Really Tippy off road - Page 3 - Defender Source
Defender Source  

Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions


Reply
 
Thread Tools
  #41  
Old August 26th, 2014, 06:57 PM
sonoronos's Avatar
sonoronos
Status: Offline
Ed
None
Member
 
Join Date: May 2010
Location: Arlington, VA
Posts: 5,530
Registry
Quote:
Originally Posted by Red90 View Post
Springs do not change their rate with age. It is technically impossible. As these springs are used in many other trucks, I doubt that their rate is the problem. He has already changed the shocks with no difference, so it is very doubtful that is the problem.
Well, it is possible for the rate to change. Corrosion, for example, can cause the wire diameter to decrease over time
, causing the rate to decrease. Creep can also reduce the rate of the spring.
Reply With Quote
Sponsored Links
Advertisement
 
  #42  
Old August 26th, 2014, 07:12 PM
Red90's Avatar
Red90
Status: Offline
John B.
1991 Defender 90, 200TDI
Site Team
 
Join Date: Sep 2003
Location: Calgary
Posts: 9,232
Registry
That would be a hell of a lot of corrosion!!! Creep has no effect on the spring rate. The modulus of rigidity of the steel is not something that can change.
__________________
Pissing people off on the "net" since 1983.

Land Rover. Turning owners into mechanics since 1948.
Reply With Quote
  #43  
Old August 26th, 2014, 07:26 PM
mongosd2's Avatar
mongosd2
Status: Offline
Frank Rafka
01 D2 96 D1 83 110
Member
 
Join Date: Jul 2010
Location: Tucson
Posts: 860
Quote:
Originally Posted by Red90 View Post
That would be a hell of a lot of corrosion!!! Creep has no effect on the spring rate. The modulus of rigidity of the steel is not something that can change.
Too bad you don't have a clue about how the spring rate is determined for a coil spring...keep quoting wiki...it makes you seem intelligent
Reply With Quote
Sponsored Links
Advertisement
 
  #44  
Old August 26th, 2014, 07:34 PM
Red90's Avatar
Red90
Status: Offline
John B.
1991 Defender 90, 200TDI
Site Team
 
Join Date: Sep 2003
Location: Calgary
Posts: 9,232
Registry
I'm not quoting any wiki my friend. There was no internet when I learned how to calculate a spring rate. Please correct me oh great one and correct all of the engineering texts in the world.
__________________
Pissing people off on the "net" since 1983.

Land Rover. Turning owners into mechanics since 1948.
Reply With Quote
  #45  
Old August 26th, 2014, 08:26 PM
Red90's Avatar
Red90
Status: Offline
John B.
1991 Defender 90, 200TDI
Site Team
 
Join Date: Sep 2003
Location: Calgary
Posts: 9,232
Registry
Tell you what Frank. Since the internet can't be trusted and I certainly have no clue. When you get to work grab whichever book you like to use and scan and post up the page with the equation for the spring rate of a coil spring. Then in slow simple words explain the equation and how I've gone so wrong.
__________________
Pissing people off on the "net" since 1983.

Land Rover. Turning owners into mechanics since 1948.
Reply With Quote
  #46  
Old August 26th, 2014, 09:04 PM
aka rover's Avatar
aka rover
Status: Offline
ed angel
95 D90
Member
 
Join Date: Dec 2010
Location: Anchorage Alaska
Posts: 1,132
Registry
Sounds like a problem with the butt Dyno :-) Have you driven another D90 to compare. I have built a few off road rigs with 3 link and 37"tires and I haven't experienced any kind of problems offroad . I do run my coils fastened top and bottom , I move my front shocks to the front of the outside the coil . I run no sway bars at either end . I like the 400/100 valving over the 380/80 huge difference offroad . Spring rates are huge I run a 375 front and 420 rear on my 110 with good all around results .
My 90 runs 375 front 275 rear I think it's been awhile . But it's a softop so not a good comparison .
__________________
95 D90 SW 4.6 ARBs 8274 37" BFGs Gigglepin twin motor 8274
94 D90 ST R380 constine green stock
85 D110 3.5 3 DR
67 NADA diesel tremec 4spd salisbury rear springs on front and a LOT MORE TO GO.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote
  #47  
Old August 26th, 2014, 09:38 PM
NPT90's Avatar
NPT90
Status: Offline
JT
D90 óriginalé
Member
 
Join Date: Apr 2011
Location: DC/MD
Posts: 2,772
Registry
Quote:
Originally Posted by Red90 View Post
Tell you what Frank. Since the internet can't be trusted and I certainly have no clue. When you get to work grab whichever book you like to use and scan and post up the page with the equation for the spring rate of a coil spring. Then in slow simple words explain the equation and how I've gone so wrong.
When's the wedding you two?

