Barchetta

Thread references

https://www.corvetteforum.com/forums...-believer.html

https://www.vette2vette.com/?q=produ...r-bar-system-5

After much excitement to get the Vette2Vette No-Flex Chassis Stiffening bar system, I have to say after they were installed I noticed absolutely no difference when the top was off. In fact it feels like the car shakes even more. Installation was preformed by a very competent Corvette mechanic who referenced these threads and the included instructions and all bolts were on tight. I was sure this would substantially reduce body flex with the top off based on all the positive reviews, and the manufactures explanation behind the engineering principals.

Top-on test referenced pre-installation when I'd approach and enter a driveway at a right angle the car would sound like it would snap in half - I assume others have experienced this sound. Post bars installation and top-on felt like the car was much stiffer as it didn't creak as much. (maybe it was the placebo effect and my excitement just knowing they were installed)

Then began the real test. On a long mountain road trip with the top off my anticipation and excitement was quite literally shaken from me as the car shuttered and vibrated terribly as if I never installed the bars. Additionally I notice a type of rattling buzzing sound coming from the passenger side bar as if it was vibrating against something.

Needless to say I was very disappointed not to mention these bars and installation cost was not cheap. I wouldn't mind the cost if they worked.

Is there anything I need to know that perhaps others have figured out that make these bars work? Is there anyone out there that found these not to work? I hope I didn't make a huge financial mistake buying these.

Your help is much appreciated. Thanks in advance.

DrDyno

How many threads do you have the heim joints adjusted to? It's doubtful your installer was familiar with properly adjusting them as the adjustment procedure is a trial and error and readjustment affair. I started at 6 threads showing (on all four heim joints)... no change noticed. I then went down to 4.5 threads showing which really tightened the car up; perhaps a little too much as the suspension felt a little too "tight." I've since settled on 5 threads showing and the Vette2Vette Stabilizers definitely work as advertised.

The first thread you referenced, above, is the thread I posted after installation...
https://www.corvetteforum.com/forums...-believer.html

corvetteronw

I put a large pipe wrench in the middle and went back and forth from one side to the other two or three times until they were as tight as I could get them without using a cheater bar.
I have a set of 3 railroad tracks just a few blocks from my home. I could drive across them with the targa removed. FX3 at the max and low 100,000 miles on the chassis. It rode better than my wife's 10,000 or so GMC Terrain or my 80,000 or so Nissan Frontier.
Have your mechanic look over the rest of your suspension to include the shocks, rubber bushings and especially the c-beam bolts.
The bars made my 91 ride like a new car even with top off. If I buy another C4 then I will install them again.
Good luck man

-=Jeff=-

Have you talked to jason about them? I noticed an instant difference on mine once vette2vette installed them and I drove off.. I have the very first set, I will not remove them

I noticed the difference, I am not saying that you did not, but I would suggest a call to jason regarding what you can do to adjust them

Barchetta

I'll check but If I remember correctly they were tightened as tight as they could go.

Could these bars that keep the frame rails under compression perhaps worsen or intensify a chassis vibration problem/issue? Such as some of the things you mentioned?

Another question - If one side is tighter than the other would this put the compression out of balance and cause vibration?

DrDyno

That is definitely NOT the way to adjust them! You really need to call Jason at Vette2Vette, as suggested above and get the right info.

Phone: 815-673-6200 (Central Time Zone)

grandspt

Mine are pretty tight with about 4-5 threads showing on the heim joints on each side.
It works but if they are not properly adjusted then you won't feel much of a difference.
Note without the roof my car still shakes just not as bad. 96 Z51 suspension and 315 rear tires 275 front tires (fairly stiff riding car).

LT5corsa

I've had mine on for over 1.5 years....

Very impressed with the difference and so noticeable with the top off!

I'm guessing you had somebody install them and you have no idea if they were adjusted right?

Installing them doesn't make them work.

Call the MFG before saying something DOESN'T work. I know too many people with this and no issues.



David

blue94

I would call them. I put mine on several years ago. Set all four joints to 5 threads and have been very happy. very tight and almost all rattles gone. If the bar is making noise "buzzing" something is not tight enough or failed.

Barchetta

The title of this thread is just my initial experience after install, not saying they will never work. Thanks for the sugestions. I will try different adjustment settings and see.

-=Jeff=-

Good to hear you will give it a try to see if you can get them set-up and working.. With your explanation I quoted and then reading the title again, it changes the 'tone' of the title.. Semantics I guess

1993C4LT1

If you don't want them after you get them re-adjusted, PM me a price.

