Outer Limits 4x4 Board

Here's a couple of graphs based on the wheel loading idea I was kicking around. I plugged some indicative numbers into excel and graphed them out. for simplicity I have assumed a perfectly balanced car (25% per wheel)

The four traces should stay as flat and consistent as possible for the best behaviour. The more spread out they become at close to maximum articulation (lets say at 27") the less stable the car is.

Obviously, gathering this data would be slow and require expensive gear. Whilst anecdotal evidence proves that a balanced car will outperform an unbalanced car even with less wheel travel, this is the only way I can really think of proving it without reference to subjective assessments.

Anyway, this is a major hijack of Spikes' thread, I hope someone's getting something out of it.

Gwagensteve wrote: One of the problems with the ramp is that 3/4 eliptic (which I have built and is kinda OK) Coils going loose, and scissor shackles all have no effect on the ramp but have a BIG typically negaitve effect of the drivability of the car in the bush.

Hey I know its a little of topic but it was a good read....

Agree with you there Steve, is very much the same with my 3/4 eliptic, whilst it is fun going up a RTI ramp to show some great flex the rear ends up doing much of the work. I rarely pull the pins out on a 4WD track as I would prefer a more stable vehicle with equal front rear travel and closer to level sitting body, having crawl gears and lockers helps too.

What I found Interesting when watching 4bies go up the RTI ramp on our Ramp days was part of the overall score was based on going forwards and reverse up it and have found that a lot of 4bies got a lower score reversing up and lifted a tire a lot earlier. Exactly why this happens Im unsure but when a vehicle scored very equal scores of front back travel up the ramp they generally did quite well out on tracks.

wow, this thread has expanded.

Steve, no need to apologise, all tech is good.
In relation to project lonnie, i have carefully removed the rear shackle mount and moved it back 20mm, which has given me heaps more droops and a much better shackle angle. Still yet to find out actual measurements but will post them once everything is welded fully.

Keep this can of worms open!

MUD-PIGSIERRA wrote:
What I found Interesting when watching 4bies go up the RTI ramp on our Ramp days was part of the overall score was based on going forwards and reverse up it and have found that a lot of 4bies got a lower score reversing up and lifted a tire a lot earlier. Exactly why this happens Im unsure but when a vehicle scored very equal scores of front back travel up the ramp they generally did quite well out on tracks.

The lower score in reverse will be mostly due to two factors. Most cars run a higher spring rate in the rear than the front, and higher roll stiffness in the rear than the front. when backed up the ramp, the weight transfer to the front will fully articulate the front quickly and the rear won't articulate very well.

As an aside, take note of which way the car is facing in flex shots. If the car has been backed up the obstacle/ramp to take the money shot it's a sure sign the front end is too stiff and car won't balance properly. (This is common with cars running whacky shackles in the rear)

3/4 is a mixed bag. It does seem to work better than scissor shackles and is a good way of getting more rear travel out of a SWB car that can't run a long rear spring, but it doesn't like lots of power and needs to be well damped to stop it "flopping" and hopping under power.

Steve.

fire away steve.......

That's a much better photo Joe. How high is the ramp? Looks about 700mm.

Steve.

with reguards to bumpstop spacing, what sort of distances between diff and spacer (at ride height ) are u guys leaving???

2" below stock seems a happy compromise - leaves roughly the same compression travel as stock, but some of us are running much softer springs than stock so we end up with very little compression travel at all - less than 1".

Steve.

Gwagensteve wrote:That's a much better photo Joe. How high is the ramp? Looks about 700mm.

Steve.

not bad for the real world.nice pic

joeblow wrote:

What are those rear arches?

TJ From memory.

Steve.

4 inch warn tj flares.

Just joining the pissing comp. My old Zuk had RUF, NT spring spacing on WT diffs with 3/4 in the rear running the Old Man Emu springs. It gave a nicely balanced amount of wheel travel front to rear. I never experienced any undue wheel hop etc due to the suspension setup, I did however have to add some weight to the rear to keep the rear tyres from just spinning. It was a great setup that seemed to work well with the combo of tyres, gears, lockers and terrain driven.



