Bri Bro

I would think that Santa needs to look at the redline roll bar with seats and a 5/6 point belt. FireAde extinguishers works well for folks on a budget.
http://www.redlinerennsport.homestea...timonials.html

camber799

http://www.dassport.com/race_944_bar.asp

Here is another source for roll bars. They are considerably more money but they make really good stuff. Big problem with bolt-in units is that they rarely are straight and they always need manipulation in order to get them to line up with the mounting points. These tend to be better about that so the installed cost may be lower.

JCP911S

Just my opinion... no scientific test results or anything, but harnesses and stock seats are not only ineffective they are positively DANGEROUS.... ..

I will not use them when I instruct.... if you think through how things happen in an impact... here are some thoughts..

1) Wrapping sub belt around front of the seat renders it useless....

2) Under impact, your body will compress the seat cushion... putting the lap belt right into your abdomen... the worst place it can be.

3) Shape of the seatback generally does not position the shoulder belts properly... they can slip off the shoulders under inpact

4) Seat does not position you laterally... in side impact, you can slide sideways, and the shoulder harness will put the entire force of impact against your neck...

5) Stock seat more likely to break in a hard rear impact.... you body will impact whatever it is that is mounting the shoulder belts... (harnes ber or roll bar)...

Not a complete list.... but sufficient IMHO...

RedlineMan

My less than humble opinion, based on extensive research of scientific study;

Patently false! The sub does keep the lap belt low, but does nothing to directly control upper body motion. Whether you are garroted by a sternum strap depends on many factors like belt length and stretch, severity and angle of impact, etc., but chances are you have a high likelihood of suffering neck discomfort!

Remove the sternum strap part and I agree with you, but only if you mount the sub correctly.

I used to believe in sternum straps too, but I learned... fortunately not the hard way. They really are the best solution for keeping the belts in place on the driver (in the absence of a racing seat), but if you factor in that the upper body will move 12-18" in "any given" 30g+ crash, their secondary characteristics become FAR less appealing.

Kurt and I are starting to sound like the same person! He must be brilliant too! I understand the concerns regarding using harnesses with stock seats. There is documented test footage of drivers becoming dislodged from the restraints. However, whether this was a truly scientific study is not known, and open to debate. The best you can say is that it "can" happen. Having acknowledged that, I feel as Kurt does that steps can be taken to mitigate these concerns substantially.

I am personally not inclined to, nor comfortable with, telling people what they have to do, or telling them they can't participate because they don't have the "rightest" safety equipment added to their cars. The farthest I will go is to suggest that if you want to push your luck, which all drivers nearing their personal limit do, that you might want to think carefully about the subject. I AM in favor of giving people the information they need to make informed decisions about increasing their safety. As it concerns PCA, you may rest assured that things are happening in this regard at the National level, and that it is only a matter of time until this information is collated and released. I hope to be in the thick of it. Patience!

Tidbits: I'm not on the roll-bar-with-race-seat-bandwagon either. Safety at the club level is about percentages, and pushing them into your favor. Absolutes are far too limiting and potentially unfair. Redline roll bars fit first time, EVERY time. I know because I've not had to FIX one! Sunday and M758 are on the money too.

Treatise on how to mount belts to follow!

wlittleman

I am getting a roll bar put in shortly so that I can use a harness. Here's my dilemna. I have side impact bags that are mounted to the stock seat. This is in addition to the curtain bags that are mounted at the top of the "A" pillar. Since I haven't gone the "dedicated track car" route yet, I am trying to make do with a DE car that's mostly a daily driver. Based on the amount of time I spend at the track vs. commuting to and from work, I contend that the probability of getting T-boned on a public road is higher than me slamming into a wall at the track. So, I've opted to keep my stock seats.

I'm contemplating the purchase of Schroth Profi II ASM. It is a 4-pt harness, but Schroth is claiming that the lapped shoulder harness provides a fuse during impact that pivots the torso enough to prevent submarining. There is video showing a crash sled with a dummie wearing this particular 4-pt harness on this webpage: http://www.schrothracing.com/products/competition/1597

I'm sure this system is not as good as a 5pt or 6pt, but any thoughts on the effectiveness of this system? I don't want to buy something that is DANGEROUS, but if it is as safe or safer than a 3pt while securing me down for the turns, I'd probably go with this.

Z-man

wlittleman:
Personally, I wouldn't use a 4-point system - while a stock 3-point system will prevent a 'submarine effect' in a front end collision, a 4-point system will not prevent this nearly as well. Why not just get a 5/6 point system? You can pull the substrap over the front of the seat. Granted, this is not as effective as the normal 'sub strap through the seat' method, but it is better than having no substrap at all!

Also: there are outfits around that will take your stock seat and create passthrough holes in them, so you can have your stock, ABS equipped seat with the appropriate pass-throughs for the shoulder harnesses as well as the substrap. If you need more info on this, let me know - I can point you to some resources, but suffice it to say that most companies that deal with car seat repair should be able to accomodate your request.

