hf1

What's the consensus on NecksGen in terms of lateral impact protection in a halo-less seat? While I don't imagine it would approach the safety of a halo-seat, is there evidence that it offers better lateral impact protection than a HANS? I just bought one in addition to my HANS and will give it a try soon.

I race Skip Barber Mazda MX-5's and none of the cars have halo-seats. As for DEing my 6GT3, I am increasingly inclined to replace its Euro GT3 seats with Sparco Ergo (removable halo) seats.

924RACR

Man, I look away for my popcorn and the thread blows up to 4 pages! Shoulda expected it.

What Matt said - center net per recommendation by both John Melvin and Tom Gideon (not sure if he still is, but was at one point years ago in charge of safety engineering for GM Racing - heavily involved with Melvin et al in all of that sled testing).

...one of the benefits of living in the Motor City, local access to these guys...

PS: Re the above... as previously pointed out, the shoulders must be stopped before the head can be stopped. The pelvis must be stopped before the shoulders can be stopped. Do the Skippy MX5's have center nets? Are they properly positioned, to hold your shoulder as well as head?

Matt Romanowski

I saw the videos at a Racing Goes Safer Lecture Dr. Melvin was at. I don't think the videos are online because they were all from the team or sanctioning body cameras.

If you really want a safe seat, look into SFI 39.1 or 39.2. Those seats are the real deal.

kurt M

I am a fan of full containment seating systems. For the most part I don’t see how the little wings on most of the composite halo seats do much of anything. In a high G hit the floor mount only composite seats flex all over the place. This movement lets the belts change tension and position. I wish they would publish sled tests with the dummies in seats rather than a flat steel bench. No one drives while sitting on a steel bench.

I like the see through type halos as with this version Kirky. The helmet restraints project far enough forward to work in an offset impact but do not block vision at all. The shoulder and hip containment is also deep enough to work during an offset hit. The down side is it harder to install in some cars.

The problems with true containment seats is that they don’t work well if at all in dual use cars and often require mods to the car to make them fit and work right. True containment systems require more than 4 bolts on the seat rails to be mounted properly. I looked at what nascar was doing and incorporated some of the advances they have made into my car. As with anything it is a compromise of needs. This seat is bolted 4 points to the floor mount, 2 to the leg boards, 3 points on the halo, to the roll bar and the shoulder areas. Once you start using a true containment system you feel exposed and loose in a standard 6 point seat much less a stock seat. I find driving to be less effort as I am not spending energy holding in place at all. I moved the seat 4 inches over and moved the steering wheel over as well. This gets me further away from the door and X improving T bone protection. I also use leg boards to help contain my legs which will flop around during a hit. In addition to the leg boards the driver’s side foot well is reinforced to help prevent the foot pocket from deforming in a front end hit.

No system can prevent death if the Gs are high enough but I think the better the system the more likely you will walk away. A 6 g hit was mentioned earlier in this thread. 6 Gs is a drop in the bucket when you look at the speeds we drive. 60 Gs can easily be reached in a protected barrier impact and far more in a hard wall hit.

leejo

Semi related factoids: David Purley - http://en.wikipedia.org/wiki/David_Purley

"He survived an estimated 179.8 g when he decelerated from 173 km/h (108 mph) to 0 in a distance of 66 cm (26 inches) after his throttle got stuck wide open and he hit a wall.[3] For many years, this was thought to be the highest g-force ever survived by a human being (until in 2003, Kenny Bräck's crash violence recording system measured 214 g).[3][4] Purley suffered multiple fractures to his legs, pelvis and ribs."

And Kenny Bräck - http://en.wikipedia.org/wiki/Kenny_Br%C3%A4ck

"In the final race at Texas Motor Speedway, he suffered a serious crash that almost cost him his life. His car locked wheels with Tomas Scheckter's, flew into the catch fencing, and broke apart. Kenny's crash saw the highest recorded g-forces since the introduction of crash violence recording systems, peaking at 214 g's.[1][2] He suffered multiple fractures, breaking his sternum, femur, shattering a vertebra in his spine and crushing his ankles. He spent 18 months recovering from his injuries."

