Front Engine Dragster chassis question: Looking over the upcoming winter to start a low budget F.E.D. to run in the 10’s only. Something I can build in my shop with the tools and equipment I have on hand or access to. I’ve had my share of high dollar drag cars and tired of the expense they incur. Getting older now and just want to go to the track and not need a “team” to support me. Plus looking for a lighter car to ease in the towing department as well. I just received the SFI 2.6A book on F.E.D 7.50 and slower and looks pretty self explanatory with the exception of minimum tube thickness. While it does spec out 4130 and Mild Steel thickness’ the question I have is in regards to the thickness at the bends. Using Mild Steel as an example... SFI calls out for .118 thickness. I can buy .120 DOM locally but won’t it somewhat thin out in the radius of the bends and possibly become thinner than .118 thus being out of spec? I can buy .156 wall DOM but that adds about another $3.00 per foot from my supplier… that's going to add up fast and never mind the additional weight!! I’m going to my local track in 2 weeks for a big event and hopefully can get some answers from the tech guys but figured I’d ask the experienced members here first! Thanks!
Get a Mark Williams FED blueprint. It has all the tubing call outs on it. Build it out of 4130, the price difference isn't terrible & being able to slip joint the tubes is well worth it. Build it to 6.00 spec. even if you plan on going slower .
The DOM I have used is .134" and it always certified. Like I always say "if you can't afford to do it right Don't do it" Pat
Mr. E is right, build it to 6.0 and when your done you can sell it a lot easer. Another option is an altered. Raildiator in front and you can drive To staging and back to the pits. One man operation.
My local supplier only lists .120 and .156 Will call them in the morning to see if .134 is an option.. its just a convenient location for me..lol I'm on a somewhat budget. Damn kids in college crap..lol, I prefer to build this myself to help keep the costs down plus I enjoy the fabrication part. So with that said, will not be using 4130.. Minimal TIG experience here and don't want to farm it out. Will build to 7.50 specs and sure if that day comes to sell, it will. Selling is the last thing on my mind...LOLOLOLOL.. This will probably be my last drag vehicle so this will be hanging around for some time once completed. But do understand and appreciate the responses on building it to 6.0 specs.
Chassis tech knows that the bend radius will thin out and is of no concern to them as long as you don't use a muffler bender to do the job. Stick with a 6" radius bender and you will be fine. 7.50 and slower you can use mild steel and wire weld it, quicker than 7.50 and you must use Moly and it must be heliarc/tig welded They call for .118 minimum and .120 DOM will pass but I find that chassis spec moly is cheaper in some cases and eaiser to work because it doesn't weigh a ton, but you do have the welding issue. Most mild steel sportsman cars are ERW tubing and .134 wall because what they call .120 wall mics out at .114 (fail) by the way I build Nost TOP FUEL CHASSIS
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