Help And Advice On New Torsion Bars

[vickiw106 1]

I need some help and advice

 

I brought (from a member on this forum) and fitted a set of 23mm torsion bars to my rally car, set them to the required height and went on our way.

 

after the 1st stage the rear had lowered by about 20mm. thought nothing of it as the suspension had no time to settle previously,

But as the day went on the rear of the car got lower and lower. In total I would say that the car has lowered itself by about 40-50mm.

 

This is the first experience I have had with new torsion bars, I know suspension has to settle but is this correct?

If I adjust it again to the required ride height will it just keep getting lower again?

 

Any advice/help would be much appreciated

 

Thanks

Ian

[Tom Fenton 1,541]

Doesn't sound right to me, I would have a talk to whoever they came from.

[boombang 2]

Bars were from me - I got them from another forum member who bought from 205 Parts. Did test with a punch when purchased to ensure hardened, and they had been on a car and used before me buying. I therefore purchased and sold on with complete confidence.

 

A short version of my PM to Ian below for reference:

 

Sounds like a worn out beam to me, if the beam is in good working order it's not possible for it to lower itself.

 

The bars have splines at each end and are fixed. For them to move position, either the splines have come off or distorted on the bars, or the trailing arm splies have come off or distorted.

 

As they cannot move position, any lowering of ride height has to be down to the height the beam has been set at.

 

Could be now that the beam has been unseized or has been lowered so ovalled sections are now not alligned, but it will still need rebuilding or replacing to work properly.

 

 

Just to check:

 

beam is known good and been inspected recently?

shocks were removed when bars fitted, and the shocks are known GWO?

between bars were fitted and the rally, was the suspension compressed at any point?

[Miles 331 1 Cars]

I can add as I had it happen to a car of mine as daft as it may sound on OE std Bars,

 

Had been fine for ages and beam given new seals 2 years ago as was rebuilt by someone else 6 years ago roughly and early in the year the O/S/R ended up almost on the bump stop so swapped the bar over for another one and all had been good so far, I did think that the splines had stripped but the bar lost its tension for some reason.

[j_turnell 136 3 Cars]

Bit of a stab in the dark here, but may be worth swapping the bars around, could it be possible that the bars have been run on the opposite side and are used to being stressed in one direction of rotation, therfore they become hardened in that direction so to speak, so if you put them the other way round then that stress is reversed potentially twisiting in the therefore weaker direction.

 

I was trying to work out which direction they twist from side to side, but im assuming they are twisiting in opposite rotations?

[vickiw106 1]

Bars were from me - I got them from another forum member who bought from 205 Parts. Did test with a punch when purchased to ensure hardened, and they had been on a car and used before me buying. I therefore purchased and sold on with complete confidence.

 

A short version of my PM to Ian below for reference:

 

Sounds like a worn out beam to me, if the beam is in good working order it's not possible for it to lower itself.

 

The bars have splines at each end and are fixed. For them to move position, either the splines have come off or distorted on the bars, or the trailing arm splies have come off or distorted.

 

As they cannot move position, any lowering of ride height has to be down to the height the beam has been set at.

 

Could be now that the beam has been unseized or has been lowered so ovalled sections are now not alligned, but it will still need rebuilding or replacing to work properly.

 

 

Just to check:

 

beam is known good and been inspected recently?

shocks were removed when bars fitted, and the shocks are known GWO?

between bars were fitted and the rally, was the suspension compressed at any point?

 

the beam is inspected every 2 rallies and was checked before putting the new torsion bars in and is all ok.

shock where removed when fitted as a dummy shocker was used to set the ride height

the car was tested driven for about 2 miles that should have been enough to let the suspension settle.

 

i have adjusted this beam on several occasion using the same method with standard tosion (older one's i admit) but i have never had this problem.

 

i have not yet ripped the beam apart to see if i can see anything, will have look tommorrow.

[vickiw106 1]

As per my post my completely stripped the beam yesterday, checked all splines (on torsion bars, beam and trailing arms) also checked shaft bearings etc. and found nothing.

 

I have now set the ride height to what Peugeot sport recommend for tarmac. And now looks very high. But this does not explain why the ride height dropped so much during the rally.

 

There is nothing that point towards the beam being faulty. The ride height drop has to be caused by the torsion bars in some way, whether this is the torsion bars "settling" or not I am not sure.

 

 

Please let me know your thoughts

 

Thanks

[Anthony 1,002]

Whilst it would be expected for the suspension to settle slightly over a few miles, figures like 40-50mm that you're quoting is certainly not right or normal.

 

Do both sides drop equally, or does one side drop more than the other?

