My 1970 Mustang project - Frame/Floorpan/Subframes.

Discussion in 'Classic Mustang Specific Tech' started by BlackGMC, Feb 19, 2007.

  1. Hack

    Hack Active Member

    Joined:
    Mar 24, 2004
    Messages:
    1,916
    Likes Received:
    8
    Trophy Points:
    39
    Location:
    Minneapolis
    I'm interested in what you do with the suspension and to see your floorpan work. I'll try to go easy. :D
     
    #21
  2. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    Thanks man, ordering steel today for the rear crossmember.
     
    #22
  3. Max Power

    Max Power New Member

    Joined:
    Jul 31, 2003
    Messages:
    1,776
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    St Paul
    BlackGMC, you put any engine you want in there. It's not like you are cutting up a Boss or a Shelby. I am a big fan of innovation, so make it cool and make it fast. I look forward to future pics on the project, as my 1970 Grande is gonna need a fair amount of similar work.

    LOL@ Hack. Yup, you sure got me figured out, pardner, I'm a hardcore Chevy lover. In my 45 years on this mortal coil, owning over 40 vehicles, I have never even sniffed at owning a Chevy. I have 4 Fords in my driveway right now. Your assessment of me is about as accurate as your assessment of GM engineers intentions. I can pass along your comments to the engineers if you would like. I am sure they would get a good chuckle out of it.

    I was thinking we could have an objective discussion about engine nomenclature, but I guess I was wrong. I would suggest if you would like to continue discussing this engine family, you woulkd like to read up on it first. This book would be a good start:
    http://www.cartechbooks.com/vstore/showdetl.cfm?DID=6&Product_ID=2277&CATID=3



    As far as the HP output of a 267 Chevy from 1981, I am not really sure why that non-sequiter made it into the discussion. If I remember right, the hot new 255 windsor Ford made a whopping 115hp that year as well. What's your point? ALL manufacturers were struggling with CAFE and emissions requirements and getting engines to comply while still making horsepower. Even Ford Turbo 2.3 and Buicks turbo 3.8 were an embarrassment. But that is a different issue for a different thread.
     
    #23
  4. Hack

    Hack Active Member

    Joined:
    Mar 24, 2004
    Messages:
    1,916
    Likes Received:
    8
    Trophy Points:
    39
    Location:
    Minneapolis
    I don't think I said you were a Chivy lover. I'm sorry I made you feel uncomfortable in that regard. No I'm not going to read a book about Chivys; I don't much care about them.

    I'm also very secure about my conclusions about changing tooling on an engine being expensive. If the engineers at GM believe it isn't I'd be very surprised, but you and I know they aren't the ones making decisions like that. There are bigshots looking at the overall picture and they are going to be the only ones making changes such as retooling/redesigning the small block V8 engine. They also have accountants to look at cost vs. benefit on the financial side. I'm not sure why you refer to engineers and talking to them as if knowing some engineers makes you an authority. I'm an engineer and my elective focus was in engines and powertrains, so the word "engineer" doesn't intimidate me at all.

    I guess I'm not going to say any more about the original thought, because the conversation seems to be digressing. I'll try not to be a further bother to the thread.
     
    #24
  5. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    I got my $50 Oreilly autoparts (competition engineering) roll bar in today. It actually follows the roof line decently. Below are some pics of it mocked up.
    [​IMG]

    In this pic you can kinda see the headliner bar right above the roll bar.

    [​IMG]
    [​IMG]

    Backing plate for the crossmember and roll cage mocked up. I and also going to weld it to the leaf spring mount. I used 1/8 (~11 gauge) steel.

    [​IMG]

    Mockup of the cross member. It still needs to be trimed to fit and aligned and leveled but I just wanted to see how it would work.

    [​IMG]
     
    #25
  6. mattrod70

    mattrod70 New Member

    Joined:
    Mar 31, 2005
    Messages:
    54
    Likes Received:
    0
    Trophy Points:
    0
    is that crossmember just a support to help with flexing across the body, and to mount the cage? or are you strengthening a weak part of the unibody?
     
    #26
  7. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    I guess a little bit of both. That crossmember is going to connect to the front and rear subframes, in hopes of making a uni-body car into a frame car.
     
    #27
  8. mattrod70

    mattrod70 New Member

    Joined:
    Mar 31, 2005
    Messages:
    54
    Likes Received:
    0
    Trophy Points:
    0
    so your going to come back from the back edge of the front subframes and t into that horizontal crossmember that you installed? if so that sounds like a good idea to brace the car both ways. what about the driveshaft tunnel? are you following the shape of the floor or cutting into the floor? maybe a pic from below would help once you finish it up or at least mock it up.

    matt
     
    #28
  9. mustangchris

    mustangchris New Member

    Joined:
    Jan 8, 2007
    Messages:
    44
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    san diego
    How do you plan on connecting your sfc's to your set up? are you just going to but it against you cross-member or are you going to run them along your framerails? What do you plan on making them with? Also what are you planning on doing for your floorboards? completly custom or original looking? Here is a pic of my set up to maybe give you some ideas. [​IMG]
     
    #29
  10. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    Crossmember mock up.

