OK on to shock oils. This part is actually quite easy but VERY time consuming as you will be replacing the oil in your shocks many times. First off if you have multiple piston options for your shocks, pick one somewhere in the middle. If you don't have any options then obviously use what you've got.

First off, go drive your car without shock oil at all. Pay attention to how the car bounces up and down. You don't need a track for this. The street or a parking lot will work just fine. Notice how it bounces up and down on the springs since there is nothing there to dampen it. I merely refer to this as "bouncing on the springs" so when I say that, you know what I mean. The rate at which it bounces is your suspension frequency. Hopefully at this stage, the front and rear of the car move up and down together in harmony without one end bouncing at a different rate or opposite the other. If you don't have a match here, you aren't done with your spring rates yet.

I start with a light oil. What you consider light may vary from what I do depending on your scale, pistons, etc so use something that you know is inadequately light. It sounds weird I know but we can't find what works without first knowing what doesn't.

Use the same shock pistons all around. Don't use something different in front than rear. Now fill your shocks up with the same lightweight oil all around. Be careful to bleed them well so we don't mess up our results. At first you can perform the shock oil tests in the street or a parking lot. Later on you fine tune at the track.

If you just drive around with this light oil, you'll notice that the car is probably still bouncing on the springs, just not as quickly. Your goal is to keep increasing the oil weight until this stops happening. It will happen at each end at different rates with the rear being a bit more obvious as there is typically more weight there. Once you find this point, it doesn't mean you've got the perfect weight. There may be a range. You may be able to keep increasing the weight for a while. You'll know it's too stiff once the wheels start trying to bounce off the street. Make note of where you stop bouncing on the springs and start bouncing on the tires. This is the usable range for oil at that end. Do the same for the front and rear. I've found that typically the front requires a heavier oil than the rear, sometimes by up to 20W different or more.

What you are basically doing is driving the car, and you can do this at the track if you are fine tuning, and are adding oil weight until that end of the car stops effectively dampening the bumps and starts wheel bouncing. Then you back it off. If the rear hits this point first, stop changing things and keep going in front until the same happens. You get the idea.

If you find balance and good dampening and you are having no problem at all with the bumps but are bottoming on landing from the jumps, you need to go up in packing in the shocks. This will mean a decrease in shock oil of course but just start low again and repeat the process until you get it where you want. If you have a very bumpy track and have no problem with bottoming on landings from jumps, go with less pack and heavier oils. Maybe what you have is good. Leave it alone.

This technique is going to take lots of time, trial and error. You may get frustrated or think you aren't making progress. Stick to it. Remember the shocks are being used to control suspension chassis movement. Don't worry too much about the affect of oil weights on cornering at this point although when you get the shocks done it should be pretty good. The car should still maintain pretty neutral handling. Cornering will come into play when we get to roll centers and tire selection.

What happens if you are still somewhat bouncing on the springs but never get to a point where you get fairly smooth and it goes straight to bouncing on the tires? Your spring rate is too high.

I suspect this step is going to get some interesting feedback, good or bad, so just get to work using the steps and find the sweet spot. Remember you'll have a shock oil range front and rear so there really is no one right combo here. Just a range to stay within although the range could potentially be large or small depending on your suspension frequency and track.

I know it's weird but it is systematic, although very time consuming.