Torque arm, worth it or not?

Hey guys. I currently have a stock rearend, but I will be getting a 12 bolt one day, and I've heard some torque arms are not compatible with the aftermarket rears, some break the transmission mount... Should I wait to get one, or what? Mods are in my sig, and I still can't get the traction I need. What next? Opinions needed, thanks.

Is the car doing something you want to fix, like axle hop or excessive wheel spin? If not, I wouldn't try to fix what isn't broke.

Excessive wheelspin, axle hop. Take your pick. Anytime below 31 that I floor it, the rear swings out from behind me. i.e. tries to go sideways. Let alone from a stop, and trying to put the power to the ground. So what do you guys think? Should I get a torque arm now, or wait until I get a 12 bolt? Should I just get some Drag radials or what? I'm open to suggestions, so please help. You know where I can pick up some CHEAP rims for the rear just for the track? Thanks.

ttt

The stock Torque Arm is a VERY long & Very Large Spring, that is why when you try and recover from a large drift in one direction, the car not only corrects but whips around so hard that most people OVER correct and more often then not, spinout. The Torque Arm is designed for Bound & Rebound in and Vertical Fashion, and for that it does wonders. But in tight turns it is being forced to work horizontally or laterally, this is something it does Not Do Well.

Here is a visual. If you take sword and use it the way it was intended, like slashing at something, well, you could do some real damage to someone or something. But, if you turn the blade 90 degrees and slash with it in the same direction, when you hit something it will just wobble around, same basic concept with the Torque Arm.

Another problem with the unwieldy Torque Arm is that under heavy/ tight turning it can allow or even pull the inside wheel off of the ground, making the power going to that wheel less effective, and with an LSD it will increase the power to the one wheel with good traction there buy over loading it with power. Then, around you go.

Most after market Torque Arms allow for a much greater range of movement and strength, in all directions. And allow the rear end to be planted much flatter. So in that respect the After Market Torque Arms do add traction. But I suspect, not the kind of traction you are referring to. I would recommend a set of LCA relocation brackets, which correct a great deal of suspension geometry especially when the car has been lowered. This moves your instant center forward and will help launching far more than a Torque Arm. But I do highly recommend a Torque Arm To Anyone with an F-Body.

I bought a MAC Torque Arm for 200.00 from them directly and it was the stoutest piece I have seen produced YET, Bar NONE! But it is a hefty undertaking and I would definitely have a shop or someone with a Lift and a good deal of time to install that particular Arm for you. It is a B*tch to get it in, but once you do, you will notice a difference.

Combine both of those pieces and you should have a combo that hooks and keeps it planted in the turns.

Hope this helps.
:D

Huh?

Originally posted by TransAm SR71
The Torque Arm is designed for Bound & Rebound in and Vertical Fashion, and for that it does wonders. But in tight turns it is being forced to work horizontally or laterally, this is something it does Not Do Well.

You are correct in that the torque arm would do a very poor job of resisting lateral forces required to laterally locate the axle. Very poor is putting it mildly--it couldn't do it.

Luckily, it doesn't have to. The PHB locates the axle laterally. You would need to completely fail the PHB and/or its mounts for the TA to see any of that lateral force. Even then it would only see a small portion of the load as the inner fender would take the brunt of it when the tire rubbed against it.

The only sort of lateral force the TA will ever see is from axle steer during body roll when the roll axis is not parallel with the ground. This will "point" the TA askew from the CL of the car making the tip of the arm want to move laterally accross the car.

Luckily, as you have pointed out, the stock torque arm is very flexible in this direction so it will resist this conflicting geometry with a very minimal force--no significant bind.

The torque arm is there to react the torque of the axle. Nothing else.

Originally posted by TransAm SR71
Another problem with the unwieldy Torque Arm is that under heavy/ tight turning it can allow or even pull the inside wheel off of the ground,

Uhm, no. When under acceleration, the torque arm can only press the axle down, into the pavement. Just like it is designed to do.

