uninformed

Get the co driver to sit on the bull bar?

John I have been asking on a few forums over the years, if we still calc the anti's for our rigs given that the book stuff is all based on solid axle 2wd. Are you saying that our values are changed by 4wd and that both axles are driving and housings reacting?

Hello all, just wondering what size and type of thread are on the fittings that go into the Fuel sedimenter on my 1998 110. The pot at the back next to fuel tank. cheers Serg

tractor would be lifting one side VERY slowly. Would that not also be more "real" world as I don't think you are going to roll over on flat ground with the engine off

no, we ran out of time. Had a plan, a 7t 4wd JD tractor and just the guy to do it……but time got away on that visit. Daan, I have read the method you describe, it requires fairly detailed measuring and being able to lift the front/rear and sides a certain amount and still weigh them. This would involve some $$$ in equipment, because there is no way in hell any place like a wighbridge is going let let us dick around like that for time and liability reasons. I am happy to go with LR's specs, Id doubt they would be wrong by much.

My COG was from LR data for the cab chassis. I added the 50mm or so. The figure is a min and a max. The max being if you are fully loaded to LR guidelines. That may be where you are getting the 1060 from. Yes i agree I have posted that same point. It is very easy to measure all the other data points with fair amount of accuracy, but the COG is tough….and the most important. Now I read somewhere that COG is COG and making the track wider will not lower it. It will reduce the tendacny to roll over at a given point but not lower the COG? is this correct?

I doubt the COG would be the same. The bottom of winch is the top of the chassis rails at the front chassis horns. The bar is tube and not that much weight, maybe 25kg. The chassis, engine, gearbox, tcase, body and tray have all moved up. With a COG height of 720mm my front anti dive (under acceleration, not braking) is 213% according to triaged calc. What I am interested in, is if we calc the antis according to triaged calcs getting our reference over the other end axle. I sort of get this for 2wd cars, where the rear end is driving and reacting over the front. But in our 4wd the front end is driving as well. 50/50 split when off road. Do they have a reaction point that is somewhere in the middle that makes things different for 4wd???

Would it not just be: the height of axle centre line (380mm) the height of centre of chassis bush (455mm) the length from axle centre to chassis bush centre. (840mm) The RA has 2 axle mount points as you know. There is no movement between these 2 points. If you draw a line through the centre of these 2 axle bushes, it disects the axle centre line. It is the axle that is the important arc swing, not the front or rear RA bush at axle. So, my wheelbase is 110 inch (minus the small amount of axle swing in due to 2.5 inch lift) Tyres are 235/85R16 on stock 130 rims. 300tdi 110 cab chassis with cut down alloy tray. Stock RAs. Tube winch bar, hyd winch.

Why do you need the length of the axle mount/s to the chassis mount?

Sam sold mogrover quite a few years ago. I dont think it ever had coil overs etc when he ran it. I was interested to see the rear axle shifting sideways at the 2:03-2:18 mark under acelleration…... Ill try and link some pics.

how do you mean?

Bill, I think there were a few positives. One being less axle roll steer, and from the same thing the axle not coming forward under the vehicle as much on down travel. The other being that if the upper A frame was not altered the new difference in length between the A frame and the longer trailing arms would mean a reduction in the rate that the anti squat raised during down travel.

yes sorry about that thread "De Ranged" of coarse it went pair shaped when I got confused by "loose" terminology and their use of IFS/IRS pictures that did not relate to Solid axle. I also started the thread from a braking perspective, but they dont care about that and seem fixated on the going forward stuff….Still some good points were made.

when under acceleration, high anti dive in the front is like low anti squat in the rear. As the links are now on the other side of the axle housing, but both front and rear housings are rotating in the sdame direction. So it appears to me that high anti dive in the front will suck the front down rather than jack it up…… This came up on pirate not long ago in a thread I started about anti dive. I am more concerned with it at speed for braking though. I also pondered the question of how the 2 ends react with each other as they way the link calculators looks at them is individually, almosty as if only 2wd…..