Seriously though, I'd buy replacement suspension (start with rear) and pull them and check them. If the shocks (or springs) are clearly soft compared to new I'd swap. If they are fine I'd go ahead and check the A-arm bushing for play.
Reply With Quote
  #48  
Old August 27th, 2014, 05:57 PM
sflash868's Avatar
sflash868
Status: Offline
Stephan Laputka
1995 D-90 SW
Member
 
Join Date: Jan 2004
Location: San Francisco, CA
Posts: 972
Thanks for all the responses.

I am used to tuning suspensions on my race car, so i'm not totally flying blind but I'll detail what i've tried since I posted. The front radius arms were contributing to the tippiness. I had those metal castor corrected bushings installed earlier this year and it severely limited the front axle movement. How severe? i was in Moab with the truck going over the crack on Golden spike and I could fit my hand into the wheel well above the tucked up tire. So that was bad and the rear was heavily compensating. However, the truck felt stiffer but that stiffness caused it to lean more due to the lack of articulation. OK.. so then I swapped it out for orange Polybushes and swapped the springs to heavy duty front OMEs and medium rear. Front articulated much better, no dive under braking so that was good. Rear OME medium duty was WAY soft. Going around a 90 degree corner under acceleration the outside rear would sit so far the tire would rub. (I tripled checked the numbers on the springs and no, I didn't put the fronts in the rear). This prompted me to swap back in the RTE rear spring which stopped this problem. ok. shocks. I ordered from a shop here in Cali Fox 2.0 10 inch shocks which I was told was valved at 80/80 (fox's valving numbers). The LR specific shocks that RN sells were apparently engineered at 85/80 but I couldn't order because they aren't available in the length I wanted. I put the rears on and left the Bilstiens up front. It's now tippy and it leans everywhere in steady state cornering. Tippy fine but leaning is springs not shocks which is why i'm all confused. After reading all these posts, I'm going to order 360 pound rear springs, the land rover designed fox shock for the front and replace the A arm joint (even though I doubt this has any effect) and repost the results.
__________________
Land Rovers are by far the best looking 4x4 on the back of a flatbed...
Reply With Quote
  #49  
Old August 27th, 2014, 06:36 PM
sonoronos's Avatar
sonoronos
Status: Offline
Ed
None
Member
 
Join Date: May 2010
Location: Arlington, VA
Posts: 5,530
Registry
Quote:
Originally Posted by Red90 View Post
That would be a hell of a lot of corrosion!!! Creep has no effect on the spring rate. The modulus of rigidity of the steel is not something that can change.
The elastic modulus does not change, true. But a coil spring's rate is determined by the wire diameter and total length of the wire (a coil spring is just a torsion spring wound into a spiral.) Creep in torsion springs (and helical springs) is called relaxation. This causes the length of the spring to increase over time and therefore the spring rate decreases.

You are right, these are minor effects.

I think most of us are pretty civil on here. I know I have been wrong many times and I am glad that folks have been kind enough to be gentle on me.
Reply With Quote
  #50  
Old August 27th, 2014, 06:38 PM
transientmechanic's Avatar
transientmechanic
Status: Offline
Adam
1972 SIII
Member
 
Join Date: Aug 2011
Location: Massachusetts
Posts: 786
Quote:
Originally Posted by sflash868 View Post
I ordered from a shop here in Cali Fox 2.0 10 inch shocks which I was told was valved at 80/80 (fox's valving numbers).
That seems really light. Aren't most people running 360/80 in this application?

The 80 rebound number (versus 360) will cause the inside rear wheel to unload very quickly around a corner which will definitely give a tippy feeling.

This unloading would also happen to the high side in any off camber situation which also seems to fit with what you've been describing.
Reply With Quote
  #51  
Old August 27th, 2014, 06:43 PM
Z.G's Avatar
Z.G
Status: Offline
Zack
300Tdi 95 D1
Member
 
Join Date: May 2013
Location: Burlington, VT
Posts: 4,670
Registry
Quote:
Originally Posted by transientmechanic View Post
That seems really light. Aren't most people running 360/80 in this application?

The 80 rebound number (versus 360) will cause the inside rear wheel to unload very quickly around a corner which will definitely give a tippy feeling.

This unloading would also happen to the high side in any off camber situation which also seems to fit with what you've been describing.

