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Suspension travel - how much? Which shocks/springs and why?


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I know over the years there has been much written and said about improving the suspension of a Land Rover. And lots of different products and setups. I thought it might be interesting to revisit this and explore what I'm currently looking at doing and accomplishing. As well as what others have done. Because some older products & kits are no longer available and there are new shocks available these days and maybe new ideas also.

 

I'll be upfront and honest and say, I am no expert and no engineer. I'm just an enthusiastic home mechanic, who doesn't always want to follow the masses or conform to the norm.

My past build (and sadly now missed) was a leaf sprung 88 Series III, which some of you may recall due to my build thread on here. Whereby I altered the suspension and added 14" travel shocks. I don't think I ever got the full travel out of the shocks and there was certainly more left in the suspension. But I got it to a stage were it was lovely balanced front to rear and certainly flexed well enough to embarrass far newer machinery.

KReJK6Bl.jpg

q01LMlkl.jpg

 

However, this thread is much more centred on coil sprung, Defender style suspension. And while I'm not unhappy with my current 88 coilers setup, I don't believe I have yet managed to get it to equal my old leaf sprung setup.

 

Some of the principles I have tried to adhere to with suspension:

  • Keep it low or as near to standard ride height
  • Maintain suspension compression as well as droop
  • Supple and comfortable off road
  • Stability
  • Safe on road handling
  • Balanced front to rear suspension

 

My current setup is somewhat simple and basic. Just slightly longer shocks (ProComp +2's sourced from Paddocks). And the longest springs I could find.

I'm not really a fan or advocate of dislocating suspension. Although I accept it may become the only real option.

All mounting points are currently stock.

I used to run Range Rover Red/White springs all round, as according this this very helpful list from another member:

http://www.red90.ca/rovers/springinfo.html

These springs are 170lbs/in and 16.95" long. I found them to be too stiff on the rear, so I have since replaced them with some Flatdog 133lbs/in +2" Range Rover front springs. In practice they seem to have the same uncompressed length as the red/white springs, although being a little softer offer a slightly lower ride height.

vDQDxV4l.jpg

My plan will be to put the same springs on the front too, as with the red/whites the front is riding about 3/4" higher than the back.

 

Question: Is it possible to buy a spring longer than 17" that is soft enough? Looking online I've not seen anything. I know Tomcat motorsport do some grey springs which are popular with trials vehicles. But I do not know the specs of them.

 

With the long springs and only +2 shocks, I'm not yet hitting issue with the rear springs dislocating. I believe I am maxing out the rear shock currently.

EjNAyIPl.jpg

*ignore the fact the bump stop is missing... 🤣

 

As a datum point, from the stop outside edge of the upper spring seat to the top of the axle tube, measuring along the outside of the spring. I'm getting about 20", which is giving me about 5 1/4" down travel from sitting on level ground. I'm sure this can be much improved.

At the front, I believe I am also maxing the front shock out also. And using the same datum points I'm getting just over 19 1/2". Giving in the region of 4.5-4.75" down travel from sitting level (remember the front sits higher than the rear currently).

Which makes for quite a nicely balanced vehicle off road.

rVlJTV4l.jpg

 

We also tried the same on my brothers 200Tdi Ninety. He is running +2" Flatdog standard rate springs all round (standard for a 90). So they are longer, but not heavier. He is also running stock mounts and +2 Terrafirma shocks all round.

 

Sitting level his 90 sits slightly lower than my 88 coiler does. Therefore the suspension should be slightly more compressed. At the rear, using the same datum points he easily gets 20" when extended. And this is using jubilee clips to retain the spring in the upper seat, without them he gets an easy extra 2". Giving nearly 8" of down travel compared to my setup making only just over 5 inches. The 90 has a 'wide' angle A-frame ball joint and somewhat worn upper shock bushes (you could see over 1/4" of travel was from here). I'm running a 20 year old factory A-frame ball joint that has never been off the vehicle and poly bushes. I also wonder if the Terrafirma shocks are actually slightly longer than the ProComps.

However the front is a different story. I have made a mod on mine to allow my front radius arms to give more downward travel. The 90 is 100% bone stock in this regard. Down travel was recorded at only 2.8", so no where near maxing the shock out and nearly half the down travel of my 88. And while the 90 performs well, you can see it has a lot more rear axle travel than front axle.

Here is a little comparison of how the vehicles currently perform off road:

 

So where too next?

 

Well I know I have a few issues to solve. Such as, under compression the rear wheels hit the seat boxes and despite having heavily trimmed arches, are also hitting what is left of them.

lL2rFXMl.jpg

Trimming the last inch of wheel arch and cutting the seat boxes is a must.

