torque arm

[6spdmalibu]

Hmmm.
I am planning on putting a decoupled torque arm set up into my Bu,
and am wondering if it would be simpler to take a mid 90's camaro rear suspension and graft it into the malibu?
As most know they have different suspension, spring and shock location mounting points.
But the after market support for handling is better for the f body.
Or would it be better to retain the g body lower rear arms, with some custom mounting brackets to allow for adjust ability on the frame and axle side for roll under steer. Fabricate a custom mounting bracket that utilizes the upper "ears" on a 8.5" rear that would mount the torque arm and a telescoping arm for braking. And then use a watts linkage for center location that would allow for roll height adjustment?

Would like to make this car able to pull as close to a G as possible eventually.
Since the rear suspension will be harder to get to, I'm concentrating on it first.

thanks, jerry

 

[Norm Peterson]

OK, I think we're on the same page as far as braking is concerned.

Let me suggest that whatever crossmember used to resist the torque arm loads be made fairly rigid. Any deflection in the crossmember will tend to become a vibration, in which case wheel hop could follow. I doubt that this would happen over an unsupported crossmember length of a few inches (i.e. tunnel width plus a little), but could happen with a relatively shallow beam tied only to the two main frame rails especially if the torque arm is a short one.

It's a good solution, but there will be a "teething period" where you get to sort out what happens as the decoupled torque arm shifts its load from the arm to the link and vice versa. You don't want it to bind up, but you don't want a "gap" where neither the arm nor the link is loaded either. These effects have to vary as the suspension moves in bump/rebound.

FWIW, approaching 1g is mostly a matter of having the right tires on wheels of adequate width and keeping the outside front tire somewhere near zero camber or a tiny bit negative dynamically. Slalom performance or Motor Trend's "figure 8" perfornance are perhaps better indicators of how readily available that grip actually is.


Norm

 

[LS6 Tommy]

...it works well except for the rub at full lock.

An IROC or WS6 steering box will eliminate that.

Tommy

 

[6spdmalibu]

So any suggestions on torque arm length (guessing a minimum of 30")?
Whether to use converging arms or parallel when viewed from the top?
Any positive or negative affects each have over the other?
Will fabricate brackets to lower and raise mounting points for further tuning.
And of course the brake link. How much travel should the telescoping arm have?
Guessing that that would probably be dependent on the length of control arms?!

Have a spare frame and body that I'll be experimenting with mounting the body directly on the frame.
Will be checking what and how (if at all possible) will take to mount it directly. Even if that eventually means welding the body to the frame. After measuring a few body mounts, figured that it will drop the body approximately an inch. A cheap form of lowering the center of gravity I hope. Though will lose a precious inch under the hood and floor boards though. So still trying to determine if I'll pursue that route. But should make it easier to install a roll cage eventually. Basically make it a unibody.

That is why I'd like to figure out what the basic plan for laying out the suspension would be.
As I could figure out what will be practical to implement under the stock body work with minimal modifications.

My first thought about fabricating a cross member, puts it just behind the foot wells of the rear passenger area. The cross member would be similar to the GNX style but connecting it to the pinion bump stop area, after room modifications for upper link. Now because the control arms with the brake arm should converge as far ahead of the car for minimum brake hop, from what I understand. What would the minimum mounting separation between the links should be? I know the further apart they are the less stress/leverage that gets applied to them.

I'll probably mini tub the rear wheel well area for eventually larger stickier tires.

Thanks, Jerry

 

[6spdmalibu]

...it works well except for the rub at full lock.

An IROC or WS6 steering box will eliminate that.

Tommy

Thanks Tommy. Currently have a camaro 12.7:1 ratio box now. Probably same thing?
But I'll worry about the front later.

Thanks again, Jerry

 

[LS6 Tommy]

...it works well except for the rub at full lock.

An IROC or WS6 steering box will eliminate that.

Tommy

Thanks Tommy. Currently have a camaro 12.7:1 ratio box now. Probably same thing?
But I'll worry about the front later.

Thanks again, Jerry

That may be a "WS" box. It's 12.7:1, for 82-92 non-16" wheel F-bodies like Z28 & Formula. The "XH" box is also 12.7:1, for the 82-95 IROC/WS6 cars. It has a slightlty higher effort & the internal stops are set for the 16" wheels, so it has a slightly lower max steering angle to keep the tires from rubbing.

Tommy

 

[6spdmalibu]

Tommy, I was thinking of drilling out the steering stop rivets on the lower control arms and re-mounting them to stop the tire rubbing.
Although that might change once I get to the front suspension. But once I'm there, the first thing I'll be doing is checking the camber curve, bump steer and ackerman angles. Basically check the overall suspension set up prior to deciding what and how to arrange or change it.

Norm, forgive my enthusiasm. I understand that the car can only be as good as the rubber that is contacting the ground. But if the suspension is not allowing the rubber to do its work, or fighting what the driver is trying to do with the car. Then some changes must be made. The reason why I am so adamant about the decoupled torque arm is to bring the roll center lower. And also because for packaging reasons and the inferior stock design limitations.
Will post some pics and dimensions in the near future, still have some research to do.


Jerry

 

[LS6 Tommy]

Tommy, I was thinking of drilling out the steering stop rivets on the lower control arms and re-mounting them to stop the tire rubbing.
Although that might change once I get to the front suspension. But once I'm there, the first thing I'll be doing is checking the camber curve, bump steer and ackerman angles. Basically check the overall suspension set up prior to deciding what and how to arrange or change it.

Jerry

That works OK in a snap, especially with manual steering, but we did that on the race car after we went to power steering to try to eliminate front tire rub & should have left them alone. After we reinstalled the stops, we couldn't get them to stay put. The rivets kept breaking off if Jeff turned the wheel too far. We ended up have the stops in the box set up for the car.

Tommy

 

[355_79bu]

not on topic but found this for your b body spindles to correct bump steer.

http://www.lefthanderchassis.com/67.html

1/2 way down the page there is a centerlink with adjustable ends . Hope this helps out .

thanks thats what i've been looking for!

Unfortunately,Those adjustable centerlinks do not have enough adjustment to eliminate the bumpsteer issues with b-body spindles. They only give you .25" of height adjustment whereas you need around .625". I made my own adjustable centerlink to fix this. see pics below

 

[LS6 Tommy]

Unfortunately,Those adjustable centerlinks do not have enough adjustment to eliminate the bumpsteer issues with b-body spindles. They only give you .25" of height adjustment whereas you need around .625". I made my own adjustable centerlink to fix this.

Any thoughts of selling those? I don't have much in terms of fabrication skills, but I'd love to be able to tune out some of the inevitable bumpsteer associated with the B-body spindles used with my GW suspension stuff.

Tommy