JMortensen Posted January 14, 2012 Share Posted January 14, 2012 (edited) Saw this video on another forum. FF to the 8 minute mark if you don't want to watch the drifting. I didn't watch all the way through, so if there is a Rick Roll at the 5 min mark I apologize. Point is, the car rolls, A pillar bar folds to a disturbing degree, and driver's head is halfway out the window! The need for the window net is pretty obvious, but the FIA bar is something that I don't think I've ever seen on a Z cage. This is something that just about everyone uses now, from NASCAR to prototype racing. I've seen Spec Miata cages built with them too, so I don't think they're illegal for lower SCCA classes. It is a straight bar which goes from the bottom of the A pillar bar to the to the halo or the junction between the A pillar bar and the halo or the A pillar bar and a gusset to the halo. Sometimes they'll go vertically down from the A pillar bar junction down through the door bars and to the rocker. The point of the thing is to give the top corner some support. The main hoop has support from the backstays, but without the FIA bar there really isn't anything bracing that top corner in most cages. Here is what it would look like on my car. I gave the quarter shot so you could see that it is actually attaching where the gusset hits. If I didn't have the gusset it would go to the junction between the A pillar bar and the halo, and then the bottom of the A pillar bar. I was hemming and hawing about actually adding this to my cage since the dash bracket on the other side is right there, but I think I'm going to just get it done. It won't be hard and I think it's worth the effort. Edited January 14, 2012 by JMortensen Quote Link to comment Share on other sites More sharing options...
surpip Posted January 14, 2012 Share Posted January 14, 2012 I'm no cadge builder but FWIW i think that bar wouldent make a huge differance, looks like you dont plan on useing the pass seat so, for your consideration: Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted January 14, 2012 Share Posted January 14, 2012 That's an awesome video. Watch the whole thing. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 14, 2012 Author Share Posted January 14, 2012 I'm no cadge builder but FWIW i think that bar wouldent make a huge differance, looks like you dont plan on useing the pass seat so, for your consideration: The FIA bar really does do something, which is why the FIA requires it. It is essentially a big gusset for the bend that I've outlined in red. Your idea is pretty close to another way that I've seen it done. I've drawn that one out for you below in green. Assuming the rocker is strong, then I think this option is stronger than the typical FIA, but it cuts down the size of the hole that you have to get through to get into the car considerably and seems to work better on newer cars with really large doors. Quote Link to comment Share on other sites More sharing options...
surpip Posted January 14, 2012 Share Posted January 14, 2012 (edited) you think the AXB bars would braise that bend but i can see how it would offer support, and if its required then there ya go. With my idea it would be almost imposible to get out he passenger side qickly, i see now your doing this on bouth sides. I dont see why tech would give you a hard time. The original idea is the way to go, all shut up now Edited January 14, 2012 by surpip Quote Link to comment Share on other sites More sharing options...
johnc Posted January 16, 2012 Share Posted January 16, 2012 The bar is called "FIA Group N Windsscreen Pillar Reinforcement" (see 8.3.2.1.4 in the FIA Group N regulations.) Here are the specs: 8.3.2.1.4 Windscreen pillar reinforcement :Cars homologated as from 01.01.2006 only: It must be fitted on each side of the front rollbar if dimension "A" is greater than 200 mm (Drawing 253-15). [Diemnsion A is the longitudinal distance from the bend at the top of the A pillar to the door hoop front mount] It may be bent on condition that it is straight in side view and that the angle of the bend does not exceed 20°. Its upper end must be less than 100 mm from the junction between the front (lateral) rollbar and the longitudinal (transverse) member (see Drawing 253-52 for the measurement). Its lower end must be less than 100 mm from the (front) mounting foot of front (lateral) rollbar. Based on the Dimension A requirement, its not required on most S30 roll cage installs because the S30 windshield is very upright. Its not a bad idea but you need to make sure that you're not hurting egress. I do install this bar on E36 Coupe cage builds. Its optional E36 4 door installs (again due to Dimension A) but its generally a good idea. FYI... I just remembered that I mocked this bar up on a 240Z and it interfered with steering and hurt getting in and out of the car for a bigger customer. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 16, 2012 Author Share Posted January 16, 2012 Well poop. I just went out to the garage and plugged the steering wheel on, and sure enough the wheel is just exactly in the same plane where the FIA bar would go. I guess I'll just have to try not to do a barrel roll... Quote Link to comment Share on other sites More sharing options...
johnc Posted January 16, 2012 Share Posted January 16, 2012 You really don't need the bar in your S30. The door opening is small enough and with the tubing you've used in your car you will not see a significant movement of the top of the A pillar in a rollover. Quote Link to comment Share on other sites More sharing options...
surpip Posted January 17, 2012 Share Posted January 17, 2012 Johnc, How much do you normally charge to build a cadge for a Z? im trying to justify weather or not i should buy a tubeing bender just wondering what the cost to have one put in would be. Quote Link to comment Share on other sites More sharing options...
johnc Posted January 17, 2012 Share Posted January 17, 2012 A SCCA IT legal cage is about $2,500 including materials. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted January 17, 2012 Share Posted January 17, 2012 Sounds about right. That's what I got quoted from a local shop here in Denver Quote Link to comment Share on other sites More sharing options...
heavy85 Posted January 22, 2012 Share Posted January 22, 2012 When the NASCAR COT first came out Ryan Newman flipped and they had to cut the roof off the get him out because of the lack of an FIA bar and a very long door opening. You might search and see if they did go back and add any extra bars. This is an extreme example with a much bigger door opening but maybe whatever NASCAR learned from it could help. Cameron Quote Link to comment Share on other sites More sharing options...
johnc Posted January 23, 2012 Share Posted January 23, 2012 There's a large difference in crash/impact energy between a 3,500 lb. car going 150 mph and a 2,500 lb. car going 90 mph. Quote Link to comment Share on other sites More sharing options...
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