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I *think* each line is 2-clicks of adjustment and it's run at 0-2 in/sec. Why that slow? because the slow speed is where a lot of important things happen. It's the range of speeds seen as a car brakes and turns in and accelerates out of a corner. To over simplify, low speed damping relates to grip and the high speed relates to ride, and this is why pretty much everything is digressive these days. Most dyno plots don't show really low speeds but it is very important, and the people at JRZ pay very close attention to what their stuff is doing in that range. It's also why there is such a huge step up in price to a 3-way shock because the way the valving works has to change pretty significantly and be made very precisely to only adjust low speed compression. When it comes to shaving down lap times however it's probably the most important knob. Anyway, I digress...
My take is that there is not very much low speed compression damping, there IS a good amount of crosstalk to the bump for a rebound adjustable only shock, it doesn't adjust very linearly if that's a word, rebound is slow to react and there is a weird slant to the curve (hysteresis I'm guessing).
That is only one corner so it would be useful to compare it to the others to see if they are all doing the same thing. I might be talking a little trash on facebook but there isn't really much you can take from that plot that says they are "bad," although there is nothing that says they are good either. I'm assuming (hoping) the noise and those kinks in the plots are just from the mounting or something.
Having seen many sweeps of JRZs run on that same dyno at the same speeds, the lines are much more clearly defined at each click, they generate full force with MUCH less displacement, and each line starts and ends at 0. And well that is all pretty important. If it takes a shock an inch of travel to generate the designed force it's not going to do you a lot of good. That's also why it would be good to see the other corners. Over a wider velocity spread they might all appear to be doing generally the same thing, but slowed down things might be very different. I found this to be the case on a set of shocks I had custom valved (and ran on that same dyno), and ended up sending them back. Turned out to be my fault because I gave the guy one damper from a different year and the oem valving had changed slightly. Regardless, the differences were very pronounced and I might not have noticed at a higher speed. And probably wouldn't have noticed driving the car for that matter.
Last edited by jamal; 04-25-2013 at 02:06 AM.
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