Strokemyaxe

I'd first like to say that if you came here looking for a performance review, you will not find one. That's largely due to the fact that the sway bar never went under that car.

Earlier tonight...

I began the install just as anyone would by pulling out the parts and inspecting the install notes. Although the notes themselves are extremely confusing, the visual diagram makes understanding the configuration fairly easy. I began to jack up the rear of the car (mistake one). After getting the car in the air, I attempted to install the lower brackets that hold the end link to the trailing arms. With the car in the air and the suspension fully unloaded, the rear spring bolts are torqued at a large angle (pushing the top of the spring bolt up, protruding into the path of the lower bracket. So I bring the car back down, back it down the drive way to let the tires settle in and pulled in for attempt two.

Now with car sitting on all four tires I flip over on my back and shimmy up the rear towards the driver trailing arm. First lower bracket goes into the hole just above the spring bolt, and I get three to four full threads of each screw into the bracket. Success! I shimmy on over to the passenger side and find that I"m still unable to get the bracket into the trailing arm due to the inability to slide the bracket far enough to either side of the spring bolt to get it inside the trailing arm end. Well $#!t. What to do now... Well it doesn't look like it needs much more room, so I'll give it a little tap with a hammer (mistake two) on past the spring bolt head. Grab a hammer. Tap Tap tap. In the hole she goes! Great, so now i begin threading the bolts into the nuts, or so I tried. After struggling with the forward most bolt for about 10 minutes, I realized the bracket itself was too long inside the arm, hitting the curve of the trailing arm and kicking the bracket ever so off center to where the bolt would not thread through the welded in nut.

Well, now I'm in it. I just hammered in this bracket past a bolt, inside the trailing arm and I come to find out the bracket needs a 1/4" of material removed from one end. I wrestled this stubborn, overgrown piece of metal for about 15 minutes in frustration before my lovely wife comes out to tell me she is turning in for the night. Well, they say the solution comes when you take a step back and sure enough it did. I realized I could just jack the driver front corner up into the air, load up the passenger rear suspension and cause that spring bolt to torque the direction I needed it to torque to get the bracket out. Pull the ebrake, jack up corner and out comes the bracket.

Grind grind grind. Paint paint paint. Dry Dry Dry. Back in she goes.

Both bolts thread in with no problem. Snug them up as good as I could with the socket I had on the ground and all donet! Or, so I thought...

Moving back over to the driver side I began to tighten these bolts up too. Rear bolt snugs up like it should. Snugging up the last bolt of the lower brackets and about 1/3 of the way threaded, the bolt strips out! Now, at this point, I'm hotter than a jalapeno's armpit. I've learned to curb my linguistic enthusiasm for four letter words 6 months ago when my daughter began speaking for the first time. So I sat, frustrated in silence for several minutes thinking about this whole ordeal. I didn't get more than about 10ft.lbs on this bolt before it's threads shred to pieces. But I realized, I can only blame myself at this point and here is why...

Now what I didn't tell you is that right away, I could tell that the hardware and these bolts were complete crap quality and of a large variety. High chromium content, multiple different acid pacifications and machinings (Probably from different vendors, but inconsistent nonetheless). Washers (a set) were 3 different sizes too and NOTHING in this kit was a Grade 8 bolt. These are performance suspension components that see a LOT of action and stress on the threads. for $145, a handful of Grade 8 Bolts should be in that set (An opinion, I know). All in all, the signs were there that this hardware was junk. Well, I figured if everyone else has installed these bars, they must have been at least usable. Well I often prove my hunch's correct by ignoring them. What can I say, I'm stubborn....

I should also mention that the powder coating was missing in several spots from the bar itself. Like that just laid it in the over and didn't even hang it.

Oh, well. Returning to Summit tomorrow. I guess I'll be calling Van Steel too and give theirs a shot.

-Stroke

http://addco.s3.amazonaws.com/wp-con...012/03/907.pdf

ramair_bryan

I had a diffident brand but I know your pain.
All these rears are a pain to install.........get it,.... rears.....
.never mind.
I ended up having a fat chick sit on the deck lid.
Bolted right up.................

jb78L-82

First off, without pictures it is difficult to understand the issues you were having installing an aftermarket ADDCO rear sway bar.

