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Front Torsion Bar Upgrade

Tech Talk for Ford, Mazda, Daihatsu & Makes that currently dont have a home.

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Front Torsion Bar Upgrade

Post by Clint »

There has been a lot of discussion about aftermarket rear leaf springs, ie. lift, ride, articulation etc. But what about the torsion bars at the front.
I know u can wind them up to give lift but at the cost of harsher ride and less articulation. Is it worth spending the money on aftermarket torsion bars to give the lift and better ride and articulation.
I ask because i had a moment on the weekend due to lack of travel in front end, and i will be replacing the rear leaves soon and wondering if it is worth doin' the lot while i am at it.
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Post by Clint »

By the way, you don't need one of those fancy inclinometer things in the dash to tell how far u r tipping. U can tell by the volume of g.f.'s screams from the pasenger seat :D
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Post by FrozzaII »

Dunno bout the Torsion Bars, but I can agree with u on the screaming g.f's... :lol: :lol:
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Re: Front Torsion Bar Upgrade

Post by HeathGQ »

Clint wrote:There has been a lot of discussion about aftermarket rear leaf springs, ie. lift, ride, articulation etc. But what about the torsion bars at the front.
I know u can wind them up to give lift but at the cost of harsher ride and less articulation. Is it worth spending the money on aftermarket torsion bars to give the lift and better ride and articulation.
I ask because i had a moment on the weekend due to lack of travel in front end, and i will be replacing the rear leaves soon and wondering if it is worth doin' the lot while i am at it.
SOME SAY YES SOME SAY NO. I didn't get mine replaced, so I couldnt tell you how it would feel with new ones.

I fail to see how they would give you better articulation. They would only allow a little bit extra up travel, if any, as the torsion forces havent changed. They would be better for load support, but that would mean harsher ride unlaiden.

IMO wouldnt bother withem until you break one. Then replace with good ones.

And yes screaming GF's are a good indication of angle.
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Post by murcod »

My thoughts on it:

The aftermarket bars are a thicker diameter, therefore harder to twist. This would mean that offroad the front end won't compress as much as before over bumps. Instead the body weight will be forced up with the front end not compressing as far. This would limit wheel travel more.

Suspension travel (providing the aftermarket bars can be fully "twisted" to the bump stops by the weight of the Feroza) would be the same for standard or aftermarket. The same for the down or up travel for any given height setting with either bar- it will be the same as the bump stops are what limits the front travel and they don't change. ;) Have look under the front end and you'll see what I mean.
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Post by Clint »

Maybe instead of articulation I should have said front wheel up travel.
My understanding is this, (prepare for the ramble).
When the Feroza is at standard height with standard torsion bars on level ground the torsion bars are at a neutral position. This allows reasonable wheel up travel and down travel, limited by the bump stops.
When the standard bars are wound up from their neutral position they are being twisted more and hence give lift but this then requires the bars to be twisted more again when the wheel wants to travel up. Now if the force required to twist the bar further is greater than the weight of the car then the car will lift instead of suspension working.
Now I thought with aftermarket torsion bars that the neutral position already gives the lift and also allows reasonable wheel up and down travel, without the need to twist them further, limited again by the bump stops.
Is this correct of am I somewhat delusional. :roll:
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Post by Croz »

Yeah Clint... this is the way I understand torsions to work... but last time i asked this most replies said the neutral position of the bar made no difference...

The way I see it the more you wind the bar the further you are from neutral and thus to get full wheel travel past the original full travel you need more force.

An aftermarket bar may have a progressive or different spring rate, or softer spring rate, but i am not sure.


I have wondered if it would also work to remove the standard torsions and rotate the spline before winding them from here so the actual centre spline of the bar is at a different point...

There is a little voice in my head going "der... thats not gonna work..." it goes away before it explains why not... :cry:
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Post by Clint »

I am sure that aftermarket one would need to be a different spring rate.

I have wondered if it would also work to remove the standard torsions and rotate the spline before winding them from here so the actual centre spline of the bar is at a different point...


I don't think this would work cause u still have to twist it the same ammount to get the same lift. ie. it is still has the same torsional properties.
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Post by Croz »

That depends, if by winding them up you are putting preload on the spring thenthere is more effort to move them, but if winding them only moves the centre then it wont make any difference...

If winding them moves the neutral position of the spring, or the resting height of the vehicle then effort to compress is unchanged, but if the centre doesnt move but instead yopu are loading them more by winding them then to remove and then put the centre spline (or resting postion) in further round in the socket it might make the vehicle sit higher with out changing the spring rate as much.

Dont mean to argue, I am just not totally convinced of the way these components work. I am at work at the moment but when I get time ill have a looka the manual. I might put t thread in general tech.
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Post by murcod »

Here's another way to look at it- not matter what rate the torsion bar is the maximum up and down travel will be the same. It's controlled by the bump stops- not the torsion bars.

Also, if the ride height is the same on two different Ferozas- one with standard torsion bars and the other with heavy duty ones- they will still have the same amount up or down travel from the suspension rest height(due once again to the bump stops being the limiting factor.) The one with the heavy duty bars will compress the suspension less over bumps as the bars will be harder to twist (ie it requires more weight on them to twist the same amount as the stock bars.)

