motorsci Posted January 11, 2009 Share Posted January 11, 2009 Me and a friend started building my roll cage, this is my hoop not to bad do you think we need to add digonal bar ? This is 1"1/2 .95 dom tubing I'll post more pics as progress continues Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 12, 2009 Share Posted January 12, 2009 Your diagonal needs to be in the plane of the main hoop if I remember correctly, and your shoulder bar bends back for seat clearance. Therefore, the diagonals should not intersect the shoulder bar. I'd just run one diagonal from the bottom right connection of the hoop to the left over the driver's head. There are specs as to where to place the diagonal in the rulebooks. Also, your supports that go from the hoop back to the strut towers shouldn't have a bend in them. Before you go any further you should get a rulebook for whatever sanctioning body you're going to run with and build to their specs. Quote Link to comment Share on other sites More sharing options...
motorsci Posted January 12, 2009 Author Share Posted January 12, 2009 Thanks for your imput. I really appreciate any response I get for the instalation of the safety equipment I put in my car. I've read the rules for the SCCA Street Prepared class, but the documentation I found was vague. Here are the rules I found: Roll cages must comply with the following: 1. The roll cage need not be removable. It shall be bolted or welded to the car. 2. The cage shall attach to the car at no more than 8 points, consisting of the basic cage with 6 attachment points, and 2 additional optional braces. 3. The forward part of the cage shall be mounted to the floor of the vehicle. If used, the 2 optional braces referred to in (2) shall be mounted, one on either side, from the forward section of the cage to the firewall or front fender wells. No braces shall pass through the front firewall. Installation of roll cages in Street Prepared cars must follow the same standards for interior modifications to accommodate the cage installation as those which are applicable to Showroom Stock or Touring cars in Club Racing. If anyone has any better info on doing this correctly, it would be most appreciated. Quote Link to comment Share on other sites More sharing options...
doublexl240z Posted January 12, 2009 Share Posted January 12, 2009 I would suggest building to the SCCA club racing specs. The club rules are more definitive and look like they fit the style of protection you are looking for. Like John said the diagonals needto be on thhe same plane as the main hoop. And the main supports going rearward need to be straight. Think that any time you bend a tube you have started to break it, bent tubes are already pre fatigued not what you want in a crash or impact. Go to some events and look at the cars there and get ideas. BUILD RIGHT,BUILD ONCE!! I'll add some pics later,I have to go in for back surgery in a little while, and I'm on the laptop. Go slow!! Quote Link to comment Share on other sites More sharing options...
Wheeler Posted January 12, 2009 Share Posted January 12, 2009 Hey, I'll say it... even though it may not comply with SCCA rules. It still looks like excellent fabrication, clean and neat. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 12, 2009 Share Posted January 12, 2009 Hey, I'll say it... even though it may not comply with SCCA rules. It still looks like excellent fabrication, clean and neat. Yeah, it really looks pretty good as far as the tube notching and the rest of it. From the last picture it looks like you may have bars from the strut towers intersecting the shoulder bar in the center and on the outsides. The ones in the center may have actually been inspired by my car. If that's the case, don't put them in unless you're going to do the bar straight down the middle of the car like I did, because their purpose is to tie into the V shape coming from the front strut towers to the dash bar. Without that tie in to the front suspension they're not good for anything at all, because they would simply flex the center of the shoulder bar. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 12, 2009 Share Posted January 12, 2009 Just noticed one other thing. It looks as though your main hoop is narrower at the bottom than it is at the first bend. This would violate SCCA's road racing rules of 4 bends of no more than 180 degrees in the main hoop. Quote Link to comment Share on other sites More sharing options...
motorsci Posted January 13, 2009 Author Share Posted January 13, 2009 Thanks for the complement this is my first roll cage. but it does apper to be a total loss your right the main hoop is more than 180 degrees so out it comes. I am looking forward to making my gusets I juist got a 1inch demple die. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted January 13, 2009 Share Posted January 13, 2009 Before you cut it out there is a +- to that 180 degree. From memory it's 10 deg so you maybe OK but check the rules. That's a lot of work to scrap and the fab does look good. Cameron Quote Link to comment Share on other sites More sharing options...
