grumpy in Az

Would like to try running at the drags one weekend but the tech officals say a roadster has to have a roll bar. Does anyone know of a company that makes a bolt in roll bar for a mid year roadster? :crazy:

bcwaller

Not if you want to use your top and keep the rear decklid. I've been looking into this for years and have yet to find something that will allow a convertible to continue functioning. Sources I have found include:
http://www.cachassisworks.com/cages.htm
http://www.ioportracing.com/rollbar.htm


[Modified by bcwaller, 3:03 PM 9/16/2002]

Hank

I have been thinking about this issue also -- am very curious as to what others have done. In the CF drag racing forum they have convinced me that running HP and speed above a certain level the cage / roll bar is common sense and not just a sanctioning body issue.

I would like to of course preserve the soft top's ability to lift up. Looking at where the lid and seats come together, I see about 1/4" of clearance -- not enough for a roll bar I'd say. Or at least, not enough for the roll bar, seats, and lid to coexist. of the 3 I'd say lid is the first to go.

What do the vintage racers do? cut up the lid?

Maybe my tube frame midyear twin turbo project car (aka pipe dream) needs to be a coupe.

Gerry

Hank

One other thing -- you probably know this already but most tracks let you run down to a certain ET (I think 12.99?) with the hardtop installed. Probably useless in a rollover and no substitute for a rollbar but might get you out there for a run or two.

gerry

bcwaller

Gerry/Hank: Any convertible with a roll bar that I have ever seen has not had a convertible frame in the car, and the rear deacklid was notched or had a hole for the tube.

I would think that the decklid could be modified to allow a mild notch, or even a hole with a removable brace if someone wanted to do it bad enough. But this means you are at the custom level (with custom $$$), where you drop off your car for a week and see what they come up with.

GregP

Try calling S&W race cars or one of the So Cal street rod shops (I'm sure there are some in AZ too ;) ). Making a bolt-in roll bar that would serve good temporary duty shouldn't be too hard. Just tell them you need something custom, and don't be restricted to what's in the catalogs. I've had S&W build custom tubes for me (chassis lower tubes were a nice intrgecate shape) and the cost was pretty reasonable. I also had a custom bolt-in roll bar with side bars made for my '27 T when I was in Huntington Beach by a local street rod shop, with a Chrome hoop even.

The "T" used a simple concept that would adapt well to a Corvette. It was a custom bent under dash inverted "U" hoop that bolted to plates welded to the chassis (yes, you almost certainly will need to weld some mounts to the frame rails underneath so the bars can bolt to the floor pan and not have to notch through the door jams to get to the frame rails). A second hoop went outside the seat and overhead. Bolt-in (tabbed) side bars connected the two to give the required support. If you want to include rear braces, they can be made to run under the rear deck. Not quite a strong, but still good.

You could also do a 60's road race style, and run just the main hoop and a diaginal front brace going into the passenger side foot well (remember the C1 in Hot Rods to Hell ?). If you measure and mock up carefuly you should be able to get a main bar that will slip around, then behind the seats. You could also run without the rear cover, and use a tanaue just for racing.

A good way to make mock-up bars is to stick piano wire inside foam pipe insulation. It bends easily, but the piano wire will make the foam hold it's shape so you can get good measurements to transfer to a drawing.

If someone wants to bring a more "stock" than mine C-2 convert by the house sometime I'll help with mocking up a main hoop and generating some CAD drawings so forum members can get a race shop to bend some up for them.

-Greg


[Modified by GregP, 8:07 AM 9/17/2002]

TCracingCA

Hi, I am another one who is attempting to re-install a rollcage back into my 64 Roadster (former race car converted back to street use but with the Race mods still evident such as the old rollcage pickup points and frame welding/gusseting). The car was re-registered for the street after the attempted failed restoration back to stock.

Therefore I have been engineering the cage to work with the convertible top and for a hardtop. The SCCA requires the cage to be higher than the driver's helmet in a convertible but in a hardtop or coupe they only require the bars to be as close to the roof as possible. Therefore race it with the hardtop on is my plan. I took a sideview of a midyear Corvette and glued a picture of the frame onto the sideview after scaling to size. I then sketched the sideview of the cage that I liked the best. I went out to the real car and took real life measurements. I ordered a generic Alston 63-82 cage and plan to modify or alter this design to match my drawings. I will have to shorted the behind the seat driver's hoop and will cut it just above the footings and reweld the bar instead of trying to reattach the footings. The angle of the footings is very important.
The other problem I had was the diagonal bars running down next to the door panels and the cages interference with the door panel. Therefore I am going to install bar "disconnects" and run no bar when in street use, then remove the items on the door panel that interfere when I reinstall the bar for racing or just remove the door panel altogether. The back convertible deck lid. It seems the best solution is to just buy an extra lid because to properly brace the frame in the back. You have to go through the deck lid. I am still playing with the idea of a horizontal connection with a reinforcement brace tie in from a horizontal brace running from the mid seatback height level. I will follow this forum because just as everyone else, I would like to get it exactly the way I would like it to work.

P.S. Corvette Corrections has done some nice cages on midyears. I would hate to ask the price, but they sure look nicely done. From Derek (TCracingCA). Take it easy everyone.


