Jboogsthethug Posted February 2, 2020 Share Posted February 2, 2020 So I can find a ton of posts about the main hoop needing to have only 4 bends and those bends cannot exceed 180 degrees when totaled up. The problem is, I can;t find that in the nasa or SCCA rule books. Is that an actual rule? My cage builder bent this main hoop for me, I am just verifying before I have him re-do it as it would open up some space. Thanks! Here is a picture for reference, notice how the hoop bends around the rear wheel tub. Quote Link to comment Share on other sites More sharing options...
Jboogsthethug Posted February 2, 2020 Author Share Posted February 2, 2020 It was the Time Attack rules that have it specified, thanks to @Ben280 for pointing that out in a message! To quote him quoting the rules: "Global Time Attack section 4.6.6 Main Hoop: "One continuous length of roll bar tubing shall be used as the main hoop. The main hoop must consist of not more than four (4) bends maximum, totaling one hundred eighty (180) degrees +/-ten (10) degrees." Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 3, 2020 Share Posted February 3, 2020 (edited) It is a rule in SCCA as well, and you should get the cage builder to fix that. It's tough to do a Z properly because there isn't a lot of room. Mikelly and bjhines both got their cars on the track (not with SCCA) with hoops similar to what you have, but I think it's a serious issue that should be fixed. If you get hit right in the dogleg area just behind the door, you're going to have your pelvis crushed before the cage gets involved. You can download the GCR here:https://www.scca.com/downloads Here is the pertinent bit: 9.4.1. BASIC DESIGN CONSIDERATIONS A. The basic purpose of the roll cage is to protect the driver if the car turns over, runs into an obstacle such as a guardrail or catch fence, or is struck by another car. It shall be designed to withstand compression forces from the weight of the car coming down on the rollover structure and to take fore/ aft and lateral loads resulting from the car skidding along on its rollover structure. B. Forward braces and portions of the main hoop subject to contact by the driver’s helmet (as seated normally and restrained by seatbelt/shoulder harness) shall be padded with non-resilient material such as Ethafoam® or Ensolite® with a minimum thickness of one-half (1/2) inch. Padding meeting SFI spec 45.1 or FIA 8857-2001 is strongly recommended. C. No portion of the safety roll cage shall have an aerodynamic effect by creating a vertical thrust. D. Roll cage or chassis design shall prevent engine intrusion into the driver compartment. E. Material: 1. Seamless, or DOM (Drawn Over Mandrel) mild steel tubing (SAE 1010, 1020, 1025) or equivalent, or alloy steel tubing (SAE, 4130) shall be used for all roll cage structures. Proof of use of alloy steel is the responsibility of the entrant. 2. Minimum tubing sizes (all Formula, Sports Racing, GT, and Production Category automobiles, and all automobiles registered prior to June 1, 1994) for all required roll cage elements (All dimensions in inches): Vehicle Weight Material Without Driver Mild Steel Alloy Steel Up to 1500 lbs. 1.375 x .095 1.375 x .080 1500-2500 lbs. 1.50 x .095 1.375 x .095 Over 2500 lbs. 1.50 x .120 1.50 x .095 1.625 x .120 1.75 x .095 3. Minimum tubing sizes for (all Showroom Stock, Touring and Improved Touring Category automobiles registered after June 1, 1994) for all required roll cage elements (All dimensions in inches): Up to 1500 lbs. 1.375 x .095 DOM / Seamless / Alloy 1501-2200 lbs. 1.500 x .095 DOM / Seamless / Alloy 2201-3000 lbs. 1.500 x .120 DOM / Seamless / Alloy 1.625 x .120 DOM / Seamless / Alloy 1.750 x .095 DOM / Seamless / Alloy (American Sedans may construct to these specs regardless of weight.) 3001-4000 lbs. 1.750 x .120 DOM / Seamless / Alloy Over 4000 lbs. 2.000 x .120 DOM / Seamless / Alloy Note: ERW tubing is not permitted in any car registered after 1/1/2003.Main hoop: 4 bends max., totaling 180º ± 10º Front hoop: 4 bends max. or Front downtubes: 2 bends max. Rear hoop supports: No bends. Edited February 3, 2020 by JMortensen Quote Link to comment Share on other sites More sharing options...
tube80z Posted February 3, 2020 Share Posted February 3, 2020 I'd recommend more than just the hoop change. Try sitting in the car with a helmet on and you may be hitting the upper halo bars. Those need to be much closer to the roof and often require a couple of bends to make it back to the main hoop. It's your money and this is one of those items you hope to never use but when you never know when you might. Quote Link to comment Share on other sites More sharing options...
Jboogsthethug Posted February 3, 2020 Author Share Posted February 3, 2020 @JMortensen Thanks for the reply and quote! I looked through the GCR and somehow missed that! @tube80z I actually gave him the same feedback, I definitely would prefer it to be a lot more towards the outside than that. I'm already too tall and that would make fitting me in even more difficult. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 4, 2020 Share Posted February 4, 2020 (edited) Yeah, bring your helmet too. My helmet was almost resting on the door halo, and I tried to squeeze it up as tight to the roof as I could. Ended up moving my seat to the right to compensate. I actually think it would have been better to block the window a bit and have it lower and further out than trying to get it all tucked in tight against the roof. Edited February 4, 2020 by JMortensen Quote Link to comment Share on other sites More sharing options...
LLave Posted February 10, 2020 Share Posted February 10, 2020 Good info here. There is just so little room for seat and cage, not to mention driver. I have been considering adding a roll bar to my build. However, since it is a street car, and I am a bigger guy, I am not sure I have enough room to get a tube in there that wont be a hazard to my head. Quote Link to comment Share on other sites More sharing options...
Jboogsthethug Posted February 10, 2020 Author Share Posted February 10, 2020 Thanks for posting a picture and the helmet recommendation @JMortensen! @LLave My suggestion is to leave it cageless if you're going to have it as a street car! I think it would actually make it more dangerous for your head especially if you're not using a helmet. Your brain bucket would get all banged up! Quote Link to comment Share on other sites More sharing options...
Ironhead Posted May 6, 2020 Share Posted May 6, 2020 All good information here, I would only add that if the relevant bars are properly padded with FIA or SFI spec padding, the danger they pose would be reduced somewhat. Hitting your head, helmeted or not, on a bar with FIA padding would certainly be no more dangerous than hitting it on the stock door frame, probably less so.... As others have said, these are small cars, and for larger drivers (like me) common sense decisions and inevitable compromises are necessary if we are going to drive them at all. I lowered the seat as much as possible, tucked the bars as tightly as possible, and will definitely pad all possible contact areas. Not much else one can do, but buy a Camaro or some other larger car. A "Halo" seat would definitely be a good choice on track only cars....probably not so much on cars that are still street driven. It is just a matter of minimizing risk as much as possible, then accurately assessing whether you are willing to live with whatever danger remains. Quote Link to comment Share on other sites More sharing options...
Jboogsthethug Posted May 6, 2020 Author Share Posted May 6, 2020 Well said @Ironhead! good things to think about. Quote Link to comment Share on other sites More sharing options...
DREW RBZ Posted May 6, 2020 Share Posted May 6, 2020 Agreed...pool noodles won't cut it! Quote Link to comment Share on other sites More sharing options...
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