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Fabricating and welding - High And TightFabricating and welding a standing-mile legal 8-point rollcage in SALT From the November, 2012 issue of GM High-Tech Performance By Justin Cesler Photography by Justin Cesler
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There is a section near the end of the Texas Mile rule book entitled Automobile-Required Safety Equipment (At or Over 215 mph) and it's where things start to get real if you're building a car of this caliber. Fire extinguisher, helmet, safety belts--that's all the easy stuff. The cage rules are where it gets exciting. "All cars that are attempting speed at or over 215 mph are required to have an eight-point rollbar at minimum. The materials and minimums are as follows..." Under 3,000 pounds, the cage rules are fairly similar to a drag race setup; over 3,000 and you are required to run large 1.75-inch round DOM with thick .120-inch walls, and, as stated above, it's got to be a minimum of 8 points to pass tech. If you're thinking that's relatively "small" for a car going 215, try to keep in mind that there are no walls to hit on the runway (well, hopefully anyway) and there isn't another car to get tangled up with. Really, for an impact, you're going to have to end up in a rollover situation, which is why door bars combined with a solid main hoop (and rear X-brace) is a good idea. Now, where can one even get a large 1.75-inch 8-point cage these days? 1 If you want to go fast,... 1 If you want to go fast, you have to do work. Regarding SALT, a lot of the work at this point is purely for safety, as the thrill of running at over 200 mph slowly starts to give way to the fear of running over 200 mph. At that speed, you don't want to find out what happens in a crash, especially if you aren't prepared for it. Welcome to the rollcage fabrication stage. Turns out our friends over at Competition Engineering offer the perfect Mild Steel 8-point kit for the third- and fourth-generation F-body platform (PN C3131), which ships complete with 1.75-inch, .134-inch wall mild steel tubes, 6x6x.125-inch steel mounting plates, and enough tubing to complete the entire 8-point structure. For the money, Competition Engineering notches the tube ends for a good fit, mandrel bends the main hoop, and includes complete instructions for the do-it-yourself racer. These cages are NHRA and IHRA approved as long as your welding can pass tech and you can order an additional C-brace and rocker bar kit to really enhance the entire cage and chassis setup. Of course, that little part about the welding is the real key as even the best rollcage is only as strong as the weakest weld. Thus it's paramount to find a good fabricator and one that is extremely comfortable building safe rollcages. For us, that was as simple as jumping in the truck, driving back up to Vengeance Racing, and letting the lead fabricator, Jey Clegg, do what he does best. Jey's been TIG welding tubes for years and cut his teeth building off-road racers before switching over to the top speed variety. The Competition Engineering kit was the perfect start for the talented fabricator, who used it as a foundation for the build. Naturally, Jey made a couple of changes to the cage from its original design (which you can see on the following pages), but that's exactly why you want to find a good cage builder. These guys can just see what needs to be done and they can do it. When we wanted to add X-style door bars, Vengeance Racing had them mocked up and TIG'd in place within the hour. But enough about Jey, let's break out the TIG machine and get welding!  2 Standing Mile racing differs...  2 Standing Mile racing differs from traditional "short track" drag racing in many ways, including the preparation of the rollcage. According to the Texas Mile rule book, any vehicle over 3,000 pounds running 215 mph or higher needs "to have an 8-point rollbar at a minimum" built from 1.75-inch DOM with .120-inch wall thickness. That's a big set of bars...  3 Luckily the crew over at...  3 Luckily the crew over at Competition Engineering offers a killer 8-point cage for the fourth-gen F-body platform (PN C3131) that ships with .134-inch-thick, 1.75-inch-diameter tubes in DOM for a quality, legal solution. The main hoop is preformed to fit within the fourth-gen chassis, and the kit includes everything a fabricator needs to complete the installation. For our build, we also ordered the optional X-brace and rocker bar upgrades (PN C3181 and C3184), to further reinforce the chassis.  4 With the interior of SALT...  4 With the interior of SALT strewn about the Vengeance Racing shop, lead fabricator Jey Clegg got to work installing the Competition Engineering cage. Jey cut his teeth building high-performance tube chassis trucks from scratch and can TIG weld and fit with the best of them. If you're planning on running fast and taking risks, you need a fabricator of this quality, even if you're starting with a good kit.  5 Competition Engineering's...  5 Competition Engineering's main hoop is bent and designed to fit the fourth-gen chassis, although it comes with long bottom legs which must be trimmed to fit the car. Here, Jey measures the overall width of the chassis, as well as the height, to figure out how much of the main hoop must be trimmed.  6 Before Vengeance Racing...  6 Before Vengeance Racing made any major cuts, they took the time to prep the floor of our Trans Am so that the mandatory 6x6 plates could be properly attached to the chassis. Jey first marks the stock sheetmetal, then grinds the factory surface away, leaving only clean metal. The 6x6 plates ship flat and Jey bends them on the bench to ensure a tight fit.  7 With the plates tacked...  7 With the plates tacked in place, Jay pulled the main hoop inward slightly (to improve the fit) and tacked it in place. The main hoop supports the entire cage structure and everything is built off of it, which makes its placement critical. You want it to sit within 6 inches of the driver's helmet (once they are in driving position), but you also want it laid back in the car to look correct.  