I would not use an aftermarket rear bar on a C3 since those bars do not use the OEM GM style endlink that was used by GM on the BB cars and the SBC C3's like mine with the gymkhana sport suspension option.

The GM style endlink on the rear bar was specifically not the same design by GM as the front sway bar endlink for a very good reason....

Use a 7/16, 9/16, or 3/4 OEM GM Designed endlink rear bar if you are going to use a rear bar.

I use this 3/4 OEM type rear bar with my front OEM 1 1/8 inch sway bar:

​​​​​​https://www.mamotorworks.com/Corvett...le-34-602628-1

Bikespace

It wasnt cheap, but it is possible to collect all the rebuilt or repro pieces for the OEM style bar. The only piece not readily available is the 7/16" or 9/16" bar. 3/4" is available new, as jb78L-82 mentioned, or you can find a used one.

jb78L-82

The 9/16 inch OEM GM style rear sway bar is available form various vendors:

​​​​​​https://www.corvettecentral.com/c3-6...f%3fcount%3d18

​​​​​​http://www.corvettepartsworldwide.co...ch_p/36931.htm

https://www.zip-corvette.com/68-74-r...-sway-bar.html

​​​​​https://corvetteparts.com/item/sway-...hoCr5wQAvD_BwE

i believe the last 3/4 OEM sway from the C2 will fit as well on the C3 since the chassis are the same...no difference

Bikespace

Thanks! Somehow I missed that when I looked, but was fortunate enough to find a used 9/16" bar.

Still, doing it the right way isn't cheap, but you know it will fit and function.

OldCarBum

When I went through Van Steel for all my suspension parts, Dan, suggested sticking with the OEM rear sway bar on my 73 BB car. He said that for street or occasional track use the OEM size bar is perfect and the other plus is that it is designed for the car and allows the use of the spare tire and cover to be retained.

jb78L-82

Any of the OEM type sway bars will fit with the spare tire carrier in place...The sway bar does not interfere with the tire carrier at all. I replaced my OEM 7/16 bar with an OEM type 3/4 inch rear bar and there is no issue.

Most BB cars had from the factory a 9/16 OEM GM style rear bar to help dial out some of the inherent understeer that the BB c3's exhibited with heavier engine that was also more forward and higher than the SBC C3's. Also, keep in mind all C3's from GM understeered at the limit as part of the corporate policy and the BB C3's had either a 15/16 inch or 7/8 inch front bar. Even with the smaller front bar than my 78 gymkhana suspended C3 which had a 1 1/8 inch front bar (BIG) and a 7/16 rear bar. Probably the ultimate setup for a BB car would be the bigger front bar and a rear OEM style 3/4 inch rear sway bar.

The most neutral setup for a stock SBC C3 would be roughly a 1 1/8 inch front bar with the 9/16 inch rear OEM type bar since the SBC C3 with the sport suspension understeer as well with the rear 7/16 inch bar (its too small for optimal balance IMHO.

Strokemyaxe

Thanks for the rec. Yes, I know that it is confusing without detailed pictures. I guess I could post the install notes. They are online.

Strokemyaxe

How do you get her to stay in place on hard cornering? :P
Why is the original mounting hardware not reproduced? Seems that if it is superior it would be made regardless of price. We will pretty much pay anything for good OEM parts. lol

Do you have a confirmed and accurate picture of what the linkage hardware looks like? I may be able to have it machined/produced.

I spoke with Van Steel a few minutes ago and ordered a new front sway bar. They recommend a 1 1/8" bar up front without a rear bar for street/light autocross. Performance alignment to match the desired use too. They can provide recommended specs and even find you a suitable shop to do the alignment. They strongly discourage putting on anything in the rear before thoroughly testing on the road with the front bar. Also, even with a full autocross in mind, the 1 1/8" bar up front is more than adequate, or so they say.

