I’m at that point where I’m about to start cutting and welding in a new frame for the Datsun. The Datsun is a unibody, with two frame rails that run from the front of the car to just about where the doors end. This all needs to come out and be replaced.
I’d replace metal for metal, but these were designed to be economic, not structurally sound. I’d eventually want to tube the cabin as well to tie in the back of the car.
So, a few preliminary design considerations;
What’s the “standard” diameter/thickness/metal type for a roll cage?
When I square of the back of the car with the front, where are the best places to ties in to?I’d be curious about the metal type/thickness for the frame replacement, but I guess that’d be subjective to the car itself.
This is my first time doing something like this. Any other thoughts/suggestions/etc are welcome.
Building a cage is a bitch. FYI, a full 10point chromoly cage is costing me 1200 from vito antonicelli.
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From the looks of it, it will take a lot of cutting-fitting-bending-repeat. I don’t expect to build a full roll cage off the bat, just something I can square up the car with so IF it becomes a torque monster, it won’t wack anything out of shape. Being a crappy unibody, the Z’s are notorious for it
From the looks of it, it will take a lot of cutting-fitting-bending-repeat. I don’t expect to build a full roll cage off the bat, just something I can square up the car with so IF it becomes a torque monster, it won’t wack anything out of shape. Being a crappy unibody, the Z’s are notorious for it
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Yeah, but i’m telling you right now, it’s a fucking bitch. more work than you realize.
Fair gentleman Z just added 4 bars to his existing cage and i KNOW that was no small task.
It’s a lot of work; I did a tube-frame back about 10 years ago for my Nova and it took a long time and lots of tacking, grinding, fitting, and then finally welding. Plus mine was all out of 1.5" DOM tubing, and 2"x3" ractangular tubing for the frame rails.
I’m at that point where I’m about to start cutting and welding in a new frame for the Datsun. The Datsun is a unibody, with two frame rails that run from the front of the car to just about where the doors end. This all needs to come out and be replaced.
I’d replace metal for metal, but these were designed to be economic, not structurally sound. I’d eventually want to tube the cabin as well to tie in the back of the car.
So, a few preliminary design considerations;
What’s the “standard” diameter/thickness/metal type for a roll cage?
When I square of the back of the car with the front, where are the best places to ties in to?I’d be curious about the metal type/thickness for the frame replacement, but I guess that’d be subjective to the car itself.
This is my first time doing something like this. Any other thoughts/suggestions/etc are welcome.
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square tubing common sizing is 1X4X.120wall with no interior cage and 1X3X.120wall with an interior cage.
round, meh, just go square
—make sure if u want to race it that you check with you sanctioning bodies to check for legalities and rules issues
post some pics of the tube chassis that you have built.
even:
post pics of anything you built?
k.
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:lol::headbang::headbang:
Adam, you dont wanna go full tube frame. Between the money and the complexity, it’s not something you want to get into, and not something for a shade tree mechanic to do. There is a reason that there are shops specifically for cage/chassis design. It’s not as simple as “I saw this and it looked good so I’m going to copy it”.
Guess I should put my primary focus in to perspective:
Most concerned is replacing the the frame rails. If I screw up thte project, this is where it can happen.
Second, is tying in the front of the car with the rear, as the car is a unibody and only two rinky-dink rails run from the front of the car to under the car seats.
Last is adding any additional structural support, not necessarily an entire cage, but something to provide minimal flexing to the car if/when the LS motor goes in next winter. The last step ca be accomplished next winter, as an el-cheapo KA24de from a 97 240sx will go in till then
Well, I did some measurments, for the sake of consistency and less “improvising”, I’m going to replace the frame with the same dimensional tubing, which is 2.5 x 2.5. The original frame rails was thin ass sheet metal, so I’m sure any wall thickness as low as 1/16 inch will be twice as thick as the original, but I’ll probably get 1/8 inch wall. Gonna pick up a few 5-foot long pieces in a few
Putting stiffening members on a structure without tying it into the rest of the car will do NOTHING. It’s like reinforcing the middle of a piece of paper with carbon fiber, then trying to use the whole sheet to suspend some weight… If you want increased stiffness, you need to tie in to the important parts of the car:
front crossmember
rear diff carier
motor mounts
trans mounts
shock/strut towers.
if you need/want pre fabbed floor pans and/or frame rails charlie osborne at zedd findings (datsunzparts.com) makes them, and they’re relatively cheap. oem cut.
Putting stiffening members on a structure without tying it into the rest of the car will do NOTHING. It’s like reinforcing the middle of a piece of paper with carbon fiber, then trying to use the whole sheet to suspend some weight… If you want increased stiffness, you need to tie in to the important parts of the car:
front crossmember
rear diff carier
motor mounts
trans mounts
shock/strut towers.
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That’s going to be done. Before I start trying the car together, I need to completely cut out the existing frame due to rust.This will be metal-for-metal replacement so I gain structual integrity to build from, not with the notion this will make it a solid car. I’ll take pics of what the frame looks like now, it’s hideous. I have full expectiations of doing the rest of the car, and I’m sure many more questions will follow with that as well. :tup:
