CK5
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1991 Volcano K5 - Family Wheeler - Fully Independent Twin Turbo BBC

Plate under the body too?

That’s the hard part about the dealer add-on bars. People kept the roll bars but not the bottom plate.
 
Plate under the body too?

That’s the hard part about the dealer add-on bars. People kept the roll bars but not the bottom plate.

Yes, I made reverse plates for under, and I used some more 1/8 steel to tie it into the cross brace under the bed. I think the cage would be way too weak without either welding the top plates to the floor (not ready for that) or adding the sandwich plates under.

For now I did the sandwich thing for the beginning of an 8.50 cert per NHRA spec, I temporarily treated it like a unibody car, 6x6 1/8" steel plates top and bottom with four 3/8" bolts. I am only building the rear half currently, not making A pillar bars and/or a front halo yet. When I build the new chassis I plan to tie the cage into that chassis, which is why I didn't just weld the plates to the floor I haven't decided if I will just go solid body bushings or try to add poly bushings to the cage tie ins. IMO the cage tie ins and body mounts need to match and I am not ready for that quite yet. The tubing is 1 5/8" x .083 wall 4130 chromemoly which is what I used in my Regal per NHRA spec. This is not going to fully adhere to any NHRA or SCORE rule book, this is going to be a compromise for useability and access. Plus its basically a 4WD dune buggy that I will also do short 300 ft sand and dirt drags, I'm not going to be going 120 MPH like a trophy truck or over 150 MPH like my Regal, nor am I a rock crawler that might fall considerably and land upside down on granite.

This was just a mockup before I rounded the corners a little and it will come apart for paint once the double roll bar is done.

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Does anyone know if this green stuff is factory for 91? Its pretty light stick on foam over 1/2" thick, but I worry a little in the midwest it will trap moisture. It seems patched in there so I am guessing not?



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Spray on 'second skin', or some other stereo related spray on. There's a few.
They don't off gas like bedliner, and can't get moisture behind it like stick on mats can.
 
I’ve seen those. The spraying would be the hard part but could be made to happen.
 
I feel like a sound deadener with a soft top is kind of pointless.

If I did anything it would be something lightweight and probably spray on, but not at this time.

I'll probably just pull that stuff out and leave it empty for now.
 
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Adding deadener to panels cuts down on the rattle and resonance and psychologically makes the whole vehicle feel tighter. Lining the floor can cut engine and road noise. If you drive on the freeway, the dominant noise is probably all of the other traffic and you're right that the soft top will just let all of that in. "Noise" is the unwanted signal, so BBC vrooms aren't part of that category.
 
Work in progress...

I added 1/2-13 weld nuts to inside the cage plates. In The future this will allow me to use a body mount bushing under it and bolt it in to tie it to the chassis, or bolt it in solid. At first I tacked the weld nuts in 4 places because they just needed not to spin. But then I wanted them sealed like the cage will be so I tacked them all the way in, ugly weld but functional and hidden. I milled a flat recess to make sure the nut was parallel on the overlap.


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Then I started adding in cage bars. I used masking tape to mockup the bar angles before I cut/bent them. I thought about putting a bend to angle the rear bar more, but its stronger when straight, and it fits against the softopper better, I forgot to take a picture of that, but it fits against it nice.

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I was going to put the front of this diagonal tube higher, right under the top tube, for a little more strength, but it moved it up and in and too close to the rear passengers heads, so I compromised and put it there, still stronger than a horizontal bar.

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Here you can see the 1" arch that follows the roof line. You don't really notice it because it matches the ceiling.

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I'm still deciding if I will add a middle floor plate to the top of the wheel well under the angle bar. I also am still adding a front harness bar and roof X brace of some sort. I also plan to brace it to the upper factory seat belt bolt.
 
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