QUOTE="Mac5005, post:...Anti forces are different front to rear.
Vehicle pitch is a factor of both.
Not to any amount under both accel and decel. Actually anti squat can affect the front handling on decel, while anti dive has much less affect on the rear handling.
Even if you have 100% rear anti squat, the front will still lift.
100% isn't much. We generally would strive to achieve 100-110% in our dirt cars. Plenty of lift at 100% in a car with 55% rear weight and minimal bite available on dirt!
If you have 100% front anti dive, the rear will still lift under braking.
Agreed. Anti dive has little if anything to do with front lift
Re-read my last post.
Anti-dive in breaking is anti lift under throttle in 4wd.
Probably similar to what I mentioned about FWD vehicles. This matters to them, because they don't have the rear transferring weight and "lifting" the front. So while a can agree on this principle, it becomes negligible due to weight transfer from the rear drive.
Now I dont know a lot about front drives, so I could be missing something there.
In 2wd there is no torque based anti lift geometry as there is no torque input to pinion.
I assume you mean in the front. The problem with this torque input is, how does the front geometry impart any appreciable force on the chassis when accelerating? Any downward force in the front is overcome by the lifting forces of the rear. (This is akin to saying I can ride a falling tower and jump up just before it hits the ground and land gently on my feet cause I jumped before I hit! Yes, I believe the physics would show I may have decelerated, or at least stopped accelerating, but so little as to have no effect on my demise!)
Yes, there may be forces in the front that could resist lift. But because the front is being lifted by the rear, they would have almost null effect.
There is still horizontal ground force pushing against tire under 2wd acceleration.
Front tires? Minimized due to weight transfer.
The principles and dynamics are the same no matter the application.
But the principles only matter if they are working against something
Again, I agree, but these dynamic actions only affect anything when they can produce a reaction. Using an extreme illustration, front forces are completely null in a wheel stand!
you can change the front geometry to change front lift characteristics. But this is dependent on many factors that can reverse in 2wd vs 4wd.
Either way the weight transfer is dependent on cog height, wheelbase, and acceleration rate.
...and resultant force vectors achieved via, torque applied, lever arm geometry, spring rate, and reaction to tire friction!
Geometry changes dictate whether this weight transfer is applied to the springs or onto the links.
It always applies to the springs through the links and ultimately the contact patch...provided it has springs. But then even with no springs, the tire become the spring!
Take a 4" lift yj spring, spring under.
Built an upper link from
Center of frame to top or truss or top of diff.
This setup will create rear lift under acceleration, proving over 100% antisquat.
I'm not arguing that the instant center location in reference to COG height and wheelbase locates the antisquat percentage,
I'm just arguing that depending on suspension design, leaf pack location and design, traction bar design etc, that setup could be pro squat or anti squat or anywhere in between.
LOL. Actually, my weigh-in here began about your's and Ben's reverse referencing to anti squat raising and lowering!
You can't say X traction bar setup will always create pro squat. It is dependent on far too many variable to have a blanket statement like that.
I never said it would create pro squat. I said it would reduce the anti squat. Leaf spring always have huge anti squat percentages. The axle would have to be so far above the front spring eye in order to achieve pro squat as to be impractcal.
Plot the points, show some numbers.
Since this calc doesn't do leafs, Ill improvise...
This shows a front leaf eye level with the axle centerline. (arbitrarily using 36" lever arm length) This results in 168% static anti squat. Under acceleration, without the traction bar, the percentage would actually rise as the leaf wraps up because the instant center rises. But the traction bar will resist the rise in the instant point, thus preventing the dynamic anti squat from rising. Or effectively lowering the resultant dynamic anti squat. Note...Nothing I do here can produce "pro squat".
This is what you would have to do to achieve pro squat in a leaf setup...this results in 62% (think, any point below the anti squat line (violet) will be less than 100%)
Or I could make the front lever arm very long!
Less spring preload, more rebound valving, or higher spring rate and more compression valving is a recipe for poor ride quality.
Heavy unsprung weight (big axles and heavy tire and wheel) with relatively light sprung weights(jeep) needs light spring rates with good preload, and fairly light rebound valving to have a halfway decent ride quality.
Changing the shock valving as a band aid on suspension geometry is a recipe for the next thread:
...Pissing blood after a weekend at Uwharie on the uber tall water bars.
he he he..love it!
Yep, we're off the limit strap topic for sure! Wonder if Chuckman is still here?! 
