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Rollcage question-lateral supports #2837773
10/26/20 08:30 PM
10/26/20 08:30 PM
Joined: Jul 2005
Posts: 1,217
Penna
7
70satelliteguy Offline OP
pro stock
70satelliteguy  Offline OP
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Penna

In order to certify ,what do you guy's have your rear lateral support bars welded to? The S&W website where I plan on getting them from shows them welded to a floor plate but someone suggested cutting a hole in the floor and welding them to the frame connectors. This is for a 70 B body running 8.50 and slower certification.
Thanks Mike

Re: Rollcage question-lateral supports [Re: 70satelliteguy] #2837824
10/26/20 11:24 PM
10/26/20 11:24 PM
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Oregon
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AndyF Offline
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I'd go down to the frame connectors. Maybe even X them so they go to the opposite frame connector.

DSC_3303 (Large).JPG
Last edited by AndyF; 10/26/20 11:40 PM.
Re: Rollcage question-lateral supports [Re: AndyF] #2837835
10/27/20 12:06 AM
10/27/20 12:06 AM
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MI, usa
dvw Offline
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Mine land on a plate welded to the top of the ladder bar brackets. Transfers the load into the entire cage structure. 8.50 cert. Been recerted twice to boot.
Doug

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Re: Rollcage question-lateral supports [Re: dvw] #2837874
10/27/20 07:06 AM
10/27/20 07:06 AM
Joined: Jan 2003
Posts: 11,910
Marion, South Carolina [><]
an8sec70cuda Offline
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Mine are welded to a plate right in the corner of the floorpan and driveshaft tunnel.


CHIP
'70 hemicuda...8 sec street car
'69 road runner 440 w/ Indy SRs
'69 road runner 440-6, 4 speed...Dad's ride
'71 Demon 340 resto project
'06 GMC 2500HD LBZ Duramax...toy hauler
'16 Grand Caravan SXT...baby hauler
Re: Rollcage question-lateral supports [Re: an8sec70cuda] #2837876
10/27/20 07:10 AM
10/27/20 07:10 AM
Joined: Jul 2005
Posts: 1,217
Penna
7
70satelliteguy Offline OP
pro stock
70satelliteguy  Offline OP
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Posts: 1,217
Penna
Thanks for the reply's. Will it cert with plates?
Mike

Re: Rollcage question-lateral supports [Re: 70satelliteguy] #2837877
10/27/20 07:12 AM
10/27/20 07:12 AM
Joined: Jan 2003
Posts: 11,910
Marion, South Carolina [><]
an8sec70cuda Offline
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an8sec70cuda  Offline
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Originally Posted by 70satelliteguy
Thanks for the reply's. Will it cert with plates?
Mike

Yes, mine is NHRA cert'd to 8.50. Well, it's expired, but it certified no problem in 2008. grin


CHIP
'70 hemicuda...8 sec street car
'69 road runner 440 w/ Indy SRs
'69 road runner 440-6, 4 speed...Dad's ride
'71 Demon 340 resto project
'06 GMC 2500HD LBZ Duramax...toy hauler
'16 Grand Caravan SXT...baby hauler
Re: Rollcage question-lateral supports [Re: 70satelliteguy] #2837888
10/27/20 08:06 AM
10/27/20 08:06 AM
Joined: Nov 2015
Posts: 448
Missouri
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jwb123 Offline
mopar
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Missouri
As far as I know, welding to plates will certify no problem. The certification is to make sure if you wreck the car the cage will protect you. BUT, you install a cage for two reasons, safety and strength of the chassis, by welding to a crossmember, or the frame, you increase the stiffness of the chassis, a lot more than plates on a sheet metal floor pan.

Re: Rollcage question-lateral supports [Re: AndyF] #2837932
10/27/20 10:07 AM
10/27/20 10:07 AM
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Trumussia
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jcc Offline
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Originally Posted by AndyF
I'd go down to the frame connectors. Maybe even X them so they go to the opposite frame connector.


The solution pictured makes me a bit uncomfortable concerning based on what I see, with the bent ends on main bar x brace, and that the bottom of the main roll bar and the x brace ends are not substantially tied together, which makes for a weak design load path for any side impact loads on lower main roll bar. Might certify fine, but IMO, a lacking solution.


Discovering "good trouble" everyday
Re: Rollcage question-lateral supports [Re: jcc] #2838063
10/27/20 04:32 PM
10/27/20 04:32 PM
Joined: Dec 2005
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Fulton County, PA
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CMcAllister Offline
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Fulton County, PA
Plates on the driveshaft tunnel are legal. I much prefer frame ties sectioned into and welded to the floor with "outriggers" from the framerails to the rockers also through the floor. Then the main hoop and diagonals set directly on those frame pieces. This rather than floor plates.

And Xs and triangles are your friends in your efforts to stiffen the thing up.


If the results don't match the theory, change the theory.
Re: Rollcage question-lateral supports [Re: CMcAllister] #2838070
10/27/20 04:51 PM
10/27/20 04:51 PM
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MI, usa
dvw Offline
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dvw  Offline
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MI, usa
The outriggers tied to the inner rocker is stronger in my thought. I plate the inner rocker as well. Cutting the floor out large makes full welding access easy. The removed portion is easily trimmed and welded back in to fill the hole. Subframe connectors are welded solid to the entire floor pan. Even with stock rear rails the chassis remains stiff. Always leaves level with no twist. Has been numerous 1.25-1.26 60 ft off the foot brakes on 10.5s.
Doug

Re: Rollcage question-lateral supports [Re: 70satelliteguy] #2838178
10/27/20 11:02 PM
10/27/20 11:02 PM
Joined: Oct 2007
Posts: 455
Minnesota, USA
humpty Offline
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Minnesota, USA
I built my first 8.50 cage this year. I also used an S&W kit, Chromoly to boot. The best call I made before the build was to our division NHRA chassis inspector. I had that guy on speed dial and he was happy to answer all my questions. By the time he came to certify the cage it was a matter of formality. No drama! As others have already noted, anytime you can tie directly into a frame component the better, including the lateral bars (referred to as D bars in NHRA general regulations). Cheers!

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