Real-Time Adjustable Shocks?

[jcorsico]

Can anyone confirm what this is?

This is an off-road.com picture of a buggy that was at Laughlin, Number 116. It looks like a mechanism for adjusting the bypass tube valve, maybe with a dial or switch in the cab with the driver? You can’t really tell from the photo, but it looks like it is only one tube on the shock (the other tubes look normal).

Jon

 

[John Bitting]

Thats exactly what it is. It is on the TLR truggy and the shocks were built by Kendall. Basically when you get on a flat road and are on it, you can close the valves make the ride stiffer and open the valves back up when you get back in the rough. The adjusters are inside the cab by the drivers right hand. We took pics of it being built for Skunkworkz. It is truley a bitchin idea on a very nice truggy.

 

[DPpatrol]

Anyone know the price tag on those babies?

jason

 

[mgobaja]

It's a good concept but just one more thing to be messing with during a race. If the are only usable during setup or tuning that would be awesome. But the last thing a driver needs to be doing at 120 mph is adjusting their shocks. I saw the car at the FUD newyears race and the handles are near the shifter on the center console.

 

[Jerry Zaiden]

I think this is one great idea on the road to many others. This is the kind of thought pattern needed in (forward progress) to this sport. I think this is a great idea for the rear of a buggy. If you notice it is a compression tube. This would close off that tube allowing the use of the valve stack in that area on the shock making the shock stiffer. Great for less body roll... Perfect for long flat roads with lots of turns! I know the rally guys do this electronicly.
Just think of electronic sylinoids that can adjust the check valve it self. With sensors on the arms telling the computer the shaft speed, position, etc... The socks could have different in cab settings to chose from. Great for different tracks.
Well anyway, I like the idea!

 

[John Bitting]

Jerry I could not agree more. The reason they went with manual valves was one less thing to fail. Tim is very into reliability for his cars. He has doubles of a lot of things for this very reason. Dual fuel systems, The Skunk shows the craftsmanship of the car. Very nicely built. He was spinning tires off the rims because of the high HP in laughlin. He had not had that problem with the other truggy with this so he was not prepared. I can guarantee it will have beadlocks in San Felipe or wherever they race next. That thing will be a real threat..

 

[Bob_Sheaves]

Hi guys,

By replacing the manual valve with a linear actuator valve with position sensor (simple hall effect), you can do what Jerry suggests, plus, by adding in a vehicle wheel speed sensor and map (not Manifold Absolute Pressure, but a programmed rate map, similar in concept to the fuel map that Holley, Accel, and others use for fuel control) you can vary the response by multiple variables. Very simple to do and even more reliable than a mechanical setup.

Best regards,

Bob Sheaves

 

[MNotary]

"Great for less body roll"

On initial turn in you may get some effect for roll, but shaft speeds are pretty slow so the shock will bypass.

I thought in cockpit supension tuning was not allowed?

 

[ntsqd]

Bob, How about we fill the shock with piezo-variable viscosity oil and just change it's 'weight' with a voltage or current ? Could do both the oil and the valve, but then we're approaching F1 active suspension complexity in the shock map.

Wouldn't be easier to make a cockpit adjustable swaybar ? Or pair of swaybars if need be ? Swaybar layouts of the Herbst Truggy rear bar are a natural for this.

TS

"Teach you all I know and you're still stupid"
-- Howdy Lee

 

[Bob_Sheaves]

If you really want to advance the "state of the art" in the high end trucks and buggies....see:

http://www.kinetic.au.com/tech.html

...from Australia (a Tenneco Automotive owned company), Kinetic Suspension has already solved these problems, at a far less cost than a fully active suspension system. By deleting the anti-roll bars completely (along with mounting and hardware), along with the mapping in the controller-this system (proven in WRC, among others) offers a big improvement in dynamic stability, without the "customizing" development time. As in a programmable fuel injection system, a laptop can take over the dynamic control of the system on the fly and allow real time tuning to be handled for development in a particular vehicle.

I am not sure on the interpretation of the rules on "cockpit controlled suspension components", but by mounting the computer outside the driver's compartment, it seems to me that you would not be violating the rules (can you tell I was raised by a NASCAR family?).

Best regards,

Bob Sheaves

 

[Dave_G]

Re: Wouldn't be easier to make a cockpit adjustable swaybar ?

Been there, done that. We made one for a short course car years ago that was cockpit adjustable. It was hydraulic with valving...no torsion bars needed.

Dave

"I know it all, but I can't remember most of it..."

