Michael Canfora

Hey guys, i have an 85 iroc z z28 camaro and i am looking to upgrade the suspension for it. i am going to pick up some rear bilstein sport shocks and 4 vogtland sport lowering springs. what else should i look for? I need some in the front but what else should i get

Thirdgen89GTA

iTrader: (5)

You'll receive 30 different answers. So prepare for some arguments.

My recommendations? Before you start going hog wild with suspension goodies consider what it is you are trying to fix or enhance.

Your 85 IROC is now 31 years old. If it has original ANYTHING in the suspension or steering assemblies, you should replace it with either OEM type, or aftermarket upgrades.

Some upgrades offer better handling without any negatives. Other upgrades come with some kind of draw back, usually NVH.

Before lowering the car, I would suggest you take a look at the strut-mounts, all bushings...etc. For the steering recommend replacing the worn items.

Lowering is great, but if you don't fix the slop you won't be able to take advantage of it.

Fixing the slop will make it handle much better than keeping the slop and slapping some upgrades on it.

You can move onto harder parts like Panhards, LCAs, TQ Arms....on and on. But those items are absolutely not necessary if you still have slop from original worn factory parts.

Michael Canfora

So what exactly should i look at? this is really my first time doing anything, and i mean anything with a car this old. I have done routine brake and rotor changes on my daily drivers but they are all post 2000. So I'm learning everything all at once. For one, the steering wheel isnt aligned well or maybe somethings loose because i really have to turn it to get the car moving left or right. Also i have squealing belts from the engine, and my speedometer doesn't work. But as for the suspension, what should i look for to tell if its been replaced or still OEM? I bought this car from a guy who planned to make it a drag car; had the 305 bored to 315 and put a full xhaust SLP system. But after that I'm not sure if he upgraded anything else

Fabrik_8

Woot!! Reminds me of me when I got my first car which was a 77 camaro with a 400 sbc. That car gave me the knowledge I have now so to speak. One thing I learned about replacing suspension components is to.change out the lower ball joints first. If they fail its not fun. And while your at it. Change out the control arm bushings. And while your at that, change out the shocks and so forth. Just my .02.

MoJoe

iTrader: (5)

Rag joint, steering box, or any/all of the linkage. With the car NOT running, have a friend turn the steering wheel backhand forth while you watch the shaft and linkage under the hood... Where does the slop / movement take place? At the rag joint? Does the steering dos input turn, with little to no movement in the arm? Does the linkage move around without moving the tires? That tells you what needs replacing.
Rock auto (IIRC) has a kick to replace the whole front linkage: inner & outer tie rods (x2), adjuster (connects tie rods), center link and idler arm.

On a 30+ year old car, most/all of the suspension bushings will likely need to be replaced.
The rear lower control arms (abbreviated LCA) and pan hard bar in the rear are the easiest.
Torque arm mount at the transmission, along with the trans mount.
Front lower control arms ( have to deal with removing the front springs).
Struts, upper strut mounts.

As for other upgrades, subframe connectors (SFC) are always a good choice... UMI (site sponsor), GlobalWest (my choice), Top-Down Solutions (Lon) is a site regular with at least the "inner" style, Spohn.

Thirdgen89GTA

iTrader: (5)

Unless you are intending on tracking it like at an auto-x or HDPE stuff just get the OEM rubber bushings and things. They are cheaper.

I spent money on the UMI Roto-joint stuff, the Global West Del-A-Lum front A-arm bushings,etc.. a bunch of suspension stuff. But all of the items i chose have an accompanying increase in "Noise/Vibration/Harshness".

Easiest way to find slop is to get the front of the car in the air so the wheels are off the ground and start wiggling things. Bad ball-joints show up as a wobble in the vertical plane (camber change)

Tie-Rods are on the horizontal plane. (wheels seem to wiggle independently of each-other.

Bearings show up as small wobbles in both horizontal and vertical plane. But more so with telescoping movement of the wheel. The bearings are part of the brake rotor, so not hard to replace if you are doing brakes. Just need them greased good, and torqued down properly. I don't remember the torque spec, but its nothing huge.

Steering linkage is easy to look at. Usually its the rag-joint and box that goes first. But the idler arm is suspect.

Its basically a game of connect the dots. Find the dots and see if the parts wiggle together, or apart.

plum92_camaro

I agree with everything thirdgen89GTA says. I believe his suspension is very similar to mine. I'd like to add to his advice, I don't recommend poly bushings anywhere except on the swaybars.

When choosing springs the most important thing to look at is the spring rate. Linear/constant rates are better for performance than progressive/variable rates which are better for loads. Find out what your stock rates are and make sure the aftermarket springs are the same or higher. An example would be, IIRC stock front IROC springs are around 700#, Hotchkis front springs are 600#, they are actually a downgrade for some thirdgens.

Thirdgen89GTA

iTrader: (5)

If your car rides stiff as hell, then yeah, they are probably the same. The Roto-joint stuff is great. But its also a good thing my car is so loud, or I might have to complain about the cabin noise from the joints. But the accuracy is awesome.

plum92_camaro

Yes it does! lol. My set up is in my vB garage. I have dynamat, it helps a lot with the noise. My suspension has helped me hurt a lot of feelings at autoX with only a 305tbi! I've only started on the rear suspension since I've done the LS1 swap. It's back on the road but haven't tracked it yet.

Tibo

iTrader: (15)

Buy a steering rebuild kit for the front, replace all the components and have it aligned. Do lower ball joints at the same time. I wouldn't replace the stock rear control arms bushings, I'd throw the whole piece out and buy the aftermarket package often sold of the rear lower control arms and panhard rod. Get an adjustable Panhard rod for when you lower it to recenter the rear. At the same time as that buy control arm relocation brackets.

SOCAL-Z

Check out www.foundersperformance.com for control arms,springs etc.