I see a LOT of C4's that don't run the targa for auto-x and no braces either. A lot of folks don't fit in the car with their helmets on.

In fact a brace like this would be illegal for Stock or Street Prepared classes with the SCCA. You'd be in a Prepared or Street Modified Class good luck with running a C4 at that level and being competitive except at the local level.

I do not remember where I saw this but a C4 runs an auto-x with the top on versus off in about the same time. The frame flexes so much either way it does not matter. If you don't like the frame buy a C5. My 2 cents.

 

It's only asking for experiences...nothing mentioned about racing from the OP. Maybe you know him personally and have great insight.

Maybe not.

 

I have had the frame stiffeners for a few years now on my GrandSport.
It does tighten things up a bit. You can feel a difference over bumps. But don't expect miracles. I am happy with the $500.00 I spent on the stiffeners, I don't feel that is an outrageous price for the improvement (but this is my opinion).
I still do not take the targa roof off much but now when I do the car is less nervous over bumps.
My first set had powder coating issues and Vette to Vette took care of it with great customer service!
Note: I am the original owner of my car so if I make a change I can feel it. Example when the original Goodyear Eagle tires wore out and I switched to the then new Goodyear Eagle GSC tires, I could feel a difference in ride and handling between the two different tire designs (I was not happy with the GSC's) !
When I had a 4 wheel alignment after I performed suspension work (urethane bushings in rear and front lower ball joints, u-joints in half shafts) I had the alignment shop align it twice because I was not happy with an alignment that was within spec. I made them give me specs that were Advanced Street Specs from this forum.
It made a huge difference in the handling of my car on off ramps!

If you purchase them, the only problem installing them was the parking brake cable has to be routed slightly differently (at least on my 96). It is not a big problem but the instructions do not mention it. In fact the instructions are vague on tightening the heim rods. I tightened them with a large crescent wrench until I felt a fair amount of resistance, then I stopped.

 

Yep, I've seen guys remove their targa for AUTOCROSSING. I did it once...the crossbar on the front knocked my coolant sensor off. Put the top back on and the sensor connector never popped of again. Yeah, I'll leave the top on. Since I'm not in a stock class, this frame-stiffener is on my list of things to try out...just not on the immediate list.

 

There is no need to run heim joints. Solid rod ends are much cheaper and serve the same function as providing adjustability. As an engineer, the best solution would be to use the stiffener and add tubular x bracing to get the best of both longitudinal and lateral increase and stiffness....

 

Gordon Killebrew actually proposed these bars back when the C4 was being built but the bean counters at GM wouldn't go for it.I have had the opportunity to drive a 1990 coupe that was retrofitted with with a 'vert brace and a 1994 with the Killebrew brace.I drove the cars with tops on and the tops off and both felt much more solid than my 1993 coupe which does not have a brace yet.Since I drive in Georgia there is the high likelihood that something in the road will snag on my undercarriage so an x-brace that hangs down an inch or more isn't an option.The Vette2Vette brace doesn't alter your ground clearance and doesn't interfere with your exhaust or transmission.It's really a case of what suits you best on a personal level.

 

The C4 frame is stiff enough. Never had any problems with the 3 different C4's I have ran and I run with Hoosier A's. There are worthy mods and there are wasteful mods and a frame stiffener on a C4 is a wasteful mod. It is not necessary. Spend your money on something more useful.

 

You're wrong. I have eaten up a set of solid rod ends with bushings and have switched to heim joint ends only for racing. You guys with that frame stiffner s**t make me . Sorry going to have to call a spade a spade.

 

 

Here we go again - someone feels the need to tell me how to spend my own, hard earned money. And pukes when he doesn't agree.

 

If someone really wants the car to feel solid they can put on a brace and achieve this. I would question the benefits of it from an outright lap time aspect though. Just my .02

 

How could the guy saying the frame is stiff enough ALSO be saying heim joints are necessary? Are you using this system or not?

If so, why comment that the frame is stiff enough?

If not, how would you know heim joints are necessary?


(I'm just curious.)

 

If you are referring to me, my heim joints are updated suspension components, such as the camber rods, tie rods, and trailing arms. The reason for them is that they maintain alignments better than the stock components. These don't directly relate to frame stiffness.

 

I was referring to you. Though my choice of noun made my question seem impersonal, it was intended to invoke responses from all. (I apologize after re-reading the way that sounds, Bob.)

For racing, I have no idea whether a stiffer frame (even if miniscule) would make a difference. And, I'm mostly thinking autocross. It SEEMS likely....

For aesthetics, it's hard to argue with a reduction in roof creak, body creak, or that type of improvement. Unless the V-2-V guy is lying by saying it eliminates body flex when jacking from the middle, it's hard to see zero value. The question is price-for-improvement IMO. I would also suggest price for the particular piece and design.

Having something that doesn't hang lower in a Corvette has merit. I say this after installing sidepipes and a more significant front air dam. Having a car that occasionally contacts the ground is annoying.

I agree there are tons of things to spend money on before stiffening the frame. Hard to think it should be eliminated from possibility -- considering the factory even installed a frame-brace in attempts to improve the open-top driving experience.

For this particular piece, the construction seems questionable -- when you consider the size/strength of the stiffener compared to the frame. But, I'm no strength-of-materials expert!

 

My opinion is that a stiffer frame is not necessary for great handling (objective performance). I feel that the only way that a stiffer frame will make your car meaningfully faster is if the stiffness translates to driver CONFIDENCE...which will help a driver go faster/drive better...some times.

Having the steering wheel move in your hands, seeing the cowl and windshield frame shudder in your peripheral vision, hearing the chassis "crash" over bumps or cracks...those things distract (me at least) and shake my confidence for second. If frame stiffening eliminated those things, I know that for ME, my focus would be more keen and uninterrupted, on the pure line of the course, and driving the car to that line. In that way, and because the car is driven by a human being, frame stiffening could help.

But objectively, as for what the CAR can do, I don't think the frame stiffness is meaningfully important.

 

I going to be calling Jason on monday and placing a order for a set. And now I just need to find avendor that carries the camber brace.

 

I actually bought this kit from Gordon in the flesh at Carlisle this year! And the man is pretty much a genius. Anyone that talks to him knows he is a C4 encyclopedia. The kit was relatively easy to install, but count on an afternoon. The front brackets are a piece of cake. The rears require a hole to be drilled on each side into the frame. An air gun works wonders on the bolts you need to remove also It is a relatively easy mod that does make a difference. I don't think you will be disappointed.

 

Van Steel

 

It's a good setup. I will be getting one for my 93 as well. It bolts up and the holes that need to be drilled are optional. Because I didn't have a punch or drill on hand I chose to bolt it up and tighten the brace on either side. I will soon drill the hole and then extend the brace.


My only issue is setting the brace up. My car is so low I can't tighten with it on the ground. I wish they had a general idea if tightening the brace or loosening it to extend it had the greater impact on the chassis. I think it's the least they could do. The only way for me to know is to try it I guess.

 

Just ordered mine today they should be here by the end of the week