i've gotten my front a arms modeled for my custom chassis, and i'm starting to get rather concerned when looking at the models. the a arms are insanely short...
i'm trying to remember my dimensions off the top of my head right now, but i know the lower a arm mounting points are 18.75 inches from the center of the car and 5.75 inches below the wheel centerline where it passes through the chassis. the upper a arm mounts are 19.25 inches from the center and 5.75 inches above the centerline. and well, the pivot point between the lower a arm and front spindle is about 26 inches from the center, and the arm itself is a few degrees lower than horizontal. do the math (as best as you can understand my description without a drawing), and the lower arm is very short and the upper arm is even shorter.
right now, i'm planning on a 7 degree king pin angle, 5 degrees positive caster, 80mm scrub radius, the roll center about an inch below the ground with the car at ride height, and the reaction point for the a arms about 130 inches out from the center or the wheel (away from the car). part of my concern here is that i plan to use heim joints with 14mm threads (hopefully not too over the top) for adjustability, and there seems to be a lot of risk of binding.
i've read up, but am still new at suspension design, and i really want it right before making anything. should i try tweaking the chassis design for lower a arms first off? depending on my wheels, i'm wondering if also perhaps trying a design with the reaction point 130 inches from the wheel toward the car since the current setup looks like a really flat version of a dune racer suspension in my opinion.
i'm terrified to think of the torrent of information that may come my way, but it's all for the better.
i'm trying to remember my dimensions off the top of my head right now, but i know the lower a arm mounting points are 18.75 inches from the center of the car and 5.75 inches below the wheel centerline where it passes through the chassis. the upper a arm mounts are 19.25 inches from the center and 5.75 inches above the centerline. and well, the pivot point between the lower a arm and front spindle is about 26 inches from the center, and the arm itself is a few degrees lower than horizontal. do the math (as best as you can understand my description without a drawing), and the lower arm is very short and the upper arm is even shorter.
right now, i'm planning on a 7 degree king pin angle, 5 degrees positive caster, 80mm scrub radius, the roll center about an inch below the ground with the car at ride height, and the reaction point for the a arms about 130 inches out from the center or the wheel (away from the car). part of my concern here is that i plan to use heim joints with 14mm threads (hopefully not too over the top) for adjustability, and there seems to be a lot of risk of binding.
i've read up, but am still new at suspension design, and i really want it right before making anything. should i try tweaking the chassis design for lower a arms first off? depending on my wheels, i'm wondering if also perhaps trying a design with the reaction point 130 inches from the wheel toward the car since the current setup looks like a really flat version of a dune racer suspension in my opinion.
i'm terrified to think of the torrent of information that may come my way, but it's all for the better.