DogInBlack

My 5 pt belts expire this year, and I'll be going to 6 with the replacement. Looking to avoid putting any additional holes in the floor of my RSA, I have seen harness bar that mounts to the Recaro sliders, and the sub belts attach to the bar.

Is this PCA club race legal?
Safety concerns?
Other advice?

Thanks

LVDell

Tucker, IIRC the sub belts CANNOT use a sub bar and rather need to be bolted to the chassis.

Bill Verburg

Interesting, here's a factory 996GT3 install, note item #11

LVDell

Bill, those are the sub bars that attach to the seat rails. I used them (and the BK line) in my GT3 but for DE only. However, from what I understand in the rule book, it specifies that HARNESSES CANNOT BE MOUNTED TO SEAT OR SEAT RAIL.

Currently, my sub belts (and lap belts) are anchored to the chassis of the car.


Here is the specific rule from rule book:
14. Five, six or seven point SFI or FIA approved competition harnesses, are required and must be properly
mounted in accordance with the manufacturer’s specifications (see Appendix B). Harnesses cannot be mounted
to seat or seat rail. Mounting must be to the chassis backed by large diameter washers (if stock mounts are not
used) or to the roll bar. No two harness straps can be attached to a single mounting bolt. No Y-type shoulder
harnesses are allowed. The angle of the shoulder harness going back from the driver’s shoulders cannot be
more than 30 degrees above nor more than 10 degrees below the horizontal plane of the shoulders. Harness
webbing must be approximately 3” for lap and shoulder harnesses and 2’ for antisubmarine straps. Addition-
ally, FIA or SFI approved competition harnesses with 2” lap belts may be used, and FIA or SFI approved
shoulder belts with a 2” section designed to fit over the yoke of the device may be used. The anti-submarine
straps should be mounted such that they will not allow upward vertical movement of the lap belt due to
“crushing” of the front seat cushion in any situation.

Bill Verburg

I am clueless here, just pointing out what I see and anxiously waiting for some answers

LVDell

I am guessing some of the more experienced scruts will chime in.

Cue Geoffrey in 3.....2.......1

jscott82

Not an experience scrut... but I think it comes down to safe vs race legal....

Yes the GT3 seat with a bar for straps is plenty strong and probably very safe... But to write the rule book it would be too difficult to fully detail every iteration of rails/seats/mounting points..... so to make things simple for everyone... all belts must connect to chasis, no exceptions....

still waiting for Geoffrey....

LVDell

Jeff, how's the car coming? Looking forward to seeing you again soon!

ilko

I was told by a PCA scrutineer that to be race-legal, the sub-belts have to be bolted to the chassis. So that's what I did. Drilled holes in the floor, installed plates, and bolted the sub-belts. YMMV.

jscott82

As bad as things looked at the track, it was all mostly superficial. The dent in the rear quarter is the only major problem, the rest are bolt on pieces… But my race budget was blown before I wrecked the car. Its going to take some time to refill the coffers before I fix it an race again…. I am now targeting getting it ready for Mid-Ohio DE in Aug.

It sounds like we still have a clucb race at CMP next year... so Ill definity see you there...

LVDell

Good to hear you will be back!

DogInBlack

Thanks everyone

38D

Correct, subs must be attached to the chassis.

It is interesting that the 993 RS has that sub bar that attaches to the seat rail. The 964 cups have 2 welded in threaded receptacles that hold the eye bolts for the subs. I wonder what the 993 RSCS has.

Bill Verburg

the 996/997 GT3 and maybe Cayman use the sub bar, afaik the 993 does not

Here's the 993RS setup, the /CS has a harness install kit that supplements this, but no pics unfortunately

RedlineMan

People often take racing rules as infallible gospel, and thus quite often do not apply any critical thinking beyond that, on their own behalf. If ever anyone wanted an example of where racing rules are utterly foolish, and completely overlooking an extremely important safety measure, this is it.

How anyone thinks an unreinforced tin floor can withstand thousands of pounds of potential force without significantly deforming, and thus rendering that which is attached to it far less than effective, is beyond me. It is insanely obvious, and yet totally overlooked by "those in the know."

As I have many times in the past, I will offer my standard test analogy to prove that a tin floor is no place to mount a safety harness; Take your floor jack, place it right under the area that your sub would mount, and jack your car up into the air. What you see happening when you do this is quite possibly the same result as if you had a sub mounted there, and needed it to work. If you factor in that the sub strap can see just as much load as any other belt in the system (easily in excess of 1000lbs, a fact most people are unaware of), it starts to become quite obvious.

I'll ask another obvious question; Why don't car manufacturers mount seat belts to simple flat unreinforced tin structures? Before anyone brings up the Cup Car sub mounts, I'll point out that at the time of the 964 and even 993, this level of safety research was in its relative infancy, and these intuitively obvious but undiscovered truths had not clobbered anyone over the head quite yet. Yes... Porsche is good. No... Porsche is not perfect.

Are there two sides to this coin? Yes, most assuredly. The flip side is that it is VERY difficult to construct a proper sub mount in a stock car without doing some meaningful cutting and welding. I seriously doubt that an understanding of this difficulty is why the current rules are left standing. I'm quite sure it is out of ignorrance.

I light of these two disparate sides of the coin, it is my opinion that a well thought out and constucted piece that relies to some extent on the seat mounting might be a good compromise. If seat mounting methods at least as stout as the factory are utilized, it seems to me to be a more reliable circumstance than one that is CERTAIN TO FAIL like an unreinforced tin floor.

End; Part I