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Your rear shock is simply running out of stroke. This is poundage. If you add preload (increase in ride height) the poundage has not changed. You have just increased the amount of stroke. Look at it this way 200 inch pounds is 200 inch pounds. For every inch of stroke it increases 200 lbs. SO if you have 8.5 inches of stroke you have 1700 pounds of bottom out poundage. This is based off of a liner spring. These 200 lbs per inch example is a liner spring. SO if you add preload the only thing you changed is the static preload or the amount of poundage applied to offset the weight of the vehicle. The bottom out poundage has not changed. It will still bottom out at 1700 lbs based on a one to one ratio you have. The 1 to 1 is shaft travel to wheel travel ratio. If the wheel travel were 12 with 8.5-inch shaft travel the ratio would be around 1.4 to 1. Either way the bottom poundage is the same but the wheel rate poundage is different for one inch of wheel travel, softer rate. So is the fox air a linier or non-linier rate shock.
You simply add more oil to increase the compression ratio in the shock so the spring rate increases more before it reaches the end of its stroke preventing it from bottoming out, be like adding 1/4" oil in your Pilots cylinder the piston would never reach TDC (Top Dead Center) because the oil used up all the space and it would slow down faster as it reached TDC (Top Dead Center) because your compression ratio went sky high!
Download this and play with the numbers you can probably figure out exactly how many ounces of oil required to fix it.
http://www.pirate4x4.com/tech/billavist ... _chart.xls your a numbers guy you will probably love that litte app.
That download comes from this article on these shocks.
http://www.pirate4x4.com/tech/billavist ... index.html
I am not a numbers guy I just guess at the oil, I know that 30cc = 1" of oil in the reservoir or the body of the shock, if go do a huge jump where I am sure I have used all my shocks stroke then stop and look at the oring and see I didnt use the last 1" of the stroke I would just remove 15cc oil -recharge the shock and go try it again, by removing the 15cc I would go up 5-10 psi on the as found nitrogen pressure. I only guess because its IMPOSSIBLE for anybody to setup shocks for every type of riding, my shocks are adjusted to give me comfort over 'most' the terrain I will ever put it on, IMO it works well on everything, if you wanted to you could make the FOX airs completely adjustable from the drivers seat and adjust them whilst driving, compression and rebound adjustments, shaft speed adjustments, compression ratio adjustments, nitrogen pressure adjustments, if you wanted to go super shock homo and be the king of the offroad shock queers you could hook that system up to a computer, add a few sensors and have the computer adjust it for you in real time based off the last shock stroke, its all how much you want to spend, how much complexity you want to add to your machine, how much weight you want to add.
The bore on my reservoirs is the same as the shocks so I could probably use that program on my shocks too by playing with the input numbers.
I cant understand why others spend 5x more on big name custom shocks and the final results is they
are ---->.......<----- that much better than my cheap POS setup over the same terrain, only thing I can think of its prestige or physiological gains they live for.
You have followed Old Blue around the dunes before? I have followed it for hundreds of miles probably closer to thousands of miles that suspension works perfect and after following Drakmans new Drakart I would say Old Blue offered a better and smoother ride, Alain really had those shocks dialed in nice on Old Blue!
When I remove all the nitrogen out of my rear FOX airs and check the total travel I am getting 9" my findings are with the suspension all stock that's about all your going to get, I doubt Turbo's shocks are too short unless he is running a different length?
The thing that hurts the Pilot the most is the length of the travel, my findings are that even with 9" of travel in the rear its not enough travel for the tires to follow the bumps entirely at full speed so you end up with the rear tires off the ground more than one would desire, the tire rebounds fast enough the car is just too far off the ground for it to reach lol now follow a Drakart through the same terrain and watch what the extra travel does.
Play with that shock program I think you will understand these shocks better, remember as the shaft goes in its displacing the oil volume in the shock compressing the nitrogen then the spring rate goes up, now if you add a external reservoir their is no nitrogen in the shock body its in the reservoir so their is a flow of oil both ways as the shock is stroked, control the flow of that oil you have compression and rebound adjustments, adjust the volume of oil in the reservoir and you control the compression ratio or the spring rate and the rising rate, make the nitrogen volume section of the reservoir adjustable and you can adjust the nitrogen pressure externally, you can get even more shock homo and add external piping to the shock body like the high dollar bypass shocks and have more fine tuning. .
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