Torsion bar ifs - How do I get more flex & droop?

Springs, shocks and all things between your chassis and diffs
Timmo
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Timmo » December 6th, 2014, 12:00 pm

In all seriousness Peter, Have you actually tried a ball joint flip? I suspect not.

One last scenario and then I'm done.........

With the vehicle jacked up on stands and the wheel off, torsion bars backed off and shock out. Suspension in the middle of its range of travel supported by a jack or stand under the lower control arm. Now that wheel can not move up or down. The distance between the lower control arm and uptravel bumpstop will not change one bit as the lower control arm is supported by the jack.

Observe the distance between the upper control arm and the downtravel bumpstop. Now, remove the ball joint from the upper arm and flip it to the underside of the upper control arm. Bear in mind the hub centre height from the ground has not changed as the whole assembly is still supported by a jack/stand in the original position meaning that the ride height will not be altered. By now positioning the ball joint under the upper arm, you haven't pushed any of the suspension/hub assembly down, in turn lifting the vehicle, you have spaced the upper control arm further away from its downtravel bumpstop. That increased distance between the upper arm and the downtravel bumpstop equates to more allowable droop. Taking into account that the distance between the lower arm and the uptravel bumpstop is still the same as it was at the beginning of the exercise means that the uptravel limitations remain the same as they were prior.

Now what you're saying Peter is, the wheel has just been set lower in its original range of travel but the travel range remains the same. Yes? Please tell me how this has happened as the distance between the uptravel bumpstop and the lower control arm hasn't changed from when we started this exercise? What you're implying is that what we gain in droop, we lose in uptravel and we are just moving the wheel in the same range. If that is the case, going by your theory, by increasing the distance between the upper arm and the downtravel bumpstop, theoretically we should be decreasing the distance between the lower arm and the uptravel bumpstop in the same proportion. But we haven't. No fancy physics or engineering degrees required, no irrelevant yo-yo analogies. Quite simple really. There are plenty of people running around with flipped ball joints, you can't tell me they are all wrong!

So more allowable droop and the same uptravel limitations equates to an increase in the range of travel. Ride height hasn't changed, the position of the wheel within the original range of travel hasn't changed, all that has changed is that you have increased the amount of droop available by increasing the distance between the upper arm and its bumpstop. Now what you do with extra range of movement is up to you. You can then wind the torsion bars back up to so that the distance between the upper arm and its bumpstop is the same as it was prior to the flip which will give you a ride height increase yet retain the same amount of droop you had before. Or leave them as is so ride height remains the same but enjoy the benefits of extra droop.

Seriously though jacnden, try it for yourself then make up your own mind mate. I have tried it just to satisfy curiousity but I do not run a ball joint flip in my vehicle as the extra droop places more strain on the CV's. You can combine a balljoint flip with a diff drop to correct the CV angles. One thing to bear in mind is, on an IFS truck the balljoint sits recessed in the upper control arm so the whole body of the balljoint supports the suspension assembly. Flipping it means it sits below the upper arm and is held in place only by the bolts. I prefer to have the suspension assembly supported by the entire body of the ball joint rather than just 3x 8mm bolts for safety sake.

A ball joint flip isn't going to give you the flex of a live axle, coil sprung truck. It will give you up to around 25mm or so of extra droop (obviously this is a general measurement and is what I got out of my rig) each vehicle being different.

Here's some reading from someone else who has actually done it, pay attention to the last post;

viewtopic.php?f=172&t=127906

Someone else who has flipped and used a spacer;

http://www.4x4earth.com.au/forum/jackar ... -flip.html
Last edited by Timmo on December 6th, 2014, 5:28 pm, edited 3 times in total.
Cheers,

Nathan

jacnden
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by jacnden » December 6th, 2014, 12:27 pm

i dont want to start a slanging match, i am sure we can throw around a few ideas without having a go at each other.

timmo, ime not sure i have the skills to do a ball joint flip. doesnt the ball have to be removed and isnt that difficult?

one thing to complicate matters my chinese car doesnt have a lower bump stop. the shocker is the limiter of down travel. if i take the shocker off i have about 1/2 inch extra travel till the arms bottom out. if my suspension travel is close to its physical limits does any of these thing make any differance?

