PST torsion bars bent...

Posted By: 67Charger

PST torsion bars bent... - 05/10/11 09:29 AM

Is it normal for there to be ANY bend in the torsion bar? My brand new PST 1.030's have a very slight sway. I have already installed the drivers side and when grabbing the other one to replace the passenger side I removed, I had the inclination to look down the bar. I was expecting perfectly straight, but instead it looks to be "S" shaped, about 1/16" out of perfect. Is this a problem like I think it is? I leave for Silver State in 36 hours.

Posted By: ZIPPY

Re: PST torsion bars bent... - 05/10/11 02:16 PM

1/16 from perfectly straight is actually quite good for a part like a torsion bar. They just aren't manufactured with a great deal of precision, and don't need to be, because the hex ends allow for a certain amount of misalignment. I have several OEM and MP bars that are slightly off from being completely straight, all work fine.

So

? No worries

Posted By: Rodney

Re: PST torsion bars bent... - 05/10/11 02:35 PM

Do the aftermarket T- bars have a right and left like the OEM parts?

Posted By: 67Charger

Re: PST torsion bars bent... - 05/10/11 03:19 PM

EDITED FOR CLARITY

No offset hexes, but there is an "R" and "L" forged into the back of the bar. The OEM .925ish 440 bars that came out had exactly 1/2 flat of rotation, 30�.

Now to be clear, I'm talking about an S bend along the length of the bar, not a twist of one hex to the other... If it's OK, then I'll install it, otherwise today I'm driving 70 miles down to Hotchkis and dropping $400 on a set from them.

Posted By: MR_P_BODY

Re: PST torsion bars bent... - 05/10/11 03:26 PM

Quote:

No offset hexes (exactly 1/2 flat of rotation, 30�) like the OEM .925ish 440 bars that came out, but there is an "R" and "L" forged into the back of the bar.

Now to be clear, I'm talking about an S bend along the length of the bar, not a twist of one hex to the other... If it's OK, then I'll install it, otherwise today I'm driving 70 miles down to Hotchkis and dropping $400 on a set from them.

Yes that S shape is somewhat normal... that occurs
during the pre loading of the bars(the company winds
up the bar to take a pre set so they arent sagging
on the car... that gives you the 30* hex difference)
put them in

Posted By: 67Charger

Re: PST torsion bars bent... - 05/10/11 03:36 PM

Quote:

Quote:

No offset hexes (exactly 1/2 flat of rotation, 30�) like the OEM .925ish 440 bars that came out, but there is an "R" and "L" forged into the back of the bar.

Now to be clear, I'm talking about an S bend along the length of the bar, not a twist of one hex to the other... If it's OK, then I'll install it, otherwise today I'm driving 70 miles down to Hotchkis and dropping $400 on a set from them.

Yes that S shape is somewhat normal... that occurs
during the pre loading of the bars(the company winds
up the bar to take a pre set so they arent sagging
on the car... that gives you the 30* hex difference)
put them in

OK, sounds good, but like I said (although somewhat ambiguously), the new bars do NOT have offset hexes. OEM bars thaty came out do, new do not.

Looks like I'll be running them.

Posted By: MR_P_BODY

Re: PST torsion bars bent... - 05/10/11 03:45 PM

Quote:

Quote:

Quote:

No offset hexes (exactly 1/2 flat of rotation, 30�) like the OEM .925ish 440 bars that came out, but there is an "R" and "L" forged into the back of the bar.

Now to be clear, I'm talking about an S bend along the length of the bar, not a twist of one hex to the other... If it's OK, then I'll install it, otherwise today I'm driving 70 miles down to Hotchkis and dropping $400 on a set from them.

Yes that S shape is somewhat normal... that occurs
during the pre loading of the bars(the company winds
up the bar to take a pre set so they arent sagging
on the car... that gives you the 30* hex difference)
put them in

OK, sounds good, but like I said (although somewhat ambiguously), the new bars do NOT have offset hexes. OEM bars thaty came out do, new do not.

Looks like I'll be running them.

I'm suprized they dont pre load them... you may find
that the first few months you MIGHT be adjusting the
ride height... the way the bars are heat treated
will give that wavy S but usually its just a minor
sag
EDIT
I would still think they pre-loaded them but just
moved the orientation of the hex when making the bars
otherwise they wouldnt need to have a left and right

Posted By: 67Charger

Re: PST torsion bars bent... - 05/10/11 04:30 PM

Thank you for putting my mind at ease. I'm guessing the no-offset is because the spring rate of these bars is about double that of the .920's so there is less preload necessary.