doublexl240z Posted January 13, 2009 Share Posted January 13, 2009 Cameron is right there is a +/- of 10 degrees for the main hoop it looks good. I think you added a number of extra tubes in that hoop that are only adding weight to your car. I don't know your expected power output but don't go to crazy adding tubes, it only decreases your power to weight ratio at no increase in performance. I will attach some pics(I hope) to give you some ideas. I have many more of different cages that I build if you want them. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted January 13, 2009 Share Posted January 13, 2009 doublexl240z, The more pics the merrier! Also any information about what rules/applications they were constructed for would be awesome. Dave Quote Link to comment Share on other sites More sharing options...
z-spec Posted January 13, 2009 Share Posted January 13, 2009 we have o respect annexe J 253 from the FIA for classic cars this is annexe K from the FIA you can find every thing on www.fia.com . About SCCA i know not much . We build about 70 rollcages a year ( not only Datsun ) and do our own certification . Quote Link to comment Share on other sites More sharing options...
MoNkEyT88 Posted January 14, 2009 Share Posted January 14, 2009 We're not worthy!! Man, if only you were 5,500mi closer! we have o respect annexe J 253 from the FIA for classic cars this is annexe K from the FIA you can find every thing on www.fia.com .About SCCA i know not much . We build about 70 rollcages a year ( not only Datsun ) and do our own certification . Quote Link to comment Share on other sites More sharing options...
doublexl240z Posted January 14, 2009 Share Posted January 14, 2009 Z-Spec those are beautiful. The only only thing wrong is that all the safety rules changes across the pond. I don't know if its the metric system or the accent, but FIA rules differ dramatically from SCCA. What is certified by FIA wouldn't be allowed on track at an SCCA event, and vice versa. MAYBE we crash differently?!?! Could be driving on the other side of the road to the track also?!! i don't know!! Quote Link to comment Share on other sites More sharing options...
z-spec Posted January 14, 2009 Share Posted January 14, 2009 For Classic racing cars we have to use 40 x 2,0mm or 38 (1,5") x 2,5mm (0.25") , and are alowed to fix it to the shell at 6 point by bolting or welding , but there is one exeption , when we fit the V bars into the main hoop we are allowed to use two extra points on the transmission tunnel ,That also means No welding or bolting to the pillars and roofsides . Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 14, 2009 Share Posted January 14, 2009 For Classic racing cars we have to use 40 x 2,0mm or 38 (1,5") x 2,5mm (0.25") , The tubes are pretty close to 1.5" diameter, but the wall thickness is .1", not .25". 1mm = .040". .25" would be 6.35mm thick, insane for a roll cage on a lightweight car. Your tubing spec matches up very well with current SCCA regs which suggest 1.5" x .095" tube for sedans up to 2500 lbs. Quote Link to comment Share on other sites More sharing options...
z-spec Posted January 14, 2009 Share Posted January 14, 2009 The tubes are pretty close to 1.5" diameter, but the wall thickness is .1", not .25". 1mm = .040". .25" would be 6.35mm thick, insane for a roll cage on a lightweight car. Your tubing spec matches up very well with current SCCA regs which suggest 1.5" x .095" tube for sedans up to 2500 lbs. You are right about that , working with inches is much more thinking for us , but 2500 lbs how much is this compared to Newton or Kg ? And what is the actually different between a SCCA legal cage and a FIA legal cage ? I think there must be a way that it meets both regulation . We can work with thinner wall for the tubes we use but we have to make a stress calculation from the cage , and save up to 1/3 of the total weight . Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 14, 2009 Share Posted January 14, 2009 2500 lbs is 1136.36363636 kg You can download the SCCA rulebook from http://www.scca.org/contentpage.aspx?content=44. The 2009 GCR is what you want. Quote Link to comment Share on other sites More sharing options...
z-spec Posted January 15, 2009 Share Posted January 15, 2009 2500 lbs is 1136.36363636 kg You can download the SCCA rulebook from http://www.scca.org/contentpage.aspx?content=44. The 2009 GCR is what you want. the minimum strenght requirment for us is 350 N/mm2 and that is not much , its like CDS 35 (steampipe) , what we use is 25CrMo4 (4130) with a strenght of 650/750 N/mm2 Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 16, 2009 Share Posted January 16, 2009 The SCCA has restrictions about connecting the hoop to the chassis on the roof section, from what I understand. It's more 'fit this template as a universal' for a lot of this stuff. There should be a universal standard. I'd be inclined to go 'FIA Lite' for club events and Gymkhana. But I'm betting there is an FIA Spec close for that kind of event as well. I know that 240! LOL The Red one awaits similar treatment... Quote Link to comment Share on other sites More sharing options...
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