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Unread 06-19-2015, 10:48 AM
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Default Vorshlag - We Make Roll Cages

Someone on another motorsports forum asked "Why do roll cages cost so much money". This was my response...



Vorshlag builds custom roll cages for many types of race cars. We've also installed pre-made 4-point roll bar kits on dozens of cars, and in the past ten years we have seen LOTS of bad cages and "cage kits". We have even CUT roll cages out of cars that were unsafe (with the customer's consent).




There are cheap $500 pre-bent cage kits out there that people think they can buy and "just find somebody to weld in my car". Even if, in the highly unlikely scenario, this "cage kit" used the right materials and had an exceptional design, it still requires dozens of hours of work to fit, notch, weld and finish. But more than likely it will have some massive design compromises made to it to keep the costs SO low on a "cage kit" where the materials alone should cost more than that. There are missing tubes, the materials are wrong, and the tubes have HUGE gaps to the chassis - putting the cage dangerously close to the driver.


We can even scratch-build a tube framed car, if that meets your needs...

There is no such thing as a cheap roll cage kit that is also good. The only decent pre-bent + pre-notched roll cage kits I've seen are FIA homologated Rally cage kits, which tend to cost $3000, still require some "fine tuning", and of course take dozens of hours to weld to a chassis.



Over the past several years we have built all manner of roll cages (road racing, drag racing, and land speed racing), but these jobs are not a money maker for us, even at the $6000 starting price for roll cages at our shop. Why? Two reasons. First is material costs - seamless DOM tubing prices have gone up, so it is $800+ just in proper tubing and plate for a full cage.



The rest is all labor. We tend to spend 65-75 hours to make a properly designed, well built, TIG welded, and class certified roll cage for road racing. We log time on every job using a software package called MyShopAssist, even though we flat-bill roll cages. Wanna know why we flat bill cages? Because its impossible to get people to really pay even for "time & materials" for what it takes to build a proper cage.



This cage above was a $6000 job, but it took over 70 hours to build and nearly $1000 in materials (minus paint, which was done by a paint shop and billed separately). The tubes fit tight to the chassis, are routed away from the driver, and the tube fit-up is second to none. It was built around specific NASA classing rules and their CCR guidelines and had photos sent to tech inspectors for approval during the build. To cover materials and our shop rate for the time logged it would need to have an $8000 price tag.



WHAT IS YOUR SAFETY WORTH TO YOU?

There's a wide range of quality among race shops building roll cages. I'm not saying that Vorshlag is the only shop that makes good cages, of course not, but there IS a big variance in quality. Our cages are always TIG welded with tight tube junction fit-ups. I've seen shops that charge as little as $2000 for a "roll cage", but those tend to be exclusively for drag racers or CrapCan race cars, or made by "non-professionals" who don't value the worth of their own time or overhead.



At these bargain prices you are going to have a cage with some of these issues: the tubing layout doesn't fit tight to the chassis, intrudes into the driver's personal space, has tubes landing in the wrong places, is missing critical load paths, doesn't have proper gussets, violates some safety standard or rule, has MIG welds and/or gross tubing fit tolerances "made up with weld", or all of the above. I could show pictures that would curl your hair, but to protect our customers' pride we don't share the "wall of shame" level of pictures of terrible cage work we've seen roll into our shop. We just quietly cut them out and throw away the evidence...



Many shops build cages that fall into the $2500-3500 range, and when we see these we can always point out corners that were cut to get there. Again - gaps between the cage tubes and the A-pillar or roof of 6+ inches is not uncommon, but higher quality roll cages tend to be very close or even touching the chassis (for maximum driver room); see above left. Sometimes that price is the upper limit for a particular customer (crap can racers tend to have budgets in this range) but we cannot build a cage for that. Too many compromises.


A roll cage should be custom built around the driver, their seat, and their safety gear

These "mid level" cages tend to be 100% MIG-welded (which is OK, just not preferred), but on those we tend to see tube notch fit-up gaps that approach .100" to .250" or more. Higher quality cages are TIG welded at all joints (exception: we MIG weld chassis mounting load spreader plates) with notch fit-up tighter than a piece of paper (.005" or less. See above right). The problem is, a high quality roll cage for road race use is a $6-10K job. Some drag racing cages can approach $15K for a certified cage (SFI 25.5C cages, for example).



