71 replies to this topic

[FTodaro]

So if you brace a composite seat is that non compliant?

[wheel]

"If I were to design a brace for a composite seat, I'd either add a lot of reinforcement to the back brace area to spread the load in the seat and your body, or I'd brace the seat from the sides to allow the back to flex like a trampoline without a saw horse under it."

Pretty much what we did with my MoMo seat.
wheel

[Chris Ashcraft]

ok, i am confused now..i have a OMP FIA compliant seat...1. Do seats go out of date? 2. I read it as FIA seats don't have to have a back brace. Is this not true?

[wheel]

All,

Seats that have been homologated to and mounted in accordance with FIA standard 8855-1999, or seats that have been certified to FIA. Standard.8862-2009 or higher need not have the seat back attached to the roll structure

1. Seats do not go out of date.
2. This means just what it says. If the seat was homologated and is mounted in according to the standards, it DOES NOT NEED the back attached to the roll cage. It can be, if you want it to be, but it is not required. If you have an FIA seat, but it was not mounted according to the standards, you need a back brace. So, if you have an FIA seat and it is mounted with brackets made out of Coors cans, it is not mounted according to the standards and requires a back brace.

[ChrisA]

Has NASA adopted this as well?

[john mueller]

Has NASA adopted this as well?

Yes, I believe so... Though I know a few have 'slipped by' inspectors. Mine was caught and required a brace for my 2012 Annual.

I don't agree with either part of that. A composite seat can be designed to act like somewhat a trampoline and catch you as opposed to just stop you. A back brace can be like putting a saw horse under the trampoline. The flexy parts will catch you but that saw horse location will stop you cold at the area of impact and force the rest of you to bend around it in way that was never intended. You can also drill composites safely. It's done all the time but to do it safely there is a lot of consideration required into where you can drill, how you can drill, and how to reinforce area around the hole. If I were to design a brace for a composite seat, I'd either add a lot of reinforcement to the back brace area to spread the load in the seat and your body, or I'd brace the seat from the sides to allow the back to flex like a trampoline without a saw horse under it.

I'm just going off from what the inspector said to me when he required me to put a brace on my car/seat. The brace should not be bolted to the seat, thus no drilling for a back brace. (weakens the area and would turn the brace into an impaling device). I used an IO Port brace, and will be enlarging the backrest 'pad' for more surface area and also will place a 1/4" rubber pad between the brace and the seat. It is not pushed hard against the seat but it's close per the inspector in my NASA region.

[Keith Novak]

I'm just going off from what the inspector said to me when he required me to put a brace on my car/seat. The brace should not be bolted to the seat, thus no drilling for a back brace. (weakens the area and would turn the brace into an impaling device). I used an IO Port brace, and will be enlarging the backrest 'pad' for more surface area and also will place a 1/4" rubber pad between the brace and the seat. It is not pushed hard against the seat but it's close per the inspector in my NASA region.

The NASA rules may differ but I don't think that would meet the SCCA rules: The back of the seat shall be firmly attached to the
main roll hoop, or its cross bracing, so as to provide aft and lateral support.

A gap between the seat and the back brace could be good or bad. At lower speed impacts, the seat could do most of the work so you don't strike the back brace at all or if you do, the seat has already taken up much of the energy so you're not striking it hard. At higher speeds though you have a problem. When you do contact the back brace there is a big spike in the forces transmitted. It's the same situation with tight belts vs. loose belts. I'm more concerned with high speed than low speed impacts so I'd tend to recommend putting it firmly against the seat if it's not firmly attached to the seat. The rubber pad is a good idea.

In my industry, we instrument dummies and run sled tests whenever we make changes to seat designs because we're never really sure what will happen. What we usually see though is that you're better off not striking something (obviously). If you do, you're better of striking it ASAP when the closing speeds are smaller rather than building up momentum first.

[Necio]

I have been in construction of my Spec Miata for longer than I care to admit or remember. I purchased a used seat; it was reasonably priced so I went for it. I spoke at length with seat manufacturers and their distributors because I tried to install it with their mounting bracket. The strongly recommended for me to start from square one, purchase a new seat and do it the right way. They told me horror stories about accidents they have witnessed over the years.