 

And then to look at new longer shocks and revised upper mounts.

Question: With so many shocks on the market these days. It is hard to know what to go for. Gwyn Lewis sells several, the OME sound interesting, but are almost £500 for 4. Claimed to be +5" over standard. There are also ProComp +5", although in other places advertised as +4". So I don't know if they are the same or not.

Britpart do some remote reservoir shocks these days with a claimed 10" of travel and Terrfirma also offer remote reservoir shocks with 8 adjustable valve positions, with a 10.8" claimed travel. Or do I simply spec my own shocks as I did with the Rough Country shocks I fitted to my leafer?

 

 

I think this post is way long enough for now. So I'll leave it here. But I'd love to know your thoughts on the topic. What would be your ideal long travel suspension setup front & rear? Does it exist? What are you views on dislocating setups? And with long springs and stock front radius arms, can you even get the front spring to unseat?

Edited by Chicken Drumstick
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I've come to a pretty tried and trusted set up over the years

I always use Superpro bushes, then Raw 4x4 +2" shocks (big body, tough and reliable); OME 764 Medium Load rears, with Gwyn Lewis 1" spacer; NTC 8477 G/B/Y front springs on Gwyn Lewis 1" spacer; D4x4 spring re-locator on the rear and rubber isolators on the front. I run Disco steels, to avoid more than a Camel cut and at the moment 215/85x16 Hankook RT03.

The front has a TF RRC winch bumper (with many, many improvements) and a G10 DLX winch (no front bash plate)

I have done the calcs and weighed the F/R to confirm the springs work well. I have flex but good road holding and I can tow. The OME springs are superb

On my 100" and the 110, I used a Gwyn Lewis shock relocation on the rear, with a +5" OME pin/pin fitment and Red/Red 110 HD rears with dislocation retention system. The Salisbury axle uses a wide angle prop as standard. Rear articulation was ludicrous.

I work on the theory that lifts require stiffer springs or more metal. I'd opt for arch cutting before fitting a big lift. The 110 was able to use standard springs , but had huge articulation on the rear because of the longer shocks. I like to stay within homologation and sensible gearing  on tyre sizes, so generally use a size of tyre approved for the vehicle. 100" and 110 were both 235/85x16, RRC and Disco were/are the same.

The RRC was a test bed for ideas and to prove/disprove products; the 110 and the Disco have been test beds to prove products for clients vehicles. I no longer run my 'little business on the side' so these days I don't really bother opting away form ideas I know work, unless someone shows me differently

I would say your biggest issue will be weight. You have a light vehicle. The Red/White police spec springs were designed for overloaded police RRC to keep at the standard level. They are hard if you weigh less than 2.5 tonnes. I would suggest the Disco V8 fronts and some arch trimming; or if you are going to carry a bit more ballast , one of the progressive Disco rears, either yellow/yellow or white/white - these work very well on a 90, very well indeed

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Thanks for the reply.

I have to say, I am curious about the front end travel. I looked over the Gwyn Lewis site and gallery, and I could not find any photos of the front spring dislocating.

I know his kit uses the +5" shocks and taller turrets with optional dislocation cones. But it seems the restriction of the front radius arms may defeat having this somewhat. As demonstrated by my brothers 90. With longer shocks on the front, he is no where near getting additional droop with all other items being stock.

 

Even on the Gwyn Lewis Challenge truck, you can clearly see the front spring is in no danger of dislocating. This has me thinking I could get away with the extended turrets without the dislocation cones. Which would suit for the ALRC regs more so.

gwyn-lewis-4x4-challenge-suspenion-01-10

 

My current thinking is, I'd like to take some more measurements on my vehicle. Both static and full droop. I'd like to pick the front of the vehicle up with the farm loaded and disconnect the shocks, this should allow me to see how much physical droop I have in the rest of the system. And then look to getting some shocks to match. If I can't make use of a +5" shock, there is very little point fitting one in my opinion.

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I can only speak for a 110 on this (they will have more articulation, due to the longer wheelbase). After I fitted my rear Gwyn Lewis set up on the 110 and built a twin shock version up for a client; a friend with a very early TD5 110 decided to go for the whole set up, front and rear. When you finally get it into a situation where it will lift a wheel, it looks like the chassis has snapped. It dislocates front and rear rather well.

If you want to talk to him about it, he is now stationed back in the UK, so I can get you a phone number

You will only get so much movement, so I think the idea of cycling the suspension without springs or shocks would be worth the time and effort

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On 7/29/2020 at 12:39 PM, Chicken Drumstick said:

hallenge truck, you can clearly see the front spring is in no danger of dislocating. This has me thinking I could get away with the extended turrets without the dislocation cones. 