Only a poorly designed aftermarket torque arm (of which there are many) that causes a bunch of suspension bind can contribute to the lifting of the inside rear exiting a corner.

Originally posted by TransAm SR71
I would recommend a set of LCA relocation brackets, which correct a great deal of suspension geometry especially when the car has been lowered. This moves your instant center forward and will help launching far more than a Torque Arm.

Actually the only way to move the IC forward or back is to change the length of the torque arm. LCA brackets will move the IC up, not forward, as well as changing the angle of the roll axis.

Originally posted by TransAm SR71
I bought a MAC Torque Arm for 200.00 from them directly and it was the stoutest piece I have seen produced YET, Bar NONE!

The Mac arm will increase bind in roll and is not something I'd put on my car if I cared about handling.

I really don't mean to sound like I'm picking on you and I appologize in advance if you take it that way. But you've really gotten a bunch of bad information from somewhere. I'm just trying to keep it from spreading.

Uhm, no. When under acceleration, the torque arm can only press the axle down, into the pavement. Just like it is designed to do. Only a poorly designed aftermarket torque arm (of which there are many) that causes a bunch of suspension bind can contribute to the lifting of the inside rear exiting a corner.

Um, No. My reference was only to turning and not to acceleration. And in a HARD turn (as I said before, which would usually include braking) I have not only seen the inside tire lift off the ground W/ stock components, but I have had it happen to me. And as far as poorly designed aftermarket TA's your right, they can bind, especially if they are not allowed to twist, which the stock TA can not do.

The only sort of lateral force the TA will ever see is from axle steer during body roll when the roll axis is not parallel with the ground. This will "point" the TA askew from the CL of the car making the tip of the arm want to move laterally across the car.

Like I said, in a turn, usually there is body roll in a turn. That would cause the axis to not be parallel with the ground. And you are right; the TA is askew from the CL. And that is the lateral force I speak of.

Actually the only way to move the IC forward or back is to change the length of the torque arm. LCA brackets will move the IC up, not forward, as well as changing the angle of the roll axis.

Maybe, just Maybe your the one with the "BAD Information". IC is where the two (imaginary lines) drawn from the Upper And Lower Control Arms meet. And In a standard 4 Link (which we do not have) if you increase the angle (not the length) of the Upper Arms or the Angle of the Lower Arms you can more effectively move the IC forward or back. Length is used only when location cannot be changed. Ever seen the 4 link setups on REAL drag cars? Length Matters, but location can affect the IC much better.

As to our bastard cousin, the PHD & TA funky 3 link rear end. The TA is used in place of the upper control arms, and the lower control arms are pretty standard.

Think of a triangle, if you increase the length of any two sides you decrease the angle at which they meet. If you decrease the length you increase the angle, bringing that point closer to the 3rd line.

If you tip that same triangle on its side so that one side is perpendicular to the ground (almost like an arrow head pointing off into space), and you consider that the top line pointing down is the TA and the bottom line pointing up are the LCA's then increasing the length will only push the point at which they meet farther away. But if you lower the point at which the LCA's contact the axle, you bring the IC closer to the rear axle. The TA will always be parallel to the CL of the car, but the LCA's are not.


And in closing, the MAC TA is 2 piece, and at the contact point to which it create to the body of the vehicle these two pieces slide together, this allows the body roll to not pull the TA off of the CL of the car, or let it go askew. It does not bind one bit; this is something that I can personally assure you of.

In anticipation of an excepted retaliation in Terms of Physics, I think the point is getting lost. We should simplify. A new TA would help; make your own decision on which one you want. Anything would be better than what the car came with. And even if you don’t get the desired effect, you should show some improvement over stock.

People fight long and hard over stupid issues like this. And there will always be someone who thinks they understand it better than the next. Regardless of what anyone says here, the decision will be left up to Michael Ozorowsky, as to whether he wants to change his current set up.


