Shock Building

[zeroracing]

I think you are on the right track, learn as much on your own as you can through tuning and working with a shock guy. I have never used a performance trends Dyno, I do like the intercomp and Roehrig. Both of them are very nice, intercomp is cheaper. Maxwell has a nice unit and they are extremely nice and welcoming people. I would recommend a computer controlled one like these style though over the order style spring loaded deals. They work, but do not measure zero point as well/easily and are a bit dated.

On the spring machine, Disclaimer I make one of them. Www.facebook.com/ultraforcespringmachine/
The main ways I use mine are:
1. After scaling my car I measure my center to center distance of each shock then compress them in the machine. Record my numbers. So let's say I have 515.5 lbs on the LR at 18.25". I can then change springs from say a 200 to a stack set up. Readjust until I reach the 515.5 lb at 18.25". Now I don't have rescale the car itself. Much easier for me, I only scale once in a while now but test them weekly.
2. After a race I take off my right side shocks and run them down until I reach my travel indicators, then I record my right side loads. I can correlate this to my lap times and tune to get the car to the "stance" I am after.
3. The third thing I do is set bump stops or stack RF, adjusting for track speed (corner speed and track itself).
4. Along the same lines as 3, I graph my load curves for each set up so I know how the wheel is being loaded. This is important when using spring rubbers since they are not linear, or bumps.
You can also use it to measure springs if they are not rebounding like they used to, or if they are stamped correctly (honestly use it very little for this)

The honest truth is many of the things I do with mine or recommend people to do can be done with math, that is how I did it before I started making the machines. It was more time consuming, did not account for shock gas pressure as well and made spring rubbers a guess. But it is 100% doable to tune your car without one, just makes it quicker and easier.

Gas fill shocks work a couple different ways, easiest is with a Schrader valve you just put them together and charge. A non-Schrader valve takes a different set up, basically you have to charge and clamp it all together. I run only where I can use Schrader (late model) so don't have a set up for refil, it is special tooling or machine. Most guys use their own homemade deal.

The shock Dyno will just tell you your curve and if something is wrong, it won't compress them for rebuilding or anything like that.

Hope this helps, and good luck.

[RCJ]

While a pnematic dyno has short coming, it is a cheap starting piont.You can start a shock manitence progam with it.Changing fluid , making sure adjustable shocks are working correctly,building shock to the factory specs etc..It will get you familar with shim stacks,bleeds ,pistons ,gas pressures.