Competition seat requirements

[noother]

This topic came up in another thread last week and there are a few of us building to sanctioning body rules so I thought I would post my research. I'm no expert on this topic so please feel free to correct me and/or add to this info if you have more info.

I'm only interested in NASA and SCCA rules at this point so If anyone is building to another set of rules please post. I didn't directly link to the documents since they are updated frequently. Please check the latest published rules as the info posted here may be outdated soon.

Here's the link to the web page to download NASA's CCR (Club Codes and Regulations) and specific class rules. The GTM fits in SU, STR and ES classes.
http://www.nasaproracing.com/rules/

And SCCA's GCR (General Competition Rules) The GTM defaults to Super Production class since it doesn't fit any other class rules.
http://www.scca.com/clubracing/content.cfm?cid=44472

I'll attempt to portray NASA and SCCA specifics in following individual posts.

Mark

[noother]

NASA:

STR and SU rules include this:
CCR 15.16—An approved suitable racing seat is required.

(The thing is there is no reference to what is approved, only what is suitable. I've seen Kirkey seats being used that don't have any SFI or FIA rating on them.)

From the CCR:

15.16 Driver’s Seat
The driver’s seat must be securely fastened and braced in such a way as to minimize
the possibility of breaking loose during an impact. Large fender washers and solid
fabricated mounts are recommended. Seats made primarily of plastic, PVC, ABS, or
other similar polymers are strictly prohibited. The installation of the seat must conform to
all requirements published by the manufacturer.

15.16.1 Racing Seat
Some series require an approved racing seat. It is strongly recommend that a racing
seat be installed in all vehicles. A racing seat is of solid design; not “tube and cloth”
designs commonly found in passenger cars. It can be very difficult to properly brace a
“tube and cloth” type seat and the vehicle may not pass technical inspection.
Additionally, the cloth or material on a “stock” seat is typically not flame retardant.
Therefore, the proper installation of a racing seat is strongly recommended.

15.16.2 Seat Mounting
The seat should be mounted to a steel floor pan with reinforcements. A reinforcement
structure should be fabricated with a minimum thickness of 0.090” for those vehicles
without a steel floor pan. The reinforcement structure should be mounted to (or within)
the steel frame / chassis / cage members.

15.6.21 Head Support-Rear
This section applies to seats without an integral headrest. A head restraint must be
used to help prevent whiplash. The head restraint should have a minimum area of thirtysix
(36) square inches and be padded with a non-resilient material such as Ethafoam or
Ensolite with a minimum thickness of one (1) inch. It is recommended that padding
meeting SFI specification 45.2 be used.

15.6.22 Seat Back Support
A seatback support must be made to hold the seat from going back in the event of a
crash. A plate should 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. 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 (8899-1999) or more than ten (10) years old (8862-2009). Please reference
the FIA regulations. http://www.fia.com/

[noother]

SCCA:

9.3.41. SEATS
The driver’s seat shall be a one-piece bucket-type seat and shall be securely
mounted. 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.
Seats homologated to and mounted in accordance with FIA standard
8855-1999, or FIA.Standard.8862-2009 or higher need not have the seat
back attached to the roll structure. Seats with a back not attached to
the main roll hoop or its cross bracing may be mounted on runners only
if they were part of the FIA homologated seats assembly specified in an
FIA homologated race car. The homologation labels must be visible. Seat
supports shall be of the type listed on FIA technical list No.12 or No. 40
(lateral, bottom, etc). Passenger seat back–if a folding seat, it shall be
securely bolted or strapped in place.
Mounting structures for racing seats may attach to the floor, cage and or
center tunnel. Seat mounting points forward of the main hoop, between
the center line of the car and the driver’s side door bar and rearward of
the front edge of the seat bottom are not considered cage attachment
points in classes with limitations on the number of attachments.
A system of head rest to prevent whiplash and rebound, and also to prevent
the driver’s head from striking the underside of the main hoop shall
be installed on all vehicles. Racing seats with integral headrests satisfy
this requirement.
The head rest on non-integral seats shall have a minimum area of 36
square inches and be padded with a minimum of one inch thick padding. It
is strongly recommended that padding meet SFI spec 45.2 or FIA Sports
Car Head Rest Material. The head rest shall be capable of withstanding
a force of two-hundred (200) lbs. in a rearward direction. The head rest
support shall be such that it continues rearward or upward from the top
edge in a way that the driver’s helmet can not hook over the pad.


