I'm in the planning and parts-gathering stages of a no-buck (almost) low powered drag car, and am going to have to choose frame material pretty soon. So, where better to go for knowledge/experience than the HAMB! I've planned to go with mild steel for five reasons (price, ease of welding, cost, ease to acquire, and affordability). Oh yeah, and it's cheaper! But, that still leaves a large amount of variables. Looking around, I've seen guys use .083, .120, .136, and .188 wall tubing in 2X3 or 2X4. Or round tube. And I've seen names like HREW, DOM and ERW bandied about. So, WTF to use? I don't want to just go overkill heavy - this should be a very light car (T-bucket or similar body) with initial powerplant being a cast off 4 cyl engine I have lying around. I'd like to upgrade to a 283 chev in the future (already have an aluminum powerglide and an early stick bellhousing); am sticking w/ engines I can afford to replace (have a 331 but am not interested in trying to race something that I can't easily afford to fix). I'd guess that the car should weigh no more than 1200-1300 lbs w/ the 4 cyl, and only get about 100HP applied to it; probably change those #'s to 1500# and 250-300HP when an upgrade is made. I've ordered the NHRA rule book to see what's legal, and been looking at what guys like Art Morrison sell, but wanted to know how some of my HAMB bretheren make these choices. After all, there are guys here who've had a ton of experience with this stuff - and aren't trying to get me to buy something. And it always makes me feel a little easier when I'm getting advice from someone who doesn't have some sales-driven agenda. Thanks in advance, -bill
I don't have any answers, but whenever I have a steel question, I go to this site: http://www.aedmotorsport.com/ Just a ton of information there.
Sounds like maybe a HA/Gr would suit your flavour do a search on here for Hambster or look here http://www.ozrodders.com/board/viewtopic.php?t=7739
HREW - Hot Rolled Electric Welded CDEW - Cold Drawn Electric Welded DOM - Drawn Over Mandrel ERW- steel tubes electric resistance welded steel tubes hope this helps bill
HREW - Hot Rolled Electric Welded CDEW - Cold Drawn Electric Welded DOM - Drawn Over Mandrel ERW- steel tubes electric resistance welded steel tubes hope this helps I would go with 2x4 .120 wall and taper the tubing getting thinner at the front like this but with out the horns and over a longer wheel base http://www.jalopyjournal.com/forum/showthread.php?t=11882
Awesome! Thanks Uzek, I'll take it. Now, just some boxing, roll bar and front axle to go... And, bills model a, another question if I may... about the choices: HREW - Hot Rolled Electric Welded CDEW - Cold Drawn Electric Welded DOM - Drawn Over Mandrel ERW- steel tubes electric resistance welded steel tubes What are the advantages of one over the other? I'd hate to go cheap and end up re-spending all the $$ a second time. Costs too much to save money that way (don't ask how I know...). And thanks to all you guys who responded, it's 11:00 here, and I gots to git up at 5:00; will have to read all the stuff later (but see our Brandy is known in Australia as well). -Bill
Use DOM tubing in the roll bar(s). The other stuff should be avoided. DOM has the same properties as cold drawn seamless at a lower price. See the NHRA rulebook for tube diameter and wall thickness. It varies as to how fast and/or quick you will run.
Anything in the roll cage structure (for NHRA) has to be min. of .118 wall thickness. Do NOT use .120 wall ERW tubing for this. It has a wider tolerance and will test thin in most cases. .125 wall DOM is much closer tolerance (and a LOT more expensive), but beware that bends stretch the tubing and it may come out thin on the outside of a curve. NHRA will not give you any tolerance! Most kit builders use .134 wall ERW tubing. Heavier than it needs to be, but it will p*** tech. 2X3 .120 wall box tubing is common for main rails. I like round rails myself, but it takes a littloe more work to get the structure solid.
okay... for a DRAG ONLY 4 cyl car and up to a lo hp 283 (less than 500) you can use 1.5 x 3" .090 DOM for the main rails. if you go over the 500 hp mark you can install 1.5" x .090 stiffening tubes from the firewall hoop forward to the frame rail. if you're planning on ever driving it on the street, or if you plan on going hi hp and don't wanna install stiffening tubes.... use .125
Thanks to all who posted & PM'ed. I'd already ordered the NHRA book before posting. But I also wanted to get a little of the "been there - done that" advice. Sometimes there's stuff to know that don't show up in a book. And thanks for the tips on ERW running a little thin - that could certainly save a few bucks by not doing it twice. Again, thanks to all! -bill
Depending on the components used, you should be able to toss togather a 4 cyl. dragger that weighs in at less than 1100#. Altered Pilot is dead on with the tubing diamensions.
I believe that the CCR roadster frame plans I have (for a T bucket) call for 2X3X.188 box tube. If that helps. jay
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