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#1
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choosing roll cages
From what I understand an SCCA-spec roll cage is better than a Class 11 roll cage. I also understand how the unit is welded is important.
I went to the SCCA site and scanned some of their rules and such. I'm sure it is there somewhere but I did not see what makes a roll cage an SCCA type. I haven't had a subscription to a VW mag in a few years but I remember seeing Class 11's being advertised quite a bit. Maybe SCCA's are advertised, too, but I just don't remember them. Anyway (and assuming this is for a 1302 or 1303), how do find out the differences? Where do I find them? Is there a way of assessing them in advance? I ask the third question because even though I am only in the planning stage for GL#2, I will not be racing my car but I will want protection against accidents.
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(2004-2008): 1971 1302 w/2056 Searching for a new project ... |
#2
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Why not consult the roll cage suppliers. If a similar question arose in the UK that is where I would go first.
Interestingly, over here apart from drag racing most of the cages are FIA (international) and MSA (National) approved. FIA cages can be used at National level but not necessarily the other way round. In the MSA Blue Book that have the regs for all motorsport thare are various patterns for the cages and some are approved for FIA use. Clive |
#3
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take a look at Ron Lummus racing they have a nice bolt in and weld in cage its nhra legal not sure about scca specs. its not the cheapest but it is nice.
you can order it throu aircooled.net if u like |
#4
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Autopower (www.autopowerindustries.com used to make a SCCA and NASA legal cage for Beetles. I don't see it on their site, but they may still offer it.
Be careful running a rollcage on the street. They can be more dangerous than running without due to the increased risk of head injuries -- especially for rear passengers. They're really meant for applications where you should be wearing a helmet...
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Kafer_Mike Build 'em fast...or let 'em sit. |
#5
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double post :P
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Lucy: 73 super beetle sport bug edition, 944 turbo suspension, 930 turbo brakes, 2165 FI, dry sump, turbo Last edited by Humble; November 5th 2009 at 20:56. |
#6
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One extra that is worth considering is to gusset the tube connections for much additional rigidity. Roll cages are worth as much for the stiffening of the chassis as for their primary protection role so that multipoint connections to the bodywork is IMO a vital part of the installation.
Clive |
#7
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What roll cage you run really depends on your goal with the car. race car or street car?
A class 11 roll cage is okay (as in better than nothing) but there are better designs out there. NHRA, SCCA, and FIA all have different cage requirements, and like Clive said what works for one may not work for others. The FIA has several standards and everyone picks and chooses for their given safety requirements. Fore the most part an SCCA track cage is probably the best bet. If you look at my race cage it's a minimum spec SCCA cage. It started out as a weld in RLR cage and I made a couple additions to keep it legal. The minimum (as of this posting) is a standard 6 point cage, main hoop, down bars, head bar, rear cage stays, main hoop diagonal, door X on the drivers side and single door bar for the passenger. For race purposes, as of July of this year SCCA and NASA, require you to tie your down bars to the A-pillars. I opted for a dash bar and passenger side door X since it's good to have equal protection for the passenger. A couple rules of thumb for cages, 10 lbs per point and $100 per point but cost/weight go up when you start cross bracing. Having done a couple of pre-made cages (weld in and bolt in) I would highly recommend taking to a shop to have the cage installed. They have the proper tools, they've done it hundreds of times and they can get a super tight fit the first time. The shop can also design the cage for the specific car and driver. That never happens with bolt in or weld in cages. I like the RLR cage and it's a necessity, but I'll replace it with a much better custom cage down the road. |
#8
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I read and appreciated all of the responses. I will reread them several times when I get home. One alarming quote I have listed below.
Quote:
I am very sure I won't be racing. I was interested in a roll cage for protection. If it offered more rigidity, too, so much the better. However, I am not planning on wearing a helmet when jamming to the beach or the local grocer.
