Looking for a few suggestions... I'm installing a 12 point cage in my current project ('37 Chevy Truck) that will be welded directly to the frame (2x3) at all mounting points. Should I just weld the Body to the frame since it can't be removed anyway due to the roll cage...or bolt the body to the frame anyway? I'll be able to weld the main hoop, Halo, Front "a" pillar down bars, Door Bars to the frame with the body off...then place the body over the cage then install my rear down tubes (thru back of cab to frame in bed) and my front thru firewall to front of frame bars and weld them in place.
sounds like a pretty serious drag truck. id suggest checking with the nhra tech and reading the rule book. i don't think id weld the body to the frame though.
I agree with Ryno. If it ever became necessary to remove the body, you could remove the roll cage if you had to. I think bolting is the only way to go.
I wouldn't weld the body to the frame. The body can still be removed my removing the cage. Or if you are real serious make the body a shell with a separate floor. You can then remove the body if you so desire.
If i were building the cage to race spec, i would weld sizeable tabs from main hoop (at shoulder ht approx) to the door jamb, from the halo to the 'a' pillars; i likely wouldn't weld to the frame, bolt thta part in. Welding up high like that turn the cab into a shear plane and give greater protection. I would set the main hoop as far forward as possible, right at the door jamb and bend the seat back bar to the cab contours. That way when the cab is placed over the main hoop you'll be able to weld the door bars and rear down bars. If the main hoop is all the way to the back you won't be able to weld all the way around and a sharp inspector will know that.
NHRA rules state the cage must be welded to the frame on a full frame car.Not specific on the body but I think I would bolt the body so if ever you needed to you could[with cutting]remove it. ROY.
Thanks for all the input and suggestions....Bolting the body in place does make better sense than welding it to the frame. What are your thoughts on doing something like MAT THRASHER'S '34 BUILD http://www.jalopyjournal.com/forum/showthread.php?t=368357&highlight=drag+truck&page=8 and as seen in the following photos: He made his rear down tubes removable ..Bolts thru the back of the cab to the roll cage (sandwiches the back of the cab betweeen the rear bars and main cage) This was a thought I had as well as doing a simular setup for the two front bars that go thru the firewall to the front frame rails. Doing a set-up like this would at least allow complete removal of the cab. A little more about the "DUTY" of this truck....mostly a STREET/STRIP type vehicle..with a lot more "STREET" time than strip. With the engine I'll be running..hope to break into the 10.90 bracket..soo a full cage is a must.
That's a very neat solution on the pick up truck. Unfortunately here in division 7 NHRA the only bolting they allow on a roll bar or cage is limited to the base of the roll bar/ cage structure and the side bars. Everything else must be welded complete. I've been building roll cages out here for almost 40 years, so Ive experienced all the transitions in the rules. NHRA dosen't make it easier, they make it harder. I suppose some big manufacturer will come along with a bolt in roll cage that NHRA will allow only after they receive sponser money. But they'll only allow that manufactured bar to be the only one due to their EXTENSIVE TESTING THRU SFI. What a bunch of ****!!!!
His rear downtubes are welded to the cross bar on the frame and are not removable without cutting the bars. They are bolted through the cab, but at the berst you would have to bend them to remove the cab. We have a simular set-up on a dirt modified. connecting the side nerf bars to the frame via tabs that allow bolting together through the body. The nerf bars have tabs on either end and when damaged they can be unbolted and replaced quiet easily.
the cage in that truck wont certify. the location of the down tubes to the rear arent in the correct location and are not allowed to be bolted. those downtubes are pointed right at teh back of the head/shoulders. In a rearward collision those tubes can and will punch a hole thru the drivers critical parts. The tubes must be welded to the main hoop up high. Those tubes that he has them on would be considered a partial funny car cage. by the rules if you put one funnycar cage bar in, you have to put the rest in. you can weld the downtubes to the fc cage but it has to be within so many inches from teh main hoop and above a certain percentage of the bend. Before you do anything else get a copy of the rulebook and work from there. it doesnt matter how you feel about nhra, its their game so you gotta play by their rulez. and I'd bolt the body down.
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