Measuring suspension points.

[rb70383]

I have another question with my project planning. Like Astroracer, my current project I'm focusing on/planning is a van. To be exact a 77 Ddoge B200 short wheel base. I a couple good ideas for the rear suspension. On the front, before I decide on what to do, I want to see how bad/good the stock setup is. So how have somwe of you measured the stock setup. remove the spring and cycle the suspension through full droop and compression? Is a tape measure accurate for this? I would say the suspension has to be in decent shape to get a decent measurement right?

[Marcus SC&C]

There are a few ways you can do it. If you really want to get hardcore pick up a good suspension design program,measure every pickup point in the steering and suspension as accurately as humanly possible,plug it into the program then verfiy everything with some dynamic measurments. Now you can go wild agonizing over lateral roll center migration and FVSA etc. Fun! Well,not for some folks.
You can also do it down and dirty just to get an idea of where you stand (and maybe get carried away based on what you find later). Take the springs out and set the van up at your intended ride height. You should align the front end to perf. specs at this height to get the most accurate measurments but you can probably skip that for the first tests just to see if it`s going to be okay overall or now. Measure toe and camber. Now run it through it`s range of travel and measure the camber and toe every inch and write it all down. If you`ve got negative camber gain in bump (compression) you`re already ahead of most all of the classic muscle cars. If not,you`ve got soem work to do. If the toe doesn`t change you`d have perfect bumpsteer. It`ll change,especially towards the ends of the range of travel but you want as little as possible and preferably no change at all in the center 3" of travel. If not,you`ve got more work to do. If it turns out to be lousy you might look at Dakota front ends. I`ve never run the numbers but the geometry looks pretty decent,bumpsteer numbers are fairly low and they have a well set up R&P. Mark SC&C

[rb70383]

Cool, thanks for the info.

[pav8427]

Try jacking your rig up so that you rocker panels are level,then use a simple surveyors transit to 'shoot' all the heights in.
Stanley works well for anything left to right.

Doug