You're thinking bilstein, fox uses different numbers, I think my 2.0s on my d2 are 85/90
Reply With Quote
  #52  
Old August 27th, 2014, 06:57 PM
Red90's Avatar
Red90
Status: Offline
John B.
1991 Defender 90, 200TDI
Site Team
 
Join Date: Sep 2003
Location: Calgary
Posts: 9,232
Registry
Quote:
Originally Posted by sonoronos View Post
But a coil spring's rate is determined by the wire diameter and total length of the wire (a coil spring is just a torsion spring wound into a spiral.) Creep in torsion springs (and helical springs) is called relaxation. This causes the length of the spring to increase over time and therefore the spring rate decreases.
Sorry. How does the length of the spring change with creep? I don't understand what you are meaning. The stress is in torsion and the creep/sage is in torsion. The geometry that sets the rate. Coil diameter, wrap diameter and number of active coils does not change. Sit down and look at how the rate is calculated.
__________________
Pissing people off on the "net" since 1983.

Land Rover. Turning owners into mechanics since 1948.
Reply With Quote
  #53  
Old August 27th, 2014, 07:04 PM
Red90's Avatar
Red90
Status: Offline
John B.
1991 Defender 90, 200TDI
Site Team
 
Join Date: Sep 2003
Location: Calgary
Posts: 9,232
Registry
Since Frank ran away, see here: http://www.engineersedge.com/spring_comp_calc_k.htm

The length of the coil is not used in the calculation of the spring rate. As long as the number of coils that are not touching stays the same, the spring rate stays the sage. Different loads, sag, whatever does not change the rate until some extra coils touch and become inactive.
__________________
Pissing people off on the "net" since 1983.

Land Rover. Turning owners into mechanics since 1948.
Reply With Quote
  #54  
Old August 27th, 2014, 08:03 PM
fishEH's Avatar
fishEH
Status: Offline
Brett Fritzler
94, 95, 96 D1's
Member
 
Join Date: Mar 2011
Location: Lake Villa, IL
Posts: 1,113
Question

Just because your front tire stuffed doesn't mean your articulation sucks.
Tired stuffed.

Good articulation. (315/75/16 for reference)


Good call getting rid of those eccentric bushings in the radius arms, they suck.
What is the part number on the rear RTE springs?
Did you try a sway bar in the back?
Keep in mind the amount of tippiness you find unacceptable may be perfectly acceptable to someone else.
You can change all the springs and shocks you want and none of it will have the results of a sway bar. People like to poo-poo them but a lot of crawlers and offroad racers run them for stability.


Quote:
Originally Posted by sflash868 View Post
Thanks for all the responses.

I am used to tuning suspensions on my race car, so i'm not totally flying blind but I'll detail what i've tried since I posted. The front radius arms were contributing to the tippiness. I had those metal castor corrected bushings installed earlier this year and it severely limited the front axle movement. How severe? i was in Moab with the truck going over the crack on Golden spike and I could fit my hand into the wheel well above the tucked up tire. So that was bad and the rear was heavily compensating. However, the truck felt stiffer but that stiffness caused it to lean more due to the lack of articulation. OK.. so then I swapped it out for orange Polybushes and swapped the springs to heavy duty front OMEs and medium rear. Front articulated much better, no dive under braking so that was good. Rear OME medium duty was WAY soft. Going around a 90 degree corner under acceleration the outside rear would sit so far the tire would rub. (I tripled checked the numbers on the springs and no, I didn't put the fronts in the rear). This prompted me to swap back in the RTE rear spring which stopped this problem. ok. shocks. I ordered from a shop here in Cali Fox 2.0 10 inch shocks which I was told was valved at 80/80 (fox's valving numbers). The LR specific shocks that RN sells were apparently engineered at 85/80 but I couldn't order because they aren't available in the length I wanted. I put the rears on and left the Bilstiens up front. It's now tippy and it leans everywhere in steady state cornering. Tippy fine but leaning is springs not shocks which is why i'm all confused. After reading all these posts, I'm going to order 360 pound rear springs, the land rover designed fox shock for the front and replace the A arm joint (even though I doubt this has any effect) and repost the results.
Reply With Quote
  #55  
Old August 27th, 2014, 09:07 PM
don's Avatar
don
Status: Offline
Don Bunnell
'86 110 3dr ST
Member
 
Join Date: Sep 2007
Location: Rumson, NJ
Posts: 4,271
Registry
Quote:
Originally Posted by fishEH View Post
Good call getting rid of those eccentric bushings in the radius arms, they suck.
Are you still running the slotted Poly's? I have them on my rebuild but won't be able to try them out for a while - wanted to know if you were still happy with them. Probably wouldn't be too good big the vehicle is too tipsy.
Reply With Quote
  #56  
Old August 27th, 2014, 09:38 PM
mongosd2's Avatar
mongosd2
Status: Offline
Frank Rafka
01 D2 96 D1 83 110
Member
 
Join Date: Jul 2010
Location: Tucson
Posts: 860
Quote:
Originally Posted by Red90 View Post
Since Frank ran away, see here: http://www.engineersedge.com/spring_comp_calc_k.htm