This cage above was a bit of a nightmare - Bonneville land speed racer, built around SCTA rules, built to be certified for over 225 mph. Lots of extra tubing, unusual "cage within a cage" design requirements, etc. That was a $7500 cage built by our crew here Vorshlag, and even at that price we made less than a basic "time and materials" job. We would flat bill that at closer to $9000 today.



Virtually all of our cage jobs pay less than our hourly rate + materials (we bill at $105/hour, and we are about in the middle of the price range for local shops). Luckily most of our "cage jobs" turn into "other added work" once they see what we are capable of.



This Land Speed Racer cage snowballed into more work: a fuel cell, fire system, interior door panels, Lexan windows, parachute mount and release system, custom seat mounting, race defroster system, and more - so it eventually became profitable (at least full hourly rate + materials on the add-on stuff).



Same thing happened on this Subaru drag racer's cage, above (who wanted to keep the interior, which made everything much more difficult). Again, we lucked out and he wanted more work done beyond the flat billed cage work (which itself wasn't full hourly rate + materials), like the seats and harnesses. This Subaru drag race cage would be billed at $7500 today.



The aftermarket fabrication market is tight and competition is fierce, so I hope this post is a warning for any up and coming fabricator who thinks they can "make money" doing just roll cage jobs. Trust me - you won't. Everyone in this industry that has built cages in the past says the same thing - roll cage jobs are a giant time suck. Sure, they are fun to do and the results can be very satisfying, but they just don't make you much money. Clutch jobs and basic wrenching pay better.



Don't forget the tools required to properly build roll cages. This goes beyond just the tubing bender - but the bender, a stand, and a good selection of tubing diameter dies (which cost $350-500 each) can tie up thousands of dollars.



Then there's the welders (TIG for tubing joints + reinforcements, MIG for the load spreading floor plates or plinth blocks welded to the chassis. We have $20,000 in TIG + MIG welders alone in our shop! Then there's the the dimple dies for gussets and chassis plates, shear & brake for sheet metal bits, the digital angle finders, a rigid tube notching set-up, various band saws, a good welding bench, tube notch contour tool, software to help layout the bends and notches, and more. To start from scratch and do cages to the level we do would require $40K in tooling and fixtures alone. Can your buddy with a $200 Harbor Freight MIG welder make your cage for less? Sure, but its going to show. "You get what you pay for"



Not to mention the overhead for the shop, adequate power, exceptional lighting, climate control, and the salary of your SKILLED and EXPERIENCED fabricators. If the shop you are looking at to build your cage is dark, dirty, hot and nasty - how nice can they make your roll cage? You know, that thing that your life could depend on in a crash?



So while some folks might be turned off by our $6000 starting price, know that this doesn't even guarantee that we make any profit on the cage work - but that's just part of this business. We won't compromise safety or quality for cost on a job this critical, but others might.

If these images above of the roll cage work we can do look like something you want or need, give us a call at 972-422-7170 or shoot us an email at services@vorshlag.com. We will need to know what type of car you have, what series/class it is being built for, what type of seat you want to use, and even your body size. Once we see the car in person we can verify our estimate, and you will need to be here for a "fitting" during the initial cage layout steps. Hopefully we can work to build the best cage that fits you, your chassis, and your racing class.

Thanks!

Last edited by Fair!; 01-31-2017 at 09:36 AM.
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Unread 01-31-2017, 10:07 AM
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Default Re: Vorshlag - We Make Roll Cages

By now we have had thousands of people read the post above (and probably saved us 1000+ phone calls) about building roll cages and what we charge. One question that comes up a lot is...

Q: Does the fixed roll cage construction cost include stripping the interior of the car?

A: No. Interior removal is a separate task.

Some folks take care of "stripping the interior" on their own, but most let us handle it for an additional cost - which is nearly impossible to put a fixed price on.



The rest of the next two posts below show examples of "interior removal" in a number of cars, but most are on a blue E46 M3 chassis. This car came to us for roll cage construction (and more) and the pictures below show the steps we took to get adequate access to be able to build the roll cage, remove interior/wiring/sound mat, and clean the interior sheet metal before fab work. These "interior removal" steps took approx 17 hours on this car; some cars could take more, some less.

If you have more attention span than the "TL;DR" crowd, please read below for more details on what it takes to get a car "ready for a roll cage".

