Check out this clever IFS articulation idea

[lax2wlg]

Just been hanging out over on the planet (planetisuzoo.com)

Check out this idea that someone came up with for their Vehicross. It make the torsion bars work with each other to mimic the leverage effect of a solid axle.

Its no longer in production, looks like a clever idea that could be adapted to fit most torsion bar setups (Toyota may be difficult since the T-Bars are mounted nice and high)

I have cut and paste it all below.

SUPER FLEXY IFS KIT


I have designed, fabricated, tested and patented a new set of parts that allow IFS to articulate in ways that were not possible before.

The parts attach to the OEM locations and require no drilling to install.

The design is such that the two torsion bars are now semi-connected and interact with each other...

The SUPER FLEXY IFS KIT allows one tire to be at FULL COMPRESSION while the other tire is at FULL DROOP, AND more importantly while the tires are in these extreem positions, the weight is ballanced between the two tires MUCH MORE evenly, and the vehical remains much more level, while increasing traction....Typical OEM syle IFS does not allow this as much.

Also, as one front tire climes an obstical and compresses that side of the suspension, the KIT transfers force to the other front tire, pushing it downward...
This does a few things...First, the tire climing the obstical has its spring rate decreased, allowing it to stuff farther and easier and sooner up into the wheelweell untill it reaches maximum compression (bump stop)... at the same time, the tire on the opposite side has its spring rate increased, pushing it down into the terrain...

For example, With this Kit, You can drop one front tire into a 4" deep rut while the other front tire is sitting on a 4" tall rock, and maintain EQUAL tire preasure on both fronts, and maintain a more level vehical as well.

Included is a SECUREMENT PIN that allows the KIT and the susension to function as per OEM design with the PIN installed (for on road use)...Remove the pin for off road use and MUCH MORE ARTICULATION.




Original thread: http://forum.planetisuzoo.com/viewtopic.php?t=44482

Interested to hear peoples thoughts on this. Anyway, I'm off to Rallywoods to break some hubs.

[catalystracing]

What a great idea, they have put some good thought into that. Wonder how it would go go Cert and WOF wise. Thanks for taking the time to put together and posting way

[De-Ranged]

its a nice idea if you have room for it most trucks with IFS that I've worked on are so tight for space that you wouldn't fit it.... and no matter what you are still limited to the amount of drop you get because of the CV's

[Team Tonka]

In the vid when he's reached max articulation he then straightens up. I reckon if he carried on at 45 degrees to the slope as the centre of gravity changed in the truck the opposite would happen. It would articulate the other way and she would be over

[Trench_rat]

very clever , took me a while to click as to how it worked. How long till you make some for the terrano mate

[diogenese]

In the vid when he's reached max articulation he then straightens up. I reckon if he carried on at 45 degrees to the slope as the centre of gravity changed in the truck the opposite would happen. It would articulate the other way and she would be over

I reckon you are right there. You would get to a point and it could flip to it's max travel in the opposite direction. That would tighten your sphincter!

[DEATH_INC]

It'd be pretty much like a tractor I think, simply rely on the rear to keep it all upright.

[slide]

You would get to a point and it could flip to it's max travel in the opposite direction.

You'd want good shocks to slow it as much as you could, at least that may delay the weight transfer enough that you could correct it before it was all-over,red-rover (well, grey isuzu).
It took me a moment to realise the kit goes at rear of swaybars, not fronts. A clever idea, could be excellent in some situations.
I guess you could go surprise some people, and deal with (any) problems later?
The rocker mechanism could be made so that it only lets half, or quarter of each torsions travel to transfer to the other side. This would make for an improvement over OE, but not have the rock-over problems of a full-transfer rocker setup.

*post edited as I've interpreted design better

[ChurchurDan]

It is effectively disconnecting the torsion bars from the suspension and allowing the vehicle to roll at the centre point between the front wheels.
I read some of that thread and he said to keep the sway bar connected. The sway bar is all the spring action he has to prevent it falling over. if it was removed the wheels would act like a beam axle with a pivot in the middle like a tractor. In some offroading it would be awesome especially if the ground is undulating, but if you had both wheels on one side up there is nothing but the front swaybar to hold up the low side front corner and it would not end well.
It would not put any more stress on the torsion bars as they are no longer flexing, they are being allowed to rotate. The only time they would still work as a spring is when both wheels are trying to move up at the same time.

