Agreed on the rear frame rails. Are you going to make a cross member to weld the rails back onto ?
I used a 2×4 .125 thick to tie them into along with my subframe bars.
My stuff is all heavy 1/8 inch but it should really keep the chassis stiff.
Bostonian 71 demon
- Thread starter B.R.E.Demon
- Start date
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I used a 2×4 .125 thick to tie them into along with my subframe bars.
My stuff is all heavy 1/8 inch but it should really keep the chassis stiff.
That's how I felt about my titanium retainers, wasn't really as light as I had hoped.
B.R.E.Demon
Well-Known Member
Here’s a clearer photo to illustrate what I’m planning and the reasoning behind it. The red line represents the new frame rail, which will be relocated to align flush with what was originally the inner edge of the factory rail. This shift will bring the rear frame rails perfectly in line with the front rails, allowing for a straight and structurally sound path for the subframe connectors.
The connectors will run from the leaf spring boxes, through the new rails, and into the original torsion bar crossmember. From there, 1" outriggers will tie them into the rockers for additional support.
Out back, the rear rails will be bobbed at the wheel well opening. A boxed section will extend from there to the quarter panel extensions. The new rails will be butted against the inside edge of the old ones and welded together, with the tops boxed in to maximize strength. The green in the photo indicates where the boxing and reinforcement will be added.
Hopefully this makes the layout and structure a bit clearer.
The connectors will run from the leaf spring boxes, through the new rails, and into the original torsion bar crossmember. From there, 1" outriggers will tie them into the rockers for additional support.
Out back, the rear rails will be bobbed at the wheel well opening. A boxed section will extend from there to the quarter panel extensions. The new rails will be butted against the inside edge of the old ones and welded together, with the tops boxed in to maximize strength. The green in the photo indicates where the boxing and reinforcement will be added.
Hopefully this makes the layout and structure a bit clearer.
rmchrgr
Skate And Destroy
Unless I'm missing something this is fairly major surgery. I know I'm stating the obvious but presumably you have a frame jig lined up for this job. Not much is going to be left of the OE unibody as you're pretty close to full tube chassis territory. At the same time most people in this situation don't make these kind of 'retro' aesthetic choices and the body ends up very low with 14x32" tires tucked under the wheel openings. Never liked the way those types of cars look myself but I get they are purpose built and a period correct appearance is likely low on the priority list.
I know you've studied this stuff to a finite degree but that said - how was this sort of thing done in 1971 (if it was) and are you going about it in a different way? Did individual racers make their own choices or were there directives given out from engineering? The Missile was the model but it's hard to know how much of that data was given out to the privateers.
What is the floor going to be like when finished, just panels? Imagine the trans tunnel will be removable for service.
Good luck with this.
I know you've studied this stuff to a finite degree but that said - how was this sort of thing done in 1971 (if it was) and are you going about it in a different way? Did individual racers make their own choices or were there directives given out from engineering? The Missile was the model but it's hard to know how much of that data was given out to the privateers.
What is the floor going to be like when finished, just panels? Imagine the trans tunnel will be removable for service.
Good luck with this.
abdywgn
dismantler
are you going to open up the back of the transmission cross member and have the tubing inside of it? maybe all the way to the upward bend of the front frame rail? guess if you did that, you could almost eliminate that portion of the frame rail and just have round tubing; or were you using rectangular?
B.R.E.Demon
Well-Known Member
Yes I have a jig available the original floors will be retained. The rules will require factory front and rear rails but otherwise its fair game the stance will be that of don Carltons 72 demon (bruise).The tire size is 14x32
In 70-74 there was no set way these cars were designed. By 75 they were becoming more standard but modifications like this or narrowing where common. The ideas that worked where given to other manufacture backed teams. They then tricked down to private guys
The floors will be factory and carpeted the trans tunnels will be removable and carpeted too
B.R.E.Demon
Well-Known Member
Yes I will be running through the trans cross and into the back of the rails. the subframe connectors will round chromoly. I have to retain the factory rails to be be class legal as a 71-72 car otherwise it would have to be rebodied as a 73 car since that was the start of full chassis
B.R.E.Demon
Well-Known Member
No car work last night — instead, The wife and I knocked out the first draft of a general rulebook for a SEGA-style nostalgia Pro Stock class. The original idea came out of a late-night BS session at the PRI show, but it quickly started gaining traction and began shaping into something that could actually happen. So originally I didn't want any part of doing something like that, but in my DIY mindset I figure if I want it done right do it my self so we decided it was time to get the ideas down on paper and see where it leads.
