Onboad shock nitrogen control

[nts007]

Alright so pretty much all the good shocks have a nitrogen pressure vessel in order to help with cavatation and whatnot. Anyway we know that lower nitrogen pressure for example 150psi will allow more compliance say on highway. And higher pressure 200-250psi are needed for really utilizing the shocks high speed off road.

So I've come up with this. Using brake line (3/16 or 1/4") that has a burst pressure of 6000 psi
4 electric sending inline pressure sensors with some sort of display
4 electric solenoid ball valves that default closed
One manual incab pressure regulator with gauge
Nitrogen tank with regulator
And assorted brass fittings

Essentially connecting to the remote resi's where the shader valve is. You use the pressure regulator incab to set the line pressure then open/close the shock you want to adjust (to line pressure). You could do all 4 to that pressure. You could do a lower pressure for the rear by setting regulator then actuating the two rear solinoids. Then adjust the regulator to the higher pressure wanted for the fronts and then actuate the front solinoids. Now maybe this is crazy but it's just an idea. That seems feasible and not overly expensive. Say I get thuren 2.5's and get them valved to stage 4. But I want stage 2 on the highway. Could this work? Now I have everything I need to do the project with the exception of the pressure senders. Which could be utilized by an aftermarket tpms display and sensors. Maybe.

What do you guys think. Here's the diagram

[Colibri]

Fox is rolling out a Bluetooth based controller for adjusting the valves on bypasses at some point in the nearish future, kind of a similar idea. Definitely has merit! I don't know if there's a massive difference in ride characteristics with nitrogen pressure changes, but I haven't messed with it much honestly. I have tuned my hydro bumps with pressure, and that definitely makes a substantial difference, so perhaps a little investigation is in order to see if it's worth while. A very cool idea Neal, you've got me curious for sure. I have a nitrogen setup, I'm tempted to fiddle with my shocks and see....way to think outside the box man!

[nts007]

My setup isn't nearly as fancy as say a computer controlled push button auto tune setup but it allows manual control. The only thing I'm not sure about is the pressure sensors to a display. Years ago Tien shock absorbers had a display for their adjustable shocks. If you guys have ideas please post. I'm going to search the parts stores tomorrow and pick up some line and compression ends. Try it out with one of my bilstiens. What I would like to know though is has anyone had experience with different charge pressures. And how well does it work. Because making them adjustable on the fly would be easy. I've always wanted to do central tire inflation but being solid axles I'd have to have exposed line outside the tire and I don't want to do that. So then I came up with this.

I'm Alison looking at 2.5 kings with thuren stage 2 but if a lower nitro pressure would make a 4 feel like a 2 I'm in!!

[Colibri]

I'll mess with my 3.0's pressure and see what it does. There's got to be a fairly straight forward way to read pressures, maybe McMaster Carr has appropriate sending units?

[DamageWagon]

nts you should delete this post and patent that idea. I could seriously ask my friend who just left King Shocks as an engineer there if this sounds right. It does to me. As far as valving and pressure goes, the pressure is tied to the aggressiveness of the valving. A soft valving can benefit from low or high nitrogen psi to soften or stiffen the effective valving, but a stiff valving profile would need a constant high pressure in order to make it smooth. A stage 1 at 100 psi is going to be great. At stage 6 at 100 psi is going to be absolutely horrible, but at 300psi is going to be much better because you are forcing the oil to flow through the valving instead of the valving staying static and only the nitrogen absorbing little hits.

In terms of nitrogen pressure changing the valving, it won't. The only way to actually change valving is if you revalve the shims. A stage 4 will always be a stage 4 but you can possibly help the little stuff by lowering pressure, but that profile might be getting on the fence of rather lowering psi helps or hurts.

If I may make a suggestion... I found out that it is possible to stuff a bypass 2.5 INSIDE the front coils, upside down. I almost went this way but did 3.0's instead. You might look into this. Bypass shocks are going to give the best ride and the best bottom out resistance in the same package, always.


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[nts007]

Haha I'm sure the shock manufacture company's already have patents on this.

Think this way though. Shock valving is also calculated based on the gas pressure. But introduce a variable pressure then you could set up a valving profile that at lower pressure drives through the shock easier and the higher pressures severely increase dampening.

Now as far as a patent. Well if you guys see this setup in the near future then you all witness the date stamp on the forum. And then they can give us all free systems.

Anyway I'm going to put together some of the materials. And if you colibri can give me a little feedback that would be awesome. The system could easily be setup to run up to 300 psi. I could also tie in my rear air bags to the system.

I believe on the new firestone air ride kit that turns the rear to air ride their shocks also get an air line to increase dampening forces as the air bags are inflated.

