Roll bar in my Comet

[Jim Comet]

I am installing an 8 point roll bar in my 1966 Comet. One thing that is not clear in the NHRA rules is, can the main hoop be tilted/angled a few degrees back so the bar is at the same angle as the side window seam to help conceal it or is it preferred to keep it as close to 90 degrees as possible? Does anyone have any experience with this? Thanks, Jim

[jayb]

Jim, you are allowed to tilt the roll bar back as you described.  Are you doing the installation yourself?  If so, I can give you a few pointers; let me know - Jay

[Jim Comet]

I am doing the fitting myself. I bought a kit from SW race cars. The tubes are all pre notched and hopefully should take just a cut to length and some finish grinding to insure a snug fit. I also got a tubemaster tool that you slide over the bar and position it against the bar you want to fit it to and it conforms to the desired shape which you use as a stencil. I am going to weld in the floor plates and tack it in place. When it is fitted and tacked I am taking it to Lou Fegers. He said for 150 to 200 bucks he can have his pro guy finish weld it for me. The only thing that really concerns me is I think I will have to get rid of my arm rests to clear the front down bars. Jim

[jayb]

Let me offer a suggestion or two on this.  Don't tack the plates onto the floor right away.  Cut a hole in the floor under the plates, then fab the plates up but just set them in place.  Build the cage with the main bars just sitting on the plates.  Then when it is time to weld over the top of the hoop, you can remove the plates and drop the cage down through the floor, and get access over the top of the main hoop.  This makes it a lot easier to weld, and you can get the main hoop positioned right up against the top of the headliner or roof for the final installation.

Too bad you haven't got a bender, you could put a bend in the side bars so that they clear your armrests.  I do that on all my cars, and also make the side bars swing-out for easier access.

Also pay attention to the D bars; these are the short bars that come off the main hoop and angle down to the floor. NHRA used to allow those to weld onto more steel plates on the floor of the car, but they are now asking that they weld to some kind of frame member.  I got stung on that one back in 2006 with my Mach 1, and had to cut the bars out and revise the installation.  I add subframe connectors to my unibody cars, and cut a hole in the floor where the subframe connector runs, and weld the D bar to the subframe connector.  That passes muster with my local NHRA tech guy.

[Jim Comet]

Thanks Jay, I already have subframe connectors welded in. I Will check out where they are in relation to the outer main hoop mounting point and see if I can angle them down to my connectors. Jim

[mammyjammer]

 Dropping the cage through holes in the floor to weld the top is a great idea! I plan on putting at least a 4 point in my 58 at some point and have wondered how to get a good weld on the top of tubes.
I put a cage in my 68 Bronco, but that was easy...I just took the top off!!

[Jim Comet]

I talked to Jim Bongard (NHRA chassis certification guy) today and he stated that: while the rule book says they can be welded to plates on the floor/trans tunnel, he highly recommends welding them to the sub frame connectors as it adds a lot of strength to the roll bar setup. He said the rule was changed to allow it 2 or 3 years ago much to his disliking.  I think I will take the extra time and tie it all together. Jim

[jayb]

Bongard had the same comments on the cage in my Mach 1.  He had me put the "D" bars in so that they connected to the subframe connectors, while the main hoop was still welded to the plates in the floor.  If your subframe connectors are outboard far enough you could probably weld the main hoop directly to them, but if not, the D bar option works good too.  My subframe connectors were a good 10" inboard of the main hoop, so the D bar connection worked well for me.