Den

Has anyone installed harness holes into their stock seats. I like the comfort of the stock seats in my 993 turbo but I want a safer harness such as the Schroth ASM rally 3 belts. I suppose the right shop could do the mod, reinforce the seat back, and make the leather fit look good.

RedlineMan

Hmmm...

It certainly has been done. I imagine any good upholstery shop could do it. If the headrest area is wide enough to give you the right spacing, find yourself a used seat and have a go. As long as you carefully plan your restraint architecture and belt paths, the seat will not be in play in terms of belt function.

4-point ASM belts will not be eligible for PCA DE, but they are certainly an improvement on OE 3-point belts for street use.

JCP911S

Eehhhhh... I don't know...

After much discussion and few facts, it is very hard to judge the true implications of mixing and matching safety equipment. Safety equipment is a system..... each component provides a function that compliments the other pieces.

For example, 5-point harnesses provide more body retention that three-points... but this makes basal skull fractures more of a risk since the difference in decelleration between the torso and head are much greater.... this is why H&N restraints have become widely used.

Also, airbags are designed to work with the anticipated stretch of three points to decellerate a heavy body.... with harnesses the body is much more tightly restrained.... an airbag going off could create a significant and potentially damaging impact... or not...

Stock seats are not designed to provide the lateral support of a full race seat... in a side collision, the body could be displaced significantly, stopped only by the immovable shoulder harness snapped tight on the neck... not good.

Stock seat cushions are soft, and will compress on impacts lowering the beltline... 5-point lapbelts do not pretension, but are held in place by the shoulder harnesses and sub belt... so they remain in the same position....which places them not on the strong hip-bones, but right over the soft abdomen... this is dangerous

etc. etc... you can speculate on all kinds of bad scenarios.... maybe they will happen maybe they won't, but personally I think using harnesses with stock seats is not safe

Bull

Depending on your height, and most importantly your torso length, you may not be able to space the holes far enough apart using a stock 993 belt. Given the current pricing for 993 seats (non-sport seats), it could be a pricey experiment.

kurt M

Better tell this to Schroth. They have a list of recommended and non recommended stock seats that they think their products work with. Most here would likely agree that Schroth knows their stuff in this area.

There just might be setups that are better than stock 3 point in a daily driver used at the track. Blanket statements or rules could deny someone of a setup that is better than stock. Street driven dual use cars have to be looked at in a slightly different light when safety improvements are considered. What might add safety on the track might reduce it on the street and denying someone the good in order to force the unattainable perfect might produce unintended but less safe conditions overall. To me this is somewhat like telling someone that you can use an SA helmet or no helmet.

Z-man

I believe the Schroth 4-point belts (as seen in the BMW E30 M3) work in conjunction with the stock seat belt tensioner. I don't think you can easily 'retro-fit' a Schroth to a seat belt system that was not developed in conjunction with Schroth.

Bottom line: if you are going with 'better than stock' seat belts / harnesses, you should go with the proper seat and rollbar setup.
-Z-man.

kurt M

Again, this is falls into my example of SA or no helmet.


I agree you should go full setup if you can but a rollbar in a daily driver will not produce better overall safety for the driver. The problem is realy only in the dual use arena. We cannot and should not eliminate dual use cars in DE so there has to be a common sense and real world based rule set to follow. Why not ban dual use in DE? Less folks will be able to do DE and then less folks will learn better driving skills. A rule set based in any way on perseptions or some kind of a gut feeling is not the way to go. Real world, real results.
Few if any venues still allow added 4 point setups.

RedlineMan

For the record;

I am not in favor of 4-point systems for track use either. The Schroth components are 2nd to none, and the ASM system is unique and interesting. Compared to stock belts it is probably a good upgrade, but I was not that "comfortable" in them either.

Kurt is working from a good base here. I am constantly preaching percentages in the face of forces that want to arbitrarily keep raising the bar. As he infers, raising the bar on intuition alone sometimes brings it down on your head. I am more needs-based. I am about giving people information - LOTS of it - so they can make informed decisions as to how much "risk" they will tolerate. Are there people being injured by harness bars, longish belt paths, roofs collapsing, belts flipping off?

In the latter case, we do indeed have some REAL DATA to give foundation to the argument against allowing stock Porsche seats with harnesses. I reluctantly must agree that it is something to be given strong consideration, and cannot argue against those that decide to ban it.

In my opinion, the best dual-use setup is a good solid harness MOUNTING bar, the race seat of your choice, and a good set of belts. If you want a roll bar, you need to REALLY think about the DECREASED safety you may have when not wearing a helmet, and prioritize accordingly.

For me, it is not about telling people WHAT to do. It is about giving them the best information to make their own choices. If the model and the resulting information are good, the result should be similar.

Z-man

John -
I agree with you. As we've all stated here before, a dual purpose street/DE car is full of compromises. A roll-bar equipped car driven on the street without a helmet is a compromise in safety, as is a car in stock configuration on the track. Heck, a car with simply a rollbar and harnesses is also a compromise for the track. (a full cage is a better answer for the track)

Based on Den's post, it seems he's getting more into this DE stuff. So for an individual who wishes to delve deeper into this addiction (er, sport, I mean), I feel that a roll-bar/race seat/5-6 point harness setup isn't a bad idea, as long as he's aware of the potential for a compromise in safety on the street with a rollbar.