[Chromolykid]

A similar idea has been tried before by an off-road racing team several years ago but it was too delicate to withstand the abuse of a race course. Technology has come a long way since then, though.

I've always wanted to mount small electric motors on the bypass valves that can be adjusted electronically to tune on the fly for different terrain and fuel consumption.

Still waiting for magnetorheological shocks to make their way into the off-road world...

[nts007]

A similar idea has been tried before by an off-road racing team several years ago but it was too delicate to withstand the abuse of a race course. Technology has come a long way since then, though.

I've always wanted to mount small electric motors on the bypass valves that can be adjusted electronically to tune on the fly for different terrain and fuel consumption.

Still waiting for magnetorheological shocks to make their way into the off-road world...

I don't see how delicate it would be though. It's all hardline and it's no more fragile than the braking system. The valves are always defaulted closed. So if by chance you did wreck it you still have pressure. I mean it's no worse than the existing shader valves being exposed.

And for me I don't mind adding a little weight. Truck just rides better every extra 1000 lbs lol

[ramv]

Shocks require a very small volume of fluid compared to say tires. Which means any leaks on the valves or upstream when the shock cycles will lose the advantage.

If you are only changing pressure when the terrain makes significant changes, why not just have the tank, regulator and gauge? This is what we do with mountain bike shocks. (or similar.)

N2 doesn't transport that well since it has to be stored as a high pressure gas (not a liquid like CO2). Changing the pressure frequently will require frequent take recharges.

Options would be air (de humidified) or a closed loop N2 circuit with a compressor, so you aren't dumping/adding N2 all the time. (N2 isn't expensive per say, it just takes some effort to separate...) (I used to work at a liquid CO2/N2/LNG/CNG manufacturer.)

[ramv]

Also the pressure in shocks is primarily to stop the oil from cavatating. Changing valving would have a way bigger impact than pressure. (Unless you are low enough pressure to allow the oil to capitated, essentially rendering the valving worthless.)

A hydraulic bump stop or boogie bumps (not familiar with them) would be more impactful. (Running lower valving, get into higher valving when you contact the bump stop.)

The above referenced mtn bike shocks are more like an air shock, where the air replaces the spring. It's not to control valving. The valving is still controlled by clickers.

[ramv]

The high end sports cars use magnetrheological shock oil. In other words, they change the viscosity of the shock oil (effectively changing the valving) with electric charge. This is a more modern version of say the old RS9000 or most modern m/c or mtn bike shocks which have external adjustments for valving. Rancho used to see an air control for the RS9000s which allowed the valving to be changed on the fly. These were crappy hydraulic shocks, but it's still the same concept. The valving is more important than the charge.

Now if you have air shocks, air bags, air over hydraulic suspension, then a control system like described could pay dividends.

[nts007]

A small 3' tall nitrogen tank is easy to strap down solid. I used to have a 5' tank strapped under my tool box in my pw. And it aired up many many tires and ran air tools no problem. There is a huge volume of air inside those tanks. It costs $40 to fill the small one and 70 for the big one. Storage and transport isn't an issue. And the shocks have such a small volume you could easily do thousands of adjustments. 70cubic feet of 3200psi of nitrogen is a phenomenal amount of air. I had the 5' tank down to 1000 psi and I let it run wide open to empty it. Took almost 20 min to empty through the valve.
I know with air shocks this would work but I curious about normal shocks. It makes a difference having little pressure vs full pressure. I mean this thread is to figure out how to make it work right. No issue building the system in my opinion. You could also use it for the bump shocks too. Adjust on the fly. Set your line pressure. Open close the valve. Done

[nts007]

These are the only two electric valves I could find locacally. And they are Not rated high enough pressure wise. I found regulators that will work though. And line.

[DamageWagon]

Maybe it's a stretch but if you figure a way to introduce some oil into the nitrogen line, or at least just into the valves, you could use hydraulic solenoids. Those are rated way higher, and it won't get to get a little oil in the IFP side of the shock. I think those solenoids need to be lined though, hence the oil


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[nts007]

I was looking at those too. But the physical size makes it a problem. There has to be air valves rated to 250psi. Just have to find them. But waiting to see if someone had tried the different pressures yet.

[DamageWagon]

Let me run through my pictures. When I was supervising Salvagnini lasers their control systems were on display all over the machines. They ran 300psi with super easy to read monitors and excellent solenoids.

Edit: check these.
- Keyence
-Kolmorrgen
-Rexroth

Rexroth ran our high pressure solenoids. They are European and maybe expensive but we ran 300 psi from a Kaeser air supply into our lasers and never had issues with our air valves. We also ran 300-450 bar hydraulic pressure.


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[Colibri]

Haven't had a chance to depressurize the shocks yet but try
http://www.clippard.com
I use their manual toggle valves on my ARB lockers. They have a tremendous variety of gas pressure valves and solenoids etc.