 

In the photo of Gwyn's 90 the lower part of the spring is hidden, there's a chance the spring tries to dislocate right there.
It happened to mine when I had stock height turrets, I fitted relocation cones at the top, and the spring started to un-seat at the bottom.

By the way, I'm planning to get a couple of his bottom spring retainers.
When better times will come, I'll finally get a new set of dampers, 12" travel.
I ran red/white RRC springs for years, switched to OME 764 (front and rear) and it's definitely better on road.

Mine is truck cab, 3-linked front and with the usual bolt-ons (and 8274 on the nose).
1925 Kg with the rear winch fitted (1100 Kg front).

 

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With Gwyn’s front  Challenge turrets, and his lower spring retainers, they hold just the inboard side of the spring to the lower seat. The outboard side then lifts away from the seat quite well.  

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16 hours ago, Michele said:

In the photo of Gwyn's 90 the lower part of the spring is hidden, there's a chance the spring tries to dislocate right there.

 

You might be correct. Although wouldn't that completely defeat the point of having turrets with dislocation cones in them?

I also thought the Gwyn Lewis setup retained the spring on the lower perch?

 

challenge-front-hook-spring-retainers01-

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Indeed, that puzzled me a little.
I'd get the "full size" spring retainers from Gwyn, for better clamping.
I'd guess (as far as I've seen on my 90) it is better to clamp the lower side of the spring because it's (maybe?) less likely to re-seat itself.
I don't know, but up front mine started dislocating at the bottom and not on top. Go figure.

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3 hours ago, Chicken Drumstick said:

You might be correct. Although wouldn't that completely defeat the point of having turrets with dislocation cones in them?

I also thought the Gwyn Lewis setup retained the spring on the lower perch?

 

challenge-front-hook-spring-retainers01-

3 hours ago, Michele said:

Indeed, that puzzled me a little.
I'd get the "full size" spring retainers from Gwyn, for better clamping.
I'd guess (as far as I've seen on my 90) it is better to clamp the lower side of the spring because it's (maybe?) less likely to re-seat itself.
I don't know, but up front mine started dislocating at the bottom and not on top. Go figure.

On the front of gywns setup the top isn't retained and rides on the relocation cone as part of the turret. As the axle drops away the spring retainer at the bottom only captures the inboard side of the spring so the spring can stay lined up with the seat thanks to the turret.

With my build, I've moved away from gywns front mounts as I'm using my own design for the 14" shocks. I'm going to retain the spring at the top and have a relocation cone at the bottom like I've got for the rear. Which in my experience relocates far better than a top mounted one.

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1 hour ago, landroversforever said:

>>>On the front of gywns setup the top isn't retained and rides on the relocation cone as part of the turret.

Yes, same here, but the relocation cone never went in action, I guess because the dampers aren't long enough (yet).

I'm going to retain the spring at the top and have a relocation cone at the bottom like I've got for the rear. Which in my experience relocates far better than a top mounted one.

One thing I don't like much about the bottom side dislocating is, the slight chance of something getting caught in the way and preventing the spring to sit back flat.
But I'm probably overthinking, here...
 

 

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I reckon it's 10 " you have to play with. I run police rangy springs at the back (rated at 170), and OME2764 at the front (rated at 220). Both are about 17" long. On the car, they compress to 12" at ride height, with about 5" untill the axle hits the bumpstop. So 5" bump, and 5" rebound untill the spring relaxes. You need a bit more, as the shock in articulation moves up further than the bumpstop. So an 11" shock should do it. The 17" length of spring I think is the result of its max compression being limited by the spring going coilbound.

I am not a fan of dislocation. This picture is quite telling:

large.evoaction7L.jpg.9bf70ba106062da992f40afc13fcab57.jpg

The front does almost nothing basically. It is quite understandable why they did it this way, because with bigger wheels, the wheels rub the wheel boxes on bump. So unless you start hacking the rear tub, you have no other option than go down wards. The problem is when it starts dislocating there is no load on the wheel that is dislocated. It is easier to have a wheel hanging loose than to compress a spring, so the front axle does not do much. What people not seem to realize if that if you have 14" of travel at the rear via dislocation, the front probably does only half of its available travel, say 5 inch. So that would result in 19" of total articulation. So why not just for 10" articulation front and rear and have 20" total articulation?

So in my mind, you need to utilize every MM of upward travel before considering dislocation.