So it looks like if you incorporate a seat back brace, you don't need an in-date FIA seat or any rating on the seat.

[kabacj]

Hey Noother,

Thanks for posting.

Although its probably over kill, I am aiming to install a full containment seat.

With all of the focus on crash worthiness in NASCAR there are quite a few manufacturers of custom full containment seats.

I figure if these things are good enough for nascar/ sprint car they are most likely good enough for me.

However since I have only driven open wheel and street cars on the track. I have never crashed anything. I dont have enough experience to know really what is needed or the pros and cons of each solution in daily use. The only thing I have crashed on the track are motorcycles. Maybe 30 times over 10 years...i've lost count. At speeds from 30 to 100 mph but only hurt 2x.

I have always used the best safety gear i could find. I figure that had something to do with the lack of injury ...plus lots of luck of course.

The question I have.

What’s the most comfortable but most immobilizing seat folks have used. For the GTM i figure ill need a seat that comes in several widths. The narrow seat would most likely fit in the GTM. I don’t have a wide torso, so maybe ill luck out that I can find an off the shelf seat that is comfortable, immobilizing, and fits nicely in the GTM. A tall order I know. Just wondering if anybody has found such an thing or has any recommendations/ experience with full containment seats.

John

[Fred Brewer]

Let me add a couple of questions if I might. Is the thought that you will just bolt you seat to the floor pan or were you thinking about something more robust with some additional tubing?

I know most of the rules call for some sort of seat back brace. Due to my height the seat is back against the bulkhead not to mention there's nothing to attach it to. I would assume with the solid bulkhead this wouldn't be a requirement but I don't really know. Are you guys planning for this at all?

Thanks!!

[Cobra 61]

Mark,
I see nothing that addresses side bolsters. Both SCCA and NASA require side bolstered seats. We got a variance because I complained of fire egress and they allowed us to rely on bolster nets on each side. Another note: you can't get in and out in the GTM with a full bolster seat. The reason the GTM is only in SP in SCCA is that it is not homoligated. If it was, then it could be in an IT_ class.

[kabacj]

Let me add a couple of questions if I might. Is the thought that you will just bolt you seat to the floor pan or were you thinking about something more robust with some additional tubing?

I know most of the rules call for some sort of seat back brace. Due to my height the seat is back against the bulkhead not to mention there's nothing to attach it to. I would assume with the solid bulkhead this wouldn't be a requirement but I don't really know. Are you guys planning for this at all?

Thanks!!

Hey Fred,

Once I get my seat I will beef up the attachment to the car. I was not planning on attaching the seat to the floor pan, but rather some tubing that spans the floor pan. I also planned on attaching the tubing to the floor pan as a belt and suspenders.

Regarding the attachment at the back, I was going to cross that bridge when I came to it. I have options to attach it to, however I dont want to pierce the firewall. Maybe ill sandwich the firewall with two plates.

John

[noother]

I'll have time to address more later but I want to get one point out there. In an attempt to better ballance the car (every little bit helps) and get more room for a racing seat, I cut out my lower tunnel frames on the drivers side and replaced them directly below the upper frames. Most racing type seats have verticle sides so making the tunnel side verticle greatly improves things here (by 4-3/4" to be exact). This then puts the steering column out of line so I relocated the bracket inboard 1-1/2" which puts the FFR carbon fibre gauge panel back into the window of the steering wheel. I have tried to fit a Kirkey Intermediate Drag seat from my '67 Camaro into the car (which is close in dimensions to the road race seats minus the shoulder bolsters) and the interferance with the original lower tunnel frames places the top of the seat right up into the outside rear corner of the cockpit.