Bill, thanks for that post regarding your vehicle. Maybe DeRanged has been following my plight of Radius arms on the various forums. I by no means think they are the be all and end all. Far from it. Everything is a compromise, and in my case engineering/legalities make it easier to play with radius arms than changing to say a 3 link. I also like that there is some roll resistance built in. I hope my planned longer RA don't loose to much of that, as the absence of a ARB in the front is handy packaging etc wise.

Throttle control plays a large roll. Some US guys build in certain amounts of antisquat so they get good "launch" or bite at take off. I certainly dont think we want to run low like 20%. John's comment on rising AS is quite important IMO.

Bill, I have seen this and a lot of us have done it. My question is, is the point of regained traction when the vehicle is at its most squated, and then as it rises with the men rising its not actually getting any more traction. My point being, while it may produce a result, I think there may be other things going on like the mass of the men and the force of them bouncing etc that may make the it seem like hop is a good thing, but I'm thinking lower AS (to a degree) will actually propel the vehicle forward more so…..

ok. Am I correct in saying you have 2 lowers and one upper? If so, your lowers will determine your axle roll axis angle, AND, when combined with the panhard starting point, your front roll centre height. Using your panhard starting point (which ever YOU feel is correct, ie half way etc) plot a line running parallel to the lowers when viewed from the side (i.e. the same angle front to back) the point (height) that this new line intersects a vertical line drawn through your axle centre is your front roll centre height. The angled line is your axle roll axis. Are your rear leaves retained each end?

The panhard is only part of the equation. It is the starting point, but a line must be drawn including your link geometry, where this passes over the axle centre line is the roll centre height. Bush65 mentioned to me he feels it changes for a panhard type suspension depending on which way the axle is articulating. In my book, it shows it being the chassis centre line intersecting the panhard as the starting point, regardless if the panhard is equal either side of centre or not…….. Does your front 3 link have any triangulation in the links when viewed from above?

I wish there was one number to shoot for, but alas…. Here is a kicker, the lower the centre of gravity the higher the antis will be for a given set up. So for our lifted rigs that actually benefit from longer links the rate at which anits drop is quicker as the COG is higher. Plus wheelbase is a big factor. As Bill pointed out to me, what happens if say you make a front link long enough it passes the half way of wheelbase, or fore/aft COG?? as an example, my mate has a 118inch wheelbasse rig. His front radius arms are +500mm over stock (yes half a meter longer) but he has a lower COG than stock. I want to make my radius arms +300mm, I have a higher COG. Even though my arms will be shorter, I will probably have less Anit dive…... Bill, typo on your wheelbase me thinks

at that particular point, maybe??? Im not 100% on your link set up Bill. Is the front 3 link +panhard? If so this is easy to figure the front roll centre height and the front axle roll axis angle. What about your rear links? Once you figure there rear roll centre height out, you can draw a line through it and through the front roll centre height. This can give you the roll centre line of the vehicle (Vehicle roll axis) As you ar probably way more aware then me, these things are fine on paper, but what happens real world is more important. Your understanding and experience is that of about 5 of my life times. Are you trying to figure it out so you have a base line if you change to a one link or change the rear? regardless, Im going to try this tomorrow and see if my rear is higher than the front, given I know there is that difference in the roll centre heights.

so the vertical sliding rod does not move/swing for/aft, just that movement is allowed at the axle housing?

ok, you ll have to explain how it works. Im currently not seeing it. DD's sliding frame is his lateral location, correct? it has to slide due to the change in length as the one link goes through travel/articulation, correct? That vertical link looks like it can swing left to right?

I can not say what the middle, vertical link is. But the 2 skinny links are part of the sway bar, and the shocks either side are just the shocks, king brand. Thats how I see it anyway

yep, if you had a 6 inch long link and 6 inches of down travel you would have about 90* of pinion change, if you had a 40 inch long link and 6 inches of down travel you would have about 8.5* of pinion change