Timmo
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Timmo » December 6th, 2014, 12:50 pm

No slanging match here mate, just making sure you (and any future people searching for the same thing) get the correct info based on facts from people who have actually done it.
In your first post of this thread you mentioned that if you unbolt the shock, you only get another 12mm of downtravel before the upper arm bottoms out. That is the exact scenario the ball joint flip helps with. You will be spacing that upper arm a bit further away from where it "bottoms out", it will still bottom out at that same point but your hub assembly will be lower at that same position when the arm bottoms out. Your uptravel will not be compromised. Think about it like this, with your upper arm bottomed out on the bumpstop, if you were to reposition the ball joint to below the upper arm, it would push the hub assembly down further and increase the distance from the lower arm and the uptravel bumpstop. So you are increasing your range of travel no matter how you look at it, as long as you have shocks that can operate within that range.

Sounds like your shocks are the limiting factor at the moment anyway. Your shock should not bottom out before it hits the bumpstop in either direction on an IFS front end. You should be able to access the entire range of travel between the 2x bumpstops. If you want to do a ball joint flip, you will need to invest in some longer shocks to make it work or you will still be limited by your existing shocks range of travel.

Like I said mate, it can be done, it will increase droop and overall range of travel but I still wouldn't be comfortable running it in my vehicle. Every mod has a downside (or a few). The downside/s to a balljoint flip being;

-It will be harder to wheel align your vehicle as the geometry is altered - you will find you have increased positive camber and may not have enough adjustment to bring it back to spec. Could lead to extra tyre wear on the outside edge.
-CV angles worsened at full droop as droop is increased, possibly contributing to premature CV wear.
-Handling may be affected - Can't say for sure as I never drove mine with the flip in place.
-The balljoint body is no longer supported in the control arm recess, it is only held by 3x 8mm bolts.
-It is illegal
Cheers,

Nathan

Peter Aawen
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Peter Aawen » December 6th, 2014, 2:00 pm

You ask 'Have I actually done a ball joint flip' Timmo? Well not to the extent of driving it on the road or track stage, cos there was no point!! But I have physically stripped down more than just a few variations of IFS front ends & seen EXACTLY what a ball joint flip would do AND physically measured the results looking for a variation in total range and, exactly as the engineering calculations & design work I have done suggests would be the case, there is NO increase in total travel UNLESS you do something to change the physical limitations on the total range of travel inherent in the design!! ?

No matter what people who don't understand the maths, geometry, & design might think, when there are fixed pivot points (rotational centres) as the centre of each arc of travel teamed with fixed position limiting devices (ie bump stops) AND fixed radius lengths (the length of the arms themselves) then you simply won't be changing the maximum/total range of travel imposed by those fixed points. That is one of the universally recognised limitations of the IFS design in the automotive design world - to change the total range of travel you'll need to change one or more of those fixed points/lengths; & while a ball joint flip or even a different shaped arm (that doesn't vary the radius length) might vary where in the range the 'static ride height' sits, it hasn't changed any of the critical fixed parameters of the arc of travel so the total range of travel won't have changed at all. Talk to any qualified designer &/or another automotive engineer & they'll support what I've said, hey, even most who can understand schoolboy tech drawing will support what I've pointed out. ;)
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Timmo
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Timmo » December 6th, 2014, 2:49 pm

I don't need to talk to an engineer or a designer or whatever. As said, I've tried it on my own vehicle and proven the results. I have even linked to people that have done the same and posted their findings! Hell, heaps of 4wder's run a balljoint flip to achieve exactly what I have pointed out and explained in my posts. I guess they all must be wrong. Pretty arrogant assumption IMHO.

I'll let this diagram that I found speak for itself, although this incorporates a spacer aswell which only increases it further.
diagram.jpg
Yes the radius lengths are fixed, but not all the pivot points are. You are effectively relocating one of them (the upper balljoint) lower to increase the gap between the arm and its bumpstop that limits its range of travel. The exact same effect that would be had by relocating the upper bumpstop lower (or trimming it). The lower arm has the ability to support the hub through it's entire range of upward movement til it hits the uptravel bumpstop. The upper arm with the balljoint flipped can accommodate this range of movement also, only now it has to move further upward as it is spaced up from the balljoint now being mounted underneath. Now on the downtravel side, the upper arm still comes to rest on the downtravel bumpstop only now the hub assembly is spaced down from the arm via the flipped balljoint. The lower control arm now is free to move that little bit lower (the same amount that the flip/spacer provides). As said prior, the radius hasn't changed, the overall length of the arc has as there is now more of a gap between the bumpstops. How anyone can't see that is beyond me. :confused:


Anyway, whatever. I'm done.