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(2004-2008): 1971 1302 w/2056 Searching for a new project ... |
#9
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Quote:
In an accident you would be shocked to see how much your body flexes and moves, a standard road-going car with cage and without helmet is far more dangerous then a simple car without cage. Your head off the roll bar is a seriously tough object to avoid. The cage will be of benefit in some accidents where you might otherwise be killed, but a liability in any lower-speed accident where you are unlikely to be killed. I ran my Audi rally car as a street car, with cage and proper padding, for years...and I can tell you that driving a caged car daily is a complete pain-in-the-ass. **assuming we're talking "cage" here and not just a rear-seat roll bar. -Dave
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'71 Type 1 - Rally Project '58 Type 1 - I bought an early!?! '73 Type 1 - Proper Germanlook project '68 Type 1 - Interm German 'look' project '75 Type 1 - Family Heirloom '93 Chevy 3500 pickup - Cummins Swap |
#10
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Quote:
1) A cage can give psychological comfort so the driver is more relaxed and therefore more responsive. 2) A cage will stiffen the bodyshell/chassis so that its response is more accurate and reliable resulting in better active protection. (less likely to get into an accident in the first place) 3) On a beetle there are no crumple zones or a stiff passenger cell to protect the passengers so a cage within the cabin at least provides a stiffer passenger cell. 4) Extending the cage forward to the front suspension area will improve chassis stiffness as well as giving the opportunity to add progressive collapse thus bringing the vehicle up towards modern standards. The effectiveness of a cage was brought home to me some years ago during our clubs national level road rally. One of the front running Escorts was pulled off a narrow tarmac single track road by the muddy goo at the edge of the verge and then ploughed through a 18" thick brick buttress to a barn. It was almost a grotesque cartoon as the Escort shape was bitten out of the solid raking buttress. The front 1/4 of the car ended up at the dashboard, where it was stopped by the cage. The driver sustained a broken ankle only (the navigator was only shaken and stirred). This all happened at between 100 - 110mph as it was a flat out section with few bends in the preceeding 2 miles. The cage demonstrated its strength on that occasion. Our MSA (Motor Sports Association - the governing body) recommend cages for road rallying even though helmets are not allowed. They don't insist on cages as the events are only supposed to be 'navigational' and standard road cars are encouraged; the sight of drivers and navigators wearing helmets on public roads would also incense the public. Clive |
#11
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I absolutely agree that a welded cage when done properly is stronger and makes the car more stiff than a bolted-in cage.
As they say: pick your poison ;-) |
#12
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even if you are Ripping it on the TWISTIES I would put a roll bar in but you could stiffen up the car by...
kafer bar, Bilsteins shocks, bigger torsion bars, urethane bushings, convertable pan stiffeners, hope that helps.. Chris.
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74 Std. GL 08 Vw rabbit 18 WR250R 07 Chevy 3500 Dually |
#13
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The roll cage can provide a good deal of stiffness to the chassis and can link the body more fully to the chassis that will further stiffen things. People often forget that the body can contribute and rely solely on the cage.
If you weld tabs onto the cage at about 1/2 way up the door frame and bolt to door frame and similarly at the top of the cage where the bend occurs. Also, the same for the front legs of the cage to the door fame and A pillar. Cross link the front legs at the base of the dash and if feasible at the top of the dash. There should be a cross tube at about mid seat back height but that would affect the rear seat availability. If so, then put a cross tube immediately in front of the seat frame, which can be also bolted to the tranny tunnel. Diagonal cross tubes across the car is a bit of a must to stop the cage lozenging but this again buggers the rear seat access. If making it removeable is a hassle then consider putting bracing gussets at the bends at the top of the cage and at the cross tubes. The principle here is to get stiff joints/changes in direction if its not possible to triangulate. Door bars are well worth having but full on door bars are a real pain except in a competition only car. Here keep the bars within the side profile shape of the seat and if that means fairly low down use gussets to add a little extra. If you can take a pair of tubes through the front bulkhead to link to the top of the Macpherson strut that will also have a strut brace (right?). Provide some good boxed sections onto the heater channels and the plate legs down onto the floor pans. I've mentioned gusset braces and these can be formed by bending some 16g over a pice of tube the same size as the cage and then weld to both members. Its a strong but smooth stiffener. Clive |
#14
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Thanks, I have a rear sway bar from Topline, urethane bushsings and trans mounts along with big shocks off a truck!
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#15
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And Thanks to Clive for the excellent info. That is pretty much what i had in mind, there is no back seat in this so that wont be a problem. I think i'm going to weld a cross tube in the middle of the roll bar and then weld tubes to where the heater tubes would be (under the back seat area) going down diagnally from the cross bar.
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