Don&Kelly

I have no rear sway bar on my '81 C3 Corvette now??
I've decided that I want a rear sway bar and a installation kit that should include mounting brackets, bushings , links, washers, spacers, in other words what ever mounting hardware that is needed to mount a rear sway bar to a '81 vette that did not come with a rear sway bar.

I was told to get the 7/16" size because bigger is not better with rear sway bars.

Does anyone know the correct size to get & if there is a installation kit that contains all the parts that I need?

Where should I get them?

thanks

mapman

My 1980 has the FE7 suspension. The rear sway bar is 7/16 inch. I would presume a 1981 with FE7 would have the same rear sway bar.

I am not aware of anyone with a "kit". Perhaps a trip to Carlisle is in order? :cheers:

The folks at Van Steel would put you on the right track. When I rebuilt the suspension on my 80, they supplied the replacement parts for the rear sway bar.

Don&Kelly

Thanks, that's what I was told 7/16" ... now to find one with a kit ... I'll check with Van Steel.

Anyone else have any information?





[Modified by Don&Kelly, 10:42 AM 4/15/2004]

Fevre

You want make sure you fornt sway bar is matched if you are going to run a rear sway bar, the FE7 front sway bar is larger than a stock sway bar. Van Steel will give you the right info.

mapman

Good point about the front sway bar. The front bar on my 1980 FE7 suspension is 1 1/8 inches.

KenSny

Let's not forget that the FE7 package was not just front and rear sway bars. It was also heavier (stiffer) front and rear springs and shocks. All the pieces have to work together or you will find the car not handling better - in fact you may find the rear end coming around way too fast (oversteer) when you add the rear bar and leave everything else in NON-FE7 condition...... Good luck experimenting with handling.



[Modified by KenSny, 6:03 PM 4/15/2004]

flynhi

Suggest you talk to VB, Van Steel and Guldstrand before making a decision. You should not just add a rear bar without considering all other suspension components.

UKPaul

The '81 should have a stock front sway bar of 1 1/8" & none on the rear as the factory std. Mine is set up like that but another forum member has added a rear bar. Apparently a good match for a 1 1/8" front is a 3/4" rear as this will give the best handling. There is a downside though. If you push it too hard through a corner the rear, on a stock '81, will roll until there isn't enough pressure on one tire to let it keep its grip. This tire will then start slipping & you've got some warning of impending doom. With a 3/4" bar fitted the car will corner very flat, keeping a load on each tire, letting you take the same corner faster. But when you push it too far and the tires lose their grip the explanation was "Bang! You'll go butt first into a ditch". Or something like that!
Essentially, with balanced sway bars (1 1/8" front, 3/4" rear) you'll be preventing any body roll, loading both tires on each "axle" about the same. Whichever one loses grip first is random so you've got to be on the ball when taking corners faster than you should be. With no rear bar there will be some body roll at the rear so you can get a controlled slide when one of the rear tires loses grip (that'll be the one squealing with a stock setup when you're pushing it hard on corners). I like this as it's controllable, but it will limit the speed that you can take a certain corner. Fitting a rear bar under 3/4" in size will allow a compromise in that you'll have flatter, faster cornering, but one of the rear tires will lose its grip before a front one does (rear tires losing grip can be fun, front tires sliding is usually a nightmare :( ). I intend to fit a 5/8" on the rear so that the cornering will be flatter but the rear tires will be the ones that will let go first (I hope!).
This was all explained to me very well by an '81 owner on the forum & hopefully he'll chime in with a better explanation than mine :)
:cheers:

Bobchad

All other things beeing equal, you shouldn't add a rear bar unless your car understeers. Adding a rear bar will increase oversteer and if the the butt end already comes around first then this will just increase this characteristic.

KenSny

After re-reading your post

What are you trying to improve or accomplish related to the way the car behaves now?

flynhi

To amplify my previous post:
Your interest in a rear bar suggests that your are intending to drive more aggressively. You can be certain that, in a 23 year old car, many components are worn and sloppy. Especially ball joints, tie rod ends, A arm and control rod bushings, trailing arm bushings, idler arm and steering rag joint.
Before you begin increasing your suspension for more agressive driving, make sure all basic components are in like new condition.

Wide, high quality tires will allow the use of larger sway bars without dangerous oversteer. 17" Bridgestones work great for me.

Even with the above, I wouldn't go larger than 1 1/8" front and 5/8" rear.

JLinCA

Don,
I'd say give the guys at Vette Brakes & Products a call. If anyone knows they will. I just bought an 81, and I will definitely be going with their products.

Gorgeous 81 by the way!!!! We almost went with white.

MEGALADON

Hey Don, haven't heard from you in a while, hope things are good.
check into the dual mount rear from vb&p. I think its the best
and have no complaints. :seeya

Don&Kelly

KenSny:
I've been working on the Vette for 2 years now & started to do some high speed auto cross ... the vette handles better now than it ever has, and it just keeps getting better ... I just thought that adding a rear sway bar was a very logical "next step"

:cheers:

Don&Kelly

I ave checked with "Guldstrand" by phone & 2 different shops locally, that along with the advise I can get on the various "forums" have given me alot of data to chew on.

flynhi:

Thanks for the 23 year old car advise, I've redone all of the bushings & bearings under the car, replaced ball joints, idler arm, I've gone to the 307 rear end, 17" Contiential X rated tires, 17" Cragar SS wheels (they look cool), lots of new stuff that I'm forgetting done under the car ...

new Crane cam, Dart Heads, TPIS Mini-Ram tuned port injection ... shocks etc. etc. -
This vette had 190 hp @ flywheel when I started, it now dyno's @ 335

It runs better than I do.

:smash: :cool:

flynhi

Sounds like you're well on the way to an outstanding Vette!
You didn't mention brakes. Suggest Zero Tolerance pistons in stainless sleeved calipers, braided lines, Performance Friction pads and Hydorboost.
Some have suggested removing the splitter block that reduces pressure to the rears.
Also, be sure to replace the trailing arm bushings and the doughnut that anchors the front of the diff.
I have the Smart Strut from VB and like it very much.