Modified rear wheel boxes:

gallery_336_1371_113020.jpg

Also, most people (as does landrover originally) run stiffer springs in the rear than the front. But the front is heavier. So if you don't carry heavy loads, the 60:40 weight distribution of your car should be reflected in the springs relating 60:40 in stiffness. Having realised the 10" limit, I opted for radius arms at the back. The radius arms are limiting the travel to about 11", and if you don't run dislocation, it is enough of flex. Due to the radius arm effectively being an anti roll bar, you can also run a softer spring as it does not lean over as much in corners/sideslopes.

This the other important consideration: you can create a lot of articulation when the car is in horizontal position, but what is this going to do at a 45 degree slope, or decline/incline? This is were the dislocation bit can get dangerous. It basically starts dislocating at times you don't want it to. 

You can improve the radius arm flex by fitting narrow bushes instead of wide bushes. Some people also drill holes in the bushes to make the flex more, but I never bothered; It also makes the axle rotate more under braking and acceleration. With regards to shock absorber choice, OME is the best choice from the ones you mention IMO. It was certainly day and night from the Procomps they replaced. And they are 11".

The result:

large.P4210220comp.jpg.16df91e161182dc3f35d162e161edc26.jpg

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Thanks for the insights and info.

I think I'm reasonably set on which mounts I'd like to go for, as well as springs. I have found some that have an uncompressed length of 20.07", so a fair chunk longer than I what I'm running now.

What I'm really undecided about are shocks. The Old Man Emu's are a tad pricey, but they are my preferred pick at the moment. Although I'd like to know more about the remote reservoir setups from Terrafirma, Britpart, Fox etc. If I'm spending the money, I'd like to do it right kind of thing.

I'm also a little undecided about shock length. I can see that a longer (longer than the 11" offer by Gwyn) shock should offer more droop, esp on the rear axle. But if this is at the sacrifice of compression. I'm not convinced I want it. I'm also not convinced extreme suspension droop actually works better, as you get to a point where the wheel is no longer pushing/pulling vehicle along the ground.

That said there seems to plenty of additional physical drop on the rear axle to make use of slightly longer shocks & springs over what I'm currently running.

P8warQkh.jpg

 

I think the prop is actually the limiting factor here and is a tad too short. However with the axle dropped this far, I do not like the prop angles at all. So it looks like a custom wide angle prop is in order first. But as these are a bit pricey, that might have to be for another pay packet.

0DQRIUjh.jpg

 

 

And thinking of safety, I think a wide angle prop for the front would be sensible too.

 

 

Just to reiterate, I'm not unhappy with the suspension as it currently sits. It compresses well and is nicely balanced front/rear. These are traits I want to retain. I am looking at moving it to the next level however.

This is how the suspension currently performs.

LwbPJyah.jpg

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10 hours ago, Chicken Drumstick said:

Thanks for the insights and info.

I think I'm reasonably set on which mounts I'd like to go for, as well as springs. I have found some that have an uncompressed length of 20.07", so a fair chunk longer than I what I'm running now.

0DQRIUjh.jpg

 

Are the 20" springs the tomcat ones? I did consider them, but they won't tell you the rate, which made it a bit risky to buy. Would be good if someone on here had a go with them. 

I reckon that polybush on your suspension arms ain't helping flex.

The front prop should be much better, as diff nose rotates pointing upwards when the axle droops.

Looking forward to see the results!

Daan

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On 7/31/2020 at 10:01 PM, Daan said:

I reckon it's 10 " you have to play with. I run police rangy springs at the back (rated at 170), and OME2764 at the front (rated at 220). Both are about 17" long. On the car, they compress to 12" at ride height, with about 5" untill the axle hits the bumpstop. So 5" bump, and 5" rebound untill the spring relaxes. You need a bit more, as the shock in articulation moves up further than the bumpstop. So an 11" shock should do it. The 17" length of spring I think is the result of its max compression being limited by the spring going coilbound.

I am not a fan of dislocation. This picture is quite telling:

large.evoaction7L.jpg.9bf70ba106062da992f40afc13fcab57.jpg

The front does almost nothing basically. It is quite understandable why they did it this way, because with bigger wheels, the wheels rub the wheel boxes on bump. So unless you start hacking the rear tub, you have no other option than go down wards. The problem is when it starts dislocating there is no load on the wheel that is dislocated. It is easier to have a wheel hanging loose than to compress a spring, so the front axle does not do much. What people not seem to realize if that if you have 14" of travel at the rear via dislocation, the front probably does only half of its available travel, say 5 inch. So that would result in 19" of total articulation. So why not just for 10" articulation front and rear and have 20" total articulation?