B.R.E.Demon
Well-Known Member
Looks like a turtle stuck on its back—but huge shoutout to Sonny for coming in clutch and helping get this thing rolled. Doors to the blaster tomorrow and then to work on the bottom
How would you know, you don't work in ounces..
B.R.E.Demon
Well-Known Member
Taking a quick pause from all the Pro Stock planning to focus on the real Pro Stock priority—the Demon. Last night, I took the C10 out to drop off the doors for blasting. Truck's doing truck things as it should. Also started marking the frame for upcoming cuts. Progress continues.
B.R.E.Demon
Well-Known Member
Made a run up to Morrison yesterday morning to pick up a pair of vintage bucket seats for the Demon. (I’ll be selling my reproduction ones.) I believe these are old A&A Fiberglass units, but either way, the covers are perfect for creating fresh patterns. I also brought the shop helper along for the ride — he slept most of the way up.
On the way back, we swung by the old Bandimere before heading home. Got a good afternoon's worth of work in: removed the old frame rail and started installing the new one, which is moved in 2.5 inches. So far, everything is square, and we’ll end up with an 18.25-inch wheel opening from the quarter panel to the rail.
On the way back, we swung by the old Bandimere before heading home. Got a good afternoon's worth of work in: removed the old frame rail and started installing the new one, which is moved in 2.5 inches. So far, everything is square, and we’ll end up with an 18.25-inch wheel opening from the quarter panel to the rail.
Lol, yeah I probably shouldn't assume I knowHow would you know, you don't work in ounces..
That looks really nice !
B.R.E.Demon
Well-Known Member
Normally, I would have used a frame jig for this, but there are a few reasons I didn’t. First, the inner portion of the original rails is still intact. I overlaid the new rail section on top of it, effectively doubling the structure. Additionally, the fully welded cage — which was previously verified for squareness — is serving as an integral jig, adding further stability. The car’s rigidity is also enhanced by multiple tie-ins between the chassis and the cage using tabs, gussets, and brackets to prevent any movement. Finally, I’m only replacing one side at a time, meaning the opposing rail remains fully secured and mounted at all times, eliminating the risk of distortion.
B.R.E.Demon
Well-Known Member
With the car torn down and work underway on the frame rails, I’ve been considering modifying the wheelbase, similar to how it was originally done years ago. The plan would be to maintain the 108-inch wheelbase but shift it forward by 1.5 inches and re-center the front end. After talking with the guys who originally made the modification, I’ll most likely move forward with it — and yes, it will be done properly on a jig.
Yeah that's good that you know you're square.
I unfortunately didn't think to use any of my carpentry skills and basically did everything by eye. There's some things I'd do differently on the next car. 1st will be taking the car to a frame shop to verify the car is where it should be and ask them where the measuring point should be taken from. Where I'm at on the car is sorta guessing stuff was correct. I ran into the part where I noticed I should have measured stuff when I installed my rear cross member which my frame rails are welded to, it seems to be correct but I will see the first time I go for a rip.
Looking very nice and great job as usual.
Yeah the diamond pleated covers for the poly seats would period Correct for the seventies during the '80s is when the square blocks came out on the covers....nice score!! Are you gun drilling any titanium bolts?
B.R.E.Demon
Well-Known Member
Yes I plan to modify every part on the car one way or the other.
B.R.E.Demon
Well-Known Member
With the weather keeping me from pulling the truck out last night, I went ahead and marked where I’ll need to notch the floor pan for the ladder bar brackets. It also will give me a chance to get underneath and tighten the rail to that side of the pan. The clamps are off now — everything’s self-tapped into place — so the next step is welding. Progress is a bit slower than I’d hoped, but I’ve got myself far enough ahead that I can take my time and chip away at it."
B.R.E.Demon
Well-Known Member
Spent the day in the shop—got the passenger side frame rail about 80% finished and knocked out the ladder bar pocket. Just need to pick up some steel tomorrow to button up the rest. A surprise afternoon storm rolled in and the C10 got caught outside, but thankfully no hail. Later, I took some measurements on the new spring box and, sure enough, it’s got 1.5 inches of relocation built in—perfect for running the altered wheelbase setup.
abdywgn
dismantler
are you altering the rear only or both front and rear suspensions?
B.R.E.Demon
Well-Known Member
Front also I moving 1.5 inches forward on both
abdywgn
dismantler
ho-boy! that's gonna be a bit of work. but work fascinates me, I can watch people do it for hours!
looking forward to "seeing" how that is accomplished.
looking forward to "seeing" how that is accomplished.
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