Bottom line here, there is no easy seat solution. I believe the path to a safe solution lies in relocating the driver inboard. In the original position with the ffr seat my helmet was touching the side halo bar and almost touching the roof, moving inboard helps both. The other significant problem is the amount of layback of the seat, I havn't found a racing seat with anywhere near the layback required. I think someone split a Kirkey and welded in a wedge to splay it out more, this may be the best solution to a seat I've seen done. I just got ahold of a full containment Recaro Hans seat and will be attempting to squeeze it in, it should be here any day. It does not have near the layback of the FFR seat but I'm 5'9" and hoping I can get away with being a little more upright.

http://i617.photobucket.com/albums/tt260/noother268/1100408387.jpg

[Fred Brewer]

I havn't found a racing seat with anywhere near the layback required.

At 6'1" this is the probelm I had. For normal driving I needed my head below the roll bars,, with a helmet it's tight. I looked high and low and couldn't find anything that would get my head low enough. Richard Oben did the mod to the Kirley seat. I opted to build my own.

http://lsspecialists.com/newseat1.JPG

[JCHRacer]

This is the seat I was looking at:

http://tillettseats.com/products/full/b2

I've used Tillet seats in my Karts and they are high quality. This one is very small and I think it will fit without frame modification. No side head support but I don't know if I really want that in the GTM due to difficulty in entrance/exit.

[noother]

The Recaro just arrived, and it fits.....kind of. It is more upright than their dimensional drawing makes it appear to be. I can get it into a good spot to reach the controls and the head bolster fits really nice just under the halo bar. The problem is the angle of the bottom puts my legs up almost to the steering wheel and laying it back like this raises my whole body up because the pivot point is behind my butt. With no helmet on, the fit is acceptable and I have about 2" of head clearance. Guess how much an SA2010 helmet adds to the top of your head.....about 2". Yep, touching the roof even though I gained a bit of clearance by moving inboard. I'll get some pics uploaded later.

I don't think this is going to work out for me in this car. It may end up going in the Camaro, hoping to push her down into the 8's next year with a little shot of N2O. A full containment seat is probably a good idea.

Joel and Fred you might have the same problem with the legs too high with what you have in mind there. The leg side bolsters don't let your legs spread out and angling them up like that sends them right up into the wheel. With my tilt column all the way up my hands brush my legs when steering, this would be both annoying, hard to steer smoothly and probably unsafe.

Conclusion: Your butt has to be damn near right down on the floor pan to have any chance of having helmet clearance.

I'm thinking a splayed Kirkey might be the hot ticket. Anyone know how Oben's worked out?

Mark

[Fred Brewer]

Joel and Fred you might have the same problem with the legs too high with what you have in mind there. The leg side bolsters don't let your legs spread out and angling them up like that sends them right up into the wheel. With my tilt column all the way up my hands brush my legs when steering, this would be both annoying, hard to steer smoothly and probably unsafe.


These pictures make the area under the leg appear quite steep when they really are just right for me and that even assumes a couple of inches of padding. When putting this together I knew my butt would need to be right against the floor, my upper shoulders right against the bulkhead. The question then is how far forward do you slide your butt to get your head to a reasonable place? I also didn't want the side bolster support too tall as it's hard enough getting in and out as it is. This picture although not really great shows a bit better how it fiits in the car.

http://lsspecialists.com/gtm07071.JPG

I think the seats Joel pointed out might work nicely,, there is also Racetech which have some really nice seats as well. My biggest probelm was I couldn't just try them before I commit to a $1000 seat.

[noother]

Hey Fred, yep, that picture shows it much better, nice work! I see now that the flat panel at the bottom rear is what it takes to get butt down.

I fussed with the positioning some more and I'm really close to having it work. I removed the bottom padding (about 3/4" thick) and dropped the seat down out the bottom 3/4" and the position is perfect for me, I have about an inch above my helmet and the seat is still quite comfy. If I could flatten the bottom rear corner I would be set. I could lower the floor with alot of work but I'm having a mental block thinking of making this build even more complicated. Modding the seat would be much easier (I do realize this would negate the FIA cert).

