I see guys cutting thier frames and putting in vertical C-notches for airbags, can I do that same idea but horizonally? I've included a picture of what I mean (don't let my amazing computer art skills intimidate you). The black and black outline would represent the original frame. The red would be the new part and the green would be the removed part. Maybe 5" on each side of the frame wider, I'd need to do the math for the exact number. If it would not be safe to do would I be ok in adding that extra part and leaving the stock frame if space allows? This will be supporting a new front suspension so it is something that will be seeing stress. Thanks This is looking down on the frame from above.
Take a careful look at each rail, envision the loads it will receive, then take a similar look at the entire frame. Consider bending, in the vertical plane, and torsion...twist, imagine the worst speed bump or driveway ramp taken at 45* entrance, that should be a good start.
If you're talking about putting a spring mount out on that new red part, I woudn't. That would put a twisting force on the frame. Think in terms of ft/lb, like a torque wrench, with the distance between the black & the red pieces as the length affected by the load. And a pounding load, as when you miss a driveway & a wheel jumps off the curb. This is why factory frames always are in about a straight line. Just my gut reaction from years of working under modified truck frames that have refuse bodies, sweepers, mixers, etc. Can't recall ever seeing one that went out sideways.
The front suspension from an 1986 Corvette. It has it's own crossmember and is a complete setup. I have the donor car here. This is a random picture of what one looks like I can show pics of the actual one tomorrow if needed. Thanks
Search Gambino Notch, excellent illustration and full photos of something very similar, One of my friends had a frame on a 55 pro streeted, they essentially did the exact same thing in reverse to inbound the frame for tire fitment, his tops of the notch were connected as he put coil overs to carry the load. You would have to connect or box the frame in my opinion, join the rails.
Well, alot frames have the rails widen immediately behind the front suspension area to becomw "perimeter frames. But in those cases they employ what is commonly referred to as "torque boxes" to contend with the various forces mentioned above ny earlier posters. IF you take into account those forces and buld beefy enough, it should work. Its just that the ariginal rails may not have adequate 'twist' resistance in stocl form. Perhaps boxing them (if they aren't already) certainly would help. Ray
I did it to an F100 frame, but for the rear with Corvette Suspension. It has been on the road for a few years now and no problems what so ever. I think if it is done with proper fabrication techniques and the original or a suitable cross member tying the rails together it won't be a problem in the front either
I'd want to see a side view of the rear end's pinion bracket on Hotroddon's. I put a 4x2 crossmember tube just forward of the pinion seal and formed a 1/4" steel hanger bracket to pick up those two large bolts. It and the rear batwing are lifting the front wheels if you hook up.
Done well, and done with intelligence, it will be more than ok imo. Lacking either or both, it won't be ok. This is one of those situations where common sense rules the day.
Boxing the stock frame will be done for sure. I've been doing some measuring and might be able to clip the stock frame with the Corvette frame. Not sure yet. Thanks for all the replies guys.
It will take some time to do and you'd have to make 2 of everything for each step, but I see it being better if you can use curves or frame sections vs mitred cuts/welds. Each mitre is a point for stress and failure. Hard to say in words, but if you look at the Vette frame you may be able to section parts of it out and end up with what could essentially be a mandrel bent frame instead of being **** welded. Anything can be done as long as you view the loads right. Become the tire and the weight and the force it will see hitting a hole in the road. As was said a stout cross member will tie it all in. Don't forget inner fish plates with rosette welds to give some internal strength, and just like sheetmetal, jump around with the welds and keep their pulling forces in mind. Sounds complicated but it's really not. My description's more complicated...
The pinion support on this is the original Corvette arm that we shortened. There is a tab at the front that uses a urethane bushing to bolt it to the stock Ford crossmember that is directly above it. I have also installed a bunch of these using this set up;
Don, The brackets look good and stout! Thanks for showing this approach. In narrowing the tread width by 1.87" per side, I ended up having to cut large keyholes in the frame to accept the control arm pair (front-ends) bushed ends. Much better to place the bracket as you have done, if the build allows this.
What about making the notches using 45's, making a 90...so it goes straight out, forward then straight back in....make some fish plates, however you think would look good. Then just like you have illustrated in red, make gussets from 2x4 tubing or whatever size matches up..... We must have gone to the same school of illustration and design..... The longer you run those tubing gussets out on the framerail, from the outside edge of the notch, the more your're gonna spread out that load force....same concept as what The Highlander is saying about using curved pieces. My idea might be uglier than making that with curves, but I think it would be stronger all fishplated up and properly welded.
Make sure you check the donor frame to see what it's made out of. Current Corvette frames are hydroformed aluminum, but I don't know when they started doing them that way (might have always been aluminum, might have been steel at some earlier time, I don't know). What I do know is that if your stub is aluminum, attaching it to your existing frame is going to get complicated pretty quickly. I think your original idea or Dub's will work just fine, you'll just need to make sure the corners of the kickouts are hell for stout, because they're being loaded in bending in two directions (or bending and torsion if you prefer). Look at the shape that Chevy used in their 68-72 Chevelle frames where they widen out at the firewalls (narrow in front for the IFS, then wide for the body to mount, then narrow again for the rear suspension). The big box section that you'll find there is what the guys above are calling the "torque box". A fully enclosed cube is a very effective structural shape when being loaded in more than one direction. Use this fact to your advantage. Good luck on your build, I hope it turns out like you want it to.
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