Krio, I believe that bottom of that graph is still showing rebound, not compression. I don't think the bottom of the graph is BDC on the dyno crank which would indicate that the bottom is compression. I believe it is still only a plot of displacement vs force in the standard form and not a plot of force vs the cranks position.

I received the pistons on Saturday and I thank Marcus for the super fast shipping. The pistons looked really nice and fit together well. I really appreciate that someone actually spends the time to make dual stage pistons for the racing crowd and all our vehicles.

I spent almost the entire day working on these pistons. I was very excited and immediately started working on them Sunday morning. It is very fun to work on pistons and watch football at the same time

I took my front two shocks from my SCTE. I left one standard just so I could compare by feel. I put in my lowest weight oil, 17.5 and the shock felt just like there was no resistance and didn't really compare at all to the other shock. I worked my way up to 45wt oil and it still had little resistance; it still felt like a standard 20wt oil shock or less and I could barely feel a difference between bump and rebound and it definitely didn't compare in damping resistance to the standard 35wt shock.

I am already at the point where my truck could maybe even go up a little more in damping actually, so I felt like the way the shock pistons come wouldn't work for what I need. So with all respect to Marcus and everyone here, like I almost always do with any toy I get anyway, I began to modify.

My intent since the beginning is to run the pistons upside down so I could get more rebound damping vs compression as I have seen it in 1:1. Whether or not this will make my truck better, I don't know, but it is the premise I am starting with. So far, they seem like they are going to work fine upside, no problems. They fit nicely.

I ended up gluing shut some of the pistons on the fatter piston with 8 holes. I closed off 4 of the holes.



What this does when the two pistons close together during rebound is check off 4 of the holes from the flatter piston. So during the rebound stroke, only 2 holes are exposed. During the compression stroke, 6 holes are open giving me a 3:1 rebound:compression which is how I decided to model it after a Bilstein 1:1 offroad buggy shock. However, there is a problem. The fatter piston only has 4 holes, so I had to open the holes up to allow as much flow as possible for the 6 exposed on the thinner piston. So this piston maybe has less than a 3:1, maybe more like a 5:2 but definitely no worse than a 2:1.

I then began to test shock oils. I tried 30wt and even with just 2 holes open it still felt like 17wt or less on rebound. I went up to 45wt and it still felt very easy to rebound, much less than my standard shock with 35wt oil in it. So I made a run to the LHS and bought oils all the way up to 80wt.

I finally ended up with 60wt oil in it. During the rebound stroke, it feels slightly less than my 35wt standard shock on rebound. During compression, it definitely feels easier to push. As matter of fact, I walked away from my bench and when I came back, I forgot which shock I had changed pistons. So I cycled the compression/rebound and could easily tell which shock was modified.

I don't know if I am staying with 60wt. Maybe I should have tuned the shock so that the compression stroke should have felt more like the standard 35wt compression, I just don't know. I'll find out when I drive it on Wednesday. I was getting a bit of bounce last Saturday. Maybe that was due to the shock oil being to high and causing a high bump damping throwing my chassis up on bumps. Maybe low compression would help here. Or maybe it was due to the shock oil being to thin and rebound being to fast and allowing oscillations. I will be paying attention to this however and tune to the best of my ability which is very little actually, but I will do my best.

I am going to spend a considerable amount of time tuning everything, then I will have our best racer test it, I will probably make further changes to suit his style, then allow him to drive the hell out of this truck and I'm gonna tell him to push it hard while I videotape it. I hope to get some good video for everyone to view.

Like I said, it is just an experiment, and I am enjoying it. It may be wrong, it may be right, I don't know, all I can say is thanks to Marcus for even making this for us and giving us a new toy to play with.