 

If it was a manufacturing fault I wouldn't have expected the bars to have ever worked properly as it sounds like they did for whoever had originally used them, and certainly there are plenty of the 205Parts supplied bars out there that are a good few years old now and still going strong, so it's not an underlying issue related to the design, material or manufacturing process. Some of the early supplied bars did have splines that could be slightly loose fitting depending on the arm/beam/endplate they were fitted to, but that issue was quickly addressed and even those bars have stood the test of time and not caused any issues.

 

For 205-length 23mm bars you'll want something in the ballpark of 290mm between shock centres, increasing or reducing that distance by a few mm depending how high you want it.

[vickiw106 1]

 

Do both sides drop equally, or does one side drop more than the

 

For 205-length 23mm bars you'll want something in the ballpark of 290mm between shock centres, increasing or reducing that distance by a few mm depending how high you want it.

 

Both sides dropped the same amount.

 

Before the rally I had set the beam to 300 mm. Taking into consideration the drop I have set it now to 312 mm as per Peugeot sport tarmac spec. It now looks a little high but I have not driven it any where so this will be reduced.

 

Don't get me wrong with this setup the car handled great. My concern is that with every rally the torsion bars are going to get softer and softer (more than normally) hence the height drop

[309PUG 2 1 Cars]

Hi,

 

It sounds to me from the information you give us that the TB's are 'soft' and are made from the wrong material and / or not heat treated correctly.

 

One thing you can do is next time you have the bars out of the beam, take them to a company that is a heat treatment specialist and just ask them to measure the actual hardness on there Rockwell m/c you should have a reading of 40 'Rockwell C' any less then you might as well chuck them in the bin.

 

Something else you can also do but might be a little trickier is take them to a metalurgist company and ask them to identify what material your bars are made from, they should be made from EN47.

 

Any other info you require, just ask.

 

Chris

Edited April 23, 2011 by 309PUG

[vickiw106 1]

Hi,

 

It sounds to me from the information you give us that the TB's are 'soft' and are made from the wrong material and / or not heat treated correctly.

 

One thing you can do is next time you have the bars out of the beam, take them to a company that is a heat treatment specialist and just ask them to measure the actual hardness on there Rockwell m/c you should have a reading of 40 'Rockwell C' any less then you might as well chuck them in the bin.

 

Something else you can also do but might be a little trickier is take them to a metalurgist company and ask them to identify what material your bars are made from, they should be made from EN47.

 

Any other info you require, just ask.

 

Chris

Chirs

 

thanks for this

 

i will pop the torsion bars out next week.

 

i think there is a heat treatment specialist by me that maybe able to help.

 

if the result of the test comes back less than 40 do you know if there is anything that can be done to them so i will be able to use them?

 

thanks

Ian

[SurGie 54]

Thats very good info there 309PUG, i found a company that sell these uprated bars close to where i live, so with that info it will help me make sure they are the correct type.

 

Cheers.

[vickiw106 1]

Hi,

 

It sounds to me from the information you give us that the TB's are 'soft' and are made from the wrong material and / or not heat treated correctly.

 

One thing you can do is next time you have the bars out of the beam, take them to a company that is a heat treatment specialist and just ask them to measure the actual hardness on there Rockwell m/c you should have a reading of 40 'Rockwell C' any less then you might as well chuck them in the bin.

 

Something else you can also do but might be a little trickier is take them to a metalurgist company and ask them to identify what material your bars are made from, they should be made from EN47.

 

Any other info you require, just ask.

 

Chris

 

right then

 

ripped the torsion bars out over the weekend and took them to a heat treatment specialist.

 

the end result was a "Rockwell" reading of 30. from what you said it looks like these torsion bars are no good. is this correct.

 

 

they also confirmed it may have something to do with the type of material they are made from. enquired about this and was very surprised how much it would cost to get the material tested.

 

i also enquired about whether these torsion bars could be hardened. they advised that they could but the hardening process also can make the metal brittle with the end result being the torsion snapping?

 

any thoughts.

 

Thanks

Ian

[Anthony 1,002]

That's a little worrying.

 

Are you sure that they are bars originally supplied by 205Parts, as they weren't the only supplier around at that time and they're obviously atleast 3rd hand by the time that you've bought them? If you're not sure, if you can get a picture of the splined ends I should be able to give you a clue as the 205Parts supplied ones have a fairly distinctive look to them compared to PTS etc.

 

If they are 205Parts supplied bars then whilst I can't be held in any way responsible for them or make any promises, I am still in contact with the original company that manufactured them and I can speak to them to see whether they would be willing to take them back and manufacture you a new set at no or reduced cost given it appears to be a manufacturing issue - had they just been a few months old I have no doubt that they would, but given they're several years old and you're not the original or even second buyer it would be a good will jesture rather than any obligation.