GAINING ACCESS + RELATED INTERIOR WORK



Removing the interior is a requirement for almost any race car. Why? Several reasons. First, the materials are flammable: Carpet, plastics and cardboard. Racing bodies do not want a car-b-que on track so the flammable bits have to be almost completely removed. Second, we need extra ROOM to add these steel tubes inside the chassis while not crowding the driver. Room to weld tubing joints is key - see the image above. Could that weld have happened with the windshield in place? No way. This is sometimes why crappy cages have huge space between tubes and the chassis - the builder is either too lazy or bid the job too low to afford to remove the glass and put it back in when the cage is built, welded, and painted.



That's right: we insist on removing the front and rear glass for any roll cage job we tackle, as well as any fixed side glass (glass doesn't roll up or down). These fixed glass panels are always in the way for cage work, not to mention that (mainly from a MIG) can damage the glass and especially films on the inside. We need room to get the TIG torch in around tubes, and the windshield and rear glass are always in the way.



To minimize chances of the windshield getting damaged during removal we hire a professional windshield company to come in and remove both the front and rear glass. They use special cutters, rope saws, and other tricks to cut through the bonded sealer on the perimeter of front and rear glass. Luckily the fixed side glass panels (below) and door glass are easy for us to remove intact.



Unlike in the movies, using a hammer to shatter glass "to remove it" is a terrible idea - glass fragments get EVERYWHERE and we don't want to be laying on broken glass while building your roll cage. Glass will end up inside the dash, inside the doors, down HVAC components, everywhere. The front and rear glass panels usually come out intact for $200, but sometimes the windshield cracks, no matter how hard they try. The longer it has been in the car, the higher the risk. We rarely use Lexan for front windshields, so if the 2-layer safety glass is crack free and without too many pock marks from small rocks, we will re-use it.



Roll up door glass almost always comes out, to reduce the chance of shattered glass going on track as well as to make room for the cage to move out into the inner door structure. We always prefer to "gut the doors" - remove the window glass and lift mechanisms, then cut out the structure and sometimes even the crash beam - to give us room to push the cage out almost too the outer door skin. More room for the driver and more room for the door bars to deflect in a side impact.



In some rare cases we can leave the door glass in place - when the customer requests it (and they have a damn good reason - such as they only have an open trailer and need to roll up windows to keep it from getting full of water between race days) or if the car is being built for a series that requires roll up windows - which is very unusual (example: USCA/Optima series). Even then we usually discourage keeping side glass.



This particular car did need the side windows, so we built custom inner door panels that were light, metal, "low profile". Making these took a bit of surgery on the factory door panels, where the upper plastic section was kept, which houses the "felt" wiper seals, which ride on the glass. A piece of .063" thick aluminum sheet was cut, formed and welded together to line up with the upper panel section - with just enough room to clear the window motor and lift mechanism.



Turned out to be a beautiful piece of work, but this work simply is there to allow adequate clearance for the "X" style door bars, which went about 4" into the area where the factory door panel/handle would reside. So these panels cover the door glass mechanisms and add clearance for the cage.



Making these door panels took about 8 hours to make. You would thing that you could just make a "flat" interior door panel, but that is rarely the case. This particular E46 M3 needed the unusual 3D shape above to clear the electric motor, and they had to look very good for this particular customer.



Dual purpose track/street cars are often the ones that need door panels to cover working class door windows. This 1998 328i above left got a 2-piece door panel to cover the electric motor and mechanism underneath. The NB Miata at right had a "X" shaped indention in the panel to clear the "X" shaped door bars of the cage, and the windows also worked. There's usually a unique solution we can come up with for each car.

REMOVING INTERIOR DROPS WEIGHT

Most factory stock cars have about 300-400 pounds of seats, carpet and insulation that get removed for roll cage addition. Yes, that is a big number. When making a dedicated race car we are always looking to drop weight, even if we have to add ballast weight BACK to get a racing class minimum - because we can put the ballast in a better location. Dropping weight is the best mod you can do to any car, but losing interior panels/sound mat/carpet makes for added NVH in the cabin (Noise Vibration Harshness), so a gutted interior usually isn't the solution for a street car.



This 4 door 1998 BMW 328i started out stock at 3229 pounds. Over the course of a day the interior was removed...



This work involved removing the front seats, back seats, carpet, door panels, headliner, radio, speakers, center console, and more.



This work shown above took 3 people half a day to do, and the dash still needed to come out for cage fabrication. Removing the dash assembly, and HVAC guts and wiring behind it, can take several hours to do correctly just by itself. It is a complicated jigsaw puzzle.