If you want flex out of an IFS soft torsion bars, swaybar disconnect and the wheels in the middle of their travel at rest would be a better set up in my opinion.
Due to the lack of torsion bar choice I have thought about modifying the TB cross member and attaching the adjusters to a transverse leaf to soften it up

[tweake]

you could fix a steering dampner or even a RTC dampner to it to slow down the movement.

[churchill]

My old RC car used to have something similar, 25 years ago now...

http://www.rcuniverse.com/forum/rc-car-general-discussions-179/9576747-revolutionary-vxi-suspension-system.html

The pic is at the bottom of the page.

Basically one spring is used to connect the lower arms together and a sway bar is used to keep the system centered.

[ChurchurDan]

you could fix a steering dampner or even a RTC dampner to it to slow down the movement.

The shocks are already doing that job. The problem as I see it is that if you were driving around the side of a hill it would want to flop over onto the down hill side.
The idea has merit but it has a few problems to overcome. Having a release inside the vehicle too make it selectable for when needed would solve most of the problems, So long a you don't forget that it is released.
I had a look under my nissan and I think it would be easy enough to do, But it needs a bit more refinement first maybe springing the left-right movement of the gadget tying the torsion bars together.

[Crash bandicoot]

I think will all that tinkering it would be just as easy to do a solid axle conversion.

[Mattman]

Josh after seeing your truck in action yesterday I think you are already getting great artic on the front.

Cheers
Matt.

[lax2wlg]

I think will all that tinkering it would be just as easy to do a solid axle conversion.

And open up a whole new can of worms/problems! So long as the running gear is stout, On a general trail vehicle, I'll take low gears and lockers first.

I think there would be a big risk in f**ng up the dynamics of the whole vehicle.

One of the reasons independent suspension is a requirement for severe duty military vehicles in many countries is because it can be set up to behave very predictably and safely in a variety of terrain. That, plus it tolerates high speed abuse better, you can drop it out of planes, and its completely rebuildable - you can never catastrophically damage it (bent case).

People may laugh at this but Its not all bad news w the Nissan torsion bar IFS.As part of a complete package it can be made to work IMO. The triangulated lower control arm is a very strong setup. The weight is distributed really well & the linked rear has good anti-squat characteristics; ie resists weight transfer. Add the 104" WB and climbing is predictable, theres no crazy weight transfers or unloadings. With a spooled front, I like this predictability.

Bit of a rant for you there Crash

[lax2wlg]

Interesting discussion, cheers

Yeah it took me a while to work it out, too.

ChurChurDan you raise some good points.

I wonder how you'd come up with a lock out system that could be engaged on the fly, on any surface, ie undulated etc

I mean, occasionally jumping out the cab to unlock one of the hubs on a tight turn is one thing, but finding a perfectly flat spot, clambering under and trying to align a tiny pin every time you want to drive off camber?!

[slide]

....Bit of a rant ....

This I like. You've obviously done some thinking, research, and more thinking and worked out some pro's and con's of the systems.
Then had the balls to write it all down.
I like the idea of taking what you have, and improving it to suit your own requirements (OE setup is always what the manufacturers think will suit the majority best, at the best cost). So whether a solid axle swap or modifing the independent suspension is better is a personal choice, and certainly the modified independent will be easier to revert to standard than SAS, should the need ever occur.

I wonder how you'd come up with a lock out system that could be engaged on the fly, on any surface, ie undulated etc

A pin with a tapered end, with a spring to actuate. So as soon as the hole lines up, the pin slides through under spring pressure. Quite how it was done would depend on space around the mechanism, and how vulnerable to damage its position was. A cable, or pneumatic operation is what I envisage.

Also I've edited a previous post with the idea that the rocker mechanism doesn't have to allow full transfer of each torsions travel to the otherside. A half or quarter would increase overall flex, with reduced body roll complications.

