I have to cut the subframe to run the tires (275-40r17) I want. So yesterday I played hookie and started cutting. The pictures will tell the story far better than I can.

This is the inside of the drivers side in front of the tire. You can see there are two levels to the "floor" of the frame here. While I'm here I'm also going to re-inforce the floor to strengthen where the swaybar mounts.
http://www.camaros.net/showroom/data/500/medium/DSC4061.JPG

The pattern I made to raise the floor to a level area. My daughter thought the beer box material I used for the pattern with the big gulp picture on it was hilarious :)
http://www.camaros.net/showroom/data/500/medium/DSC4063.JPG

The filler piece
http://www.camaros.net/showroom/data/500/medium/DSC4064.JPG

The 11 ga re-inforcement.
http://www.camaros.net/showroom/data/500/medium/DSC4065.JPG

This part is going nowhere :)
http://www.camaros.net/showroom/data/500/medium/DSC4066.JPG

The curved part of the patch (11 GA)
http://www.camaros.net/showroom/data/500/medium/DSC4067.JPG

This sway bar is going to have to change huh !!!!!!!!! Can these things be heated and bent without damaging them?
http://www.camaros.net/showroom/data/500/medium/DSC4073.JPG

I guess you can only put ten pictures in at once???????????


The steering box location was by far the one I was worried about the most. It turned out to be no big deal......
http://www.camaros.net/showroom/data/500/medium/DSC4074.JPG

What it looks like inside there....
http://www.camaros.net/showroom/data/500/medium/DSC4075.JPG

http://www.camaros.net/showroom/data/500/medium/DSC4076.JPG

Patch welded
http://www.camaros.net/showroom/data/500/medium/DSC4079.JPG

A different angle
http://www.camaros.net/showroom/data/500/medium/DSC4080.JPG

And the payoff for all this effort :)

http://www.camaros.net/showroom/data/500/medium/DSC4081.JPG

Now all I have to do is the other side of the car :)

Lance

Looks like great fab work! Congrats.
How much would you expect this to reduce the lateral rigidity of the frame? I realize it's still boxed, but it looks like you're removing a significant amount of material.

Nice job, thanks for posting the pics!
David

Looks like great fab work! Congrats.
How much would you expect this to reduce the lateral rigidity of the frame? I realize it's still boxed, but it looks like you're removing a significant amount of material.

Hmmm I thought about that before I did it. Seriously :) (not trying to be a smart alec with that statement at all)

I think that the way it's done with the curved sections that it's not that big of a loss. The frame is two barely welded together stamped C shapes. The outer one is quite a bit thicker that the inner one. The outer one carries more load as a result, unfortunately that's where I had to cut. I also have added pieces to the top and bottom surfaces where the cuts are to carry the thicker portion of the frame to the inner face. I'll post pictures of that this weekend after I finish it (I hope). I still have to put the LS1 in and make the cut for the A/C compressor. After that it'll be off to the sand blaster and then back into the garage to have the complete seam between the inner and outer portion of the frame to be welded completely from end to end (have you ever really looked carefully at the factory welds :sad:) As a side note does anybody have ideas on what they've done to their factory frames to stiffen them? I have some ideas but I'm looking for ideas fropm what other people have done also.......

Lance

Nice job, thanks for posting the pics!
David


Your welcome

I need a bigger personal showroom though :(

Did you ever figure out what you're doing with your sway bar? I'm curious to see the outcome of all this.

Did you ever figure out what you're doing with your sway bar? I'm curious to see the outcome of all this.

Nope I haven't figured that out yet. Seems there's quite a few opinions whether you can heat them and bend them. Some people say yes and others say no. I actually thought about cutting it in the middle too and just joining it with a sleeve. Have to be quite a hefty sleeve though. ATS also sells a sway bar that is a different style that might work better but it's gonna take a bite in the budget I'm sure :)

The Subframe is at the sandblasters today so when it gets home today I'll weld all the seams completely and remove all that junky factory weld globs. Then it'll get primed and painted and put away till I get the body shell painted.

I'll 2nd the nice fab work. Really good on the welding. The after-grinding smoothness is flawless. Most people would have left the welds exposed. It scores more points for cleanliness.
Nice work on recessing the bolt, and a grade #8 at that.
If you address all the little details on the whole car, like you did on the frame, It'll be a sharp ride. Keep the pics coming as work progresses.

I always wondered what the inside of those frames looked like.

