My maxed out suspension lift :)

[Ascinder]

Sorry Beau, but I just can't get past the fact that the same amount of force is required to lift the same amount of weight to the same height. It shouldn't matter if the bar ends are in position "A" or position "B"...

Ok, I'll break it down into simplest terms. I'm going to just use arbitrary numbers and angles, so don't take anything for gospel.

-1: On a stock VX lets just say the torsion bars are cranked 20 cranks from the factory. We all know the VX rides, behaves, and was in fact designed for this amount of torsion in the rods. Lets also say that this amount of torsion gives you 3" of clearance at the wheel well and that the A-arms are deflected 15 degrees downwards. The VX is no doubt supported by this amount of torsion in the system.

-2: On a typical lifted VX lets say it takes 3-4 cranks(turns) to gain each extra inch of clearance between the tire and wheelwell. I've heard numbers all over the place, but usually people crank about 14-15 cranks to get about 3 additional inches of clearance which now brings the total to 6". The A-arms are now at 30 degrees downward lets say since they are what is moving to provide you with that lift. The torsion bar is still supporting the same weight of the VX, but now it is under more tension because you are in effect loading up a spring. Everyone notices this in the stiffer handling of your VX. It's like winding up a catapult. We can all agree that if you keep cranking on your torsion bars, it puts more stress on them the more you crank until they eventually snap.

-3: On a reindexed lifted VX, you are unloading the bars so they are not supporting any vehicle weight. You are then basically pre-positioning your 30 degrees of lift and 6" total clearance into your A-arms. Keep in mind the VX is still not being supported by the suspension at this time. When you put the torsion bar splines back into the A-arms, they aren't under any load yet and if you let the VX down, your tires would push themselves up towards the wheelwells. Here's where the trick comes in. We know from my first statement here that the factory cranked the bars 20 turns to get your VX to ride and behave like they designed. You only have to put those 20 turns back in and it will support the weight and handling of the vehicle. That's the difference. You just don't have the extra cranks in the system so the torsion bars aren't working as hard to put you at the right height. Your 6" of lift is still there since you had already moved the A-ams into place beforehand. The trick with reindexing is that you technically aren't cranking your torsion bars to provide any lift you are just repositioning your A-arms to the lifted angle and using the torsion bars to support your VX as intended.

-4: In cases of extreme lift like mine, I did both. I indexed the bars to gain most of my lift, then cranked the piss out of them to give me even more until I was almost riding on the bumpstops underneath. CVs do not like this by the way. The extreme angles they end up with inevitably tear the boots because as the A-arms move down more, they also move inwards. This pushes the CV cages into the cups and makes them ride where they werent supposed to. It also further compresses the boots on their bottoms and pulls them at their tops(referring to the inners, outers will be reverse). When you keep in mind that the boots are rotating at high speeds, and that the rubber is compressing/getting pulled in each revolution, you can see why lifted rigs tear boots. The same stresses are being applied to the cages and balls within the CV cups. That's another reason lifted rigs should watch their CVs.


Hope things are as clear as dirty water now instead of just clear as mud

[ZEUS]

Hmm... I dunno about all that - I understand the theory but disagree with the terms. The alteration in height is simply a change in suspension geometry. Whether reindexing or not, you are repositioning the torsion bar by the 'cranking' action - the lever at the frame end of the torsion bar positions everything suspended from that point. Adjust the bolt = adjust the angle of the A-arm. The harsh ride comes from the increased angle of the A-arms fighting upward travel (bumps are transmitted to the frame more than they would have been had the A-arm been closer to horizontal), not by an additional load inflicted by the positioning lever. The same physics apply to a coil suspended rig (particularly the front end). When longer coil springs are installed the axle sits further away from the frame which effectively force the increased angle of the control arms to transmit force to the frame. Reindexing is only needed because of the short length of the adjusting bolts. If the bolts were an inch longer, reindexing may never be needed. "Torsion" is simply a term for the action of the spring during suspension travel. For the lever to be the means of adding torsion (ie spring rate) there would have to be a another element added to the spring...

Now if you were to add a heavier motor, a winch, an exo-cage, a large person, and a big bumper... cranking on the torsion bars would inflict a certain amount of twist into the torsion spring to maintain stock height. But this is in the terms of stored energy versus an increase in spring rate. So in that scenario, then certainly the springs would wear out prematurely. However, if the VX were kept at stock weight yet lifted, the leverage applied from the steeper angle of the A-arms would be lessened, (a decrease in stored energy) so in theory the springs should be more resistant to 'sag'.

