OK - so Torsional stiffness Torque/Rotation = KG/L where K = Pi/2 x (Radius)4 ---- (Thats radius to 4th power or squared twice - cant seem to make superscripts work) and G is a constant for steel and Rotation is in radians. But all you want to know is difference in stiffness, so take G as a constant and just look at difference in R4th/L And since L is constant here at 40 in, difference in stiffness is simply (.505)4 / (.495)4 or 1.08329 - translated 8.3% difference in stiffness between 300 Sport (or Newport Sedan / Conv, etc.) at 0.99 and H at 1.01 H vs New Yorker 12.8% stiffer H vs Newport wagon 17.5% stiffer And by the way, to convert to stiffness you need distance from
center of rod to centerline of tire - if you want absolutes, need
to go thru more calcs incl dealing with G Shear Modulus and
radians. But unless you are playing with different wheel offsets (going to aftermarket wheels - moving out increases moment arm and increases torsion which effectively "softens" car spring rate - moving in effectively "stiffens" but you get interference) or changing hub dimensions (such as may be if changing to disc brakes, etc). PS - If you are also playing with Anti-sway bars on front only,
it would not be unusual to soften spring rate if increasing sway
bar stiffness on that end - otherwise you would need to play with
back of car to keep handling balance (oversteer / understeer). For example, if you add a rear sway bar to a car that did not
originally have one, and you do nothing else (no change to rear
spring rate or better front bar increase in stiffness to balance
handling), be prepared for rear end to come around fast in a hard
turn - potentially severe oversteer condition. (Personal
experience, lesson learned)
Edward Mills
Antique Tractors 1930-1960
Antique Cars 1960-1985
On 6/20/2016 1:45 PM, 'Rich Barber'
c300@xxxxxxx [Chrysler300] wrote:
__._,_.___ Posted by: EMills_ATC <millserat@xxxxxxxxxxxxx> To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to https://groups.yahoo.com/neo/groups/all/manage/edit For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylang __,_._,___ |