[Modified by TCracingCA, 7:55 AM 9/20/2002]

427Hotrod

I am really interested in what you are doing with your setup. I also looked at the Jegs and Alston cages to see what I could make fit. Like you, I want to retain the soft top. I think I have it figured out how I would do it, but would really like to see any pictures of what you have so far. How is the main bar shaped? I want it to be slightly angled inward on the uprights similar to a regular Camaro bar or something. Does it? The appearance of the main bar is almost as important as the strength and design of it. I want it to really stiffen te car, but I don't want to look too dorky riding around on the street.

If you have any pictures could you E-mail if possible?

JIM

TCracingCA

Hey Jim 427Hotrod,
Sorry I didn't get a reply back to you sooner. My Computer took a virus hit. I had to clean it up (Disk Scan, Defrag, Norton). I am back. The roll cage from Jeg's sounds like the one you would like better. The primary hoop goes up about 30" and they do one bend angling it inward about 30 degrees for 10" then bend it (60 degrees) to run across the top. The main hoop is 46" wide up to the 30" high point but across the top (after the 30 degree angling and the final 60 degree bends at the top) the bar is about 26" from end of bends (60 degree) on both sides. It is nice looking. The overall height is about 44" which I estimate to be about 4" or 5" too high. It doesn't have footings, so you can weld them on at any angle if you plan on lying it back. They notch the other bars for you but I would have to do some modifications of the existing and also fabricate it the way I want. It is also heavier. The Alston unit, before I got started found out that they will make you one out of the 4340 chromoly to your specifications so I am using the Jeg's now as a pattern for the custom Alston unit. I hope this helps.
P.S. the Jeg's unit did not come with any drawings, no instructions. Also the weight caused the shipping to be $100 from there to California. The steel is far easier to assemble because it is easier to weld steel than to weld 4340. If you have access to a TIG it would make life easier also. I plan on assembling with a MIG.

Lastly I don't have a scanner and just bought my first digital camera. I hope to soon but not tomorrow be able to import pictures. I started the reinstallation of the cage but then decided to lift the body and redo some of the welding on the frame. I also took a set of the offset trailing arms from Van Steel and modified the ends to run the Guldstrand spherical bearings and the toe adjusters. So the ends basically have been modified for a stock size. The Van Steel units take a non-stock sized (smaller) Poly bushing and I hate poly. I have all heim joints, borgeson joints, del-um bushing on street or concentric metal bushing for race. Naturally I need a kidney belt going up the freeway.

GregP

I have an S&W cage in my coupe. It has an "angled section" in the upper corner like you mentioned and I wish it didn't but had nice single curves. The reason is with the angles the back ends of the side bars (windshield and across top) need to be too low. You can see them through the window openings in my sig. To move them higher (to the top flat bar section) puts them too far inboard, would be running right through the top of your head. Where they are they will certainly need to be padded for when your head bangs into them from the side.

-Greg


[Modified by GregP, 8:47 AM 9/23/2002]

kenmo

How about for C1's ?

TCracingCA

Thanks Greg, Because the car will be driven as a convertible most of the time I wasn't too concerned about the bars showing with the hardtop and the convertible is only used if it rains unless I am on the freeway moving. It would bother me if I was banging my head on the bar. I can still change my design before final installation. I appreciate the observation.

PRNDL

grumpy, how fast is your vette?
Convertibles do not need a rollcage unless they are under 14.00 seconds.
As mentioned already, if you have a hardtop for your convertible you are then subject to the hardtop rules which means a rollcage is needed if you are under 12.00 seconds (I THINK, not sure).

Am i being naive about this? What is the danger in a straightline race topping out at 100 mph? I think it is much more dangerous to be on the highway at 80 mph with potholes and semi/tractor trailors whizzing around not to mention soccer mom suburbans cutting you off, compared to 100mph at the end of a straightline 1/4 mile. MJ

Denney

Now I do NOT condone this, but thought I would throw this out for consideration because someone at the recent drags told me that it had been done on someone elses car (a mid year also) years ago...This fellow told me that a friend of his raced a convert mid year for years with a "rollbar" that actually was not attached to the frame and it just got mounted down through holes in the jack compartment storage cover (and bolted to the floor fiberglass in some manner). The guy could apprently put it in and take it out anytime and he said the NHRA never checked to see that it was actually mounted to the frame. Obviously if safety is the concern this is totally dumb, but if just meeting the "rules" is the goal, it's something to think about, I suppose, as it would not really require any mods (other than an extra jack compartment cover with holes cut in it).

Hank

On motivation -- I'm running high 12s with an out of tune mild street 502. Just bought the dyno 2000 program and I see HP all over the place to put in this winter. Big valve Al heads, bigger cam, headers -- it's going to be a lot of fun to optimize the combination.

It's also a scary thought to be in 11s at 120 in the 1/4 with a 36 year old roadster, with only a crappy lap belt holding you in. I want the rollbar for integrity of my body if something should break or happen -- which is not hard to imagine given the forces involved. A helmet in a rolled 66 convertible going 100 mph is not much comfort to me.

Part of me wants to just keep it cool, drive the car as is and enjoy it. Then I think about all you crazies on the forum with 540s, no-points beautiful dragsters, etc. and I want to GO. Build a bit more flow into the prime mover and get the bar to protect me. If I can find a way to do the roll bar that will help a lot. No doubt it's like anything else in this hobby -- time and money and creativity will fix it. I prefer creativity to time and money so if I can borrow from the experts here I will.

Gerry