After having read this thread and integrating information from the manufacturers and distributors, I've reached the following conclusion: racing seats are required to be replaced and upgraded including mounting brackets and other componentry after a certain period of time.

According to them -racing seat manufacturers-, racing seats do indeed have a life term. Weather of all things; deteriorate the shell's composite materials. I mentioned to them about the rule of back braces to seats which are over a certain number of years. They were confused and incredulous about this rule. Frankly, I am with them on this one. A piece of metal supporting my back with very limited flexibility sounds dangerous to me.

I think of racing seats as helmets now. There comes a time when the helmet needs to be replaced whether or not a driver has been in accident. There comes a time when the seat will be required to be replaced.

Thank you for the information and Happy New Year!

R

[Danny Steyn]

On the subject of Composite seats (fiberglass, Kevlar carbon, mixes), the difference in construction between a seat that is designed to have a back mount and a seat that is not, is considerable. To think that you can drill some holes and somehow secure a composite seat back that has not been designed for it is presumptuous. I would not do this EVER.

I am not affiliated with Racetech in anyway, I just like their seats. If you look at the difference between their 4009 series (their very popular $1,100 seat - no back brace, no shoulder containment) and their 4119 series ( $2,200 seat full shoulder containment and designed for back brace) you will see the substantial difference in reinforcing around the entire back of the seat at the mounting points. It is this additional bracing area (seen in these images) that can be problematic in fitting this seat to an already caged Miata as it adds a few extra inches of width at the shoulder height, and these can foul the main hoop/belt bar and diagonal back braces.

I am just surmising, but I suspect that the full shoulder containment (stopping the entire body from moving laterally) adds additional loads to the bottom seat mounts and might necessitate the additional back brace to keep the seat from flexing at the bottom. Just a guess.

[Jim Boemler]

According to them -racing seat manufacturers-, racing seats do indeed have a life term.

The manufacturer of your shift knob will tell you to replace it regularly too. I wonder what the common denominator could be?

[davew]

A friend of mine did a lot of research on Snell, SFI and FIA standards. I am paraphrasing what he told me.

The expiration date is not based on the life expentansy of the part in question. It is a promise that the part will pass all current specs in place up to that point. For example, I buy a seat today that has a FIA certified date of 2017 on them. Even if FIA changes their requirements in 2016, this seat is still usable until 2017. It may or may not be within the 2016 specs, but will be usable none the less.

My interpritation of what wheel said was: SCCA has adopted FIA spec # xxx.yy as a minimum standard for seats that do not require a seat back brace. Until such time as FIA comes out with a new standard, the expiration date is not part of the SCCA requirement. My assumption is that when FIA comes out with a new standard, SCCA will have a grace period and then require the new standard.

Just my opinion
Off to Sebring
Dave

[CruzanTom]

The manufacturer of your shift knob will tell you to replace it regularly too. I wonder what the common denominator could be?

Maybe the shift knob manufacturers are looking out for your safety. One of the first "crashworthiness" cases in SC against an automobile manufacturer was filed in 1962 and involved a white gear shift knob made of white tennite butyrate in a 1949 Ford. Mickle v. Blackmon, 166 S.E.2d 173, 252 S.C. 202 (1969)

The white knob deteriorated due to UV rays, while a black knob would have been UV resistant. Ford switched to black knobs in 1950. Janet Blackmon was a seventeen year-old passenger in a car involved in an accident and was thrown against the knob, which shattered on impact. As the court stated:

Janet was impaled on the gearshift lever, which entered her body behind the left armpit, penetrated to her spine, damaged the spinal cord at about breast level and caused complete and permanent paralysis of her body below the point of injury.

The knob did not cause the accident but enhanced the injuries

Where the manufacturer's negligence in design causes an unreasonable risk to be imposed upon the user of its products, the manufacturer should be liable for the injury caused by its failure to exercise reasonable care in the design. These injuries are readily foreseeable as an incident to the normal and expected use of an automobile. While automobiles are not made for the purpose of colliding with each other, a frequent and inevitable contingency of normal automobile use will result in collisions and injury-producing impacts. No rational basis exists for limiting recovery to situations where the defect in design or manufacture was the causative factor of the accident, as the accident and the resulting injury, usually caused by the so-called 'second collision' of the passenger with the interior part of the automobile, all are foreseeable. Where the injuries or enhanced injuries are due to the manufacturer's failure to use reasonable care to avoid subjecting the user of its products to an unreasonable risk of injury, general negligence

principles should be applicable.

quoting Larsen v. GM.