By winding the suspension up with either bar type you are moving the front suspension top A arm bump stop closer to it's limit- the bar makes no difference to this. Have a look at the front suspension set up and it will be clearer- look for the bumpstops above and below the suspension arms on each side.
Last edited by murcod on Tue Aug 24, 2004 9:01 pm, edited 1 time in total.
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barred

Post by lowndsie »

ok well being very simple minded i'm not sure that i followed all that was said above. but having fitted heavy duty tjm torsion bars i can comment on them.

to be honest i cant feel much difference in the handling when going over bumps. they seems to flex close to the same as the others. it's mainly the rear leaves that like to jump around. i havent tried them in the scrub yet so not too sure on the wheel travel. they do look thicker than the previous and i got bout two inch lift from them.

anyway, i hope thats of some help to someone......
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Post by murcod »

A picture says 1000 words- I've doctored a pic of the front suspension and added in the bump stops. Hopefully you'll see what I mean then.

PS: I stuffed up earlier when I said the lower bump stop limits downtravel! I'll edit the post...

Image
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Post by murcod »

Another pic showing where the torsion bars fit into the front set up.

Image
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Post by Clint »

I know that the bump stops limit the travel but does the suspension ever reach the lower one,pic above, (except when landin’ big jumps :armsup: :D ).
With the original torsion bars wound up, is the force required to push the front wheel up to it’s limit (i.e. to the bump stop) greater than the weight of the car and hence lift the car?
What I am trying to get at is, are we using all available travel in the front end with original torsion bars wound up?
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Post by Croz »

Clint wrote:With the original torsion bars wound up, is the force required to push the front wheel up to it’s limit (i.e. to the bump stop) greater than the weight of the car and hence lift the car?
What I am trying to get at is, are we using all available travel in the front end with original torsion bars wound up?



Thats my arguement as well. Imagine the bar is rubber and a mate holds one end and winds it up... as does the rear adjustment... then grab the other end and wind it the other way, as if you are the front suspension twisting it back in wheel travel... then it is going to be harder to twist than if the other end wasnt twisted.

How far can you twist the bar??
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Post by murcod »

Clint wrote:I know that the bump stops limit the travel but does the suspension ever reach the lower one,pic above, (except when landin’ big jumps :armsup: :D ).
With the original torsion bars wound up, is the force required to push the front wheel up to it’s limit (i.e. to the bump stop) greater than the weight of the car and hence lift the car?
What I am trying to get at is, are we using all available travel in the front end with original torsion bars wound up?


Try jacking the front up on one side with a trolley jack under the lower arm and see what happens. Remember that the shocks will have an effect when driving along and should provide varying resistance to compression depending on how fast they are compressed.
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Post by Croz »

I have done this when I was cutting down my bump stops... the efect of lifting just one wheel does not compress the front suspension much... only when I had the car basically sitting 80% on one wheel in a rut did it compress a long way, but i didnt get in there and check it out... have to go again :D
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Post by Clint »

Just a thought i had while doin' some research on the subject.
Could you replace the shocks with some coil overs and wind back the torsion bars a bit. Is there room and would it help at all?
Just throwing some thoughts out there.
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Post by Croz »

Dunno about coilovers in the stock locations, but a mate has an ex rally feroza with secondary shocks mounted behind the front arms. You mightbe able to mount coils like that.

Next time i see him Ill try to grab some shots of the car and the set up.
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Post by *BESTY* »

COILOVERS :shock:

If you're gonna go to that expense, SAS the front !!

Problems you will encounter will be the chassis design....not straight, where to mount the control arms etc.
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Post by r0ck_m0nkey »

Croz wrote:
Clint wrote:With the original torsion bars wound up, is the force required to push the front wheel up to it’s limit (i.e. to the bump stop) greater than the weight of the car and hence lift the car?
What I am trying to get at is, are we using all available travel in the front end with original torsion bars wound up?



Thats my arguement as well. Imagine the bar is rubber and a mate holds one end and winds it up... as does the rear adjustment... then grab the other end and wind it the other way, as if you are the front suspension twisting it back in wheel travel... then it is going to be harder to twist than if the other end wasnt twisted.

How far can you twist the bar??


Going off your rubber theory, this is how adjusting the front works.

Now lets say you can only twist the rubber your holding onto 90 degrees each way (giving 180 degrees of twising range). You move the rubber 45 degrees one way, your mate rotates it the same amount thus keeping the rubber flat and straight, this is what happens when you adjust the suspension, it keeps the torsion bar in it's same state, adds no extra twist.
Now, with you both holding the bit of rubber at 45 degrees, you hold it still (as you represent the adjuster end) your mate can now only rotate it another 45 degrees in the same direction or 135 degrees in the opposite direction, to stay within the original 180 degrees of movement available. This is what happens to your front suspension, it now has less room to freely move in one direction (downward travel) so less twist occurs in this direction. But now it has more room to freely move in the other direction (upwards travel) which allows the torsion bar to be twisted past what it was designed to from standard.

That possibly all makes sense.
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Post by rOd »

Unfortunately, the reality of lifting a stock IFS only results in almost zero down travel. :cry:

If I still had the Feroza, I would probably just do a 50mm bodylift with 31" rubbers and leave the suspension at standard height.

But then the gearing would be even crapier. :roll:

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Post by SimplyPV »

rod.. with a feroza stock.. you WONT be able to get 31's on there without lifting........
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Post by rOd »

SimplyPV wrote:rod.. with a feroza stock.. you WONT be able to get 31's on there without lifting........


Yes, I KNOW that.

Which is why I said 31" tyres with a 50mm bodylift to give it more clearance around the guards.

Some extra trimming of the body might also be necessary (MAYBE).

The only reason I suggested this is to try and save some of the down travel of the IFS. Rather than cranking the bastard right to the bump stop.
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