Brack crash video - http://www.youtube.com/watch?v=aVpux5JxqEk

Amazing.

mglobe

I'm far from an expert on the issue, but I'm not sure that the flex of a composite seat is a completely bad thing. Something needs to absorb the deceleration, and it's better that it's components of the car than of your body. Harnesses & seat belts are designed to stretch to do just this. Seems to me that some flex from the seat can be helpful for the same reason.

hf1

No expert here either, but that's what I thought, as well. That's also why cars have collapsible crumple zones instead of rigid cages (with no give) for crash protection. You want the stuff around you to twist, bend, and collapse more so that your body does less.

Matt Romanowski

I'm no expert either, but what they (Dr. Melvin, Dr. Trammell, and the other experts at Racing Goes Safer) is that the seat, belts, and HNR should keep the driver as still as possible, letting the car crumple. While harnesses due stretch, they keep using stronger materials so they don't stretch as much and hold tighter in a crash.

Sterling Doc

The net should not be "far away" - it should wrap around the side of the seat, and be directly around, in contact with the halo. I have seen the videos in a medical conference as well - impressive how far belts (and people) stretch. I haven't had time to look online, but will try to later.

Doug007

Hard to find definitive examples but here are a few where a center net would have helped:

Below is a screen grab from the video showing how much the halo can move... Fast forward to 5:50


Here is another one with weak looking halos

http://www.hmsmotorsport.com/docs/Wh...t_Side_Net.wmv

Bob Rouleau

My comment was in regard to older designs which are not "see through". Some people have purchased those seats without realizing that the halo part needs to be cheek high, otherwise you are wearing blinders - i.e., can't see to the side. Newer designs are see through which eliminates that.

My problem is that I need to keep my car street legal and I can't figure out how to get a net to work.

kurt M

This.

you want the G forces to be a clean as you can and you want to keep the gear all lined up. plastic seats deform all over the place and you end up with all kinds of unintended angles and jagged G force traces. You go to all the trouble to mount the seat and line the belts up per the instructions and in a offset impact the seat flops over 8 inches. During the time you most need things to be lined up they are not.

Belt stretch is not intended. The time delta when the car is crumpling and slowing and you are not slowing with it is time that you are not loosing energy but gaining energy delta between you and the car. you are in a way negating the crumple zone. it is soaking up energy and you are carrying on in motion rather than dumping energy into the crumpling car. At some point you do stop moving forward and then you have to deal with the grown speed delta between you and the car. Keep in mind in a wreck you don't hit the tire wall, the car does. You hit the car.

Rceron

I have my Racetech (w/Halo) on it's own slider mechanism. Instead of the nets, why not remove your passenger seat for the trip to the track and place your halo seat and slider in it's place? At the track you can swap out your street legal driver's seat and put in the halo seat. 4 bolts...take you all of 15 minutes to do this. In any case I do this at home for each event but I trailer my car.

YourFace

[QUOTE=Bob Rouleau;10638707]My comment was in regard to older designs which are not "see through". Some people have purchased those seats without realizing that the halo part needs to be cheek high, otherwise you are wearing blinders - i.e., can't see to the side. Newer designs are see through which eliminates that.

Simple solution: Get manufactures and track circuit owners to post safety guidelines regarding their products focused on "racing". Rennlist may issue feature "notices" to member, promoting safety guideline for products, as in this case. It may perhaps prevent fatality as it has occurred at Mont Tremblant.

kurt M

From what I have been reading you need to mount to more than just the seat rails. look at the poorly made metal seat dump the driver out. (in my prev post I used the term plastic seat when it could be better said unreinforced seats). In order to be strong enough to keep you from dumping out to the side the seat needs to be able to resist some real high loads or it will flex and bend plastic or metal. The metal seats can be made with many mounting points to tie them into the cage and car.

A halo is not a replacement for a well installed right side net IMO.