Quote:
Originally Posted by beta
Have you had a chance to measure yet? I think we need a stock setup to measure properly I think.
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yes! crap! sorry!
now, keep in mind all-a-yoos-guys that these are not EXACT measurements. i do not have the proper tools for that. that being said there is some variability and therefore leeway i'm awarding myself. in general, i believe these measurements are reasonably accurate to +/- 2mm. READ... that's a possible 4mm margin of error.
ok... stock suspension, stock alignment, stock wheels, stock tires...
Ty = 522mm
Tz = 769mm
By = 696mm
Bz = 186mm
Cy = 743mm
courtesy of
aerobod, S=(Cy-By)-{((By-Ty)*Bz)/(Tz-Bz)}
S(stock) = (743-696)-{((696-522)*186)/(769-186)} =
-9mm [sig figs]
-9mm obviously translates to a negative scrub radius, which is quite well suited to mcstrut suspension setups. this number is no surprise then, especially on a BMW.
now... on to my current setup... stock suspension, stock alignment, 19.0" x 8.5" et35, 245/35r19
Ty = 522mm
Tz = 766mm
By = 696mm
Bz = 183mm
Cy = 750mm
S(v3.2mc) = (750-696)-{((696-522)*183)/(766-183)} = -1mm [sig figs]
-1mm is way better than i thought it would be! i half expected to find some seriously wonky and positive SR and totally start second guessing myself on whether or not i should consider getting some track wheels, or just run what i brung. turns out the only real PITA is going to be the weight of the wheels.
it is also worth noting that adding the shim kit makes sense for me at this point. it may cut down on tire life, but it will also fool the car into thinking i have a close-to-stock SR, and add neg camber at the same time.
and please... somebody... by all means check my math. i'm human and make mistakes.
also, if somebody wants me to start a new thread with this info, just let me know.