    [​IMG]
    [​IMG]
     
    #30
  11. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    I got the crossmember completed and mounted today. Man it was a hassle getting it to sit level with only jack stands holding it up. Here are a few pics.



    The first one is the finished crossmember, minus the driveshaft loop, which I will install in a few days. You can notice I welded two pieces of angle iron to the bottom connecting the two pies that way it will line up straight.
    [​IMG]

    The next two are the crossmember finally welded into its new home. I started working on joining in the rear section and you can see with the plate welded to the inside of the rear leaf spring mount.

    [​IMG]
    [​IMG]
     
    #31
  12. lauras70mach1

    lauras70mach1 Member

    Joined:
    Aug 1, 2004
    Messages:
    203
    Likes Received:
    0
    Trophy Points:
    17
    Location:
    minnesota
    How many times have you bumped your head on the temp. crossbar?

    Nice work so far...
     
    #32
  13. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    Man, don't even ask!! The hard part is getting tools to work around those damn things, welder, welder hood, grinder and the damn SawZaw! Future reference anyone putting in temp bracing, make sure you climb over it a few times to make sure that it is at a managable height. My back is killing me crawling over those damn door bars about fifty times in a single hour.
     
    #33
  14. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    Well my project was on hold pending the delivery of the new welder. I got the welder Thursday and I finally got to start using it today. Anyways, I cut out a section of the driveshaft tunnel so I could weld in the upper part of the driveshaft safety loop. I got some 3/4 by 1/8 flat steel to make a skelton where the old tunnel was connecting the rear portion of the car to the new safety loop. Then I got some 18 gauge sheet and made a new tunnel. Let me tell yall this trying to bend 18 gauge cold rolled sheet metal was tuff!!! I finished up today mocking in the the passenger side rear seat pan. You can see I welded some of it in and I held the piece in place by using sheet metal screws. This way everything is fitted tightly together and then you remove 1 screw at a time and fill in the hole with a weld, so simulating spot welds. I did the same thing on the tunnel.

    I can say this, the new rear section is stiff. Before I ripped everything out the rear seat pans would flex and bend. The one I have in there now coupled with the new tunnel, bracing and crossmember stiffened everything up. It does not move at all and that is only with one side in!!


    Enough talk here are the pics....

    [​IMG]
    [​IMG]
     
    #34
  15. Hack

    Hack Active Member

    Joined:
    Mar 24, 2004
    Messages:
    1,916
    Likes Received:
    8
    Trophy Points:
    39
    Location:
    Minneapolis
    Looks good!
     
    #35
  16. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    More progress, I got the other side screwed down..



    [​IMG]
     
    #36
  17. 351w_swap

    351w_swap New Member

    Joined:
    May 24, 2004
    Messages:
    263
    Likes Received:
    0
    Trophy Points:
    0
    are you going to use the screw holes to spotweld the panels in? That crossmember doesn't look to have much structural support in the center, is it just for a driveshaft loop? nice project, mine is something like that, just a little more involved
     
    #37
  18. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    Yep, after I removed the screw I used a drill bit twice the size of the hole and increaced the top piece of metal, then the hole in with weld. As seen in this pic.

    [​IMG]
    [​IMG]

    The two sides of the crossmember are joined togther with a piece of 2x1/8 steel, bent in a 'U' shape, that is what the 18 gauge sheet metal tunnel is attached too. I think it is plenty strong. I banged on it with a hammer, stood on it and even jumped up and down on it and it did not move one bit, everything stayed nice and level. Granted I only weight about 160, but I don't think it will be a problem. IMO when you tie everything in together like I have, everything that is attached to the rear crossmember acts as one huge piece, that is what provides the strength. Granted I am not a car engineer, but for my purposes it think it will work. The before and after stiffness of this rear section is night and day. The before would deflect and bend, now it is as solid as a rock. Besides at heart this is still a unibody car, keeping with the uni-body idea plus adding in a cross member and other things makes it even stonger. I may be wrong thou...
     
    #38
  19. 351w_swap

    351w_swap New Member

    Joined:
    May 24, 2004
    Messages:
    263
    Likes Received:
    0
    Trophy Points:
    0
    I know tying it all together provides strength but even 1/8 steel is pretty flimsy, either way, im sure its a good improvement.

    This is my project.
    [​IMG]
     
    #39
  20. BlackGMC

    BlackGMC New Member

    Joined:
    Feb 6, 2007
    Messages:
    247
    Likes Received:
    1
    Trophy Points:
    0
    Holy crap, your car looks very nice!!!!!!!!!!!!!

    What thickness of metal did you use for your crossmembers and frame? (3/8)???

    Did you weld in a plate of steel on the inside of the rocker panel??? I did around my crossemember but I was debating on running it all the up to the front.

    Nice job, yeah yours is a little be more involved than mine.
     
    #40

Share This Page