heavy85 Posted November 20, 2009 Author Share Posted November 20, 2009 I think this about answers it. Front of bar is in line with back of seat. I think I'll remove the nubbin and slide the top forward slightly so that I can raise is closer to the roof. Should still be wedged in there still. As you can see, parallel to the window frame would be too close to my head. Cameron Quote Link to comment Share on other sites More sharing options...
heavy85 Posted November 24, 2009 Author Share Posted November 24, 2009 You dont have a horizontal harness tube as part of the rollbar. I thought this was required but dont see it in the NASA rules? What's the general consensus here? I was planning to do both what you have back to the rear strut tower bar as well as the harness bar but I would have to use a bent harness bar and after seeing your picture I'm questioning if it's really needed? Cameron Quote Link to comment Share on other sites More sharing options...
johnc Posted November 24, 2009 Share Posted November 24, 2009 Harness bars in the main hoop are not required by SCCA or NASA. Harness mounting is a separate item from roll cage construction. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted January 3, 2010 Author Share Posted January 3, 2010 Some progress finally. Open for comments before I stick it in for good. Also still debating adding the bars from the b-pillar bend back to the rear strut tower (like 74_5.0L_Z) and how to handle the harness bar unless I just keep it like this and use the rear strut tower bar for the harness like I have been doing. Like that run-on sentence Cameron Quote Link to comment Share on other sites More sharing options...
bjhines Posted January 4, 2010 Share Posted January 4, 2010 I might add a few things here that have been slightly confusing to me in the past. The way our local track HPDE rules go... Our S-30 cars can get away with 1.5" tubing with 0.095 thickness DOM as long as you are building a full cage. When you are only building a 4 point hoop then you must use 1.75" 0.095 DOM thickness tubing. The thickness changed recently on the 1.75" tubing. It used to require 0.120 wall thickness for the 4 point hoop, now it is only 0.095" thickness. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted January 4, 2010 Author Share Posted January 4, 2010 I might add a few things here that have been slightly confusing to me in the past. The way our local track HPDE rules go... Our S-30 cars can get away with 1.5" tubing with 0.095 thickness DOM as long as you are building a full cage. When you are only building a 4 point hoop then you must use 1.75" 0.095 DOM thickness tubing. The thickness changed recently on the 1.75" tubing. It used to require 0.120 wall thickness for the 4 point hoop, now it is only 0.095" thickness. Yep - that's why I chose 1.75x0.095 Cameron Quote Link to comment Share on other sites More sharing options...
jt1 Posted January 4, 2010 Share Posted January 4, 2010 You could add a bar between the two bars that go from the main hoop down to the strut towers, just above the belt holes in the seat, and use that for the shoulder belts. Then the belts would be sloping downward to your shoulders. That would also let you eliminate the bar directly between the strut towers. jt Quote Link to comment Share on other sites More sharing options...
johnc Posted January 4, 2010 Share Posted January 4, 2010 Harness bars in the main hoop are not required by SCCA or NASA. As of 1/1/2010 this is no longer true. Section 9.4.B.2.b: Cars must incorporate a main hoop horizontal brace at the approximate level of the driver's shoulders but not lower then the shoulder belt mounting point as described in section 9.3.18.D. It must be the full width of the main hoop unless a double "X" brace is used. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted January 5, 2010 Author Share Posted January 5, 2010 As of 1/1/2010 this is no longer true. It must be the full width of the main hoop unless a double "X" brace is used. I see that in SCCA but nothing in NASA. It also doesn't mention if that tube can be bent or has to be straight? I assume this means I can't add bars from the b-post back to the strut bar like 74_5.0L_Z did then run a diagonal off that? Wouldn't attach to the main hoop directly but would avoid have to add bends in the diagonal. Cameron Quote Link to comment Share on other sites More sharing options...
bjhines Posted January 6, 2010 Share Posted January 6, 2010 ^^^ I sure hope the harness bar can be bent on the ends for seat back clearance. there are a lot of cars that need a little set back into the hoop. Quote Link to comment Share on other sites More sharing options...
johnc Posted January 6, 2010 Share Posted January 6, 2010 As a SCCA tech I would allow the curved harness bar. There's no mention in the SCCA rules about the harness bar being in the plane of the main hoop. Quote Link to comment Share on other sites More sharing options...
Kris.Is.Awesome Posted January 6, 2010 Share Posted January 6, 2010 As a SCCA tech I would allow the curved harness bar. There's no mention in the SCCA rules about the harness bar being in the plane of the main hoop. Yeah, most harness bars are NOT in the same plane as the main hoop- being that the hoop usually is too far forward to keep the harness bar in plane. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted April 3, 2012 Share Posted April 3, 2012 Bringing back from the dead. This thread is super useful IMHO, but the link to the dimensions on the first page broke with the software update. Here is the fixed link: http://forums.hybridz.org/index.php/gallery/image/3103-main-hoop-dimensions/ Dave Quote Link to comment Share on other sites More sharing options...
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