[flattire]

I have an off road buggy with King coilovers and bypass all around. I was reading about lowering shock pressure (150) to help ride in choppy terrain. Sounded like what I wanted. I tried lowering pressures to 100 and also 50 all around on the bypasses. Couldn't tell any difference at all.

I suggest try lowering pressures to see if it makes any difference to you before going too much further. It's a good idea on the pressure adjustment concept but it just might not make any difference.

[DamageWagon]

I have an off road buggy with King coilovers and bypass all around. I was reading about lowering shock pressure (150) to help ride in choppy terrain. Sounded like what I wanted. I tried lowering pressures to 100 and also 50 all around on the bypasses. Couldn't tell any difference at all.

I suggest try lowering pressures to see if it makes any difference to you before going too much further. It's a good idea on the pressure adjustment concept but it just might not make any difference.

Make the adjustments on the coilovers, not the bypasses. Smoothie shocks benefit from changing pressure more than bypasses do. With bypasses just adjust the bypass tubes. Again though, lowering nitrogen psi only has benefits of you have moderate to soft valving, otherwise you may actually benefit from a higher nitrogen psi because with a stiff valving of the psi is low the little hits will compress the nitrogen instead of forcing oil through the valving which then means your shock has no control. Upping pressure forced the oil too flow through the valves - the ride is still stiff but will be better.

I've never adjusted my pressures but that's because I don't have a tank. If I had a tank I definitely would, especially since I hit high speed whoops and do low speed rock crawling with the truck. But having the 3.0's and the bypasses really helps to bridge that gap, and bigger shocks will always be better than dickering with nitrogen pressure. I would spend the money on bigger shocks instead of an in-cab nitrogen control.


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[nts007]

Good things to know. That's why i started the thread. If it indeed would work on the shocks I have no issue building a valve system with hardline. If I knew for a fact that with say a Thuren stage 2 valve at 150psi it would ride like a cloud on the highway and then bump to 250-300psi and have the same control as a stage 4 then I would happily invest the money into the system. A good friend of mine builds commercial automation systems and I've asked him if he could make a digital system controller and he said no problem. And he may have a line on control valves with psi sensors. He's looking into it and getting back to me hopefully soon.

[DamageWagon]

If you had a stage 2, adjusting nitrogen pressure could give you a range like stage 1.8 to stage 2.3. It isn't going to give you a big change. For sure the biggest thing is that adjusting pressure down will help smooth the little bumps, but adjusting pressure up with soft valving isn't really going to give you more control. The oil is flowing through the valves no matter what, the problem is that it's so easy for the oil to flow. You have to change valve shims if you want a different profile.

Now, not to derail the thought but to give a different idea, going with a bigger shock will make a huuuge difference. I got to ride in a cummins 3g truck a few weeks ago that had 2.5 coilovers and 4.4 bypasses front and rear, and it rode like a fuggin cloud. We were hitting parking bumps and berms and roundabouts at 40-50mph and you almost couldn't feel anything. But with the same valving you could hit Baja whoops at 80mph. With my shocks, I went with 3.0's up front, and for sure they were worth it. Because of the larger piston diameter, the little hits move the shaft more easily and make it ride smoother, while when you hit something hard, a bigger diameter piston and valves are able to resist that force better than a smaller piston. This allows one shock with a fixed valving to gain better small bump compliance and gain more bottom out resistance over a smaller diameter shock, all at once.

For you though, I think a softer valving plus boogie bumps would be heaven. You would probably really enjoy that and it would keep you safe.


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[nts007]

Well your idea there is very nearly what I was thinking. But doing 2.5s for now. I'm still kicking around the idea of rear 4link vs thuren leafs. Problem with the leaves is going to be sag again. But before I dump money into the truck I'm going to build a shop this year first. I need a place to work on this bastard.

Back on track

The Bilstien 2.0s I have use a nitrogen charge on the end of the resi. But the problem is the tiny hose connecting them. Now adding more nitrogen to the resi compresses a floating piston into the shock oil. Wouldn't lowering and increasing that pressure act like a spring in some sense where it would move the "wall" a bit. I was going to try different settings but I ran my nitrogen tank down to 130psi running an air nailer for a couple days. It was already half empty anyway. Going to get it refilled and see what's up on mine too.

But too low will be no good. Also though to be properly effective I would have to use a significantly larger hose between shock and resi since this puny one on the 2.0s is really useless. Since I never use the last 3" of shock travel anyway I could almost pull the resi out and put the sliding pistion in the shock body and just charge it from there. Going to experiment eventually. Part of this has come up for me since it seems come winter the nitrogen looses pressure. Drops 70-80psi easily. And it's a tiny volume