PLRX

Many racers here do autocross, and track events, and dont use them. I have driven my C4s to the test, and never used those things.

Now, the Camber Brace does makes a BIG difference, and that was the reason I bought it for The Ghost.

1993C4LT1

Sweet, thanks Pete. I'll just get one of those then.

Tom400CFI

Really? This guy (who had good results), says it is...
...so what IS the proper procedure?

Tom400CFI

Barchetta

^^^ Good point Tom. Yes, I'm confused too as to what IS the proper adjustment. One says as tight as can be is the solution, another says no you need to count threads drive and adjust. Do these bars eliminate 100% of the shaking? If not, then how do you know if they're properly adjusted?

DrDyno

OK. First of all, I have no idea what CORVETTERONW is describing with his pipe wrench. But, for you and TOM400CFI (although you should call Jason and get it from the manufacturer, himself), the correct procedure (according to my conversations with Jason) is as follows:

After installing the brackets, install the bars with equal threads showing at the heim joints, front and rear... there are four heim joints, two for each side. Two are reverse thread. Each bar gets one with standard thread and one with reverse thread so that by turning the bar you will tighten or loosen both fore and aft, equally, leaving an equal amount of threads showing at both ends of the bar. (Obviously, you have to start with equal threads showing to maintain equal threads showing.)

I started with 7 threads showing and went driving over my favorite bumpy road... no difference.

I then readjusted both sides to 6 threads showing and took a second drive... car was a little tighter.

I then tried 4 threads showing and although the car handled the bumps very well, it seemed a little "jittery" at cruising speeds.

So, I backed off to 4-1/2 threads showing all around and it was like driving a new car. Eventually I went back to 5 threads figuring the heim joints would have less stress on them (probably not necessary).

It was a little PITA having to stop and readjust after each try but, well worth the final outcome. Harbor Freight sells a set of short wrenches which were very helpful (I didn't have to jack the car up with each adjustment). If memory serves, you'll need a 13/16 and a 7/8 wrench.

Here's what the heim joints look like and, you should have equal threads showing fore and aft for each side of the car.

MavsAK

From my understanding you have to do these in increments, as per dr dyno's advice, from reading the threads. I'm interested in picking up a set of these, since they're said to work (and the vert x brace doesn't. Counter intuitive to me at first until I really thought about how these work. They essentially preload and reinforce the frame rails.

Too much load, and the car would be skittery, and probably rattle your teeth out, given the C4's firm suspension. Remember the C5 and all vettes past 4, have a stiffer frame and lighter spring rates in the shocks and leafs. There's a reason for this! Our frames, are essentially where all the "give" in the chassis is, which makes the rails a spring, given the high spring rates of our leafs, and shocks, transferring it directly into the frame.

Stiffening the frame, that much, like these bars would probably do at maximum tightness takes the dampening effect out of the frame rails.

Modern suspension design, is about making the frame as stiff as possible, while the shocks and springs are as light duty as the car can be, to perform it's handling goals. This is for several reasons, one of which is it's easier to get a car with a stronger frame to perform than one with a limp noodle chassis. Another, is the practical side of being much more comfortable to ride in.

Max Stiff on these bars, plus our C4s rock hard suspension, is about as close to Race Car (ask anyone who's driven a race car, how "good" they feel off a prepped racing surface if they've ever done it... I can safely tell you phrases like "I felt like my fillings were about to fall out" will be heard.) as it would get.

Each car will also age differently, as no two cars, especially after 25+ years are a like. I'm sure my 89, has endured things, that say Tom's C4 never has, and vice versa. That is going to have an effect on the car's rigidity as they age. To say nothing of any shock and spring combo preferences we each might have. That's why there's a range of adjustment on these bars.

With stuff that has adjust ability, start on the conservative or near stock side (specially with suspension and chassis related issues) and work your way up until you find your personal sweet spot. Just my two pennies.

grandspt

So is this supposed to be an issue that my GrandSport and LT5CORSA'S car have a different outcome with the roof off?
The cars have different suspensions assuming LT5CORSA'S is a ZR1. I have owned my car since new 28 orig. miles so I am very attuned to my car. Corvettes back in the 80sand 90s had higher manufacturing tolerances than today (every car is a little different).
The bars made a big difference with the roof on but for me not so much with the roof off.
Any questions??