looking for some suspension references

[jin1481]

If anybody has or knows where to find a diagram or something that points out all the suspension parts on the LT1 Camaro it would be awesome. I want to start researching future purchases and basically get to know a little more about my car and how it works.

[Tru2Chevy]

I don't know of any diagrams, but the suspensions are fairly simple to explain.

How much do you know?

Front has upper and lower A-arms, with a coil spring and a strut
Rear has lower control arms, torque arm, coil springs, and shocks.

There is also a sway bar on the front and rear.

If you do/don't know what/where those things are, post back up and I'll explain.

- Justin

[Tru2Chevy]

Disclaimer: I don't know your level of knowledge, so I'm making this as simple as possible.....


Here's part of the rear suspension under my '87 (same design as your LT1 car):



The red piece in the center is my BMR torque arm. That is connected to the rear and the transmission.

The light blue part that's off to the left just inboard of the rear tire is one of the rear lower control arms (LCA). There is another one in the same spot on the other side.

Just to the right of the LCA you can see a thin strip of yellow. That is one of my rear shocks. Again, there is one in the same spot on the other side.

The black/rusty u-shaped stamped-steel bar going horizontally across the back (behind the axle) is the panhard bar. That centers the rear axle under the car.

- Justin

[jin1481]

thanks thats very helpful, i know a little bit just needed a little help in understanding where it all went. most of what ive picked is from websites trying to sell it so its cool to see it in place.
if you dont mind breaking down further each piece and what it does that would be really helpful too. I have a basic grasp of what each piece does but it would be nice to know why and when i should upgrade a part.

[Pampered-Z]

I’ll take a shot at this. I think I can cover the basics ( plus I'm on another 4 hour conference call and board out of my mind! ).

The rear suspension is made up of few different parts. A 3rd and 4th gen have what is basically a 3 link suspension.

First, all of the factory parts are stamped steel, rubber bushings/grommets. Adding additional HP or traction and normal wear and tear over the years cause the parts to loss their effectiveness. Basically the rubber deteriorates and the stamped steel bends. Also the factory is giving you more middle of the road settings. They are giving you fair traction, handling, ride comfort and limit road/suspension noise. So changes that add to one will detract from another. So after market is stronger and used poly bushings that give better control, but making your car hook or corner better will often effect ride comfort. A drag racing suspension is not meant to corner well, and a road course suspension isn’t good for drag racing.

For the sake of making this easy, all aftermarket parts will have poly bushing which are better then rubber, the trade off is the since poly is “stiffer” so does the car ride become stiffer as more parts are added. But hey, Who bought their F-body for a smooth ride?
Spherical ends replace poly, are more pure race, harsher ride, more noise. How much is too much is personal preference!

1) Torque Arm. It’s basically a lever to apply the engine power and somewhat uses the cars own weight car back onto the rear, mostly it keeps the rear/trans aligned. This is a piece that mounts to the rear center section and to the trans. As you apply power the front facing part of the rearend or pinion wants to rotate upwards. In effect the power is rotating the rear instead of the tires. The torque arm keeps the rear at the proper angle and helps the power go into rotating the tires, nor the rear. A stock unit keeps the factor setting which I think is around -1 degree? This Pinion angle is the difference between the output of the transmission to the angle of the input to the rear (or yokes ). The U joints allow the drive shaft to rotate smoothly with each end at a different angle. The more angle you have the more stress you place on the joints. At a point the stock stamped steel can deflect or bend causing you to loose traction or not apply the power as fully to the rear wheels. An after market unit is stronger, and many are adjustable so you can change the pinion angle. As an example, at -2 or -3 degrees you can get better traction, but you add wear to you U joins.

2) Lower Control Arms (LCA) The control arms locate the rear front-to-back, keeping the rear tires square with the front tires so the car tracks straight. Again, as you add power the wheel getting more traction will want to move forward faster then the other wheel, in effect twisting front to back. They are also a pivot point for the rear. And again, worn rubber bushing can cause bouncing and such. Problems with wheel hop can occur. Again, aftermarket are stronger some are adjustable, but adjustable have a special use, moving the rear forward/backward effect the driveshaft length. If you don’t need adjustments, don’t but them!