Just goes to show ~19000 posts doesn't ensure the content is factual.
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Last edited by Timmo on December 6th, 2014, 5:34 pm, edited 1 time in total.
Cheers,

Nathan

Peter Aawen
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Peter Aawen » December 6th, 2014, 3:00 pm

Timmo, I'll say it again - all that has done is the static ride height of the vehicle has been raised by 25mm, it hasn't effectively increased or even changed the overall range of movement provided by the suspension design. Put a schoolkids compass point on the chassis end pivot points & set the radius to the length of the arms out to the pivot point on the spindle & swing an arc for each arm & compare the radius lengths, they are the same.... Then draw the lines in to show the upper & lower limits imposed by the bump stops & compare across the drawings - there will be no change despite the ride height being 25mm higher.

As for lots of people doing ball joint flips to gain travel, just cos lots have done it without understanding doesn't mean it's right!! TopGear even did an expose on many of the mods that people claim will improve ride, handling, speed, lap times etc to show that they didn't do squat despite the millions of $$ being spent on them each year by people who believe they are the bees knees.... There is also an old saying about millions of flies & what they eat..... :eek:
An Ex-Service person is someone who thought enough about their country & how great it is, how lucky we are to live here, to write a blank cheque made out to 'The People and Commonwealth of Australia' for the value of 'Up to & including my Life!'

Timmo
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Timmo » December 6th, 2014, 4:04 pm

As I said, I'm done.

I stand by what I have already said and will leave it at that.

I'm not wasting any more time on it.
Cheers,

Nathan

runsonrum
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by runsonrum » March 16th, 2015, 10:10 am

No offense timmo...but peter is right. You have no idea what you are talking about. The amount an ifs setup can travel up and down is governed by the length of the upper and lower control arms. The only way to increase length of travel is increase the arc in which they can physically travel. Take a look at an American offroad racing truck. They run full independent suspension and have massively long control arms and coilovers to suit for this reason. Flipping or spacing the ball joints is just going to push the body/chassis up further away from the control arms/diffs similar to a drop diff kit and offer no increase in the actual wheel travel

Timmo
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Timmo » March 16th, 2015, 10:21 am

That's nice.

You can dig up a thread and have an opinion on something that was long forgotten 4 months ago.
I've already said my piece and posted diagrams/pictures. You believe what you wish.

I'm not getting into this debate again.
Cheers,

Nathan

Dree Mon
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Dree Mon » March 16th, 2015, 8:44 pm

If you shave or remove the upper bump stop, you will get more droop, not exactly like a ball joint flip will, but very similar, No I havent done it myself but with a diff drop I would, if you have/own an IFS you'll know how it works and why it's considered a suspension modification. the spacer kit is sold everyday for a reason,

I'm not as over this debate as Timmo, but over it enough Lol

Luxy02
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by Luxy02 » October 23rd, 2015, 3:24 pm

you definately get more travel.It's simple with bj spacers in I get a lot further up the flex ramp :)

typhoeus
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by typhoeus » October 23rd, 2015, 5:49 pm

Seems to me that a 50mm spacer under the ball joint will push the outer ends of upper and lower control arms 50mm further apart. If bump stops are halfway along the control arms, then the distance between the points of contact with the bump stops will be 25mm further apart. This constitutes the extra travel (of 25 mm). be it up or down depending on details of the design, so I think Timmo is right to a degree, Other issues around steering geometry could cause problems but the basic logic is correct

jacnden
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Re: Torsion bar ifs - How do I get more flex & droop?

Unread post by jacnden » June 1st, 2018, 7:30 pm

So it's nearly three years since we have added anything here. I have done a ball joint flip , really just to see what it does.
I also added a 1/4 " spacer.
I've got to say it doesn't seem to have done much if anything , to down travel. Maybe fractionally , bit hard to confirm
The torsion bars are wound up about 2 1/2 " and I have 15mm diff drop.
What it has done is make wheel alignment easier, where before it was at the limit off adjustment it is now in the middle of the range
I have done huge amounts with the rear suspension to get a lot of flex to make up for the inherent limited flex in the front. Might post some pics when I get a better connection

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