Just my opinion,
-Z.

dgz924s

Well after witnessing the aerial display of Joey Hand at Mid O, I wouldn't be very concerned about comfort. Personally I will take an ugly, hard as concrete race seat that totally is no fashion statement to the stock seat over being comfy. I will buy a Lincoln or MB for comfortable seating.
Sorry for the attitude but your life means more to me than your comfort does! Like Joe stated, if you are going to track the car go with the proper equipment.

Old saying in a cycle shop years ago said....."If you have a ten dollar head buy this engineers hat. If your head is worth 100.00 buy this helmet."....circa 1973

Dal

kurt M

My bet is almost none of the cars owned by the standard Rennlister (if there is such a thing ) in this forum is built to the standard that that car was. Few would come through the not wrinkle free tumble cycle that the Factory built and then Pro added to safety frame, built from the ground up BMW did. With this said and following the no compromise formula, anyone that tracks a lesser car regardless of amount of street or track use is a reckless and almost suicidal for driving an unsafe car as there is a better one out there. Bet there is a $10,000 super well built brain bucket for sale. The absolute rule would dictate we all get one.

All of our cars and all our equipment is a study in compromise as is/was the BMW.
I am not trying to say anyone is wrong for wanting good, better or only the best only that any absolute that is dictated to the track driving body as a whole needs to be real world based and not emotional. Can this discussion be had or is there too much emotion to do so in a public forum? I know this is a hot button topic but I think it is an important one and there are few places that this conversation could be had in good form that here.

JCP911S

I don't believe I made any blanket statements... I am simply pointing out that all safety equipment has potential good and bad consequences depending on the scenario, and the user needs to consider them before making a decision.

A manufacturer may test equipment in a head-oh and show increased safety, but not in a side collision.... etc. If Schroth has data and support, then excellent.

I am just urging caution that something that intuitively seems safer may not, in fact be safer.

kurt M

I agree fully with you and was not pointing a finger in anyone’s direction or in general. I hope this is not the inference gleaned. That is the angle I am looking to explore. What can be done to dual use cars that improves the overall safety from a % standpoint. Are there things that people can recommend without the "Full cage or get off the track" view as this is not obtainable regardless.

RedlineMan

Well...

Since you've openned your big mouth... Yes, I think we can have a constructive discussion here (or perhaps in a new thread). Anyone who gets emotional will be straightened out. I'll jump off the cliff.

Emotional control is a key aspect of this. As Kurt infered above, solutions to perceived problems are very difficult to make properly if one looks only from a perspective of the emotion that created them. In such instances, emotion is almost to be expected, but does little good in furthering a positive solution. At best, it should be regarded as nothing more than a motivator. Rational reality-based research must rule the day.

The current Top Dog issue is harnesses with stock, headrest-integral seats, as found in most Porsches. Some "proactive" groups have been looking closely at it for a while. The fatality at the Glen last year really set people's emotions ablaze, as might be expected. NE Region has since been motivated to ban this combination. This incident apparently pushed them over the edge they were already standing on.

If I am incorrect in any of the "facts" I am about to state, please excuse me and provide proof to refute my error. It is my understanding that the driver in question was found to have escaped his shoulder belts. I further understand that he was found to have suffered head and neck trauma.

My questions are: 1) Did this escape kill him? I have been told that the gentleman was not in the best of health to begin with. It is my understanding that we will never know the cause of death, or whether some medical moment triggered this sequence, as an autopsy was not performed. 2) What was the architecture of his person relative to his equipment? In other words, was his setup scrutinized against a known set of standards to determine its likelihood of effectiveness? This also begs the question, "is there a standard available," but that is another issue.

Some may discount the direction of my interest, saying that "He expired... that's all that counts, and we need to do something." I submit that this is the kind of emotional thinking that creates an avenue for unitended consequences to flourish, and I will always be most eager to avoid trading bad for worse, or even no better.

I understand that the issue of occupants escaping the shoulder straps is a real phenomenon. I have been told it can be made to happen repeatedly on a test sled, given proper setup. My feeling is that many people in charge of putting on events would say that "if it can happen once, that is once too often." I can understand that reaction, but it also is the kind of emotional reaction we are trying to discuss here. Never having a driving event again because someone might have a heart attack makes just as much sense to me, or as little.

My questions are; 1) What are the percentages? That is ALWAYS my first question, by the way. Create a comparison of the number of times this is known to have occured with how many people benefit from a good stock-seat-setup, and never crash because of it? Tough call, I know, but that is how I approach it. 2) Can a reasonable set of guidelines be drawn, much less accepted? Perhaps this is the real reason to ban a certain setup, as trying to get consensus - let alone true understandning of the parameters - is often nearly impossible.

OK.. my head hurts. Let 'er rip!

dgz924s

I am sorry if my reply was a bit too emotional, was not intended to be. It is just that when the MAN calls ones number you take a different more emotional side. Life, yours or mine instantly becomes a touchy area for this old dude. Just trying to keep others from following me circling the drain! Hope all can understand my POV.

What ever route you take I hope it is a smart one!

Dal