The length of the coil is not used in the calculation of the spring rate. As long as the number of coils that are not touching stays the same, the spring rate stays the sage. Different loads, sag, whatever does not change the rate until some extra coils touch and become inactive.
Nope, didn't run away, I just hate debating this shit with morons who have never tuned a suspension before.

http://www.pontiacracing.net/js_coil_spring_rate.htm

So what do you think happens when a spring is shot, it can't support the "load" and it compresses so that the coils are touching. It gets worse when new shocks are added, shocks are re-vavled or nitrogen pressure is increased to compensate for the spring sag. Then it turns into a slinky…

edit: Look at a spring that has sagged or has been elongated from being retained and stretched and you'll find the coil diameter has changed, thus effecting the static and compressed height, which does change the spring rate
Reply With Quote
  #57  
Old August 27th, 2014, 10:07 PM
Red90's Avatar
Red90
Status: Offline
John B.
1991 Defender 90, 200TDI
Site Team
 
Join Date: Sep 2003
Location: Calgary
Posts: 9,232
Registry
The geometry of the spring in our application cannot change enough to affect the spring rate other than sagging to the point of having coils touch at which point the rate increases. Find any used Land Rover coil spring, as sagged as you want and other than the free length, the rest of the dimensions will be basically as new.

Despite you thinking I'm a moron, with no experience, you will just have to accept that you are incorrect in those assumptions. You are provide zero technical information to this discussion. Your link shows the same equation that mine does, strangely enough because it is the equation....

A "shot" spring has sagged/crept. Look up creep to understand what this mean. It occurs from springs that are stressed beyond what the material is capable of sustaining, usually through poor design and/or materials.
__________________
Pissing people off on the "net" since 1983.

Land Rover. Turning owners into mechanics since 1948.
Reply With Quote
  #58  
Old August 27th, 2014, 10:22 PM
Z.G's Avatar
Z.G
Status: Offline
Zack
300Tdi 95 D1
Member
 
Join Date: May 2013
Location: Burlington, VT
Posts: 4,670
Registry
My only question John, are you suggesting that steel doesn't fatigue with age/temperature/corrosion? Surely a weaker spring would have a lower rate?
Reply With Quote
  #59  
Old August 27th, 2014, 10:41 PM
sonoronos's Avatar
sonoronos
Status: Offline
Ed
None
Member
 
Join Date: May 2010
Location: Arlington, VA
Posts: 5,530
Registry
Quote:
Originally Posted by Red90 View Post
Sorry. How does the length of the spring change with creep? I don't understand what you are meaning. The stress is in torsion and the creep/sage is in torsion. The geometry that sets the rate. Coil diameter, wrap diameter and number of active coils does not change. Sit down and look at how the rate is calculated.
D, in the engineers edge link you posted, which corresponds to the diameter of the helical coil itself determines the length as well as the number of active coils. The larger the coil diameter and the more active coils, the longer the wire and therefore the lower the spring rate. The equation in the link you posted is a "shortcut" equation. From an engineer's perspective, a coil spring is a torsion beam spring wrapped into a helical shape. As the spring compresses, it experiences both torsion and elongation.

There is plenty of literature on coil springs and relaxation. If you google "coil spring relaxation" you will find academic papers on the subject.
Reply With Quote
  #60  
Old August 27th, 2014, 10:43 PM
Red90's Avatar
Red90
Status: Offline
John B.
1991 Defender 90, 200TDI
Site Team
 
Join Date: Sep 2003
Location: Calgary
Posts: 9,232
Registry
Fatigue is something else. It is when something cracks or breaks at a load below its normal failure load due to cyclic loading. If that happened the spring would break.

The spring rate is controlled by the geometry of the spring and modulus of stiffness of the material. Nothing can change that stiffness.
__________________
Pissing people off on the "net" since 1983.

Land Rover. Turning owners into mechanics since 1948.
Reply With Quote
Reply

Lower Navigation
Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions

Tags
off road

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Land Rover Defender Survives 22,000 Mile Really, Really Cold Trip waveridin1959 Misc. Chit-Chat 7 March 6th, 2014 09:35 PM
Really? Plastic Defender parts? Really? Roving Beetle Misc. Chit-Chat 12 October 6th, 2010 09:02 PM
Tippy lifted Truck Rugbier Defender Technical Discussions 26 May 22nd, 2009 02:10 PM
Really really basic question..... CaptMidnite Defender Technical Discussions 1 January 5th, 2007 10:24 AM
Worst day off-road.. (really long, i'm bored) sflash868 Misc. Chit-Chat 24 October 23rd, 2006 01:42 AM


All times are GMT -5. The time now is 06:37 AM.


Copyright