softer suspension

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Anton
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Re: softer suspension

Post by Anton » Mon Feb 02, 2015 2:16 pm

Those are standard shackles, and what looks to me like +2 springs. Honestly I don't know anything about +2 springs except that most people find them a bit harsh - I don't know if they change any angles (changing castor angle etc).

I still suggest you start with squirting WD40 between the leaf springs to see if that helps (it helped a lot with my "normal" leaf springs). If it's still too hard, at that point I'd suggest you think about going back to standard springs, or (best option if you can afford it) you think about anus YJ springs, which are well known for giving a seriously comfy ride when compared to standard springs.

Having been in ScottieJ's YJ equipped blue mean machine, I know they're worlds apart, and probably as good as a coil spring setup.
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Re: softer suspension

Post by ScottieJ » Mon Feb 02, 2015 3:13 pm

Those are definitely lift springs, they have the same set up as Trail tough bonz eye springs but they look like copies as they dont have the same leaf arrangement.

I would possibly try removing the bottom leaf from each pack as that will reduce the spring rate and soften them up.

Could you post a better picture of the shocks as I'm not sure what brand they are? There is a possibility they are part of the rough ride, especially if they aren't long enough to be used with the lift springs.

Also what tyre pressures are you running?

And yes Anton YJs are lovely :mrgreen:
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Re: softer suspension

Post by kdalton » Tue Feb 03, 2015 2:18 am

I live in Australia but I use this forum because its so good and handy.the shocks are Monroe gt gas shockers which are supposed to be heavy duty.i don't know how old they are or if they are the right length I will look it up on the internet. thanks

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Re: softer suspension

Post by kdalton » Sun Feb 15, 2015 6:22 am

so take out the bottom leave .the leave with the clamp around the leaves. thanks

Anton
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Re: softer suspension

Post by Anton » Sun Feb 15, 2015 12:52 pm

Taking out that bottom leaf will lower the SJ a bit at the same time, bear that in mind.
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djc
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Re: softer suspension

Post by djc » Sun Feb 15, 2015 1:55 pm

reminds me David at Llama recommended the Yj conversion - I just dont understand why SJ springs are made so stiff when the SJ weighs in at under a ton. Is there a guide re fitting YJs somewhere, I did a search but didn't find here.
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Re: softer suspension

Post by twiss » Sun Feb 15, 2015 2:01 pm

SJ springs are stiff because they aren't very long... I got some Llama +2" springs and they are a bit longer and more comfy... did need longer shackles though with the extra length
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Anton
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Re: softer suspension

Post by Anton » Sun Feb 15, 2015 2:36 pm

The longer a spring is, the more it will flex for any given load. Each centimeter of a spring will bend by the same amount as every other centimeter along the length of the spring when placed under a load.

So if you have a spring twice as long but otherwise identical to a standard SJ spring, it'll "give" twice as much under the same load, resulting in it feeling "softer".

That's why cutting coil springs down makes them ride harder, and why making leaf springs longer makes them softer. Think about what it's like to jump on a diving board from the very end versus near the middle or versus the bit near the stairs/ladder - the further out/longer the spring, the softer/more bouncy (and more the need for good shocks).

Also, YJ springs have a low friction surface between the leaf springs that means the leaves slide against each other better, meaning they flex better. You can get UHMWPE tape, put it between your leaf springs, and get a softer ride. Mine's softer when it's been raining, because I really need to sort out my leaf spring packs with some UHMWPE or something.
1985 SJ413VX (SJ50V) with SPOA, rear disc brakes, 31x10.5R15 Kaiman Malatesta tyres, an MOT and a lot left to do!

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djc
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Re: softer suspension

Post by djc » Sun Feb 15, 2015 4:44 pm

Couple of things Anton - you do say 'otherwise identical' and that is key, without mods the SJ chassis is stuck with mount points at whatever distance they are. If the stock springs are too stiff for bodyweight (and I reckon they are) then reduce cross-sect area of each leaf. 3 or so leaves is good because you get a smooth continous deflection that is progressive (the shorter leaves kicking in at greater deflections so the spring is progressive).
There are spring-makers out there - I think i'll call one or two and see what can be done using wide but thin material. It isn't technically impossible to get a properly compliant spring out of the fixed length of chassis mounts and the suspended mass of an SJ (noting the suspended mass is a lot less than kerb weight too.

The other thing - that avatar's a tads disturbing :lol:

i mean the one before, it's changed again, do you have it on a timer
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Anton
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Re: softer suspension

Post by Anton » Sun Feb 15, 2015 7:45 pm

Yeah, I was just pointing out why longer springs are softer...

When people swap to longer springs (rears up front, YJ's, Hilux, Navara etc) generally they make a new mount point on the chassis either end. I like the way Scottie did his - it bolts on, so VOSA can't complain (probably wouldn't anyway, but it's nice to know they can't).

You could get them made up, but I wouldn't bother if that turns out to be £££. Just get rears up front (maybe with slippery tape between them too) and (I think) bedford rascal springs out back, or YJ's, or read Ladaman's adventures in going with Nissan Navara springs.

The options are just about limitless!

As for the avatar, it changes every time someone loads a page with my avatar on it. If you're looking at me being all smiley-nosey-psycho, press F5 and you should be looking at my truck instead.
1985 SJ413VX (SJ50V) with SPOA, rear disc brakes, 31x10.5R15 Kaiman Malatesta tyres, an MOT and a lot left to do!

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