Note that pic was with NT diffs under not the wide tracks

and the oldie but a goodie pic but actually does illustrate the point quite well. The rear still had some travel left in it whilst the front was at full stuff, if we had cut even more out of the front or run a smaller tyre it would have had a bit more travel

Since Grimbo has i will post up.

Mines a half RUF on a WT (Rear hanger moved back to suit the RUF.

Flexin the front out as below. (2"BL, 2"ome RUF,31s on 7s)

Shock is limiting by about 1/2 to 1" i beleive.

nic, you had to move your hanger back becuase you have a NT chassis right?

in the end i cut and moved it back 20mm, giving a nice shackle angle, however i still need to do the rhs (stupid uni work), which is a bit harder as there is brake/fuel lines in the way which i need to move out of the way before i start grinding, but pretty simple job. will post pics whenever its finished

Nah, i did this the same way on my Old NT drover.

but this is on the WT chassis and body now i have done the same.

if want any pics i can do.

I'm about to do a full RUF with Chassis extension this weekend.
should i fish plate the extension or can i cut the chassis on an angle /= like that and make the extension =/ like that and weld it up?
I hope this makes sense.

Thanks

nicbeer wrote:Nah, i did this the same way on my Old NT drover.

but this is on the WT chassis and body now i have done the same.

if want any pics i can do.

yeah pics would be cool, just wondering why you moved it instead of redrill?

Spike_Sierra wrote:

nicbeer wrote:Nah, i did this the same way on my Old NT drover.

but this is on the WT chassis and body now i have done the same.

if want any pics i can do.

yeah pics would be cool, just wondering why you moved it instead of redrill?

Will grab a pic for ya. didnt redrill as sfa space on the WT to redrill plates longer.
i still have the custom rear hanger to play with lol for the heep springs.

Potter wrote:I'm about to do a full RUF with Chassis extension this weekend.
should i fish plate the extension or can i cut the chassis on an angle /= like that and make the extension =/ like that and weld it up?
I hope this makes sense.

Thanks

Just fish plating is a MUST but both would be better
Check with your local engineer

cool thanks

Heres pics of my NT with WT diffs at full flex on 1" bumpstop extensions.(front only)
It has 2" raised springs and standard? shocks. (on standard mounts)
It has 210mm travel(total) in the front. The bottom of the tyre is 575mm off the ground.
The shocks are limiting me now and before I go RUF I'd like to get the best out of these springs.
My question for those with RUF is what shocks do you use and how much have you lifted the top mount?

PS: The front is hard on the bumpstop and the rear has about 1" space.

not a gd comparison as mine in mine but i am running hilux ones up the front still i think. i have spaced the top down a bit but thats all.

i am going to dissconnect and measure it up again in that same spot for longer ones or mods.

I have std shackles as well. thinking 1" longer too.

Anyone interested in some genuine Suzuki springs? (Which are made by Mitsubishi funnily enough)
They are 965mm from eye to eye (centres) which makes them about halfway between Sierra fronts and rears.
They are 50mm wide , same as Sierra.
The centre pin is 35mm further forward than Sierra fronts.
I haven't finished fitting mine yet but I don't think its as hard as a full RUF.
No chassis extension needed, just slightly longer shackles.
Not quite as good as full ruf but a LOT easier.
Jas.

Jas,
What car are these springs from?
How much lift do they give?
And did you redrill the rear spring hanger, or just bolt straight in?

CairnsZook wrote:Jas,
What car are these springs from?
How much lift do they give?
And did you redrill the rear spring hanger, or just bolt straight in?

I got 4 pairs of Suzuki Carry springs. I have 2 pairs for sale if anyone is keen.
Stock I think they'd give about 1" over standard Sierra springs but I used my lower 2 X 2" lifted leaves under them to make it closer to 2" lifted.
At the moment its bolted straight in to rear hanger but as I said centre pin is 35mm forward so the tie rod interferes with the pitman arm at full compression. I'll have to redrill the rear hanger 12-15mm back or the perches, dunno which yet.
Jas

The top(shorter) springs are my 2" lifted (bent).

This pic is with the rear bolted to original hole in hanger.

Sounds like a pretty good compromise.
I'll be interested to see how they perform.

heres a pic of my remounted front springs rear hanger. moved around 20/25mm back



and one of the shackle angle(need to be played with to get desired height.)