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First off, please understand that comments such as, "Oh, you would've been better off with Brand X," mean absolutely nothing without a detailed reason as to why Brand X would be significantly better at this price point. I have no doubt that I have not reached even base camp on the way to the pinnacle. I openly welcome points of view based on facts. I hope to continue to learn by such comments.
Now then, I have had my Yellows since early '04. They have seen a bona fide track wreck, excessive trunk weight in supporting an elaborate sound system, and many "hard" miles whether it be track, autox, or questionable driving practices on backroads. According to some suggestions, the shocks were overworked by the 500/550 springs I was running last track season. The shocks were sent off to True Choice Koni Racing Services in Ohio to be revalved and made double adjustable.
To that end, I have the "dynos," both before and after service. I have zero idea as to what I'm looking at and request some insight from you all. I cannot tell from the "before" plots if the shocks had been pushed beyond their service limits. This is important to me so as to understand what I was driving on last year and to give me a hint of what I might be able to expect this year.
The first two pictures are the fronts. The last two are of the rears. All photos can be clicked on for larger views. Thank you for looking and offering insight when applicable.
Cool. They read just like you would think. The old ones had basically no bump resistance, and the new ones obviously have much more range (the difference between the first and second circle) and much more resistance. Go slow on adjusting the bump side of things, it acts like additional spring rate, but can give challenging characteristics...
Since the lines are essentially straight horizontal, there are no fancy actions. (Nor are they really needed unless you are a superstar with a huge budget.)
Those look cool. I kind of get it. I too have never seen this kind of dyno and have only seen a dampening force/shock speed plot. This is kind of like its simulating the fullrage of motion on the shock and testing how much bump and rebound there is at different points in the stroke. I cant tell whether it is high or low speed though.
Originally Posted by TubeDriver,Jan 17 2008, 12:34 PM
Looks nice!
Is that linear valving? I thought Konis were digressive?
Digressive damper valve
US Patent Issued on July 13, 1999
The invention relates to a digressive damper valve and more particularly, to a blow-off valve for a vehicle damper providing rebound performance with a relatively high damper rate at low velocity inputs and providing relatively low flow restriction operation at high velocity inputs in a digressive performance manner, so that high handling control is achieved without compromising impact harshness.
Linear and Digressive Designs
There are two basic piston designs used in most circle track racing: linear and digressive. The linear piston has a high flow rate at low shaft speeds and hence little resistance. The resistance increases as the shaft speed increases. The rate of the shock continues to increase as long as the speed increases.
The digressive piston design has a low flow rate at low shaft speeds that provides a lot of resistance and control. The resistance rate increases with increased shaft speeds to a designed level and then tapers off. As the shaft speed continues to increase, the resistance stays uniform above a certain shaft speed. This "pop-off" characteristic works well for reducing the possibility of building excessively high amounts of resistance usually associated with sharp increases in shaft speeds due to running over bumps and holes in some racetracks.
Another development that has become popular involves using more rebound resistance than compression control. If we read the older automotive design books related to shock design for production automobiles, we see where the design criteria calls for equal resistance in both directions, compression, and rebound in combination with the action of the springs. Because springs naturally resist compression and aid in rebound (unloading of weight), we need less compression and more rebound control in our shocks to be truly equal in each direction of movement.
We cannot use a true 50/50 rated shock (where the resistance is the same on both rebound and compression) when installed in combination with a spring. Correct thinking would have us install a shock that has more rebound control than compression resistance. More and more teams are utilizing split valve shocks that are higher in rebound resistance, resulting in faster turn speeds due to a more balanced movement of the front and rear suspension systems.
01-16-2008, 06:01 PM
Koni shock dyno's
I openly welcome points of view based on facts. I hope to continue to learn by such comments. 