 

Certainly the issues that you've had are not normal and I've not heard of any other occurances of this happening despite the significant number of them out there being used in various applications, and I do know that when the bars were originally made an OE bar was tested both in terms of hardness and material type and the new ones made based on that.

[vickiw106 1]

That's a little worrying.

 

Are you sure that they are bars originally supplied by 205Parts, as they weren't the only supplier around at that time and they're obviously atleast 3rd hand by the time that you've bought them? If you're not sure, if you can get a picture of the splined ends I should be able to give you a clue as the 205Parts supplied ones have a fairly distinctive look to them compared to PTS etc.

 

 

i cant be 100% sure the bars are from 205parts, i can only go on what the seller told me.

i will take a picture and post it on here

whats the difference?

 

 

 

If they are 205Parts supplied bars then whilst I can't be held in any way responsible for them or make any promises, I am still in contact with the original company that manufactured them and I can speak to them to see whether they would be willing to take them back and manufacture you a new set at no or reduced cost given it appears to be a manufacturing issue - had they just been a few months old I have no doubt that they would, but given they're several years old and you're not the original or even second buyer it would be a good will jesture rather than any obligation.

 

as i am (i think now the 3rd owner) i think it maybe best to sort it with whom i brought them off. i will let you know

 

thanks

ian

[SurGie 54]

Right iv had a call back from that company and i was told that when he rang their TB/ARB makers, they were told that they wont say what there hardness or material is made from as they dont want them copied.

 

To me that sounds like an excuse as i could buy some and get them tested and the info about the correct hardness etc is available on the net any ways, so i wont be buying from them.

 

They did say they sell loads to rally drivers for 205/206/Saxo etc but that could be selling talk tbh.

[feb 47]

Thats very good info there 309PUG, i found a company that sell these uprated bars close to where i live, so with that info it will help me make sure they are the correct type.

 

Cheers.

 

 

Right iv had a call back from that company and i was told that when he rang their TB/ARB makers, they were told that they wont say what there hardness or material is made from as they dont want them copied.

 

To me that sounds like an excuse as i could buy some and get them tested and the info about the correct hardness etc is available on the net any ways, so i wont be buying from them.

 

They did say they sell loads to rally drivers for 205/206/Saxo etc but that could be selling talk tbh.

 

Which company are you referring to?

If they are NOT the ones that supplied to 205 Parts we should not put irrelevant info in this thread.

TBH regardless, it is totally irrelevant IMHO as the origin of the bars that the OP is talking about could be dubious...

Edited May 26, 2011 by feb

[Tom Fenton 1,541]

Right iv had a call back from that company and i was told that when he rang their TB/ARB makers, they were told that they wont say what there hardness or material is made from as they dont want them copied.

 

To me that sounds like an excuse

 

Sounds like protecting their interlectual property to me, and I am not at all suprised at the answer they gave you.

[SurGie 54]

I see what you mean and i could always put another thread and waste more space.

 

However, this company that supplies them only sells them and does not make them. So i took the initiative & called them back and managed to get them to give me the direct number of the engineering place that makes them.

 

In time i will know more and will post the info of the company that makes them and their minimum amount of hardness and material type. But i will only post this info if its allowed on this thread for others to read.

 

Other members in this area could buy a set directly from the engineering place to save postage and maybe get them cheaper.

 

Cheers G

 

EDIT > All i want to know is the minimum amount, so i know they will last to save a lot of hassle and time. We all know, as does this beam company that some TB can get saggy and pretty useless due to the material or hardness etc. I dont want to have to take them back in 6 or so months time for instance.

 

Lets face it, i could buy a set and get them tested via other companies that can test them, so its not like it would be secret would it.

Edited May 26, 2011 by SurGie

[petert 585]

I can concur that at 30Rc you have a problem. I also agree that they must be 40Rc minimum to be any good. I've had quite a few batches of torsion bars made over the years. One batch was incorrectly hardened, in this case 21mm bars. They were fine on the road, but on their first rally outing, where more loading is induced, they just went flat, just as you described. It's no use putting them back to their original height. It's like bending a metal ruler past its elastic limit. Once bent too far it will stay bent.

 

Assuming they're a suitable material you could get them re-hardened and tempered. It's a totally reversible process. However, for the cost involved for analysis and further heat treatment, I'd just buy a new set from 309PUG.

 

Hardening and tempering torsion bars correctly is expensive. I've suspected for some time that the UK market has some nasty torsion bars being sold as the price is just too cheap. This totally confirms it. Stick with 309PUG. He sells a quality product.

Edited May 27, 2011 by petert