 

The reason the front is not compressing above probably has more to do with running HD springs.

Here’s a 90 on standard height factory springs running 255/85 16’s. With the right setup, there’s no problem getting enough upward travel front and rear...

 

F64310B3-5802-4BF3-8E5E-1BEA3DF28ABB.jpeg

1341A4D8-AE9E-4B57-ABB6-ECFCC47A8BD4.jpeg

2CCF7DB9-8E67-4305-A142-146BBB917C7F.jpeg

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On 8/1/2020 at 9:18 PM, Daan said:

Are the 20" springs the tomcat ones? I did consider them, but they won't tell you the rate, which made it a bit risky to buy. Would be good if someone on here had a go with them. 

I reckon that polybush on your suspension arms ain't helping flex.

The front prop should be much better, as diff nose rotates pointing upwards when the axle droops.

Looking forward to see the results!

Daan

Thank Daan. Yes they are the Tomcat ones. I'd like to know some specs on them too ideally.

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On 8/1/2020 at 9:18 PM, Daan said:

Are the 20" springs the tomcat ones? I did consider them, but they won't tell you the rate, which made it a bit risky to buy. Would be good if someone on here had a go with them. 

I reckon that polybush on your suspension arms ain't helping flex.

The front prop should be much better, as diff nose rotates pointing upwards when the axle droops.

Looking forward to see the results!

Daan

Your rear prop spacer is not helping the U/J angles as it shortens the horizontal length between U/Js. a corrct length prop would lessen the angles a little.

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15 minutes ago, missingsid said:

Your rear prop spacer is not helping the U/J angles as it shortens the horizontal length between U/Js. a corrct length prop would lessen the angles a little.

Agree. But the spacer was a cheap option. Nobody sells an 88 coiler rear prop off the shelf ;)

A 90 prop is too long, so I used an 88 one with spacer for now. Has done fine thus far, but is now a limitation. I'm hoping to get a custom one from Gwyn.

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2 hours ago, Chicken Drumstick said:

Agree. But the spacer was a cheap option. Nobody sells an 88 coiler rear prop off the shelf ;)

A 90 prop is too long, so I used an 88 one with spacer for now. Has done fine thus far, but is now a limitation. I'm hoping to get a custom one from Gwyn.

Try 'The Propshaft Clinic' and Bailey Morris as well. I think the latter supply Gwynn

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I would get an old rangy one that has wide angle u/js and shorten that.

I use standard 88" at the rear and rear 90 at the front. The radius arm setup means the angle is minimal. Also a reason to get max bump travel, rather than droop.

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I took a prop that was too long and ground down the joining weld, shortened the tube and rewelded.

The push in and weld yoke slug gives you a square joint to check your tube cut face against and it also ensures it runs true. You just reweld the seam, I'm not a great welder but mine is fine.

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  • 2 weeks later...

Wheel base has no effect on articulation.

 

Springs and shocks are only "tuning" the available articulation. The front radius arm set up has a higher roll stiffness than the rear "A frame/trailing arm" set up. Getting the front to perform to its best and tuning the rear to suit is a good start. The early narrow radius arms offer more articulation over the later wider type. Bush brand will also determine the amount of articulation to a degree. Softer the better (as long as they last) Not all polyurethane bushes are the same hardness. The two limiting factors (for articulation) of a Radius arm are its length and the separation between the two axle bushes. The longer the arm the better. The closer the two bushes the less resistance they have. But bush separation can be counteracted by bush design. Point in case, the D2 Radius arms have greater axle bush separation, but the bushes have more rubber and look to have a greater range of movement over the later defender type. Plus the D2 arms are about 100mm longer.

 

Another option could be to get a stock Defender Radius arm and bore the axle bush holes to take Nissan Patrol bushes (larger, more rubber, more range of movement)

In short, with stock links etc, run the softest spring reasonable in the front, and tune the rear to suit. The rear is easy to get to flex, but having silly flexy rear makes for an unbalanced vehicle. Keeping the vehicle as low as possible is a good help to Lower COG and keeps the geometry better for on and offroad use, intern making softer springs less of a detriment.

 

cheers

Serg

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Regarding the comment of spring rates higher in the rear. There is a couple of reasons to do that. To tune the roll stiffness of the links. You can use a anti roll bar, but springs is a sort of cheat. Of course this is determined by the link set up front and rear, and their roll stiffness compared to each other.  The other reason is spring frequency. The rear should always be higher than the front. Its got to do with pitch and ride etc. Yes weight over axle will determine spring rate, but unless very very light rear, the rate would be somewhere the same or higher in the rear. 

cheers

Serg

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