Mechanical setup discussion

How i got to my theory is because how ARB works. I know that stiffer the ARB the outside tyre take more of the total load.
*Number are only for example purpose *
Suppose with a detached ARB outside tyre has 500kg and inside tyre has 300kg
Total load transfer is 200kg
NOW if i attach stiffer ARB the total load transfer will remain same (200kg) BUT this time outside tyre will take more of it because of stiffer ARB.
So lets say now outside tyre has 600kg and inside tyre has 200.

So i expected this kind of sharing could also happen with changes in spring rates. Since springs also act as a antiroll along with other motion such as dive, squat.etc.
So similar to ARB effects i expected springs to change how much load is shared depending on stiffness.
I posted this again just to be clear what i meant.

 

@Slip_Angel if you make front and rear ARB twice as stiff, does the overall load transfer change?

 

As far as i know total load transfer does not change.
load transfer is dependent on CG,mass of vehicle,wheel base(longitudinal), track width (lateral) and amount of Gs
It is certainly NOT dependent on suspension or arb etc

 

I agree. Your post above seems to be thinking on different lines though.

 

No no i understand that total load remains the same i even said it many times.
What i meant is how load is shared with the changes in ARB stiffness and suspension rates etc.
Again i know total load transfer stays the same.

 

Ok, I think your example figures are a bit messed up and aren't helping here.

You have total load of 800kg, so that's 400kg on each tyre at rest or in a straight line.

If you have 100kg load transfer, one tyre now has 500 and the other 300. On this single axle a softer or stiffer ARB won't make any difference to that outcome. It will affect how long it takes to reach that outcome, but there won't be any extra load transfer.

The key is that we have 2 axles, so changing the ARB at one end can change how much of the load transfer happens at each end of the car (the total remains the same). A stiffer ARB at one end makes more of the load transfer happen at that end, and therefore reduces it at the other end. In broad terms, that means the stiffer ARB end loses grip (load sensitivity) and the other end gains grip (same reason).

So don't think in terms of the ARB changing the load transfer between the 2 tyres it's connected to, but changing the load transfer at that axle in comparison to the other axle.

Of course there will be a change in weight transfer, but again that's pretty minor and liable to cause confusion

 

I think i'm trying to say the same thing but unfortunately i can't say it properly.
Here is the link of what i think about ARB->>
https://www.racingsimtools.com/single-post/2019/07/26/10-Tuning-the-Anti-Roll-Bar

 

Ok, yeah. I think the difficulty there is it talks about the front ARB as adding a certain amount of load transfer, like it does that in isolation and then you add that into the mix. I think what actually happens is you change the effective roll stiffness at that end of the car (because of the ARB) and that changes the distribution of the (same) total load transfer, giving an extra 100 lb at the front of the car (which takes it away from the rear).

That article could lead you into thinking the 100 lb load transfer is a direct product of the ARB on the front axle itself, which isn't right. If the rear axle were airborne you would get the full 350 lb load transfer at the front axle (assuming the rear somehow stays off the track for long enough!), and that figure wouldn't change regardless of having an ARB on it or not. (yes, obvious flaw in my example here: with only the fronts on the track, you wouldn't get the same load transfer because of much less overall friction)

 

Yes this is exactly what i was trying to say.
Only thing i was asking is if this kind of distribution change could also be caused by springs ?
As one axel with stiffer springs with have to work more to resist the motion of body and hence the changes in loads.

 

Back to ARB, stiffening front and rear doesn't change the total load transfer. Changing front or rear ARB (or both by different amounts) will change the balance of load transfer front or rear, but not the total.

Front and rear springs are the same situation, but longitudinally instead of laterally.

So softening rear springs won't change the load transfer (final load transfer; it will affect the transition). Softening one rear spring more than the other will change the load transfer balance left and right just like differing ARB adjustments for lateral acceleration, but the total remains the same.

The springs don't permanently 'hold' any load and alleviate that load from the tyres. 10000N/m springs and 80000N/m springs will both end up passing the entire load transfer onto the tyres, they'll just do so in different ways. Standing on a large high jump mat doesn't make the earth take any less of your weight than standing on the soles of your shoes - it'll just compress more.

 

This is all i wanted to know. Thanks.

 

When you drive at 200kmh constant speed and steering a circle path, once with soft springs and arb and once with stiff springs and arb (keeping the stiffness ratio front to rear as constant as possible), and without running into bumpstopper:
Would you expect the Suspension forces of the telemetry to be the same (as load transfer is same) or differ in both trials?

 

No. Suspension Geometry can induce positive or negative shifts of horizontal to vertical force moments.

If you raise the inner control arm pivot points far enough that the angle of the A-Arm is >45°, it will rise rather than droop from the lateral force transfer.

 

I agree this is the unknown variable. Maybe I should have written "significantly differ", or differ more than a possible change of COG height allows for.
Note that soft springs are more compressed by aerodynamic forces. So the question was also for compensated average ride height, being equal