Sunday, April 12, 2009

stub calculation

the primary thing that determines the ride height of the front end is the distance between the axle and mounting point of the strut at the body. a shorter distance here will lower the car by whatever that is, for the most part. now that the upper assembly is finished on the new, modified struts, i can compare it to the original:

    

on the left is original, 650mm. on right is modified, 590mm. 60mm is roughly 2 1/2", or about 1" more than i want, so that should mean that the stub needs to have a length from its base where it threads onto the damper to its shoulder where it contacts the strut mount/bearing of 1". that would mean that with it (the stub) my new length between steering knuckle and mount would be 1 1/2" shorter than stock, resulting in a lowering of the front end by that amount. 

heres the rub: a length of 1" (ignore the threads on top for now) is less than the necessary thread depth to screw onto the damper fully...it needs 37mm, and thats just under 1 1/2". 



basically, the shortest i can make it from end to shoulder is 41mm; that would leave just 4mm of material above the female threads before the upper shoulder and male threads, the same as the wall thickness. the longest would be 61mm; that would actually duplicate the same ride height its always had, and any more than that and i would be lifting the front end. 
  thats a maximum lowering of just 20mm. somethings not right...