But the weight of the interior bits is easy to see. The finished car still started and ran - no critical wiring was touched yet - and it dropped down to 2795 pounds later that same day. Some of this 434 pounds lost would be replaced with two race seats (approx 25 pounds each, with brackets and such) and a roll cage will weigh between 65-100 pounds as well.



Later we dropped another 70 pounds by removing the power sunroof cassette and replacing it with the lightweight carbon fiber roof panel, above. That means 504 pounds came out of this car before the cage and seats went back in - that's significant.



Wiring is another mess that can eat time, but there is a lot of weight that can be dropped by pulling out all of the unused copper - nearly 50 pounds on this car's interior wiring alone!



About half of this was behind the dash. The trick is knowing where to stop - if you are going to do a 100% re-wire, then yank away. Just know that you can spend 30-50+ hours wiring a race car from scratch, even using a partially built "chassis harness". But doing partial "factory wiring harness surgery" can take a dozen hours to find those easy 25-30 pounds.



Almost all racing bodies want to see a main kill switch as part of their safety regs, and we often relocate the battery to the trunk for better weight distribution - and to make wiring the main battery kill switch in the cabin easier. We moved this full sized battery above from an S197 Mustang's engine bay to the trunk.

continued below

Last edited by Fair!; 02-01-2017 at 12:03 PM.
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Unread 01-31-2017, 05:06 PM
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Default Re: Vorshlag - We Make Roll Cages

continued from above



As cars get "gutted" for race prep like this, they tend to lose more weight from the back than the front, worsening the front to rear weight bias. This is why we try to overshoot the minimum weight for a given class, then add ballast back - usually located behind the driver. The weight box shown above can hold hundreds of pounds of ballast securely, which helps push the weight bias rearward.



We need to weld the cage to the metal floorpan and inner chassis structure. Most modern cars have stick-on tar based material some refer to as "sound mat", and much if not all of this needs to be removed when adding a roll cage. Obviously we cannot weld to areas covered in this tar. Removal can take several hours to do correctly, but on this car that work knocked another 17.7 pounds off the tub, and every pound matters.



There are a number of ways to do this, but the best process we have found that doesn't damage the floorpan or paint underneath the sound mat is to use a heat gun and gentle pressure from plastic and metal scrapers. Getting the tar paper warm and soft allows a metal scraper to work it loose, as long as you don't dig in with the corners of the tool - which can scratch the paint (possibly requiring more bodywork when/if the cage and interior are repainted). Removing these heavy tar materials cleanly takes patience and some skill.



Once the sound mat is all heated, softened, and pried loose from the interior, firewall and trunk you have to remove the adhesive residue from the tar backing.



With the carpet, seats, panels, dash, wiring, and sound mat removed it is time to get the metal cleaned up.



With all of the interior and glass out we rolled the M3 above outside for a thorough cleaning with a pressure washer. This removed mud, grease, and "interior funk" but didn't make a dent on the sound mat adhesive residue.



After about an hour of soaking the adhesive with solvents, then using rags and elbow grease to wipe up the softened goo, the sound mat adhesive was removed and the interior was finally clean enough and had enough access to start the cage work.



This is now a clean slate and is what the interior needs to look like before we begin to measure tubing for cuts an bends. The seats, glass, interior and dash are all out of the way. On this E46 M3 it took us about 17 hours to get to this point. Remember, this is not "roll cage construction", just work needed to begin fabrication.



On this E46 M3 - which had a heavy factory power sunroof - we were able to swap out the factory steel roof to an aftermarket carbon fiber panel. That meant we had ample room during cage construction to access welding the top bars, which just made the cage work that much easier. Removing the factory roof took about 7 hours.



This roof removal is not required, but on this car it made sense. Factory sunroof assemblies are heavy and removing those + the headliner gains 3-4 inches of headroom. On this car the sunroof assembly weighed 72.0 pounds and the steel roof panel weighed 24.1. The replacement AJ Hartman carbon roof panel weighed in at 6.9 pounds. So this roof swap not only gained us room during cage construction, it helped drop 86.5 pounds. Out of the roof.



INTERIOR REMOVAL IS IMPORTANT

I hope these two additional forum posts better explained what goes into interior removal for race cars, and why it must be done before we can begin roll cage construction.



The actual "cage fabrication work" on this E46 M3 took 68 hours, but the interior + wiring removal/clean-up, custom door panels, roof removal/replacement, seat mounting, and dash mounting were all additional work - before we could even start the cage. That's part of "building a race car", and it takes time.



Cheers,

Last edited by Fair!; 01-31-2017 at 05:18 PM.
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