Posted By: autoxcuda

Re: PST torsion bars bent... - 05/10/11 05:41 PM

At somewhere in the over 1.00" they go to no offset.

My MP .99's have offset. My MP 1.14" don't. I got decent adjustment left in my 1.14" 's.

I haven't starred down at a set of bars to have an opinion about the "S" curve you are seeing.

Posted By: Hotchkis

Re: PST torsion bars bent... - 05/10/11 06:24 PM

Quote:

EDITED FOR CLARITY

No offset hexes, but there is an "R" and "L" forged into the back of the bar. The OEM .925ish 440 bars that came out had exactly 1/2 flat of rotation, 30�.

Now to be clear, I'm talking about an S bend along the length of the bar, not a twist of one hex to the other... If it's OK, then I'll install it, otherwise today I'm driving 70 miles down to Hotchkis and dropping $400 on a set from them.

67Charger -

Are you sure the bar is actually curving? Those bars are tapered in the center which might give the appearence of a bend.

We would suggest calling the company from which you purchased the bars. We've never seen a curve in any of the bars we've used (our own or Firm Feel's) so we would suggest you have it checked out.

Just as a bit of Torsion Bar info for the rest of you if you're interested, most of the new high performance bars are not offset like the factory bars. The hexes are identically lined up which is better for lowered cars.

Stock Mopar bars have a 30 degree offset. This offset is what sets up the "preload" and suspension geometry. But that's for a stock spring rate.

Stiffer bars will not twist as much with the load of the car on them, so the ride height and geometry won't be right if they had the same offset. We've seen this problem with 1.16 bars on a challenger, you actually run out of suspension adjustment before the ride height is back down to normal. You need a lot less than the stock 30 degree offset.

Install new bars the way you normally would. The lower control arms will end up lining up with less angle on them. But that won't reduce your physical travel, since the bar will not twist as much under load. The stiffer bars will reduce the effective travel though, they just won't twist as much. So you can actually lower the car more (reducing the physical travel available) since you won't be using that travel.

1.03 bars will give a much more "modern" feel to the handling of your car. New cars run much higher spring rates than our old mopars, which were seriously under sprung in stock form. But it's important to match parts, you'll want to upgrade the shocks to handle the new larger bars.

Hope this helps.

Posted By: 67Charger

Re: PST torsion bars bent... - 05/11/11 03:31 AM

Posted By: sublimehemi

Re: PST torsion bars bent... - 05/11/11 06:27 AM

received mine the other day,just checked mine and they are perfect.

Posted By: MR_P_BODY

Re: PST torsion bars bent... - 05/11/11 06:34 AM

Never seen them look like that... I was part of the
design team that designed/built the transverse torsion
bar set up in the F and M bodies... I did all of the
bars for the pre proto's for that design

Posted By: 67Charger

Re: PST torsion bars bent... - 05/11/11 08:31 AM

Well, due to lack of time and therefore options, I put them in. My rationale is the fact that a torsion bar is just a straightened out coil spring, or vice versa. The curve is nothing it won't incur during normal suspension cycling. It was NOT, however, how the factory designed them.

Hotchkis,

You guys will be getting my future business. I bought my full set of Bilsteins and a 1 3/8" front sway bar from you at MATS last month, and the fact that you took the time to chime in with some helpful info when PST wouldn't even return my call is a pretty heavy determining factor. Granted, the PST bars were 1/2 the price delivered, but I can see why.

Posted By: Hotchkis

Re: PST torsion bars bent... - 05/13/11 04:34 PM

67Charger � WOW! You�re not imagining that bend! We hope they�re okay and your Silver State trip goes without a hiccup.

Thanks for your business at MATS. We like being out at events like MATS. It gives us time to get personal time with our customers.

Let us know how your car works with the new shocks and sway bar! Nice quarter mile times listed with your cool �67! DO you drive it on the street a lot?

Posted By: 70blackfish

Re: PST torsion bars bent... - 05/13/11 05:48 PM

I would get straight ones, that is not right.

Posted By: roadhazard

Re: PST torsion bars bent... - 05/13/11 10:57 PM

Quote:

I would get straight ones, that is not right.

Was putting some bars in my Charger and had to look at them after I saw your post.

My you have little hands and feet

Posted By: 67Charger

Re: PST torsion bars bent... - 05/14/11 06:17 AM

As you can see in my other post, the Charger has been sidelined. I'll try again to contact PST and see what they have to say about them and hopefully get them to either take them back or hand pick me a pair.