I like playing in the muddy waters!

Ok, I'll break it down into simplest terms. I'm going to just use arbitrary numbers and angles, so don't take anything for gospel.

-1: On a stock VX lets just say the torsion bars are cranked 20 cranks from the factory. We all know the VX rides, behaves, and was in fact designed for this amount of torsion in the rods. Lets also say that this amount of torsion gives you 3" of clearance at the wheel well and that the A-arms are deflected 15 degrees downwards. The VX is no doubt supported by this amount of torsion in the system.

-2: On a typical lifted VX lets say it takes 3-4 cranks(turns) to gain each extra inch of clearance between the tire and wheelwell. I've heard numbers all over the place, but usually people crank about 14-15 cranks to get about 3 additional inches of clearance which now brings the total to 6". The A-arms are now at 30 degrees downward lets say since they are what is moving to provide you with that lift. The torsion bar is still supporting the same weight of the VX, but now it is under more tension because you are in effect loading up a spring. Everyone notices this in the stiffer handling of your VX. It's like winding up a catapult. We can all agree that if you keep cranking on your torsion bars, it puts more stress on them the more you crank until they eventually snap.

-3: On a reindexed lifted VX, you are unloading the bars so they are not supporting any vehicle weight. You are then basically pre-positioning your 30 degrees of lift and 6" total clearance into your A-arms. Keep in mind the VX is still not being supported by the suspension at this time. When you put the torsion bar splines back into the A-arms, they aren't under any load yet and if you let the VX down, your tires would push themselves up towards the wheelwells. Here's where the trick comes in. We know from my first statement here that the factory cranked the bars 20 turns to get your VX to ride and behave like they designed. You only have to put those 20 turns back in and it will support the weight and handling of the vehicle. That's the difference. You just don't have the extra cranks in the system so the torsion bars aren't working as hard to put you at the right height. Your 6" of lift is still there since you had already moved the A-ams into place beforehand. The trick with reindexing is that you technically aren't cranking your torsion bars to provide any lift you are just repositioning your A-arms to the lifted angle and using the torsion bars to support your VX as intended.

-4: In cases of extreme lift like mine, I did both. I indexed the bars to gain most of my lift, then cranked the piss out of them to give me even more until I was almost riding on the bumpstops underneath. CVs do not like this by the way. The extreme angles they end up with inevitably tear the boots because as the A-arms move down more, they also move inwards. This pushes the CV cages into the cups and makes them ride where they werent supposed to. It also further compresses the boots on their bottoms and pulls them at their tops(referring to the inners, outers will be reverse). When you keep in mind that the boots are rotating at high speeds, and that the rubber is compressing/getting pulled in each revolution, you can see why lifted rigs tear boots. The same stresses are being applied to the cages and balls within the CV cups. That's another reason lifted rigs should watch their CVs.


Hope things are as clear as dirty water now instead of just clear as mud

[Ascinder]

That actually makes sense, but I could have sworn I read that you are putting increased tension(torsion) on the bars to acheive the lifting. In essence, winding up a spring to have it apply pressure(downwards in this case) to gain clearance. Maybe my info was bad. So it's just suspension geometry breaking bars and not indexing? Somethings missing there.

[ZEUS]

That actually makes sense, but I could have sworn I read that you are putting increased tension(torsion) on the bars to acheive the lifting. In essence, winding up a spring to have it apply pressure(downwards in this case) to gain clearance. Maybe my info was bad. So it's just suspension geometry breaking bars and not indexing? Somethings missing there.

I think it's that combination of weighty accessories, hard-core use, and the springs' struggle to control oversize/heavier tires/unsprung weight. I've never known anyone who has broken a torsion bar tho so can't really say - I would love to hear what that sounds like!!! ...On someone else's rig!

[SlowPro48]

Sorry Beau, but I just can't get past the fact that the same amount of force is required to lift the same amount of weight to the same height. It shouldn't matter if the bar ends are in position "A" or position "B"...

From the torsion bar's viewpoint, it DOESN'T matter - as long as the VX is just sitting there...

When you're actually using your suspension travel, however, it DOES matter!

For the sake of discussion let's say there's 1,000 lbs on each corner of the VX and the distance between the center of the torsion bar and the hub is 1 foot - so with the VX just sitting there, the torsion bar feels 1,000 ft-lbs of torque. Like you pointed out, unless you've cranked so much the suspension is topped out, the only significant variables involved are mass of VX, gravity and length of lever, which are all constant.