Real clean fab work! Nice job. :thumbsup:
A little trick for things like this where you get a big change in cross section like at the back of the subframe. On something like that I like to add 2 pieces of 1/8" or even 3/16" plate horizontally against the back side of the cut. They should extend well into the areas that are uncut on both ends. Looking into the cutout area they would be viewed edge on and equally spaced vertically. Trim the outter edges to fit snug against the contour of the outter filler panel. I weld them inside the uncut ends and all along the back side then mark and drill the outter filler piece with a row of holes large enough to plug weld it to them. When you`re all done grind and smooth the plug welds. This ads a LOT of lateral rigidity to the part as it`s very hard to bend steel plates edge ways. Mark SC&C

This sway bar is going to have to change huh !!!!!!!!! Can these things be heated and bent without damaging them?
Swaybars are made with spring steel, I'd put money down that if you cut and weld in the center then thats going to break unless you go ridiculously big. Also, you can't just shorten it, the ends won't reach far enough and will rub on the springs. You can't fix this by using longer end links, they just don't fit on lowered cars. That looks like an addco bar like mine, does it actually hit the tire? With my '69 the offset is pretty wide and I only have issues with the fender, simple rolling fixes that. So far I haven't been able to get the front end to walk out on me, just the back goes first under braking, neutral cornering or corner exits. currently 245/50/17 front, 255/45/18 rear. As soon as the rubber goes in the back I'll put in some 275/40's back and keep the 245 front size. That should make the handling more neutral. I'm sure Pozzi has some insight about this hehe.

Real clean fab work! Nice job. :thumbsup:
A little trick for things like this where you get a big change in cross section like at the back of the subframe. On something like that I like to add 2 pieces of 1/8" or even 3/16" plate horizontally against the back side of the cut. They should extend well into the areas that are uncut on both ends. Looking into the cutout area they would be viewed edge on and equally spaced vertically. Trim the outter edges to fit snug against the contour of the outter filler panel. I weld them inside the uncut ends and all along the back side then mark and drill the outter filler piece with a row of holes large enough to plug weld it to them. When you`re all done grind and smooth the plug welds. This ads a LOT of lateral rigidity to the part as it`s very hard to bend steel plates edge ways. Mark SC&C

I did double up the floors and roof of the cut areas but I didn't think to run intermediate gussets....oh well guess I'll do that on the next one :)

Swaybars are made with spring steel, I'd put money down that if you cut and weld in the center then thats going to break unless you go ridiculously big. Also, you can't just shorten it, the ends won't reach far enough and will rub on the springs. You can't fix this by using longer end links, they just don't fit on lowered cars. That looks like an addco bar like mine, does it actually hit the tire? With my '69 the offset is pretty wide and I only have issues with the fender, simple rolling fixes that. So far I haven't been able to get the front end to walk out on me, just the back goes first under braking, neutral cornering or corner exits. currently 245/50/17 front, 255/45/18 rear. As soon as the rubber goes in the back I'll put in some 275/40's back and keep the 245 front size. That should make the handling more neutral. I'm sure Pozzi has some insight about this hehe.

Great input, thank you. Your right about not being able to just move the ends inboard. They need to move inboard and then be bent back out to match the mounting point. Basically the angle on that outboard end needs to change to sneak in behind the tire. The tire definately hits the bar so I'm going to have to do something I just haven't decidedd what yet. I painted the sub frame yesterday so it's effectively done till I get the body painted and start putting stuff back together and come up against the sway bar problem again......

Excuse the mess but I need a bigger garage (but then don't we all :) )

http://www.camaros.net/showroom/data/500/medium/DSC04145.JPG

http://www.camaros.net/showroom/data/500/medium/DSC04125.JPG

Lance

That turned out Excellent! Congrats on a job well done. :thumbsup:

On a related note... do you have any more pics of your notch to clear the A/C compressor? I'm looking to do something very similar.

This is what I have here at work. I'll try to remember to take some better ones tonight.

http://www.camaros.net/showroom/data/500/medium/DSC04139.JPG

I didn't think I'd ever have to say this... but your subframe is too shiny! :D it's hard to make out detail.

What is the front/aft hole shown in the notch area? Is this hole stock or added for A/C lines?

I didn't think I'd ever have to say this... but your subframe is too shiny! :D it's hard to make out detail.

What is the front/aft hole shown in the notch area? Is this hole stock or added for A/C lines?

The hole is to run the smaller of the two a/c lines. It was the only clean way I could figure to route the line. I still need to get you some more pictures as you're right it's hard to tell what exactly is going on there. The hole is not stock I added it. In this picture the hole isn't there yet but you can see the issue with the fitting. I'm just going to attach a 90 degree fitting to it and run it aft to the firewall bulkhead fitting.

http://www.camaros.net/showroom/data/500/medium/DSC04127.JPG

Actually, that pic clears up a lot of questions I had.
What metal stock did you use for the notch?

Actually, that pic clears up a lot of questions I had.
What metal stock did you use for the notch?

1/8" thick sheet. I carried the vertical one all the way down and welded it to the bottom of the existing crossmember try to make it as strong as I could. The tube for the hose passage is welded to both front and rear faces and to the inside of the spring pocket. That motor mount location is probably stonger than it was stock now. The tube does make getting the top frame stand bolts/nuts in a bit tougher but it is doable.

Lance

I have to cut the subframe to run the tires (275-40r17) I want.

I was wondering what size/ offset wheel you're planning to use?
Nice work, by-the-way.