That's your legal lesson for the day. If a car manufacturer is required to be cognizant of an occupant's safety, then we SM drivers should be more so. While [SMs] are not made for the purpose of colliding with each other, a frequent and inevitable contingency of normal [racing] use will result in collisions and injury-producing impacts.

[Ron Alan]

So if you're saying we as drivers have to assume and take responsibility for our own safety, aren't there certain drivers we should hog tie in the paddock and never let on track?

[Bench Racer]

aren't there certain drivers we should hog tie in the paddock and never let on track?

Start with the one's that require 6 no starts for one race.

[Keith Novak]

A friend of mine did a lot of research on Snell, SFI and FIA standards. I am paraphrasing what he told me.

The expiration date is not based on the life expentansy of the part in question. It is a promise that the part will pass all current specs in place up to that point. For example, I buy a seat today that has a FIA certified date of 2017 on them. Even if FIA changes their requirements in 2016, this seat is still usable until 2017. It may or may not be within the 2016 specs, but will be usable none the less.

I'm fairly certain that's not correct. It pretty much goes against the whole safety industry standards of how standards are maintained. The date on a Snell label is not the manufacture date. It's part of the standard number much like a part number. Change the requirements, change the standard number or change the number just to show it's still the current standard. SFI standards have a revision date and a recertification period. There are standards that haven't changed in 10+ years but per SFI the gear needs to be recertified every 1,2, 5 years, or never. That recert period is to allow evaluating whether the part still meets the requirements, not due to the standard changing but the condition of the part. FIA may work differently but it's always hard to find their information in English.

They can't promise a part will still meet the standard once it's left their facility because they don't know the life of the part after that. Did it stay in the box? Probably still good. Did it catch on fire? Probably not so good. The sanctioning bodies decide which standards to use and how they will adopt the new standards. They may provide a grace period. Window net recertification under SFI is required every 2 years but not enforced in SCCA. If it's belts or HNR system, they may require it be recertified per the SFI schedule.

Regardless of how the SCCA or others decide to implement the rules, people using the parts should remember that the orgs that write the safety standards put expiration dates on the certification because they understand that over time the part may not provide the level of safety it did originally.

[Jim Boemler]

Dave's point was that the date wasn't about an individual part, but about the specification for the part -- they're two different things.

[Keith Novak]

Dave's point was that the date wasn't about an individual part, but about the specification for the part -- they're two different things.

The date is about the age of the individual part. It is not about the date the spec was released (ignoring Snell where the helmets aren't individually dated but the specs are updated at about the same frequency as the helmets' service life). Otherwise, all SFI 16.1 belts would be dated 2008.

[Jim Boemler]

I think you're still missing Dave's point, Keith. I'll let him come back in to hopefully explain it better.

[David S.]

Well, I got my seat bases in from Good-Win Racing today. Overall very happy with them. My only gripes were having to notch the end of the slider to clear the rear mounting bolts and the fact that the slider hits the mounting bolt so it doesn't go all the way back. Both of theses could be caused by the fact that I may not be using the correct OEM bolts. They thread in right and have a big washer on them. Any ways, on to the pics!

First is a pic of the seat base next to the slider.


This is what it looks like with them bolted together and sitting in car. The hardware that comes with the bases works perfectly.



As you can see, the slider gets in the way of where the rear bolt goes in to hold the base into the car. (Sorry for the bad pic, it didn't look that blurry on my phone)


A few minutes with the cutoff wheel and it was good to go.


This is where I got tired and quit taking pictures so the only other one I have is of the seat installed. Basically I just sat the seat on the slider where I wanted it, marked the holes, drilled them out, and bolted it down. Due to the shape of my seat bottom and the angle I wanted it at, I had to offset it a little from the steering wheel. I am sitting slightly to the left of the center of the wheel. With the car stationary it is not enough to bother me, but if I drive it and don't like it I will have to make some adjustments.



Now to get started on installing the MiataCage!

[Jim Boemler]

Seems like a lot of effort to avoid using the stock sliders, which work fine, fit perfectly, and are cheaper and lighter.