adjustable nitrogen levels

xnoregretsx

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im not too sure about this

but if you run 75psi instead of 150 in lets say a 12" king resivoir shock
does it only have half the dampening?

or would it just mess the shock up?


is it possible to run lines and electric valves to the resivoir bodies
and adjust the psi of the shocks to suit your type of driving conditions?


i have a friend who wants to put 1/4" hydraulic lines and 1/4" valves with a charge tank (like airride on a bagged truck) and a regulator to keep it at 150 psi or below.


i figured id ask before he just went n messed up 5k$ in shocks.
 

07FJRog

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it would after a while, the charge helps keep the oil from foaming. pressure changes also affect the stiffness of the shock
 

dislocated1

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I know very little on the subject, but you need as much pressure as it takes to counteract the piston flowing through the shock oil.... under that you wont open the valve stack just move the IFP. Over that, you will increase the rod force on the valving which is a band aid for improper valving
 

Baja peso

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I know very little on the subject, but you need as much pressure as it takes to counteract the piston flowing through the shock oil.... under that you wont open the valve stack just move the IFP. Over that, you will increase the rod force on the valving which is a band aid for improper valving

That is correct.
 

partybarge_pilot

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All right peanut gallery LOL, he asked about valving changes. Nitrogen has very little effect on valving. It will effect preload similar to an air shock, the bigger the shaft size the more noticeable this will be. Cavitation, Depends on which end the reservoir is coming out of. Foaming, usually the result of cavitation and boiling due to low pressures under the piston. You can still get this with full pressure in a shock, it just recovers faster under high pressure.

All in all, playing with nitrogen pressure will have little effect and is a band aid fix at best.
 

Baja peso

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All right peanut gallery LOL, he asked about valving changes. Nitrogen has very little effect on valving. It will effect preload similar to an air shock, the bigger the shaft size the more noticeable this will be. Cavitation, Depends on which end the reservoir is coming out of. Foaming, usually the result of cavitation and boiling due to low pressures under the piston. You can still get this with full pressure in a shock, it just recovers faster under high pressure. All in all, playing with nitrogen pressure will have little effect and is a band aid fix at best.
You are right and we are absolutely wrong and therefore we become the "peanut gallery"? The shaft effecting the cavitating(which you did not acknowledge earlier) under the "no effect on dampening" comment is interesting. When you figure out that the piston function supersedes the shaft displacement because of the blatent obvious you will have to generate an interesting come back. Motorcycle suspension education has been adulterated by you.(sorry) Please don't take this personal but you are 100% off on your shock knowledge here and the other sites you misinform. Your fab work is very nice. Cavitation can occur regardless of the location of the outlet, it is just more manageable out the bottom. How about that shock oil temp???
 

partybarge_pilot

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I don't view cavitation as an aspect of damping, I view it as a problem. With the low rebound rates most off-road trucks run, cavitation on rebound with the reservoir out the bottom is very rare. Cavitation under the piston on Comp with the resi out the bottom is also really rare if theres pressure in the shock. As for being 100% wrong LOL, there are many was to solve problems.......
 

Baja peso

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I don't view cavitation as an aspect of damping. With the low rebound rates most off-road trucks run, cavitation on rebound with the reservoir out the bottom is very rare. Cavitation under the piston on Comp with the resi out the bottom is also really rare if theres pressure in the shock.
Take a shock that the res comes out the bottom and mount it in a vise. Remove the end cap off of the res. With the shaft half way in, pull it out quickly and watch the floating piston. The piston will jump the opposite direction then it will quickly jump back the other way. This is called cavitation. You stated nitrogen psi has little to no effect on "damping", well you don't have "damping" during cavitation. So now your stating cavitation is rare under psi. It is not rare and guys like RG and M Smith and others are still battling this today and all their reservoirs come out of the bottom. All shock producers battle this. Please quit telling people that nitrogen pressure is minimal in shock performance. With out the proper psi your gonna be in trouble quickly. You are wrong.
 

Baja peso

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All in all, playing with nitrogen pressure will have little effect and is a band aid fix at best.[/QUOTE]

You make it crystal clear in your shock knowledge. Pease quit poisoning others with your knowledge. Oh ya, RG has "finally figured it out", something you have known for a long time . RG is the 2009 SCORE champ and that is before he figured out what you already knew. Get real.
 

Samco Fab

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Adjusting nitrogen pressure is just one of many many ways to work with tuning. 200 psi is the industry standard baseline, but sometimes more is a good move in a few situations.

A few years back I put a set of King bypass shocks on a H1 Hummer that had very heavy spring rates. It had the resi out the bottom, and I could not generate even close to enough rebound forces with 200 psi, you should of seen the washer stack I had before i bumped the pressure up to 400. More pressure was a big improvement in that situation.

Too much pressure in lightweight vehicles can cause ride quality and ride ht. problems, on heavy stuff more can often work better without many issues. We have commonly used 300 to 400 psi in some shocks.

More pressure will add more spring force, but the spring force does not rise like a normal spring unless you have a tiny resivor or a really big shock shaft. This flat spring force does not give you the body roll and bottom out control that a regular spring gives, it acts kind of like preaload on a coilover or torsion bar...not really a good thing in my opinion.

I would say the least amount necessary to work well is the best pressure, but that could be 50 or 500 psi!!
 

partybarge_pilot

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You make it crystal clear in your shock knowledge. Pease quit poisoning others with your knowledge. Oh ya, RG has "finally figured it out", something you have known for a long time . RG is the 2009 SCORE champ and that is before he figured out what you already knew. Get real.

You really need to relax LOL........ I never said your BFF RG didn't know how to drive, he could win in what ever he was driving. If you had actually been to the races and watched him go through fallowed by somebody like BJ, you would see how out of control his car is at the same speed versus something with different shocks. Dakar has definitely taught him a few things about valving. To quote Mark Post from SF last year when I was talking to him about his shocks, "We've got things that Robby doesn't know about". I do think that we will see a much different handling RG truck at SF and it will win.
 

Baja peso

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You really need to relax LOL........ I never said your BFF RG didn't know how to drive, he could win in what ever he was driving. If you had actually been to the races and watched him go through fallowed by somebody like BJ, you would see how out of control his car is at the same speed versus something with different shocks. Dakar has definitely taught him a few things about valving. To quote Mark Post from SF last year when I was talking to him about his shocks, "We've got things that Robby doesn't know about". I do think that we will see a much different handling RG truck at SF and it will win.

Spin it any way you want. You are wrong. It is nice to know Mark Post confided in YOU.
 
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All right peanut gallery LOL, he asked about valving changes. Nitrogen has very little effect on valving. It will effect preload similar to an air shock, the bigger the shaft size the more noticeable this will be. Cavitation, Depends on which end the reservoir is coming out of. Foaming, usually the result of cavitation and boiling due to low pressures under the piston. You can still get this with full pressure in a shock, it just recovers faster under high pressure.

All in all, playing with nitrogen pressure will have little effect and is a band aid fix at best.

If you are wrong, can I be wrong with you?
 

mexracer10

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I am by no means an expert, but i have seen first hand in a 5-1600 one of the 4 rear 2.0 fox shocks was low in pressure how much i dont know, but the end cap of the resi came off like a bullet and hit the mirror inside of the car. Now who knows if that was the cause of the cap coming off. but it would make sense if the pressure was too low then with a sharp hit you could force the ifp into the end of the resi. And like others have said its just one of the many wasy to tune a shock specific to the vehicle
 
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