tomzz

It seems as if DE sponsoring Clubs are changing their rules about seat/harness set ups for DE events. The Porsche Club of America (PCA) seems to be the first and rumors are that more Clubs will follow. As of Jan 1 2008, all PCA DE events will follow the new PCA Seat/harness rule. The rule will require that 5/6 pt harness systems be used with a seat designed for this purpose that has integrated head restraints with shoulder strap holes and a submarine belt slot in the seat base. Straps thru the Z OEM head rest will not pass inspection. Side belts do not have to go thru a slot. Harnesses will not be approved for use that are more than 5 years old (date on harnessses). Harnesses must also be attached to a roll bar or harness bar that allows for factory reccomended angles of attachment.

So, at the minimum, our 350Z stock seats cannot be used with a 5/6 pt harness if we attend PCA events in 08. I chatted with a PCA DE event director who indicates that some "tuner" seats will pass muster (along with full race side slot seats) since they have integrated head restraints. Do any/all "tuner" seats have submarine strap holes?? I thought they did not have sub slots.

* Anybody else run into this in other Club DE rules yet?
* What seats seem best for the 350Z for this situation? I would not like to go to a full race seat.
* What seat model has the best mix of track use support and regular street use comfort??

betamotorsports

iTrader: (1)

Most groups will allow the Schroth DOT approved 4 point safety harness as long as the shoulder belts go through designed openings in the seat back. This should allow seats without the opening for the sub strap.

Billhyco

iTrader: (14)

Schroth wouldn't work being a 4pt harness. all in all its really not a bad idea...think about it. Your doing 140 down the back stretch with nothing more then a standard seat belt and seat. However, the sub belt hole will be a tough one. I see A LOT of cars with upgraded seats and 5/6pt belts but no sub hole.

gixracer

iTrader: (2)

porsche club in 09 will be making hans devices manditory also

tomzz

Hans too? Looks like Nissan and others need to rethink a
"Track" model. I am not sure if the fancy 911 GT3 seats even have submarine straps. I have asked the Porshce Chapter Coor to check on the sub strap rule info. Looks like a Whoopie Cushion might be needed for the longer trips to the DE track events if Full "race" seats are the only option?? I have not seen the BMW Club go this way this year.

350zippy

tom,
we had a discussion at peachstate pca event:
1.no more 4 point street/track belts.
2.if running a 5-6 point harness- a racing seat will be required with proper anti-dive fixation/roll bar to support harness.
3.if you have stock Z seats - use stock seat belts (5-6 points not allowed,even if you have it).
4.if you have racing seats but no proper fixation for 5-6 points harness- use stock belts.

the european (aftermarket) GT3 seats have a cross bar bolted to the seat rails to support use of anti-dive straps.
regards
jose

tomzz

Well , looks like I need to see if Santa takes returns on socks and slippers before the end of January. How many slippers and socks does it take for a set of Momo Race Seats?

first350

iTrader: (24)

I run JIC's seat, it's got the submarine hole in the bottom...I assume this would pass their inspections - it's one of my favorite and most useful mods I've done to the Z.

I know you mentioned not going to a full race seat, but thought I'd through this out there...it's a tight fit, and holds you securly, but is still semi-comfortable (I've done 3-4 hr drives w/ it w/out any issues). The nice thing w/ this is that you can get all the mounting hardware from JIC, and it actually fits - no custom fabrication needed!

shot in the car w/ the 6pt harness:


shot of the bottom of the seat prior to install:

tomzz

Thanks first350,

very helpful information. Will look at this seat option.

How do you use your OEM seat belts for around town driving? I have my harness attached by the appropriate anchors, but how (if) do you utilize the regular seat belt with the strap holes and high sides of the race seat?

mhoward1

We were told that it would be head restraint systems, not necessarily Hans.

Modern passenger cars are capable of providing a high level of protection. It is strongly recommended that vehicles used for both daily transportation and track use not compromise existing safety equipment. Vehicles used for the HPDE must, at minimum, meet State Inspection Standards. No additional safety equipment is required to participate in the HPDE other than the use of a SNELL SA2000 rated (minimum) helmet.

Many drivers attempt to install competition harnesses in passenger cars to cope with the higher g-forces encountered during track driving. For the vast majority of vehicles, it is not possible to safely mount competition harnesses because there is no proper place to mount and position the shoulder harness as well as making sure that the anti-sub strap passes through the center of the seat bottom cushion. In many cases, “harness bars” that are used for shoulder harness mounting are too small, untested and of unknown strength.

Most harness bars should only be used to guide or position a harness. They must never be used for the anchorage of shoulder harnesses unless FIA Ceretified. Harnesses must be
anchored to a structural member or bulkhead with proper reinforcement, ideally the OEM location of the rear seat belts. Keep in mind that “peak loads of any lap or shoulder mounting point in a 35mph impact to a solid barrier is approximately 3,000 lbs for 60 to 70ms for a person of 175 lbs.”

Shoulder straps should never run downwards from the backrest (or backrest slots) more than 30 degrees from a horizontal plane without a harness guide bar that can take the load applied during a crash. The backrest of any seat (including race seats) are not designed to take this load and will collapse. The recommended solution for dual-purpose vehicles is to use 3 or 4 point harnesses that are designed as OEM replacement and have US-DOT
designations that meet FMVSS209 specifications.

If a driver so chooses, competition harnesses can be used for the HPDE but they must without exception, be installed in compliance to the current SCCA GCR (Section 20). Competition harnesses that fall under the SCCA GCR are covered in this document in Section 6.

