This morning another CF member, FB3, and I put Z51 anti-sway bars on our stock 2006 C6 Corvettes. His is a couple and mine is a convertible, both with TPW of 5-15-2006. I bought the bars and bushings from Fichtners, and FB3 bought the bars and bushings from Fred Beans.

My convertible went up on the lift first. We pulled the front bar out, with the links attached, and put it on the workbench to swap the links to the new bar. D*mn, there does not look like much difference in diameter between the two. Whip out the dial calipers: Stock - 1.220". Z-51 - 1.220". Measure FB3's new Z-51 front bar -1.220". WHAT ? ? ?

Off to the CF where a quick search turns up a post from 9-05-2005:

What is the diameter of stock versus Z51 anti-sway bars?

A quick check with the calipers found:

Base.....Front = 1.005" Rear = .689"

Z51......Front = 1.222" Rear = 1.008"



Time to speculate -
a. The 2006 stock suspension got the 2005 Z-51 bar.
b. Convertibles with stock suspension got the Z-51 bar.
c. A line worker in Bowling Green made a mistake .
d. They were out of stock bars when our cars were built.
e. None of the above.
f. All of the above .

As a metallurgist I know that the elastic modulus of two steel bars is the same, irrespective of chemistry or heat treatment, so I put the stock bar back on my car.

The stock rear bar was skinny, 0.690" diameter, and the Z-51 rear bar was as described in the 2005 post, 1.010" diameter, so the new Z-51 rear bar went on the Corvette.

FB3's coupe goes on the lift next and we go directly to the rear bar to change it out, pitching the skinny stock bar and putting on the heaftier Z-51 rear bar. Before we drop his car down, we look at his front bar: "Gee, that looks thinner than the Z-51 front bar; get the calipers."

2006 C6 coupe, stock suspension, front anti-sway bar is indeed 1.005" diameter, so FB3's front bar gets changed to the Z-51 bar, too.

SO . . . . . is the news to anyone? Or did I get the only 2006 C6 base suspension Corvette convertible with a Z-51 front anti-sway bar, and stock rear anti-sway bar ? ? ?

And will Fichtners take back just the front Z-51 bar and bushings ? ? ?
If not, I will list it for sale on CF and someone else with stock or F55 suspension need only buy the rear Z-51 bar from Fichtners or Fred Beans.

 

One other question that I have regarding clevitekid's and my experience today, is could the mismatched bars on clevitekid's car have caused a handling problem if it was pushed to or near the limits?

If so, I would think that would be a pretty big liability for GM .

 

Interesting stuff.

It could yes but any reasonable driver with some basic knowledge/skills with higher speed handling/cornering will know when that limit is reached. It would take a seriously technical cornering situation to actually get into trouble with the car based solely on that minute sway bar disparity, one might be in just as much trouble with a stock and proper Z51 car at that point as well IMO.


On a related note, did you weigh the sway bars at all? Just curious as to how much heavier the Z51 bars are both front and rear.

 

No, we did not weigh the bars, and I really didn't think about it when we were doing the work. I really doubt if there is any significant weight difference though.

 

OK, so I went back out in the laboratory to weigh the bars we have:

Base front bar: 6.8 lbs.
Z-51 front bar: 10.5 lbs.

Base rear bar: 2.5 lbs. (Really, it is almost embarrasingly small !)
Z-51 rear bar: 6.8 lbs. estimate, same diameter and length as front base bar.

 

Any chance it has something to do with helping the rigidity and structure of a vert? See if you can find another non Z51 vert and have them measure their sway bar. Just a thought.

 

I briefly considered this, but thought that with the less rigid structure of a vert, the last thing you would want is a stiffer suspension trying to twist the body into a pretzel.

But, please keep the ideas coming until the truth is revealed, from whatever source.

 

I vote on mistake at BG.

 

I have a 2005 vert base suspension and although I never measured the bars, I did notice the Z51 bars were larger than both the front and rear of the original bars I took off. I placed them side by side on the floor and could see the difference! No doubt about it. Hope this helps...

 

 

Are the paper P/N tags on the bars? They should be. That's the easiest way to determine what bars you have. Here's a photo of my rear Z51 bar I removed.

If your rear or front bar doesn't have the paper tags I'd be taking them off. There's a chance that these bars could have been removed for some problem and somehow installed on your car. During my NCM delivery tour the guide was quick to point out all the "bad" parts they find and set aside.

Tom

 

The same thing happened to me. Z51 sway bar on the front with a puny little one in the rear on a '07 F55. I put mine down to a mistake on the line. I'll just be replacing the rear.

Al