Move upper arm mount rearward to allow caster adjustment

Woody500 said

Seems like you've induced an 'S' curve that looks more normal with 1/4" k-frame drop,. Explain 'slight lock'. And also, bump steer in chassis roll is affected then?
Setting that curve usually the best you can get.
Its all just compromising to get smallest amount of bump possible with a reasonable curve, right?

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none of the measurements were done with the K frame moved forward. that idea was after i measured and got these results. The K frame drop reduced the 'S' curve, i could have probably dialed out the bump steer by leaving the K frame mounted to the chassis in it's original position and moving the steering box and idler arm.

the slight lock is just 1/2 turn on the steering wheel.

the steering box and idler arm are at an angle so turning the wheel lock to lock it effectively changes the height of the steering system in relation to the suspension. A steering rack is linear so doesn't have this effect on lock. i did all the testing with the original steering system, not a rack, and the reason two of the curves became a 'C' shape is because the steering link was shortened to the length that would be required to fit a steering rack (which would be too short to be ideal).

i don't have final measurements after the modifications yet but made sure i'll have enough adjustment to dial out bump steer once the suspension has the desired Caster and ride height set. Having done bump steer on many cars it doesn't take much, in as in as a little as a few thousandths of an inch, to raise or lower a steering rack to affect bump steer.

because i'm using spherical joints and ball joints on the lower arms then accuracy is easier to achieve, if it was all rubber bushed still then with all the movement available in the bushes under load accuracy will be completely lost to the point of why even bother.

another thing that affects Caster is vehicle rake. Raise the rear and you lose Caster on the front.