The appendix lists detailed drawings and descriptions to guide harness installation to ensure compliance. OEM replacement harnesses having the DOT label will have been tested to FMVSS209 Federal Certification. They will be specific to a make and model or be included on the list of make, models, and possibly seat type for which they are certified. It is mandatory for the driver/owner to produce this documentation to allow inspection of the vehicle. These documents can be obtained from the manufacturer and
should be included with the harnesses. If this documentation is not present, it must be assumed the harnesses do not meet FMVSS 209 and will not be acceptable.

If you choose to install harnesses we recommend Five (5) or Six (6) Point Harnesses (GCR Section 20) with either SFI 16.1 or FIA #8853/98, #88853/85, or D-
###. T/98 certification labels. Belts must not be older than 5 years. Replacement at
expiration date stated on the certification label is strongly recommended. Note: only one belt in a set may contain the label.

Harnesses must be installed per GCR Section 20. See Appendix Figure 1, 2 and/or 3 for detailed drawings and description of proper installation and threading. Harnesses must be anchored to the frame, structural member of the car, or reinforced bulkhead. Each belt in the harness must have an individual mounting point. For example, there must be 2 mounts for the shoulder harness, 2 mounts for the lap belts and 1 mount for each anti-submarine strap.

5-point systems are recommended for vehicles where the driver is seated in an upright position. 6-point systems are recommended for reclined seating positions or when the Antisub strap cannot pass through the bottom of the seat. Lap and shoulder belts must be at least 3 inches wide. The anti-submarine strap must be 2 inches wide. If the driver is
using a HANS device, the harness must be HANS compatable and may have different specifications. Belt material must be Nylon or Dacron polyester. Hardware must be metal with a metal-to-metal single quick release system.

Shoulder straps should be anchored to the roll bar and never run more than 5 degrees upwards or 30 degrees downwards from the backrest (or backrest slots) from a horizontal plane without a guide bar or roll bar that can take the load applied during a crash. The backrest of any seat (including many race seats) is not designed to take this load and can collapse.

The anti-sub strap should be mounted just behind the plane of the drivers chest to where the plane of the spine would intercept the floor board and pass up directly between the legs through the bottom of the seat. When a 6 point competition harness is used, it is permissible for the leg straps to be secured at a point common to the lap belt, and pass under back rest, under the driver and up between his or her legs.

THSCC/TZC also enforces an “Equal Protection Policy”. This requires both driver and passenger have available the same level of protection. This applies to Seats, Harnesses,
Padding and all installed safety equipment.

I hope this information helps and isn’t too much.

Stack

How do you have your shoulder straps mounted? It looks (but is hard to tell) like you have them mounted to the floor, running up to the shoulder slots. This will not pass any tech worth the paper its written on, and in fact, could be fatal if you were to be involved in a serious collision. If the seat back were to fail, you could suffer spinal compression.

The shoulder slots are guides only, and should never be used as load-bearing. You really need a structural harness bar (actually you need a 4-point roll bar with an integrated harness bar, but that debate is unrecognizable as even a dead horse.)

gixracer

iTrader: (2)

will the bcr harness bar be approved with proper race seats?

Stack

Depends on the club... we'd probably approve it for our DE (though we still haven't seen one in person, which we'd need to do). Haven't read the exact wording of the PCA rules in a while... my guess is they would accept it, but thats just a guess.

tomzz

Thanks folks. This is all very good and helpful information.

I had done what I thought was due diligence for a safe DE set up and still allow the use of the OEM seats and belts for street use: 4pt padded roll bar with proper harness bar , top rated 6 pt harness. mfg spec attachment points for all harness points, correct angle on shoulder straps coming thru the inside of the head restraint bars. (I do not have a rock back plate between the seat backs and the roll bar - horizontal harness bar)

So what is the weak safety link(s) in this set up that would require a full race seat? Is it that the sub strap coming up and over the seat will allow me to slide out? Is it the straps coming thru the head restraint bars are unsafe?

tomzz

forgot other Race Seat Q

How difficult is it to climb in and out of a full race seat during everyday use?

Stack

I can't speak to PCA's specific reasoning for the wording of the race seat requirement. We allow stock seats to be used IF the harnesses can be mounted properly and function properly.

Main problem with running harnesses through the headrest is that it creates an unnecessary tension point behind your neck. When those belts get stretched tight, the belts are cinched in, possibly creating neck injury of some variety. But run outside the headrest, you run the risk of the belts sliding off the shoulders in an impact. We'll look at the harnesses with the driver strapped in, and usually recommend a strap behind the headrest to keep the shoulder belts in position. This is the purpose of an 'H' strap harness (which are hard to find these days though).

Your anti-sub strap would be a cause for concern run over the front of the seat as it still allows for some submarining. With the 6-points, a better, and more accepted routing would be from the lap belt anchor points run over the back of the seat bottom, under your legs so you are sitting on the anti-sub strap.

Stack

There are plenty of seats that would meet PCA requirements, but not be full race "shells". Most of these are relatively easy to get in and out of.

tomzz

The PCA DE coor I have talked to said that the sub strap hole in the seat must be original design and installed to allow the substrap to be in the position you detailed. I have not been able to find any "Tuner" seats (w shoulder strap holes) that have a sub strap hole. They said "ya gotta have a sub strap hole". That seems to mean full race seat??

Stack

What I'm saying is ...

Something like this:


Versus this:


Or especially this:
http://www.kirkeyracing.com/index.ph...TMLID=Featured
(ok, maybe overkill, but you get my point I hope)

tomzz

well, it looks like my wife has offered the final justification (not found in the new PCA DE rule book) to consider

"Well sweetie, you may as well get those nice MOMO seats to go with your MOMO gloves. You will look cute in the seats in the baby Z".

Ahh - accessorize!, accessorize!