Additional areas I need to address are a quick disconnect for the steering wheel and an X-brace following the middle roof line. I have a QD for the wheel, just need to adapt it to the column. With my head so close to the roof I would feel alot safer with some bars up as high as possible.

http://i617.photobucket.com/albums/tt260/noother268/Hans2.jpg

http://i617.photobucket.com/albums/tt260/noother268/Hans1.jpg

http://i617.photobucket.com/albums/tt260/noother268/Hansdimensions.jpg

[noother]

Mark,
I see nothing that addresses side bolsters. Both SCCA and NASA require side bolstered seats. We got a variance because I complained of fire egress and they allowed us to rely on bolster nets on each side. Another note: you can't get in and out in the GTM with a full bolster seat. The reason the GTM is only in SP in SCCA is that it is not homoligated. If it was, then it could be in an IT_ class.

Hey Richard,

I know you warned me about most of this stuff before. As always I greatly appreciate and value your input.

I don't see anything in the rules here either addressing side bolsters, maybe they imply a 'racing seat' should have side bolsters. My experience in life has been to know the rules well, because the enforcers often have things in their head that they think are rules and are quick to tell you you can't do something. It's an art to be cordial and break out the written document and try to jointly arrive at the conclusion that benefits me and move on with a good relationship. My focus with compliance is to build to the letter of the law if possible. Did the scrutineers produce anything written about side bolsters?

It is difficult to get in/out but this ain't no daily driver. If I have to crawl in and out upside down and backwards (the way I was born btw), It's worth it to be in a safe seat and car.

We will get to that homologation thing someday.

mark

[noother]

Let me add a couple of questions if I might. Is the thought that you will just bolt you seat to the floor pan or were you thinking about something more robust with some additional tubing?

I know most of the rules call for some sort of seat back brace. Due to my height the seat is back against the bulkhead not to mention there's nothing to attach it to. I would assume with the solid bulkhead this wouldn't be a requirement but I don't really know. Are you guys planning for this at all?

Thanks!!

Fred, good questions.

I cut out my floor to mod the tunnel so I have a clean slate here. I was planning on adding some square tubing to mount the seat to, the arrangement to be determined after the seat position and mounts are finalized. Then maybe a sheet of aluminum on bottom, thicker than the rest of the belly panels. Aluminum can absorb a heck of a lot of energy before failing so that's what I want below my butt.

The seat back brace rule, I think, is independent of having a solid bulkhead. It would prevent the seat from going either way and I'm sure there are designs that will work with little to no room.

Mark

[Cobra 61]

Mark,
in NASA, it was a supplemental 3 years ago. The side nets are the alternative for us. In SCCA it was the "window net" and they didn't care about the seat nets. Although they wanted the bolster seat, it was obvious it would not work in our car. My debate was fire egress and they enforced the window net only as their rules says (para phrase) all cars with roofs must have a window net. Although the driver is in the middle they did not know what side to have us put the net on! For us it serves no safety purpose what so ever, only one more obstacle the driver has to deal with.

Richard

[Fred Brewer]

Mark,,,
Seat looks terrific. I wish I could get my old fat butt in and out of something like that. I’m still very interested about how you’ll mount it so please post up more picture as you move forward. I like to pirate others ideas given a chance.

I’d also like to see how you end up mounting your belts. I remain a bit concerned that the angles on mine are not the best so I’m looking forward to seeing how others do it.

[eseethal]

I have the Tillet seats (B6) in my GTM, fit very nice and look really great, and once you are in there, they are quite comfortable (not even my wife complains). There is even an FIA homologated seat available, the B6F! The seats are listed here: https://www.tillett.co.uk/car-racing-seat.asp

Eugen


This is the seat I was looking at:

http://tillettseats.com/products/full/b2

I've used Tillet seats in my Karts and they are high quality. This one is very small and I think it will fit without frame modification. No side head support but I don't know if I really want that in the GTM due to difficulty in entrance/exit.