Car in question is my 31 coupe. plans are for a sbc and spring on the bones with suicide axle and big kick up in the rear and another in the cowl. Aprox how much 2x3 should i get? I could prob figure this out but me and math are not getting along at the moment so i thought i would ask yall. And another question what wall thickness did you guys use for your rails? How about one more?.... Did you use round stock for your cross members or is square the way to go. Im guessing round would be cleaner and easier to work with in this area but id rather ask then get it wrong. Theres no such thing as a dumb question right? *Edit*... I have a junk model A frame for front and rear spring cross member mounts Thanks again Bryan
1/8" wall should be good. The kickup will probably require you to get more than one stick of tubing (it comes in 20 foot lengths)...you need to get in there with a tape measure and figure out how much you need, draw a full scale drawing on the floor if you have to to make it easy. Also think about the taper at the front, how you're gonna do that. round crossmembers do look a lot better than square.
Hmmm, length of desired frame times two plus width of desired frame times two for a 'square' frame sounds about right, eh? Add a few more widths if you intend to make your crossmembers outta the same ****.
Pete,sounds like math was an "I`ll never use that in real life" kinda thing LOL. A refresher course in geometry would help me a lot at times. On the frame, get more than you need of everthing, you will use it before you know it. Measure,ponder, measure,think about it, CUT ,weld, have fun. Jerry
1998 S-10 frame is direct bolt-on. Seriously though, I have heard of guys building the frame out of wood first to get everything mocked up... then you'd know exactly how much to get.
That right there is the smartest thing ive ever heard a rock star say i forgot all about sporting wood first... time to go to home depot!
Shouldn'ta oughtta said that...he'll run a wood frame on this heap!! (But on the plus side, it might be easier to FIX!) Go the S10 route.
i got a stack of 2x4" sticks under my coupe for that VERY reason... build it outa lumber first, get all the ******** "oops i shouldnta cut it like that" out of the way and then i got full size templates to cut the steel out of. T
I could be mistaken, but aren't re-pop "A" ch***is typically built out of 2" X 4"? I'd agree that .125 wall would be fine. The 4" let's you do the taper more "original" looking if you're planning to do the taper. Maybe check the A ch***is you have for the rail dimensions. Regarding crossmembers, if you're doing a "K" member of sorts for the transmission, round would look nicer in my opinion (what do I know though) but then you have to deal with "fish-mouthing" the tubing where it meets, not all that difficult even without a notcher but more involved than square or rectangular tube.
I've got an A ch***is here I could check if you need it.....but I agree with the above statement. I like 2X4 tubing. I think it looks a little sturdier than 2X3.
I used about 30' of 2x3" x.125 tube,for my A sedan ch***is. Your dimentions may vary,according to how you do your x_members.etc.Sparky
Here's the Model An frame dimensions from the wescott page, it's in Adobe acrobat format, so you'll need that to see it. Here's a free download if you need it:http://www.adobe.com/products/acrobat/readstep2.html And here's the frame dim.s http://www.wescottsauto.com/pdf2/FR-2.pdf Oh yeah, 2"x4", .120 or .188 wall would be the way to go. The more HP you put in the car, the thicker the frame wall section needs to be, as well as good crossmembers and triangulation of said crossmembers.
Hey Bryan, do you have a place to buy the stuff? I found some place in the bowels of Detroit once but they were closed when I went there even though they said they'd be open. I think it was a snow day though. Anyway, outside of Home Depot Racing Supply and Lowes Kustom Kar Paradise I have a helluva time finding anybody that sells raw material. I know they're around, I just don't know where.
I buy steel from a couple places around here. Metal Mart on Dequidere & 12 mile in Madison Heights, Metal Supermarket in Troy, 1250 Rankin Avenue. Both places have given me good deals and will deliver cheap.
yea ive used both of them metal mart is cheeper and faster. I live like 3 min from metal super market so in a jiff i just go there. I did some half h*** mesurments today and figured 44 feet would be more then enough to do some preety healthy kick ups and do a sweep. but ill start with the wood this weekend and see what i end up with.. it was like 190 bucks for 44 feet for 2x3x1/8 wall but the frame i have does look more like 4" so perhaps that is the way to go.
Thoughts 'bout fabin' a tube frame..... Round tube (pipe) is great for compression loads, but not for torsional loads. Think about it, when was the last time ya saw an automobile frame made of round tubing? Ask any real Cobra or faux Cobra kit car owner 'bout pinched arms, from door gaps that close up under torsional body loads; Cobras have always used round tubing for frames. Any frame ya build has ta be able ta handle torsional as well as compressional loads. If it can't, count on sagged side rails, ****ed up tyre wear, poor panel fitment, and shopping cart handling. This holds true for cross and ''K'' members, as well. Any load bearing member has ta be able ta handle these forces well, or they are jus' extra weight on the drag strip.
I don't have any experience with Cobras (I suppose we're talking kit cars?) but regarding square/rectangular tube vs. round tube I've always felt that pound for pound the round will out-perform sq/rect. Material for a K-member I would envision 2 parallel tubes of small dia. tubing in the .083" to .095" range with angled braces to support the load and add torsional rigidity to the frame ***embly. pimpin paint...when you say torsional load are you referring to bending? I'd take torsional to be rotation/twisting along the length of the material. I'd take the round there too. Just my $.02
A round tube should resist torsional loads better. The rectangular tube, set up the way you'd set it up in this case, is better capable of handling bending moments. Anyway, you don't see modern race cars welded up from square tube. I think a lot of the square tube structures you see are built because it's easier to cut the angles and weld the **** together. Bryan, maybe you should make your frame rails out of sewer pipe. And use the rails as gas tanks. Hell, make 'em pontoons and run it out to Boblo once in a while. Oh, by the way, thanks for the metal store suggestions. Good info.
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