As to this subject. I am done. Trust whom you want and Good Luck.
:) :) :)

I second Jon's opinion, the torque arm is there to control the rear end torque, preventing squat during acceleration and preventing dive during braking.

Lateral forces are controlled with the track bar or panhard.

The relocation brackets correct pinion angle and maintain proper roll axis and also maintains proper wheelbase.

The amount of stress to the tranny mount is not as excessive as you think. The force vector decreases because the arm is quite long. There are people running alot of hp with a stock arm and in cases where they have bent the arm, it was close to the pumpkin where the highest amount of forces exist (torque rotation of the pumpkin).

A stronger stock style arm is a very choice since it prevents any flex in the arm. Also it is vital that there is no bind at the arm pickup point. It must be able to (like stock) to move in/out and rotate on all axis (x,y,z).

Steve

Originally posted by TransAm SR71
Maybe, just Maybe your the one with the "BAD Information". IC is where the two (imaginary lines) drawn from the Upper And Lower Control Arms meet. And In a standard 4 Link (which we do not have) if you increase the angle (not the length) of the Upper Arms or the Angle of the Lower Arms you can more effectively move the IC forward or back....Think of a triangle, if you increase the length of any two sides you decrease the angle at which they meet. If you decrease the length you increase the angle, bringing that point closer to the 3rd line....But if you lower the point at which the LCA's contact the axle, you bring the IC closer to the rear axle.

In anticipation of an excepted retaliation in Terms of Physics, I think the point is getting lost.

No need to fight long and hard.... But I will give you your retaliation in terms of Physics. ;)

The side veiw instant center is not found the same way on a Torque Arm suspension as it is on a 4-Link or 3-Link.

THIS (http://www.JonAadland.com/Ta.jpg) is where the IC is located on a Torque arm suspension.

As far as the other stuff, an F-body that lifts a rear tire off the ground certainly has something wrong with it, but it isn't the stock torque arm. I'll go into more detail if you like.

Cheers.

Originally posted by TransAm SR71
The stock Torque Arm is a VERY long & Very Large Spring, that is why when you try and recover from a large drift in one direction, the car not only corrects but whips around so hard that most people OVER correct and more often then not, spinout. The Torque Arm is designed for Bound & Rebound in and Vertical Fashion, and for that it does wonders. But in tight turns it is being forced to work horizontally or laterally, this is something it does Not Do Well.

Another problem with the unwieldy Torque Arm is that under heavy/ tight turning it can allow or even pull the inside wheel off of the ground, making the power going to that wheel less effective, and with an LSD it will increase the power to the one wheel with good traction there buy over loading it with power. Then, around you go.


A torque arm is essentially a spring. However the things you describe just don't happen. And a torque arm certainly does not cause car the spin. That is down to the very poor shocks installed on the cars and the fact they car has a solid axle. There is NOTHING WRONG WITH A STOCK TORQUE ARM for handling.... ask me how I know..... I've only won a lot of National SCCA autox's with a stock torque arm, even when I was allowed to change it.
;)

The pulling the wheel off the ground is not the fault of, nor has anything to do with the torque arm. First, the shocks act as droop limiters (jack the car up and disconnect the rear shocks and drop the axle, just watch how far it'll drop). Second a larger than stock rear bar will pull the inside rear tire off the ground under REALLY hard cornering, which is one reason I dont' use much larger than stock rear bars (front is a different story). Third, I'd be very surprised if you acutally go the inside rear up off the ground on the street. The only time this happens is on autox cars with r-compound tires while trail braking (again, first hand experience). The TA doens't work laterally (though it's a good sales pitch). The "triangle" you refer to in a later post is essentially the LCA's and the panhard bar. Think about it, the TA is mounted in the center of the axle, when the car rolls around the axle, the arm simply doesn't move. And a TA is different than two upper control arms. They can and do cause some bind if poorly designed (think Mustang), something an F-Body isn't suspect to.

