A base valve is a valve that is never seen or often explained well either. It is a piston valve that is fixed in the tube towards the head end of the shock, opposite of the end that the shaft is going in and out of. The base valves main job is to reduce pressure in the oil column before it gets to the divider piston or the device that is replacing shaft displacement. In our case we are using it to hold the oil column in place as we push the main piston through it, this stability in the oil column creates better oil platform for the main piston increasing the grip that is made in the car. When done right the base valve can be a great help to the car but when done wrong the effects are bad when the track gets rough.
The SRT Piston or Slick Rough Track Piston is a piston design to allow more bypass through the piston when hitting a bump. Image that your car is in posture, down on the nose speed through the corner when all of a sudden you hit a large hole. Bam just like that the shock is going to move a lot of oil from one side to the other and the shims are not going to allow it to happen. This will completely upset the car, breaking traction on the tires and allowing the guy on the outside of you to pass. Grip in the slick is the name of the game and when you can keep your tire attached to the track this will increase you r grip all the time. Now to determine hole size and when you think you would need a piston like this, well let's just say ALL the time, because it just seems to work well in all conditions.
Elite shock option is a Base Valve and a SRT piston combination that makes for the best you can have in a shock. The base valve make sure that the shock is function right and the SRT keeps the tire connected to the ground to make more traction in those slick conditions. This is truly the most grip a car can make outside of cheating your tires.
13 Series come in two lengths, 6" and 7" lengths. When ordering shocks make sure you get enough length in the rear shocks. If your left rear shock is to short it will pull the left tire off the ground.