[diogenese]

How about small diameter coil springs on either side of the sliding member, they would allow the load share across the axle but retain some of the anti roll.

[lax2wlg]

You've obviously done some thinking, research, and more thinking and worked out some pro's and con's of the systems.

That, and not having the fab skills or resources to do a solid axle swap

But Having owned/operated/worked on both, I'm really of the view that there is much more to a capable general trail/exploration vehicle than the front suspension system. I love the brute simplicity of the solid axle, and in the rocks (read the ROCKS), there is no other option. I also think that a solid front axle probably makes any vehicle more capable out the box, but not necessarily stronger. Strength and capability are different things. Spaceships have a lot of moving parts too but they can penetrate the f**king earth's atmosphere.

The state of IFS in the world automotive scene would be an interesting spin off thread. eg when are we getting portal IFS on production vehicles? And why did Toyota go back to torsion bar IFS for the 100 Series Land Cruiser, but kept the Prado strut system for the FJ Cruiser?

[lax2wlg]

How about small diameter coil springs on either side of the sliding member, they would allow the load share across the axle but retain some of the anti roll.

the rocker mechanism doesn't have to allow full transfer of each torsions travel to the otherside. A half or quarter would increase overall flex, with reduced body roll complications.

So what you guys are saying is the whole idea of giving it some resistance, or limiting the range of movement could be used to tune the systems safety, specific to the vehicle?

A pin with a tapered end, with a spring to actuate. So as soon as the hole lines up, the pin slides through under spring pressure. Quite how it was done would depend on space around the mechanism, and how vulnerable to damage its position was. A cable, or pneumatic operation is what I envisage.

I found another thread on the planet... looks like a guy developed the system further, it mentions using an air line.. I copied and paste it again. These guys seem to be measuring it based on increased wheel travel, I'm guessing still within the safe range, but more easily accessed by the leverage effect (I'm guessing). Note they tout the system as giving 'more stability'... interestingly in none of these threads increased rollover risk or safety is mentioned. Check out those sweet HD tie rods too.


Super Flexy IFS kit: Speak Now or Forever Hold Your Peace.

Postby VXorado » Fri Feb 01, 2013 1:25 pm
The time is finally here... Now is your chance to get a SFIFS kit if you missed out on Bigmeat's very limited production run. For those who are new the concept, it's a kit that connects the torsion bar loading & transfers IFS flex from one wheel to the other. It will mimic some characteristics of a solid axle and ultimately give you more stability & flex when you're in situations that force suspension articulation. I tested the kit about a month ago and posted my results at the bottom of this thread.

This kit is designed for a 2nd gen Trooper/Vehicross. There might be a kit made for 1st gen Trooper but it will be from other members here on the planet.

New design: I have moved the fixing pin location to make it more accessible and easier to remove/insert. I've also included a setup with an air cylinder to remotely lock/unlock the kit from the cab. This requires 100 PSI on board air system.

Price:
Kit without air cylinder setup: $425
Kit with air cylinder/switch ready: $525
Shipping will be additional.

Each kit costs around $270 to have fabricated + cost of stock. The prices could get up to a 30% discount based on the number of orders. This price is not inflated, it only covers my basic costs.

I had a poll set up but couldn't see who voted which made it useless. Please reply to the thread or PM me if you want a kit.


Test:
I installed the SFIFS kit on Sunday and did a quick test last night for suspension flex. I lifted the front passenger side tire until the rear passenger tire started lifting from the ground. I also did the same test on the rear tire and measured height in each scenario.

Results:
Front tire lift with SFIFS off: 24.2"
Front tire lift with SFIFS on: 26.5"

Rear tire with SFIFS off: 27.2"
Rear tire with SFIFS on: 28.8"

I'm happy with the results. I have 2.5" of down travel left in the IFS and the SFIFS used all of it to level out the VX when I lifted the front tire. Less lift or spacers on the upper control arm would add to the articulation. I bet a stock height VX/Trooper would get 5-6" in the same test because of the increased down travel.

Here are a few pics of the suspension in action.
SFIFS off


SFIFS on




Thread: http://forum.planetisuzoo.com/viewtopic ... 22&t=67860