Non-FIA Composite Seat Brace

[walterclark]

SFI publishes a standard for "Stock Car" seats, SFI 39.1 and 39.2, that could apply to aluminum seats if the manufacturer so chose but I dont think Kirkey seats claim this until you get to their 91/92 series full containment seats (they cost $2000+ list). This certification is required of seats at the top levels of NASCAR and ther are a few manufacturers of them.

In this SFI 39.1/39.2 approved range I would go for a Joie seat http://www.joieofseating.net/. Kevin has one.

I havent seen an entry level Kirkey seat I would sit in and race...well maybe autocross. But at my 200+ pound weight I need to choose stronger stuff than someone weighing say 120 pounds to get to the same safety.

Back when I bought my first seat - a Sparco Evo2 - I didnt appreciate all this. The Evo2 that I bought in 2003 was larger than the Evo seat but no stronger despite being made for a larger person. The FIA 8855 requires each model (the Evo and Evo2 are different models per FIA) be tested with a "50th percentile Hybrid-II or Hybrid III dummy" that is the equivalent of a 5'9" person that weighs 170 pounds, rather than scaling the dummy size to the seat size or in the Evo2's case the 95th percentile Hybrid-II or Hybrid III dummy that is 6'2" and weighs 223 pounds. And they are subjected to 10-20G 50ms "impacts" to the rear and sides and cannot sustain any permanent structural damage but no deflection limits are specified. Thus the larger seat could legally be weaker than its standard sized equivalent when normalized against it likely occupant. As they Evo and Evo2 were identical in construction except width and based on my uncalibrated efforts to do things like twist the upper seat back which suggested to me the Evo2 was easier to deflect (same pressure, but more leverage applied to the "wings" at shoulder height) I concluded the Evo2 was less safe than the Evo I bought at the same time. When I went looking for a seat at the end of 2010 with head and torso containment I kept this in mind and looked for a seat that was much more strongly built than the 8855 typically required. At the time 8862 was still new having only been released a few months earlier and there weren't any seats mere mortals could afford that were or expected to be so certified. Construction (at the time Cobra was more than willing to talk with me about construction and their own testing), fit and price is how I ended up with the Sebring Pro GT.

8862 doesnt replace 8855, it is defined as a an "Advaned Racing Seat" standard where 8855 is the base "Competition Seat" requirement. 8862 changes and raises the testing a good bit. First they will test the worst case seat in a model line (meaning likely the weakest seat which is probably going to the the largest size) mounted in its worst case configuration (meaning highest position in most cases). It is subjected to specified load deflection tests at several specified test points with both maximum deflection, visual damage and permanent deformity limits. The standard then says all sizes in a given model line must be made exactly the same as the one certified. While this guarantees the smaller seats are stronger (as was typical with 8855 seats), the bar has been raised so the weakest seat is now much stronger. These updated test methods dont easily translate to the 8855 crash test dummy "impact" tests for the non-engineer but I am told the limits are MUCH more restrictive and most of the 8855 seats from 10 years ago dont survive these tests.

[Chief Geek]

Thanks.

We'll be using the stock Miata seat on which Dave performed a foam-ectomy for now. I was thinking that an upgrade will be in order when we decide to start running non-baloney-skin tires. (that and a completed cage)

I wonder how big a deal it is to find a proper racing seat that would fit both of us.

Paul

[KevinGale]

In this SFI 39.1/39.2 approved range I would go for a Joie seat http://www.joieofseating.net/. Kevin has one.

I havent seen an entry level Kirkey seat I would sit in and race...well maybe autocross. But at my 200+ pound weight I need to choose stronger stuff than someone weighing say 120 pounds to get to the same safety.

The Joie is a nice seat but it wasn't cheap! I did have the entry level Kirkey seat and the top of it folded over when I hit a tree hard at Ascutney. Now admittedly it wasn't mounted perfectly the harness bar wasn't high enough but at the time no one thought it was a problem. Now tech is very fussy about that. Still the Joie seat I have now would have taken that hit and not even noticed it. I really didn't like having the seat bend. At first I thought I might have broken my neck because the chin of my helmet was on my chest and I couldn't pick up my head. There were a few moments of panic before I figured out the top of the seat was holding my head down.

[Mopar 151w2]

I have a Kirkey "Intermediate Road Race", and it is greatly superior to the "entry level" Kirkey.

Note the extensive reinforcement ribbing and double walls at critical points.

[walterclark]

Thanks.

We'll be using the stock Miata seat on which Dave performed a foam-ectomy for now. I was thinking that an upgrade will be in order when we decide to start running non-baloney-skin tires. (that and a completed cage)

I wonder how big a deal it is to find a proper racing seat that would fit both of us.

Paul

I would suggest going somewhere to sit in a few and not just try to match butts to online catalogs. I think you may have missed the "expos" around here unless the one scheduled for this weekend in Marlboro, MA is rescheduled because, well the state is shut down. Places like HMS Motorsport carry a number of different seats (most of their catalog - but they dont carry Kirkey) at their store in Danvers to sit in in. I bought mine from them.

[Chief Geek]

Makes perfect sense. Buying something that "intimate" with only online info doesn't feel right.

Paul

[Mopar 151w2]

Kirkeys come in sizes - their catalog has a section on how to measure. For those (like me!) who are constructed of spare parts, Kirkey offers "made to measure" seats - which mine is. Kevin is one of those lucky guys who is a standard size - most Lajoie's are custom made, with a measuring device not unlike the one for shoes. Kevin plopped his butt in one of the standard size at a trade show (Speedway Expo) and did'nt want to leave!

[KevinGale]

Kevin plopped his butt in one of the standard size at a trade show (Speedway Expo) and did'nt want to leave!

Yeah then I spent the next few hours convincing myself that I really wanted to spend that much on a seat. I kept sitting in the seat and obsessing about it. My wife only had one question. "Will it be safer?" I said "Yes, a bit." and she said that if I didn't spend the money on the seat I'd probably spend it on making the car faster and she knew which one she preferred.