I'm not an Engineer or anything but I, stayed at a Holiday Inn last night.
@Hackerbilt sorry I could not help myself
Here's the underside of the crossmember:Hey PovtinGuy! All the times I looked at your car and slobbered all over it I never noticed your rack was inside the front crossmember. How did you do that? I need pictures! I want to copy that and your cooling system! John
Your setup has been an inspiration since I first saw pics of it. In the end, our configurations will be pretty different. I'm using a spring over configuration instead of behind. Also, the front crossmember will likely be 4x2 rectangular tube, and the R&P will be mounted behind it, with the bellows and rods going through holes in the frame. I do plan on dual dampers of some type connected to the steering arms, but I'm leaving selecting the specific dampers until it's time to put them onAh, great minds, Zandoz...I've been running my R&P for 20 years and have made all the mistakes and enhancements, so you don't have to. From the kingpin to the R&P rod is 6". And the steering dampers are at 4" on the arms. I got RPM's standard arm, but with no holes so I could make it fit just like I wanted it. Note my R&P is in the front crossmember; if your's will be behind you may need a little more arm (RPM's are real long, I cut off about 3"). The dampers are motorcycle units on eBay: Universal High Quality Adjustable Steering Damper Stabilizer Safety Black. Adjustable and only $50 each. FYI, I have never had front shocks, but am putting some on this winter for smoother highway cruising. I'm using Houdailles. There's a thread on them, and they will be on my project thread soon. Questions, grasshopper?
I imagine Ron at RPM could make any arm you might dream up. I wouldn't worry about Ackermann. It's just not important. Doesn't affect handling. I ran really bad Ackermann for 20 years and didn't see any tire wear or other effect. Dampers...don't get me started. The only damper marketed for rods is by So-Cal, and it's just a stock Volkswagen unit. I looked at lots of dampers, most of which are big clunkers for off-road vehicles, before I found the motorcycle ones. They look great, come in many colors and have Heims already.
The 6" is from the Heim straight up the arm to a line thru the kingpin. But if you need 7" or 8" you should be good. Again, RPM could make one longer if needed. Looking forward to your build; take pics!
Frame build...I was lucky to have a pro who was even more picky than me to build my frame and do a bunch of other fab. If they don't have a frame table I'd keep looking. You might talk with our sponsors re a custom frame.
You will likely have to do some trial and error type r&d on the hole placement... What do you mean, no second chances? I have welded many screw ups closed and redone them, lol.... More than I care to admit.Your setup has been an inspiration since I first saw pics of it. In the end, our configurations will be pretty different. I'm using a spring over configuration instead of behind. Also, the front crossmember will likely be 4x2 rectangular tube, and the R&P will be mounted behind it, with the bellows and rods going through holes in the frame. I do plan on dual dampers of some type connected to the steering arms, but I'm leaving selecting the specific dampers until it's time to put them on
I'm glad to know that RPM's arms are a possibility, but I'm wondering if they will work to get the ackerman right with my short wheelbase (92" is my target). I'll need arms that will result in a greater angle...I suspect I may have to have them custom built.
I do have a question about the 6" distance between kingpin and the R&P rod/heim. ..but I'm not sure if I'll put this so it makes sense. Is the 6" measurement the angled distance from the center of the king pin to the center of the R&P heim? or is it the right angle distance between the parallel lines through the king pins and through the R&P heims?
Right now, my main need as far as steering goes is to figure out where to position the sleeved holes in the frame for the R&P bellows and tie rods. It's one of those no second chance to get it right things.
You will likely have to do some trial and error type r&d on the hole placement... What do you mean, no second chances? I have welded many screw ups closed and redone them, lol.... More than I care to admit.
If I am I visualizing it correctly, sounds like you just need to figure out where the rack will mount, in regards to the frame to give a location for the center of the tie rods. Then you will have to figure the angle, if any and the travel due to spring deflection and camber. Shouldn't be too bad if you have your rack and frame dimensions. Mark my words, no matter how hard you try and how much you figure, something will bite you and make you say or at least think real bad thoughts! Then get the welder out and erase, try again...lolI'm talking about a 3-1/4" sleeved hole...not something I would think would be easy to move say a 1/2". Plus there would be the added expense of having the frame shop make the adjustment.
Basically I just need to figure out how much room I need between the front crossmember and the R&P unit to allow room for bracketry. The unit needs to be almost against the crossmember, but with the un-adjustable feet cast on the pinion housing at about a 35-40° angle to the crossmember.
Since custom steering arms are pretty much a certainty, they'll have to be made to line up with the R&P unit, where ever it lands.
If I am I visualizing it correctly, sounds like you just need to figure out where the rack will mount, in regards to the frame to give a location for the center of the tie rods. Then you will have to figure the angle, if any and the travel due to spring deflection and camber. Shouldn't be too bad if you have your rack and frame dimensions. Mark my words, no matter how hard you try and how much you figure, something will bite you and make you say or at least think real bad thoughts! Then get the welder out and erase, try again...lol
Not sure what rack you are using, some have bosses cast in, some have bands around them. I have seen them mounted just under the frame, behind the axle, on studs in the frame. There isn't much loss of clearance because they are still above the oil pan, etc... Unless you run into a parking block, or the like. Sometimes I find I have to just get out in the shop and hold the parts where they go and start going through the motions and see what makes sence. Pretty tuff to envision without looking at and touching them for me, but that's how I learned. Good luck!Welll, sorta.
The vertical position is a given. The centerline of the R&P and the frame hole will have to be centered on the frame rail. There is no wiggle room for a 3.25" hole in a 4" tall frame rail.
The issue is the horizontal position of the hole. It needs to be as far forward and as close to the crossmember as possible. The farther rearward the greater adverse effect on the turning radius. The problem is that there will have to be R&P mounting bracketry between the crossmember and the R&P...and that bracketry will not be simple.
At this point I've not even come up with bracketry that isn't dangerously close to a product of Mr Rube Goldberg.