I am always thankful to be able to learn from these experiences.

jb78L-82

What can I say except my racing experience and my personal experience with my C3 that a 1 1/8 inch front bar only on a C3 is going to understeer like a pig on the street or autocross without a 7/16 inch rear bar or 9/16 rear bar. The gymkhana C3's like m 78 with a 1 1/8 inch ront bar and factory 7./16 inch rear sway bar UNDERSTEERED with moderate speed from the factory. Well documented with articles at the time.....

pauldana

bolded is correct^^^

naramlee

The ultimate rear sway bar was rancho of all people... but thats like gold to get now

i have no idea how the corvette gets overlooked now... Addco seems to be making the bulk of the rear bars from what i looked at, none of the big guys do, hotchkiss, helwig, QA1 (now makes a front) eibach, none of them make a rear

and as pointed out, the attachment style of Addco is WRONG, using eyelet with bushed links on the rear sway bar will introduce binding, there us a reason GM did it the way they did

v2racing

Again I will say I have absolutely no binding with the aftermarket style links on my Van Steel narrow 5/8" bar. I have run the suspension through full travel on each side with the other centered, at its lowest travel and at its highest point of travel. You just have to pay attention to the geometry and have the links in a neutral position when the car is sitting on the wheels. That way it has travel in both directions. We have gone round and round on this many times on this forum. Is the stock type links better, probably. Are they easier to setup, probably. Can the aftermarket type work just as well for racing or street use if properly setup, absolutely!!!

Mike

jb78L-82

Mike,

I am certainly not arguing that the non GM style rear sway bar endlinks CAN be made to work. However, for the uninformed or uninitiated, as you point out if the aftermarket endlinks are not setup properly, as you point out, OR are not used with an adjustable spring loaded endlink, the potential for binding is very real. Logically, just looking at the 2 different styles of sway bar endlinks, there is going to be more resistance through the travel of the swaybar using a non GM rear sway bar endlink. Can it be made to work? Yes, but again, GM, purposefully did not use the same endlink in the rear with the C3's.

One more point, almost no car manufacturer today uses the aftermarket sway bar endlink either in the front OR the rear..There is a reason...potential binding if the suspension movement. My duaghter's 2001 Grand Prix which is 17 years old now, used a traditional front horizontal swaybar endlink on the front bar BUT does not on the rear swaybar...articulated ball joint type connection. Why?

Bikespace

Well, it looks like it is. https://www.zip-corvette.com/65-82-r...k-bracket.html
The Zip link above also has a good drawing of all of the parts you need to do it the OEM way.

I was pretty sure that when I pieced together a complete set, I got some pieces that were not reproductions, but were restored original pieces. Maybe I just looked at them. The pieces I have now appear to be the new repros available from Zip. At any rate, I didn't see anyone selling a complete "kit", but just the individual pieces. That could have changed by now, too.

Superior or not (I'll let others fight it out), there can't be a huge market for these pieces. And for not much more than what I paid to buy everything (which was more than the Addco kit), you could fabricate a fully-adjustable, customizable, race-style setup from parts using heim-jointed linkages superior to the OEM C3 setup.

v2racing

If the earlier comments on the aftermarket links would have been more inline with this last post, I probably would not have chimed in. I pretty much agree with everything you say here, but yours and others post made it sound like the aftermarket type don't work and WILL BIND. Not if setup properly is all I'm saying.

Mike

naramlee

My mustang and s10 run muscle bars anyway for the tuning options, but even they use heims, i need to look at the rear and see what it will take to rework it, it cant be that bad

trying to avoid the rear end untill front/interior work is finished

my deal with bushed eyelets is they are designed with inherent bind included in their design, thats just how they work, it doesnt show up in rubber nearly as much as poly/thermo, which is why you treat them as a size larger sway bar

OldCarBum

I would go with what Van Steel recommended to you.
They advised me to upgrade my front sway bar to 1 1/8" and see how the car handles with all my suspension upgrades and the OEM rear sway bar.
If I feel I need a larger diameter rear sway bar, they can supply me with whatever I need.
They felt going too large of diamenter in the rear to start off with would be a mistake they see many people make as any suspension upgrade can change the dynamics of the system.
Everyone posting here is right for what works for their suspension system and driving needs.
It just might not be right for you and what you need.

The13Bats

There is somewhat of a misnomer that the stock linkage for a rear c3 sway bar is the only one that works and all aftermarket bars are junk,

It depends on the type bar and linkage if it will move as it should or not,

Some aftermarket bars surpass stock because the links are adjustible...