have a 200 lb/in rate, 22" tall unloaded (RE ZJ coils are 240 lb/in)
Rustys 3" coils give 3" and have 150 lb/in rate.
Rancho 3" coils, at least the old coils give about 2 1/4" of lift on an XJ and have a very high 235 lb/in rate.
OME coils give 2.25" - 2.5" of lift and have a 148 lb/in rate
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
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"
"Big Bronco" SPring info here: http://www.patricksnorton.com/bronco/lifttech.html
From NAXJA: http://www.naxja.org/forum/showthread.php?t=14157
Here's one I've accumulated over the years from various peoples postings. Take it with grain of salt....
Spring Coil Rates:
Tera 4" TJ coils give 4.5" of lift on an XJ and have a 200 lb/in rate , 20.25" tall unloaded
Tera 3" TJ coils give 3.5" of lift on an XJ and have a 170 lb/in rate
Rusty's 4.5" coils give 5" of lift and have a 150 lb/in rate, 22" tall unloaded
RE's 4.5" ZJ coils give 6"-6.25" of lift on an XJ and have a 200 lb/in rate, 22" tall unloaded
Rustys 3" coils give 3" and have 150 lb/in rate.
Rancho 3" coils, at least the old coils I had give about 2 1/4" of lift on an XJ and have a very high 235 lb/in rate.
OEM is supposedly 147 lb/in rate.
OME coils give 2.25" - 2.5" of lift and have a 148 lb/in rate
Compiled from various sources.
From http://www.pirate4x4.com/forum/showthread.php?t=259408
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.
Tera 4" TJ coils have a 200 lb/in rate , 20.25" tall unloaded
Tera 3" TJ coils have a 170 lb/in rate
RE Rubicon Express 4.5in ZJ coils are 240 lb/in. give 5.5" ish of lift on an XJ 22" tall unloaded
RE 5.5XJ coils are 4.5ZJ coils.
Rusty's 6.5" 22" long, 12 wraps of 5/16" stock
Rusty's 4.5" coils give 5" of lift and have a 150 lb/in rate, 22" tall unloaded
Rustys 3" coils give 3" and have 150 lb/in rate.
Rancho 3" coils, at least the old coils give about 2 1/4" of lift on an XJ and have a very high 235 lb/in rate.
Rockkrawler 6.5" are 165 lbs/in
SJ Sky Jacker 3" ZJ coils 218 lbs/in
SJ 6in XJ RR coil is 13 coils and same height and thickness as the RE ZJ4.5in XJ5.5in coil.
From http://www.pirate4x4.com/forum/showthread.php?t=111316
Pro-Comp 4" coils:
uncompressed length=19"
Spring Rate=150-155 lb/in
I think the O.D. was 5.1" or 5.25"
From http://www.pirate4x4.com/forum/showt...threadid=87811
XJ front springs
OEM is supposedly 147 lb/in rate.
Tera 4" TJ coils give 4.5" of lift on an XJ and have a 200 lb/in rate , 20.25" tall unloaded
Tera 3" TJ coils give 3.5" of lift on an XJ and have a 170 lb/in rate
Rusty's 4.5" coils give 5" of lift and have a 150 lb/in rate, 22" tall unloaded
RE's 4.5" ZJ coils give 6"-6.25" of lift on an XJ and have a 200 lb/in rate, 22" tall unloaded (RE ZJ coils are 240 lb/in)
Rustys 3" coils give 3" and have 150 lb/in rate.
Rancho 3" coils, at least the old coils give about 2 1/4" of lift on an XJ and have a very high 235 lb/in rate.
OME coils give 2.25" - 2.5" of lift and have a 148 lb/in rate
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
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"
"Big Bronco" SPring info here: http://www.patricksnorton.com/bronco/lifttech.html
From NAXJA: http://www.naxja.org/forum/showthread.php?t=14157
Here's one I've accumulated over the years from various peoples postings. Take it with grain of salt....
Spring Coil Rates:
Tera 4" TJ coils give 4.5" of lift on an XJ and have a 200 lb/in rate , 20.25" tall unloaded
Tera 3" TJ coils give 3.5" of lift on an XJ and have a 170 lb/in rate
Rusty's 4.5" coils give 5" of lift and have a 150 lb/in rate, 22" tall unloaded
RE's 4.5" ZJ coils give 6"-6.25" of lift on an XJ and have a 200 lb/in rate, 22" tall unloaded
Rustys 3" coils give 3" and have 150 lb/in rate.
Rancho 3" coils, at least the old coils I had give about 2 1/4" of lift on an XJ and have a very high 235 lb/in rate.
OEM is supposedly 147 lb/in rate.
OME coils give 2.25" - 2.5" of lift and have a 148 lb/in rate
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12-11-2012, 11:02 AM
#9
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Year: 1998
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HELP!
Hey accel when you installed your rustys 3" hd coils did you have your front sway bar links in?? I've heard you need extensions for stock sway bar links but i really don't want to get any! I just want to be able to swap in 3" lift coils and have three inches of lift and not have to mess with control arms, sway bar links etc!!
Thanks
Thanks
12-11-2012, 01:10 PM
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Year: 2001
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Hey accel when you installed your rustys 3" hd coils did you have your front sway bar links in?? I've heard you need extensions for stock sway bar links but i really don't want to get any! I just want to be able to swap in 3" lift coils and have three inches of lift and not have to mess with control arms, sway bar links etc!!
Thanks
Thanks
12-11-2012, 03:47 PM
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Year: 1998
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Wait so is it preference for the sway bar links or what cause one is saying no and one is saying yes?!! And i'm in scott county around burnsville/savage area!
12-12-2012, 11:38 AM
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I ran the 3" lift without longer end links for about 3 months. You can get the nuts to fit on but the angle is a bit extreme and the setup is bit ineffective. Felt kinda weird on big bumps. I ended up cutting them in half and welding an extension rod in the middle to make them longer. Cheap easy fix if you have a welder. If not then JKS disconnects are a good upgrade.
12-12-2012, 11:49 AM
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Don't get Rustys HD Coils unless you're actually going to need them. A winch and a bumper is needed.
When I bought my first lift I got them because I though I'd be adding a bumper really soon. Well without the extra weight they are super stiff (duh) they gave me 4" of lift almost 3 years ago and haven't sagged at all.
Get something else.
When I bought my first lift I got them because I though I'd be adding a bumper really soon. Well without the extra weight they are super stiff (duh) they gave me 4" of lift almost 3 years ago and haven't sagged at all.
Get something else.
12-12-2012, 12:17 PM
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Year: 1998
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Engine: 4.0, bolt ons for days...
180lb/ft coils are nothing. do you guys think everyone just makes the same length spring for every lift and just makes them stiffer to lift more? my RE 3.5 coils were shorter than my rusty's std coils (240lb vs 150lb). most of the time if you have a ****ty ride people jump and blame suspension. at 3" lift with whatever coil and good shocks (which you have) thats not the problem.
whats your tire pressure? whats the load rating of the tires?
whats your tire pressure? whats the load rating of the tires?