BUT - let's say you take that stock ride height VX out for a spin, hit a big G-out and bottom the suspension. Let's also say for the sake of discussion front suspension travel from normal ride height to bump stops is 5 inches and spring rate is 300 lb/inch* - so at the point of bottoming out, your torsion bar feels 2,500 ft-lbs of twist. You hate bottoming out so easily though - so you raise the ride height a couple inches by cranking the torsion bar. Now you've got seven inches of travel from ride height to bump stops. Sweet! You can go even faster through that G-out before you bottom out the suspension - at which point the torsion bar now feels the effects of 3,100 ft-lbs of torque (two more inches at 300 lbs/inch = 600 ft-lbs more torque) and like any other spring it probably doesn't like being twisted by 3,100 ft-lbs as much as it does 2,500 ft-lbs...

Cranking the torsion bar increases ride height but that's just a side effect of increased pre-load. It's fine for small adjustments but Ascinder's method adjusts ride height directly, allowing you to keep pre-load within stock range even for larger adjustments to ride height.

*yeah I know - proper units for spring rate of torsion bars would be in force/angle but lever length is same so using force/distance doesn't have any bearing on outcome - for that matter, all these numbers are made up for simple illustration purposes

[taylorRichie]

I like turtles!

[Triathlete]

I like turtles!

[SlowPro48]

I like turtles!

I hear you like ponies too.

[Ldub]

Cranking the torsion bar increases ride height but that's just a side effect of increased pre-load. It's fine for small adjustments but Ascinder's method adjusts ride height directly, allowing you to keep pre-load within stock range even for larger adjustments to ride height.

So by this theory, reindexing the torsion bar "magically" reduces the amount of force required to lift a given amount of weight (load) to the same height?

OK, if you say so...

At this point, I'm willing & able to agree to disagree...

Also, reindexed or not, the suspension travel from like heights, through the full available motion (when it hits the bump stop) is the same, creating the same amount of torsional force for a given amount of travel.

[tom4bren]

The bottom line is that it appears safe to lift 3" using the torsion bar crank (been proven on a fairly large number of our VX's). If you need to go much higher than that though ... better start looking at other options such as a body lift.

[ZEUS]

The bottom line is that it appears safe to lift 3" using the torsion bar crank (been proven on a fairly large number of our VX's). If you need to go much higher than that though ... better start looking at other options such as a body lift.

HEY! You keep your clear water comments to yourself!

[tom4bren]

HEY! You keep your clear water comments to yourself!

Now let's talk about tie rods ... do whatever you want to those ... they never break.

[ZEUS]

Now let's talk about tie rods ... do whatever you want to those ... they never break.

Well actually... with an offset from Hell...

[SlowPro48]

Ldub - I see what you're saying - had to do a little more visualizing there. You're right. I'm wrong. As long as the torsion bar is not pre-loaded to the point where the suspension is topped out, it doesn't matter if the lift is achieved by reindexing or by cranking the torsion bar - when ride height is increased, suspension travel from "baseline" to bump stop is increased - therefore max torque the torsion bar can experience is increased the same amount no matter which method you use. If you crank past the point you're topped out you would increase the max torque seen by the torsion bar, however, as each ft-lb of preload at the top of travel is a ft-lb added at the bottom of travel. But I doubt if anybody would keep cranking after the VX stops going up. There's probably not that much adjustment range is there? You'd have to re-index to do that! OK I gotta get back to my crack pipe now. Thanks for the mental excercise!

Tom - Yeah there's no problem with safety - I wasn't saying that. It's just that the VX won't handle as well if you crank so much preload in that you're riding way higher in the stroke than the designer intended. At three inches higher than normal ride height you're probably not that far from being topped out. When off-road racing on two wheels you want race sag (that would be the equivalent of VX ride height with you and your gear in it) to be set so that you're about 1/3 down into the stroke and I imagine it's a similar setup for best suspension compliance when you're in the four wheel realm too. It's not good for handling/traction if you're topping out all the time. But then I guess the aim here isn't good high speed off-road handling anyway is it? Nobody's running in a rally or a SCORE desert race or anything - they just want more ground clearance to prevent getting hung up and keep from ripping stuff off the bottom of their VX as they crawl over rocks!

[tom4bren]

But then I guess the aim here isn't good high speed off-road handling anyway is it? Nobody's running in a rally or a SCORE desert race or anything - they just want more ground clearance to prevent getting hung up and keep from ripping stuff off the bottom of their VX as they crawl over rocks!

Nope - it's all about the big tires.

Go big or go home.