roadrat

TIA

Larry Cable

what's your specific question - just out of curiosity?

4pt - much better than factory 3pt (for the track), not as good as 5/6pt (for the track)

usually only relevant if you dont have the facility to fit the 5/6 "crotch" belts (no hole in seat)

biggest issue is submarining...

MJG911

4 point totally unsafe for the track, due to that submarining. I would never use one. 5 or 6 only.

roadrat

Track use. I read this.....


If you would like to use an approved 4 point system the only expectable option for using a 4 point safety belt system is if they are equipped with automatic anti submerge provision…retracting/locking vehicle’s system…otherwise known as Auto Control, designed with inertia reel to allow you to lean forward under normal circumstances and will lock you down as soon as sudden movement is detected. www.schroth.com is the only company we know of that make such a belt.
(note: 4 point safety belts are deemed unsafe because of no submerge provision or active tensioning.)


It's poorly written but I think it's saying that the Schroth 4 points are acceptable. I use to run one in my M3s a decade ago on the track

Larry Cable

It was Schroth I was thinking of when I wrote my initial comments.

Schroth claim their AS system "works"; is a 4pt less safe that 5/6, yes, is it better than 3pt yes... YMMV

roadrat

Thanks for the input!

008

I ran the schroth 4 point on my E46 M3 but it plugged into the existing belt anchors. Only time I've ever had harness that wasn't cage mounted and had anti submarine strap. Do they make a fitment for the 991 that isn't cage/roll bar mounted? If not, is it just that you don't want to swap seats?

Honestly, my bigger concern with a lot of Porsche solutions is that most bars are just harness bars and they may keep you in an improper position in a rollover/collapse scenario.

I was in a heavy accident years ago where a properly welded in cage saved me. I'm not sure a lot of the solutions out there today are any safer than what has been tested and approved by the Feds.

roadrat

Same with me with the E46 M3. I may have jumped the gun assuming they made the same thing for the 991.

This is going to be my first trip back to the track after a decade off so I'm trying to pull out all my old notes from the TWS days. Harness was one of those things

drcollie

A 4-point harness, or ANY harness is dangerous in a car with no roll bar (at a minimum) or preferably a cage. As an Instructor, I will not strap in and use a 4-point harness in a student's street car, which baffles some students at the DE who think their car is sexy with harnesses in them and it shows they are a serious driver. But all it tells me is they didn't do their research. Why? Well, if you roll the car over and put it on the roof, the standard 3 -point will toss you out the side in a rollover event to to the center of the car. You wind up in the console area when the roof collapses. With a 4- point you are strapped to the seat and if the roof comes down your head becomes the fulcrum point unless you are lucky enough for the seat back to break. Submarining, while it sounds dramatic, is not your concern - its a rollover.

I have pulled people out of rolled cars at the track. We like to find the driver and instructor in the footwells of the car or splayed across the console, not with broken necks. Would you want to be locked into the seat in this Aston Martin?



Or how about this BMW that flipped over at a DE event? If your body is strapped tight to the seat in this car, what do you think is going to happen to you?



Harness bars and 4 points are usually fine for autocross, where your speeds are rarely above 45 mph and they help keep you from sliding, but I think they are dangerous at the track.

A safety system in your track car has three elements.

1) One piece seat (won't break)
2) Cage (rollbar if you cannot bring yourself to do a full cage)
3) 5 or 6 point harness.

You need all three pieces. About 12 to 13 years ago, a 911 owner was killed at Summit Point during a DE event when he lost control of his car and went backwards at speed into a tree at the end of T1. He had a rollbar, and a 5 point harness in the car, but stock seats. As the car impacted the tree **** end first, the seat back broke and his head slammed into the rollbar and it broke his neck. He was dead on impact. This is not to scare you guys, but to reiterate how important it is to have the entire system. Had he had a proper 1 piece seat he would have probably survived. Had he not had a rollbar in the car he probably would have survived.

I prefer to go with street belts in a street car when I instruct, and even in my own car. You have to do it right or do nothing at all IMHO. Just the voice of experience talkin'.....don't want anyone to get hurt out there.

jlanka

Thanks for that info Doc. So I have a "real" roll bar (Cantrell: 991 roll bar ) and Recaro Profi XL's along with Schroth harness

You would instruct in my vehicle?

Jeff

drcollie

If you have all that, you don't likely need an instructor.

jlanka

Thanks for the compliment, but I'm still a yellow. I'm just tired of holding myself in the turns and getting sore. So I decided to do it right.

chuck911

The most important safety component you can improve is the nut behind the wheel.