Steering Issue

[GMracer]

Working on my tube chassis right now for my 2001 Silverado, and planned to move all my control arms upwards to set it up for a low ride height. Problem is my rack can't be lifted, I have 1/2" from oil pan as is, so I thought about just flipping it to having it go in the spindle from underneath, but now I run into clearance issues. So what I'm thinking about doing is when I mount to engine 1-2" higher up. Still flip the tierod, but then convert to a heims steering system. Here are some pictures, if anyone has a better idea speak up! Thanks guys!



you can see the clearance on a stock engine height and rack height


here is the same rack height with my control arms in mock up height, 20* angle upwards while the lower arms sits at 0*


now if I flip them, you can see it would hit the control arms, not as bad angle but still not where it needs to be.


here is a picture of similar heims setup I plan

[GMracer]

no one?

[Norm Peterson]

Are you saying that with the LCAs horizontal that the UCAs will be running 'uphill' from the UBJ toward the chassis by 20°? If so, that sounds a bit scary, as the roll center would be significantly below the ground level and a "zero steer" spindle arc would not at all agree with the outer tierod arc (translation: BUMPSTEER). If it's just for a cruiser, the roll center issue is probably minor. But I suspect that the bumpsteer would get really annoying rather quickly.

It might be possible to tame the bumpsteer by skewing the UCA and LCA chassis side pivots in either/both plan and side views (I think that's what GM did with the G-body and the earlier "Accudrive" arrangements for UCAs inclined at much shallower angles than 20°). Got a 3-D suspension program handy?


Norm

[GMracer]

no no, the upper control arm and lower is factory geometry, the 20* is what the tierod angle is if I left it at stock location, while the lower is 0* Im going to flip it, (hense the picture) to bring it back done then raise the rack to get it on the same plane as LCA, I was just seeing if any of you guys saw another option I may have overlooked.

[Norm Peterson]

In that case, the RC height should be OK. But there will still be huge bumpsteer. 20° seems like an awful lot to be compensating for with a bumpsteer correction kit, and torsion on the steering arms concerns me a bit.

Maybe we need a front view sketch, drawn somewhere near to scale . . .


Norm

[GMracer]

am I misunderstanding you or you misunderstand me haha

Above is what I currently have as a dilemma, Factory mounted steering, but I moved all my control arm mounts upward since I want to retain factory geometry yet at a lower ride height.

20* is NOT what I'm going to run it was simply showing you what it would be if I were to mount it like that, when it's all said an done I will raise my rack up and flip it to the bottom of the spindle and the tie rod will lay at 0* along with the lower control arm. I don't know why you need a sketch if you look at the pics and read what I'm saying it clarifies it.