3/4 Frame for first gen?

[Tinker]

Hey all, just something for people to discuss, like or dislike. I just finished up my frame yesterday. It took a lot of engineering and re-engineering, and the photos really don't do it justice. This spring I found cracks and buckling in the floor under the rear seat, even w/ bolt in connectors. I looked @ weld ins and while the DSE's looked great, I wanted to be able to unbolt the car yet if ever necessary, so here is my version. Main rails are 2x3x.12 and the whole unit is under 40lbs. (just simple 1X2 bolt ins are 15) The whole thing is welded to the stock stub and will roll under the car and bolt right up.

Now it's crunch time cuz I want to be @Joliet for the GG show in Sep.

[dhutton]

Sounds like a good idea but it looks like you gave up a couple of inches of ground clearance. Hard to tell from the pic but it looks like it. I think that is the advantage of the DSE connectors, they don't sit low.

Maybe you could channel the floor so the rails could sit higher but still allow it to be removed.

Looking forward to some pictures of it installed.

Don

[freebird]

I like it. Can you give better pics of the rear crossmember? did you make it or was it something purchased?

[Tinker]

I fabbed the rear crossmember myself, the center arc was make from four pieces welded together the rest is 2x2 tubing. I probably have over 8 hours on that piece itself. The whole frame fits nice and tight, thats why it took so long to build. As far as ground clearance, I am giving up some, but they are 1/8 inch from floor pan, and the mufflers sit 1/4 inch lower anyway. My old leafs w/ lift bars sat 3" lower, so I'm actually going to be better.

[Silver69Camaro]

What are you going to do about the rear rails? Those are only .045" thick 2x3 open channel "rails".

[Tinker]

I am running the stock rear framerails. I do have the airbar 4-link setup, so there are twin crossbars on the cradle that will hopefully strengthen things up. Plus with the four link the rear 18 inches or so are not a direct stress member. Is there some better idea short of installing new rails or basically back halving it? I am doing more to this car than before, but it's still too nice to completely chop up.

[JRouche]

Originally Posted by Tinker

Hey all, just something for people to discuss, like or dislike.

Great welding. looks good.

Ok, only cause you asked. Just curious on a couple spots. Why lay the 2x3" tube down instead of putting it vertical. For room? May be stronger vertical. I see some flexing there.

That is a pretty long length from the rear tube of the latice to the rear cross member. I see that piece taking ALOT of load and possibly flexing. And cross bracing doesnt help much for torsional stiffness but Im wondering if the cross bars (lattice) were brought all the way back to that rear cross member if it wouldnt help. And if you thought it would help, no need to change anything. Maybe just add another lattice to fill that gap I see. Just rear of the lattice you have to the cross member.

Ok, what I do like!! The welding looks great. I really like how you tied the frame into the original frame. Id love to see some closer pics of that. Looks like you spent alot of time and thought on that.

It looks good, just the far rear section looks a lil needy IMO. JR

[nvr2fst]

Hello Cris,
I see you have your hands full. Great start. I originally planned on doing something similiar, but channeling the subframe into the body, extending the subframe just a tick past the firewall and turn radius into the rockers. The rockers of course were to be redone utilizing them as part of the chassis for ridid strength. I may still have some photos from the initial cutout and mock up to help you out. Where are you located in WI. Im in Delafield.
PM me any time if I can help you out.
Dave

[camaro2nv]

Originally Posted by Silver69Camaro

What are you going to do about the rear rails? Those are only .045" thick 2x3 open channel "rails".

Run the Morrison clip.

[Tinker]

Hey thanks for all your input. I knew I could get some opinions on both sides of the fence. For now, this is it and we'll see how it holds. I did do a lot of laying under the car and thinking. The tube is layed down to match the original rails and maximum clearance. I could put more bracing, but the exhaust is in the way. There is only 12" from the lattice to the rear crossmember. I am hoping the fact that the lattice follows the drop in the main rails adds a third dimension in the frame. Just bouncing on one corner sure seems to have stiffened the torsional capabilities of the frame. Anyway, it is time to put 'er back together. Thanks for all the input maybe my next car will have a full frame and cage, cuz I sure enjoyed this bit of fabrication and by looking at some of your rides, overkill isn't in any of our vocabularies.
Keep an eye open for updates in the new members rides posts.