Yes, as a septegenarian, I go back to "the good old days." And, I would certainly be upset if an expensive suspension analysis program couldn't even calculate something as basic as percent anti-squat. RE: Slope of 100% anti-squat line BillyShope (Automotive)
#Antisquad line how to#
Please see FAQ731-376: Forum Policies for tips on how to make the best use of Eng-Tips. It has the virtue that the geometric method for establishing the IC is entirely straightforward. For instance I don't know how it measures antisquat - in previous versions it often used hardpoint derived definitions, now it tends to use instantaneous centres and so on, which are more accurate and do not require assumptions about how the mechanism works.įWIW I don't even bother looking at those numbers, I use the pitch and hip point rise during an acceleration run and a braking run.Ĭan you point me at a picture of the sort of suspension you are most interested in - I default to 4 near parallel longitudinal links and a watts link, as that is our old production suspension, and is still used on the V8 Supercars. Since the ADAMS model is a true MBS the behaviour of the model is correct if the model is accurate- but that does not exclude errors in interpretation. Norm RE: Slope of 100% anti-squat line BillyShope (Automotive) Less net forward force combined with the same perpendicular force opposing the torque does sound like a larger anti-squat value. I can see where a heavier rear axle will "bleed off" more of any given horizontal accelerating force (taken at rear axle height) without affecting the torque reaction at that same point, so the relationship between the reactions at the chassis side of the SVSA would change slightly.
Might even help track what happens as the nose rises a little better (a closely related question that came up on has had me pondering this lately). Would it be of any advantage to work with a composite CG made up of the unsprung mass and its CG height and the front unsprung mass and its CG height (which usually is different) instead of the total vehicle mass CG height? That will normally give a slightly greater slope than using the total mass CG (at least in most cases and textbook diagrams) but lets you work from the contact patch, which might be easier to visualize than a point below grade. RE: Slope of 100% anti-squat line cibachrome (Automotive) 27 Apr 07 10:21
#Antisquad line software#
I'd be interested in knowing if the anti-squat, as calculated by the different software packages, changes with changes of rear axle assembly weight input. Specifically, the ratio of CG height to wheelbase must be multiplied by the ratio of total weight to a value equal to the total weight less the rear axle assembly weight.
As I was explaining all this to a non-engineer, I suddenly realized that the line must still pass through a point, on a vertical line through the front tire patch, at a height equal to the CG height.
#Antisquad line Patch#
Some time ago, I realized that the line must pass slightly below the rear tire patch IF the weight of the rear axle assembly is taken into consideration, but I considered this as merely a displacement and not a change in slope.
When calculating percent anti-squat for a RWD beam axle car, the 100% line is commonly assumed to have a slope equal to the CG height divided by the wheelbase.
0 kommentar(er)