I think he has the right thing in mind as far as IC location is concerned. He is just confusing the IC location with the fact that the control arm angle effects anti-squat.
The IC will be at the mounting location of the TA and then the intersection of the LCA and TA mounting point. If the car is lowered too much the angles get out of whack (duh:) ) and the IC moves down. Not really back or forth. Then that effect anti-squat. AS is a line drawn from the center of the rear tread to the instant center location. Small angle = very little anti-squat. Large angle = +anti squat.
My car has 315 R compound tires and is set up for ESP competition. It has a stock TA and has never lifted a rear tire of the pavement.:p

I'm not sure why you're discrediting the 3 link + tq arm suspension, I mean Griggs Racing ditches the 4-link for
to use the 3-link + tq arm on the mustangs.

He quotes:
Rear upper control arms whose function is to locate the axle housing laterally as well as control it's rotation (they don't do either very well). They give the car a very high rear roll center, and bind as the car leans into a corner. The binding causes a sudden increase in the wheel rate that results in the Mustang's characteristic "snap" oversteer.

So in a mustang it's a definite detrimenting factor. Especially since the mustangs front roll center is very low, and in-turn you have a very steep roll axis (front to back).

Changing IC with a short tq arm is usually what all these aftermarket companies are doing (BMR, SPohn, Globalwest), and i've experienced the feeling of the these short arms. Basically it causes the car to act differently and shifts its weight differently. Reaction times are indeed different as well.

The stock torque arm will not create bind or lift an inside wheel, it doesn't make sense. It simply moves up/down and twists. It flexes enough and has that rubber bushing to have plenty of these motions.

If you're having lifting.. it's probably a cause of a poor acting shocks like sam said or bind/looseness in the control arm/panhard due to construction of the member or its bushings.

The panhard controls lateral movement and the control arms control roll steer which is important when the axle is subjected to extreme cornering forces.

I think what Michael is looking for is a dragstrip solution rather than a cornering upgrade. In that case, he might benefit from a shorter torque arm.

This thread got more than a bit sidetracked, starting with "The stock Torque Arm is a VERY long & Very Large Spring . . .", "Um, No. My reference was only to turning and not to acceleration. . . . ", and the text that accompanied each of those replies.

Michael - have you tried posing this question on the dragstrip forum? Not trying to discourage you from the cornering stuff, just that the straight line guys may have some tips that might not necessarily occur to the regulars here.

Norm

I know little to zip about suspension theory, but I have made the following observation: when I switched from a stock to a Spohn TA my 60' times increased markedly.

YMMV.

Rich Krause

Good idea. I'll post in drag racing forum. Thanks.

Originally posted by rskrause
I know little to zip about suspension theory, but I have made the following observation: when I switched from a stock to a Spohn TA my 60' times increased markedly.

YMMV.

Rich Krause

They got worse with the spohn TA? :think:

Originally posted by 96-speed
They got worse with the spohn TA? :think:

DOH, I meant improved.

Rich Krause

Originally posted by rskrause
DOH, I meant improved.

Rich Krause

Ok...wasn't sure since its not uncommon to add a 'performance enhancer' and get slower!

thanks!
Ryan

How hard was the install? How hard was setting pinion? Any other impressions other than 60' performance?

Thanks:bow:

Originally posted by lons94z
How hard was the install? How hard was setting pinion? Any other impressions other than 60' performance?

Thanks:bow:

It was very easy to install. The pinion angle is easy to set, but you need to get the car on a lift that raises it on the wheels (rather than a frame lift) to be able to set it.

There is a noticible amount of virbration/noise from the TA.

Rich Krause

rskrause, what would you say to the hard core drag racers that are running 10's with their stock TA? do you think their time will be faster if they upgrade to a better arm?

edit: sorry to bring up such an old post, i didnt realize it was this old lol