8 Stealth. Not that any portion...  8 Stealth. Not that any portion of this build is about being subtle, but this is exactly how you want a main hoop to fit if you're going for a show-quality finish. This is the type of attention to detail you need from a fabricator. Otherwise you're going to end up with a decent, but not perfect, end result.  9 With the main hoop tacked...  9 With the main hoop tacked in the correct position, Jey turned his attention to fitting the rear bars to the rear deck of the Trans Am's floor. These bars come notched on the main hoop side, but will need to be trimmed to length and cut on the correct angle to fit the 6x6 plate correctly. Remember, if you cut it too short, it's useless, so take your time and get this right.  10a A rollcage build is all...  10aA rollcage build is all about symmetry and safety, and the other down bar goes in the same as the first. With both of them tacked in place, Jey moved on to building the main hoop cross bar (harness bar), which also needs to be trimmed to length.  10b If you're working with...  10b If you're working with a tubing notcher, make sure you account for the notch when you trim the bar.  11 The cross bar needs to...  11 The cross bar needs to be installed within 4 inches of the driver's shoulders in the final seating position. In reality, you want this bar as high up in the main hoop as possible without it sitting above shoulder height. The belts should come up to the seat at a slight angle without too much rise.  12 Moving backwards, Jey...  12 Moving backwards, Jey began installing the optional rear cross braces that come in the Competition Engineering kit. As a kit, these cross braces are basically just two bars, which is exactly what your fabricator will want to start with. The first bar needs to be cut and notched to fit, while the other will need to be split in two, notched, and then welded.  13 In order to properly weld...  13 In order to properly weld all of the tubes, Jey removed the partial cage assembly from the Trans Am and got to work welding it together in the Vengeance Racing shop. Removing the cage structure allows Jey to weld every inch of the cage without compromise.  14 While you don't have to...  14 While you don't have to TIG weld a mild steel cage, it is  15 With the cage in the car,...  15 With the cage in the car, getting full 360-degree welds in certain areas would be difficult, if not impossible. Here you can see the rear down bar and optional X-bracing connects to the main hoop. In the WS6, this area is tight up against the headliner. With the cage removed, we know everything is welded and fit perfectly.  16 Turning our attention...  16 Turning our attention back to the chassis, it was time to begin working on the "door bar" portion of the rollcage system. Both Texas and Mojave require 8-point style rollcages for 200-plus miles an hour and each require "at least 1-door bar be installed on each side of the vehicle." Again, 6x6 plates go in first, MIG welded to the factory floor.  17 The Competition Engineering...  17 The Competition Engineering 8-point rollcage system ships complete with two door bars (one per side) and comes pre-bent to wrap around the seats and hit the front plate. If you're running a Camaro (or flat) door panel, this is the perfect setup. However, on our Trans Am, Jey needed to add another bend halfway down the bar to clear the factory armrest.  18 After a couple of quick...  18 After a couple of quick measurements, Jey broke out the tubing bender and added the additional bend to the door bar. This bend allows the door bar to hug the Trans Am door panels perfectly, providing maximum room in the cockpit while maintaining a tight, finished look within the interior.  19  20 A typical 8-point cage...  20 A typical 8-point cage would normally stop with the first door bar; however. we weren't about to stop there. After some debate, the Vengeance crew decided it would be best to add a dash bar to the cage design, which would tie both sides of the windshield area together and provide a solid mounting point for an additional door bar.  21 The cross bar welds to...  21 The cross bar welds to the chassis using small plates; after it was installed, Jey turned his attention to building the second part of the door bar "X." This portion of the build is off the cuff and doesn't come in the Competition Engineering system, although a good fabricator should have all of the supplies they need in the existing kit, which is what makes it a perfect start for a build of this caliber.  22 Bam. Now we're starting...  22 Bam. Now we're starting to get serious! The "X" door bar design provides a ton of structural integrity and should be significantly more durable than a single bar thanks to triangulation and the fact that it ties into the front dash bar. Plus, look at it...  23 Almost done, it was time...  23 Almost done, it was time to turn from fabricator to interior designer as Jey began working on re-installing our stock carpet. This is, for lack of a better description, a major pain in the you-know-what. You can only cut once, so take your time here and get everything tight to the cage. No one likes a sloppy carpet.  24 The dash, seats, carpet,...  24 The dash, seats, carpet, center console, and steering column slid right back in place, and the Trans Am really looked like it was ready to head out on the tarmac. Of course, we still have a lot of work left to do, but we’re much safer now and we’re competition legal thanks to Vengeance Racing and Competition Engineering.
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1999 Pontiac Firebird Trans Am - Street Heat
Almost no other GM model pulls off the aggressive look quite like the fourth-gen Trans Am, and when you modify one like Nathan Turjillo from Las Vegas has, well; you end up with a real showstopper....
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