how not to fail lemons tech

8/12/2019 How Not to Fail LeMons Tech

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These are the members your cage has to have. For thesame bits arranged in a halo design see Rollcage Figure1B, and for easy add-ons to make the cage even safer(add-ons we very strongly recommend for your miserable

junkheap) , see Rollcage Figure 2.

How Not To Fail LeMons Safety Inspection Handbook

v2 updateJanuary 1, 2014


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Heres your halo design. Its got all the same elements, really, as the regular cagein Figure 1A, theyre just arranged a bit differently. Halo cages are fine.




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Like a Halo type, the Lef t/Right design incorporates all the key cage members ina slightly different order. This is a good, strong, totally acceptable arrangement.




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These add-ons give a lot more protection for very lit tle extra work. We dont 100%demand these pieces in every cage, but the more of these extras you include, thesafer youll be. (And the more likely to pass with no heartburn.)




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Tube bends just create more places to fail, so dont

use any more than necessary; dont make themany sharper than necessary; and never create areverse bend that would let a tube bow out or foldunder stress.




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Ifsorry, whenyou roll, the cage flexes down while your body flies up. Thats whyyou need at least two inches of clearance between the top of the tallest guys helmetand the area enclosed by the cage.




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The door bars keep Billy JosPontiac out of your lap in aT-bone. Ideally. Use tube of thesame size and grade as your

main bars or better. For extraprotection, you can tie themtogether and down to the s illswith some vertical members;for more safety and addedcomfort, you can also gut thedrivers door and bow thesebars into that area.




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Not a great welder? Then just stick to fixing old lawnchairs. We need to see smooth, nicely penetrated,unburned, 360-degree welds at each joint, not somethingslapped together by a jitter y raccoon on Dexedrine.




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In a crash, downtubes can tear through sheetmetallike paper. Spreader plates (so named for helping

to spread out the load) are the solut ion. Platesshould be big (24 square inches minimum is a goodrule of thumb); beefy; continuously welded to solidbody or frame parts; and shaped to conform to

the structure below.




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Good, pro-quality bends come f rom good,pro-quality tools; those Harbor Freighthand-pump-and-die jobbies are worthlesshere. Stretched, crimped, or pinched

tubes will get you an ins tant fail.




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Backstays keep the main hoop from folding over or flattening down from the top.They need to be straight with no bends, securely attached top and bottom, andright around 45 degrees off horizontal.




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Every cars different, but places like shock towers and rear -seat bases often getreinforced at the factor y, which can make them good mounting points. Just makesure the spreader plates are formed to the weird-shaped contours beneath.




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We dont care how they do it down ta the local dirt trackdont do this for LeMons.If youre that desperate to tie your shock towers together, use a separate bar. Thebackstays need to go all the way down to the car with no bends or interruptions.




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A head-on crash can generate 80g of decelerationthatmeans your beer-swilling, 220-pound frame suddenlyweighs about nine tons. Extremely strong seat mountsand very precise belt angles are needed to keep all

that mass from slipping righ t through the webbing orcrushing your own internal organs.




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Heres the basic D-slider belt wrap. It doesntmatter if the far end is a harness bar, someother tube, or a purpose-built end plateyouuse the same wrapping regardless.




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Know why they call it a firewall? Because it keeps fire away.Nodaylight allowed heregood, solid metal or purpose-made rubbergrommets required. Duct tape, boogers, bare holesnot so much.




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Come ongive us a quick-release metal bracket, solidly mounted w ith real nuts andbolts. That way, when you go upside-down your 20-pound fire extinguisher doesntget loose and land on your nads. Yes, its happened.




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Stock tanks in the stock location are fine. But if youre to switch to afuel cell, what most catalogs call fuel cells are really just big plasticgas cans with drain holes. A real fuel cell has a separate metal case, aninternal deformable fuel vessel, splash- and leak-fighting foam filler, and

purpose-built fittings and mounting. Every thing else is just another gastank, and frequentl y less safe than s tock.




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Always mount any non-OE tank or cell high enough to avoid punctures, low enough to avoidrollovers, and far enough away from the cars edges to avoid t ypical accidents. It also needs tobe very solidly located, correctly vented and plumbed, and (unless its a current FIA-cer tified cell)100% isolated from the cabin by a continuous metal bulkhead. Yes, that includes hatchbacksand wagons.

How Not To Fail LeMons Safety Inspection Handbookv2 updateJanuary 1, 2014


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Rats-nest hoses and wires are, admittedly, entertaining. Alas, they also have anasty habit of snagging control lines, causing mysterious cutouts, and catching onfire. Thats why Al Gore invented the Zip-Tie. Use em.



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A few minor cracks orstars? No biggie. But end-to -end cracks, sof t areasthat compromise strength,or anything obscuring thedrivers vision is a no-no.Remember, a small crackcan turn into a big one underracing stresses, leading toa black flagso if youve gotany doubt just replace it.Glass doesnt count towardthe $500 limit.


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