2A) Because the LCA is the low pivot point, if you change the car height (lowering springs) or have added power you may want to change the pivot point. LCA relocation brackets are installed to allow you to do this. Lowering the pivot point will reduce the deflection as the rear rotates as you move the pivot point further from the axle.

3) Pan hard rod. There are actually two, an upper and lower. The key one is the lower. The lower pan hard rod is used to center the rear right to left and is a pivot point based on the height of the car. Again, as the car lifts or squats, or is lowered the pan hard rod will move the rear side to side. After market allow you to adjust the rear better.

4) Sway bar. Controls the roll or pitching of the body. It keeps the car from leaning to one side and somewhat front to back. In straight line racing, the front sway bar is not so important, most remove it. But the rear still has value as it assist in keeping both rear tires planted equally. Most stock sway bars are hollow and bend/flex. After market and solid. Much stronger and some use alternate mounting locations. In the case of something like an S+W swaybar, allot better control, less ride comfort.

5) Shocks/Springs: Springs soften the ride and keep the car at a certain height, the shocks dampen the bouncing. In straight line racing, you want the front soft so the car “rocks back”, known as weight transfer. This is to help plant the tires. The rear shocks should be firmer. Now, there is a line you can cross. Not enough of this transfer and you don’t get as good traction, too soft and the car can bounce and loose traction. After market shocks and springs allow you to adjust and fine tune this movement.

Not a factory piece, Spring air bag.... If you even watch a car launch the body tend to lean towards the passenger side, the torque is twisting the car and basically lifting the driver’s side off the ground. A cheap trick is to install and air bag into the passenger side rear spring. This helps to keep the spring from compressing as much, keeping the car more level.


Hope this helps and makes some sense?

JB

[jin1481]

that was very helpful thank you.

Another quick question i just installed the slp eibach lowering sport springs but my car didnt look any lower after i left it to go back down to north carolina, which was about a week after installation. Is it normal for a car to take longer then that to settle, if not is there a way to adjust the ride height with those springs and its my fault for not instructing my mechanic to make it lower.

[Pampered-Z]

Originally Posted by jin1481

that was very helpful thank you.

Another quick question i just installed the slp eibach lowering sport springs but my car didnt look any lower after i left it to go back down to north carolina, which was about a week after installation. Is it normal for a car to take longer then that to settle, if not is there a way to adjust the ride height with those springs and its my fault for not instructing my mechanic to make it lower.

First, no there is no adjustment, also it shouldn't really settle, at least nothing that noticable. Nothing you did, not your fault. YOu should check how much the springs are suppose to lower the car. I have the SLP performance springs and they lower it about 1/2".

[jin1481]

ok, they said up to an inch on slp's website

[BonzoHansen]

As usual, Sliderule is right: "A drag racing suspension is not meant to corner well, and a road course suspension isn’t good for drag racing. "

Drop estimates are always just that - estimates, and that is from new OE, not 50k mile worn springs. It all depends on the car itself - weight, etc. Comparisons from the 'before' height can be tough since the old springs may have sagged.

IDK if 4th gen springs have any weird tapers to deal with, but they may need to be removed, trimmed and reinstalled until desired ride height is achieved. This is usually done in ½ coil increments because you can always remove more spring but you can never put material back.

For street cars/daily drivers, be careful you can lower the car too much and create clearance issues (speed bumps, potholes, etc.)

I have never researched 4th gens so I don’t know what is out there, but I don’t like poly in rotational applications like lower control arms. Poly will bind (i.e. noise) and wear oddly due to lateral load. It is fine for items like sway bar bushings. The less the car is driven the less poly is an issue. . I prefer solid greaseable bushings. My 77 and Scooter’s 3rd gen have Global West solid LCA greasable bushings with delrin inserts. Zero noise, zero deflection, next to zero impact on ride quality (due to free movement) and excellent wear if greased properly. But 4th gens don’t have stamped lowers, so again I am out of my realm or experience.

http://www.globalwest.net/

Just don’t buy right from GW, their service is terrible. Try Jegs or ATS.

[Mike]

some good pics of rear suspension

[jin1481]

cool, thanks