 

[pjc]

Agreed Jerry!

I forsee software contolled shocks. Cheap valves and precision actuators are alredy available. Software wouldn't be too hard. The question is, what pattern of the suspension travel would you modify? Off the top of my head, I think less body roll would be desireable.

PJCinLV

 

[rdc]

~sighs and pulls out his wish list~

Hmm... Just for kicks you could valve each corner differently, lol

David - No one of consequence.

 

[FABRICATOR]

This a good thread and is at the core of future off-road suspensions.

I concur and have mentioned here before that you will see a lot of things happening with not only
the by-pass tubes but also with the fluid displaced by the shaft or “reservoir oil”. Depending on
mounting methods, the shock can have total control of wheel movement. I believe it is Ryerson who has an ingenious coil over/bypass shock. It uses a longer body (or shorter spring) and has a single by-
pass tube mounted upon the top 4 to 5 inches of the body, above the spring. This is the most important section of piston travel in any off-road shock as it can absorb the energy of the hardest bumps before
bottoming and/or keep it from bouncing back out when the spring is compressed all the way. As
mentioned, this particular shock is longer than a typical coil-over counterpart. This could be done more efficiently with an internal by-pass arrangement.

What Bob is saying is also promising with regards to electronically controlled shocks. This would likely involve “pulse width modulated” valves. This is a high tech label for a variable flow valve which is computer controlled. Actually these are inside of all electronic transmissions and most electronic fuel injections. The electronic part would be relatively easy to setup. These valves can take a lot of heat and are very reliable, but the problem is flow. None of these valves flow anywhere near enough fluid for off-road racing. However, they could be used to control a modulating or relay valve to do the heavy work. I see no reason why they could not be an integral part of the shock piston itself. This would eliminate bypass tubes. With a little homework, and duplicating existing position and flow parameters, the starting point of performance of this arrangement would be about equal to that of the best by-pass shock. It’s not that far away.

What pattern to modify is also a good question. That's why I mention starting off with existing parameters of a good working system. The programming and speed of the computer could enhance and improve performance to be sure. However to go much farther it may take input from the driver. At the present time, the people inside the car are the only possible input as to what is coming up with the terrain and turns. For the computer to calculate on-the-spot for all possible conditions and speeds without driver input is imaginable. But, like all other enhanced electronics, would require more comprehensive programming, more sophisticated sensors, and higher operating speeds. With enough sophistication it could control roll, sway, dive, squat, and everything else except good old driver error.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

 

[Donahoe]

hmmm???

NEVER LIFT!!!!!

 

[FABRICATOR]

Dave,
Here is a picture of a system that is not adjustable, but it does go on and off. This conglomeration is in the middle of the sway bar which has been modified into two short sway bars placed end to end. Device connects or disconects in center. A simple splined or keyed sliding collar would have done the same. PCI truck.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

 

[FABRICATOR]

Picture of Ryerson coil-over shock with single by-pass tube.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>

 

[Bob_Sheaves]

Hi Kreg-

You might remember a phone conversation between Walker and Walter Voss back in late 89. Walker wasn't any too enthusiastic about the idea of electronically controlled ANYTHING. What I described before on this board is a simpler variation of that system.

Lee Hyd. Mfg. (NOT the steering gear guy) makes the applicable linear control valves (flow of up to 250gpm) with a needle seat oriface max of .375 inch dia. Flow control is from "0" to fully open in .001mm increments on the transducer. This would give you acceptable flow control over the entire range of use.

Utilizing a shock dyno to map out the operating characteristics and temperatures (you would need to compensate for this also), or alternatively, measuring a vehicle on the "track" in real world conditions would give you the proper, IMHO, starting point for the mapping in the computer.

Best as always,

Bob Sheaves

 

[Dave_G]

Re: and Walter Voss back in late 89.

Holy smokes! That's a name I haven't heard in years... I would suspect he's dead from cerosis of the liver by now. That guy could really put the scotch away.

"I know it all, but I can't remember most of it..."

 

[Bob_Sheaves]

Hi Dave,

Sorry, I guess I wasn't a good friend to Walter after I left the corporation- I lost track of him. I heard that one of Eaton's cronies replaced him as head of Jeep Motorsports around 95-96 or so. Too bad too, he was one of the good guys...tipped a few at his house many times during my tenure at JTE working for him on the off road stuff. I lived in Milford at the time- about 10-12 miles from his house on the lake here in the Metro Detroit area.

Best as always,

Bob Sheaves