For the record, my PCA region (NNJR) will not allow 4-point seat belts to be used in DE's.

-Z-man.

rockitman

My humble opinion...your on a track... a dangerous environment for motorized vehicle's. Spend the money to save your life. Fixed back race seats, 6 pt. harness, rollbar and H&N device are a bare minimum. It should be the price of admission to drive on the track in the first place. Total cost, less than the price of a set of wheels and a modified exhaust system.

wlittleman

"For the record, my PCA region (NNJR) will not allow 4-point seat belts to be used in DE's."

So, from what I gather, even if the belt has anti-submarining (ASM) features, I may very well not be allowed to run some DE's; being that it is still a 4-pt. The schroth video comparing a 3-pt belt vs. 4-pt belt seems to suggest that this particular 4-pt belt works better than the 3-pt. But, then again, they're in the business of selling belts.

Luckily, I can purchase and attach a sub belt to the Profi II ASM if and when I find someone to slot my seat for that sub-belt. I can see why running a daily driver as a DE machine compromises safety. What seems to be safe on a track compromises its safety as a daily driver, and vice versa.

Kind of wish I was built solid like a cockroach.

gbaker

You bet your sweet bippy it's scientific. Just check crash sled videos of offset frontal impacts. In certain circumstances it will happen every time.

RedlineMan

Thanks G;

I have NOT seen tons of sled footage of this, so it is not known by ME. I was aware of one clip that has been used by a US importer to "prove" the case against these setups.

Perhaps it would have been better said by asking whether many different setups such as crossing belts, H-strap, etc., had also been tried to see if there could be some improvement made? I personally don't think it is particularly scientific to do a bunch of tests that show a pattern without trying differing setups because the inference will then be that ALL harnesses with stock seats will fail ALL the time. As you would likely agree, such inferences can be highly speculative at best.

So... since you have mega-tons more experience with this than anyone here, how do YOU feel about the question at hand? Can stock seats and harnesses be made to function properly?

RedlineMan

Howdy;

I don't think you will find a lot of support for the 4-point system in PCA, or many other clubs I'd wager. I've experienced one, and was not overly impressed with the result. I also would not be keen to mix and match systems by adding a sub to a system that was not necessarily designed for one.

The ASM feature of the Schroth 4-point compensates for not having a sub, and the resultant "lack" of lap belt retention, by offering a section of material with a known and controlled amount of elongation. This allows the torso to project forward and, pivoting at the waist, to roll over the lap belt to some degree. By rolling over it, this creates some retention of the belt in a low position, where a regular harness system without a proper sub would hold the torso back, create more downward torso compression, and facilitate the submarine effect.

The problem with this is that anything that prolongs the event has been found to be less than optimal. The stretching of the ASM would seem to do this. Is it better than a 3-point? Probably, but a stick in the eye is probably also better than a nail, but you'd still be blind.

You can use a 6-point system in cradle fashion - without needing sub holes in the seat - to construct a fairly effective retention system, at least in terms of lap belt and hip control. It would seem the jury is still out on the upper torso portion of this debate!

gbaker

John,

Your comment about testing is spot on, i.e. unless all the variables are considered, one cannot draw a generalized conclusion. Because the combination discussed here is not seen in pro racing ranks it is not studied in that arena, and casual racing/DE organizations cannot be expected to conduct detailed safety research. Hence, one could conclude that no one knows...

However, if you examine offset sled testing where the seat has no lateral containment of the shoulders, and the loads are sufficiently high, one belt will come off the shoulder with the other belt loading the opposite side of the neck.

In other words, if you can keep the driver in the seat the set up discussed here should work relatively well. But once the driver is launched out of the seat, all bets are off.

kurt M

Does the stock belt work better in this case?

rockitman

A stock3 pt. belt with just a helmet is safer than and 6 point harness with a helmet from an H&N force standpoint. In a crash, with a 3pt., the torso has a considerably more movement forward at impact. This allows your torso to be kind of flowing with the head. In a 6 point config... your torso stays pinned to the seat, while your head and neck violently move forward and/or to the side. So if you do harnesses, for god sakes get a H&N device.

kurt M

Side impact is the scenario in question at the moment. H&N is an importaint factor but lets come to this next. Is it better to be in stock 3 point and stock seat in a side or multiple impact event than “sit on the sub type” 6 point in a stock seat? Mr. Baker has data that sounds interesting and I would like to explore it in more depth.

Add on questions that pertain to the use of harnesses and stock seats. In a non intrusion rollover would it be better to be in a 3 point or a 6 point with stock seats? Is there data on this? What is the percentage of rollovers with significant driver’s compartment intrusion? What is the percentage of rollovers to impacts as a whole?

As to being able to move more in a 3 point aqnd this being better. I thought the prevailing thought was less movement in an impact the better overall. OK my head and neck are all together but moving foward and hitting my helmet on the wheel or door will introduce energy to the neck as well. Thoughts?