Seat back brace
Posted 04-24-2017 09:27 AM
Sorry, should have been more specific. NASA tech does require it on any non FIA seats and out of date FIA seats. Doesn't need to be directly bolted but it must be there to brace it. Kirkey suggest that seat back brace is bolted so I'm on the fence on that as well but for safety sake will probably bolt it in.
Posted 04-24-2017 09:32 AM
Just having the brace does not add any side to side security. the brace needs to be attached to the seat. Make your plate larger and add a nut/bolt or two
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Posted 04-24-2017 09:35 AM
. Doesn't need to be directly bolted but it must be there to brace it.
Maybe the rule has changed or I'm confusing my organizations...but I seem to remember a big discussion about bolting to composite seats? Which directional loads is the seat brace intended for? Asking this to anyone in the know for future reference...
Posted 04-24-2017 10:08 AM
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Posted 04-24-2017 10:28 AM
Seat back braces are not required. The driverâ€™s seat shall be a one-piece bucket-type seat and shall be securely mounted, so as to provide fore/aft and lateral support.
No disrespect to Wheel, BUT, securely (I understand it's a GCR word), is a very subjective word and different tech's will have different definitions of what securely means. Bolts plate to seat and you'll have zero issues.
Agree with Dave to increase the plate size. If you chose to make your attaching tube cleaner, you could go smaller in diameter and have a single tube bent as required. Or a single straight smaller tube attached at an angle from your cage cross tube to the larger seat plate.
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Posted 04-24-2017 10:33 AM
I just quoted the SCCA rule. There were many discussions, over a long period, about FIA seats, sliders, back braces, yada yada yada. The CRB just decided to go back to the old rule. Mount it securely. If a tech inspector can grab the back of the seat and wobble it around, they won't pass it. My car has a back brace with a very large plate to distribute the load. It does not move 1 mm. If you are going to be the one sitting in the seat, consider what will happen to the seat in any type of impact, and mount it accordingly.
Posted 04-24-2017 11:38 AM
Well, if you are going to complain about it, we can always change the rule back and require a back brace and you can figure out a way to mount one on an FIA seat that was not designed for one. I have not heard one single issue where a seat, FIA or otherwise, has been bounced because of a little flex. If this is really a problem we can always go back to a restrictive rule.
Posted 04-24-2017 11:39 AM
I did my composite Ron and bolted it. I like it, it was flexing too much.
I think Craig mentioned to me though I didn't have to.
I/O got 3 kinds now
Posted 04-24-2017 11:47 AM
Posted 04-24-2017 12:06 PM
I'm not going to look and post another time a seat manufactures info. One of the big time composite seat manufactures is implementing a composite square tube into the rear of their seat to accommodate bolting to support brace/roll cage. Same company has a kit to mount composite seats to support brace/roll/cage.
Posted 04-24-2017 01:11 PM
JD, clear. I was responding to Ron. That's why personal conversations are better than web posts.
My post was tongue in check...I like the SCCA rule clarification! I wish NASA would adopt! But in the meantime in all seriousness I do want to know if the back brace per the NASA rules does not have to be connected to the seat as was posted by others...
Posted 04-24-2017 02:33 PM
15.6.21 Seat Back Support
A seatback support must be made to hold the seatback from failing in the event of a crash. A plate shall be used to distribute the load. No bolts, corners, or sharp objects should be placed in such a manner that could lead to a possible puncture of the driver in a high impact crash. Seat back support need not be attached to the seat itself. Proper design and installation is crucial to safety and it is recommended that the driver employ the services of a professional race car builder for this, as well as all other vehicle safety items. An exception may be made for those seats homologated to, and mounted in accordance with, FIA 8855-1999 or 8862-2009 standards. Those seats that qualify for the aforementioned exception must conform to the entire FIA 8855-1999 or 8862-2009 set of regulations, as applicable. This includes a mandatory seat replacement, or use of a seat back brace, for any seat more than five (5) years old (8855-1999) or more than ten (10) years old (8862-2009). Please reference the FIA regulations
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