Joe B.

Cross frame brace, camber brace and use a targa truss if driving with the top off.

rocco16

My Vette isn't a uni-body. I know of no Corvette that is. Doesn't your Corvette have a steel frame and a fiberglass body? Should.

I agree with your last statment, for the same reasons.
The only thing these tie rods could do is reduce elongation and/or compression of the frame rails.

BTW, the only welds that flex are welds that are broken.

Tom400CFI

I guess the term "unit body" is debatable. What the car ISN'T is body-on-frame...that is for sure. Also for sure is that it ISN'T a "space frame". That doesn't leave much classification left. The fact that the "structure"/"frame" (what ever you want to call the thing that everything else bolts to) is integrated with the rear firewall, floorpan, hoop and windshield frame, suspension pick-up points...that kinda makes it a "unit body" car. That they bolt and glue SMC panels to the structure, rather than stamped steel doesn't change a thing. Only function (debatable) diff is the rear 1/4 panels.

Strip an F-body down to the barest, naked most form, and then a C4. There isn't a LOT of diff.

You're right that welds don't flex, but the 4" from one spot weld to the next could potentially allow for deformation/flex of the main members between those points. Don't know if it DOES on a C4. I know someone who welded up every seam on a Buick GN and said it made no difference. Haven't heard if anyone has tried (and tested) it on a C4...

grandspt

I have recently (October 25th) purchased and tried the C4 Frame Stiffeners from Vette2Vette (Jason).
I have owned my 1996 GrandSport with Z51 suspension since new.
My car always handles fine on smooth roads.
But unfortunately here in New England we have a lot of ruts and potholes.
The car has always had a creak/popping noise coming from the roof panel when going over bumps and ruts. I do not take off the roof panel because the car has awful cowl shake and steering wheel shake. The whole car feels disconnected on all but perfect roads with the roof off!
Now I have no connection with Jason or his company or product but after installing the Frame Stiifeners I think they are worth the money.
My creaks and pops are gone. The car feels noticeably stiffer. Now I know some will say that is subjective. But I have owned the car for 15 years and know every noise and strange feel in my GrandSport.
It feels better with the Stiffeners!
I still do not take the roof off because I am not comfortable with the feeling of cowl shake (although I did try it after the installation and it was slightly better).
But I did have a problem with the powder coating on the rods. The coating chipped off at the adjustment point where you apply your 7/8" open end wrench. I contacted Jason and he put me in touch with his dad Dan. Dan told me he took a rod out of stock and it chipped on him as well. The items will have a thicker powder coating on them now. And the instructions will now say to use an adjustable crescent wrench to adjust the rods instead of the 7/8" open end wrench.
And Dan will be sending me new ones to replace my chipped ones!
So far they have been excellent to deal with.

Kris_K

Kris_K

No way, the last subframe connectors (90s mustang) I bought only cost $90. Since these cost 5x more they have to be different...right

Kris_K

I have a Camber Brace in mine, eliminated the cowl shake with the top off.

Tom400CFI

The camber brace can't possibly eliminate cowl shake with the top off; it's not addressing flex issues in that part of the car! Cowl shake is cause by one or both of two things;

1. Flex in the rocker/rail area of the structure
2. "parallelograming" of the door posts. -The door posts tilting side to side together, allowing lateral movement of the cowl and windshield.


NO WAY, did a camber brace improve on that issue. It's all in your head. ...And I can say that b/c I too spend the dollars on a camber brace and installed it in my '92. Made zero difference in cowl shake. It can't. The camber brace attempts (I say attempts, b/c I don't know that it does anything meaningful), it attempts to stiffen an area of the car that is well ahead of the problem area(s) that is involved in 'cowl flex'.

Cavi

I agree that the cowel shake will not be solved by the camber brace. but I do believe that the camber brace along with these no-flex rails would do wonders for the overall feel of the car.

l98tpi

C4 Structural Design

http://auto.howstuffworks.com/1984-corvette1.htm


This was the best description of the c4 chassis design I could find. Along with this, I still do not see the benefit of the no flex kit, except some weight addition. But, anyone can spend their money any way they wish.

grandspt

Thanks for the link l98tpi that is an interesting article. The stiffeners look like they are adding strength to the side rails which are spot welded together in pieces. It is not a one piece length of solid steel, and I do not believe they are even high tensile strength steel.
But whatever, it helped my car feel better, lost those creaks and pops I had. And at a total weight of just 22 lbs it did not make my car any slower!!
At 175lbs 5'11" I can afford to gain 22 lbs in my car

Tom400CFI

It sure is hard to get good technical info on the C4 frame! From the article:
"Welded to the backbone was what Chevy called an "integral perimeter-birdcage unitized structure"

I'd like to know exactly where the "back bone" is "welded" to the rest of the unit structure.

93Rubie

I agree, that article is from the book Corvette 50th Anniversary by the Auto Editors of Consumer Guide. It has a boat load of technical errors. It states many times in the C5 section about the new LT1 in those cars. There is a reason I got the book from Ollies for $10.

You want a REAL technical info, read Corvette From the Inside by former Chief Engineer Dave McLellan. He was the head guy from 75-92. Straight from the horses mouth.

For grins and giggles, the C4 frame was by all accounts much better than the C3 frame which dated to the early 60's.

AustinJohn

I realize this thread hasn't seen any action for a long time but for the benefit of anyone who does a search and finds it, I'll add my 2¢.

My '94 coupe is just shy of 200k miles but I've wanted to try the No-Flex kit since first reading about it. I pm'd with Ron and a few other members who had installed it, got positive feedback and did an install in September just in time to drive to Funfest, about 2200 miles round trip. For some reason the length rod needed to get adequate tightening on my car was significantly shorter than all the other rods Vette2Vette had sold but at my request I shipped the original rods back to them and they willingly cut them first 3/4" shorter and then shorter again at no additional cost other than me paying the freight both ways for both cuts. The Vette2Vette folks guessed the car had been in a wreck but lots of inspection didn't disclose anything.

Unfortunately the "second stage" and not the final rods were installed for the Funfest trip so the rods were only partially torqued (~40ft/lbs) but the benefit was significant. Since installing the final version and re-torquing to 80 ft/lbs. I've driven another 1,000 miles and with the roof in place, the car drives like it just came off the showroom floor. With the roof off, it's not perfect but significantly improved. (My friend Corky Bell, "Mr. Turbo", used to refer to my C4 as my "Flexible Flyer" but not since I installed the No-Flex System.)

Having read the thread I know there are skeptics, those with other uses for their car $$ and those who don't have discretionary car $$ and my purpose isn't to try to convince anyone otherwise but just to share my experience.

John

H P Bushrod

Read the rules John:

http://forums.corvetteforum.com/foru...s-or-more.html