4 point harness
I assume that you are referring to the LATCH system mounts for baby seats. Every harness manufacturer is very clear that these are not to be used for harnesses as they are only required to withstand the low weights associated with baby seats. They won't hold an adult's weight in a crash.
question:
r u assuming that my 4 point is unsafe because of the fact that ur assuming im using factory seats? because howabout aftermarket bucket seats with the proper places to fit in a harness, would it make a difference at all?
ok if u say that it is unsafe how would i make safer then a regular seat belt add a crotch strap and a harness bar?
r u assuming that my 4 point is unsafe because of the fact that ur assuming im using factory seats? because howabout aftermarket bucket seats with the proper places to fit in a harness, would it make a difference at all?
ok if u say that it is unsafe how would i make safer then a regular seat belt add a crotch strap and a harness bar?
First off, I haven't told any stories about "my friend". I'm only speaking from documented fact and not "common sense" as you are. I also feel no need to do your research for you, as it is literally your *** that is on the line.
What I said was that a 4-point harness without an Anti Submarine device is a lot less safe than the factory 3-point belts. It may seem to be common sense that more belts are better than less, or that being held tighter is better but that is disregarding the way that a body moves.
In a normal 4-point your body hits the belts evenly and the forces then cause you to slide forward evenly. Your hips then slip down and forward, and you slip out of the harness. In a 3-point or a 4-point with an ASM one shoulder is allowed to move forward slightly, which causes your hips to rotate downward and into the seat. It may not seem so on first blush, but that is the way that it works. There are tons of tests out there showing this, but a nice concise explanation can be found in the ASM section on this page: http://www.schrothracing.com/main/Engineering The section on the 2" lap belt width on that page is also very interesting. When you think it through, the standard 3-point seat belt design is incredibly elegant. Safe and convenient.
As to harness stretch you are simply wrong. Again, while it may seem to be obvious that belts couldn't possibly stretch to twice they're length under stress it is completely wrong. Think how much force is being put on them. If a serious crash on a track can result in over 100 G's of force, let's say that in your Evo you see a momentary force of 50 G's. If you weigh 150lbs you are suddenly hanging nearly four tons from those belts. Do you really think that five foot long belts would only stretch five inches if you hung a four ton load from them? Makes more sense when you think it through, right?
Also, no real race car has a 4-point harness. Show me one that does. Any real race-prepared car will have a six-point harness - maybe a five depending on the class.
What I said was that a 4-point harness without an Anti Submarine device is a lot less safe than the factory 3-point belts. It may seem to be common sense that more belts are better than less, or that being held tighter is better but that is disregarding the way that a body moves.
In a normal 4-point your body hits the belts evenly and the forces then cause you to slide forward evenly. Your hips then slip down and forward, and you slip out of the harness. In a 3-point or a 4-point with an ASM one shoulder is allowed to move forward slightly, which causes your hips to rotate downward and into the seat. It may not seem so on first blush, but that is the way that it works. There are tons of tests out there showing this, but a nice concise explanation can be found in the ASM section on this page: http://www.schrothracing.com/main/Engineering The section on the 2" lap belt width on that page is also very interesting. When you think it through, the standard 3-point seat belt design is incredibly elegant. Safe and convenient.
As to harness stretch you are simply wrong. Again, while it may seem to be obvious that belts couldn't possibly stretch to twice they're length under stress it is completely wrong. Think how much force is being put on them. If a serious crash on a track can result in over 100 G's of force, let's say that in your Evo you see a momentary force of 50 G's. If you weigh 150lbs you are suddenly hanging nearly four tons from those belts. Do you really think that five foot long belts would only stretch five inches if you hung a four ton load from them? Makes more sense when you think it through, right?
Also, no real race car has a 4-point harness. Show me one that does. Any real race-prepared car will have a six-point harness - maybe a five depending on the class.
Last edited by redteam22003; Aug 5, 2008 at 07:03 AM.
I don't know what you're rambling on about in the first couple points - and if this wasn't a serious safety issue I wouldn't bother reasoning with someone who uses English such as "it still don't proofed anything". But to the rest of your points:
3) Lighter means that they're carrying less momentum. So sure, they aren't the same - the street car is going to hit harder for a given speed, posing a greater threat to the occupants.
4) We're talking about the safest setup, not single bad incidents. And - I am the boss, so I can't help ya' there.
5) All certified harness straps have to meet the same strength rating no matter how wide. Also, 2" wide lap belt straps are much safer than 3" or 4" straps for the reasons explained in the link I provided. They fit your skeletal system better.
Don't get mad at me - all that I'm relating is what I found out while researching the best harness system for my RallyCross car. The bio-mechanics of the human body are very complex, and there's a lot more science to protecting it than "hell, throw a couple big straps on there and you'll be good to go".
3) Lighter means that they're carrying less momentum. So sure, they aren't the same - the street car is going to hit harder for a given speed, posing a greater threat to the occupants.
4) We're talking about the safest setup, not single bad incidents. And - I am the boss, so I can't help ya' there.
5) All certified harness straps have to meet the same strength rating no matter how wide. Also, 2" wide lap belt straps are much safer than 3" or 4" straps for the reasons explained in the link I provided. They fit your skeletal system better.
Don't get mad at me - all that I'm relating is what I found out while researching the best harness system for my RallyCross car. The bio-mechanics of the human body are very complex, and there's a lot more science to protecting it than "hell, throw a couple big straps on there and you'll be good to go".
Last edited by JWA; Jul 24, 2008 at 08:12 PM.
If you have a harness bar and a passenger in the back seat, and you crash, and the passenger hits the bar and dies, they can charge you with murder 2 under the depraved heart / reckless disregard method of murder. It is rare, but it has been done.
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From: Calgary, AB Canada
No, in your case I was just saying that the long straps aren't considered to be safe. To be honest, I'm personally less concerned about long belts stretching than submarining. If it is a 4-point without an ASM device, then you need either a crotch strap or to switch to a Schroth with one. A harness bar is best, but you'll still need either a crotch strap or ASM device. As for the seats, an aftermarket seat that is intended to be used with harnesses is likely better than the stock Lancer seats, so you're good there.
wouldnt something that is FIA approved have been tested for saftey for submarining and stretching and etc?
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'FIA approved' doesn't mean a thing if the products are installed wrongly. Attaching seatbelt to some hole on the floor or a harness bar that is bolted on is not really 'FIA approved' even if the seatbelt itself has earned the rating.
Think of it as wearing a helmet front to back.
Think of it as wearing a helmet front to back.
I'm not really sure how that works, as you sure would think so. I could see that the submarining is just the way that it is for a 4-point, and the ratings are on the material and construction, but I don't understand why any manufacturer would make and sell a belt that was too long to be safe. Plus, a lot of cars have a fairly long run of the belt down to the reel on the stock belts, though I have noticed that most modern cars have the reel as close to the top anchor point as possible.
As to harness stretch you are simply wrong. Again, while it may seem to be obvious that belts couldn't possibly stretch to twice they're length under stress it is completely wrong. Think how much force is being put on them. If a serious crash on a track can result in over 100 G's of force, let's say that in your Evo you see a momentary force of 50 G's. If you weigh 150lbs you are suddenly hanging nearly four tons from those belts. Do you really think that five foot long belts would only stretch five inches if you hung a four ton load from them? Makes more sense when you think it through, right?
Also, no real race car has a 4-point harness. Show me one that does. Any real race-prepared car will have a six-point harness - maybe a five depending on the class.
Also, no real race car has a 4-point harness. Show me one that does. Any real race-prepared car will have a six-point harness - maybe a five depending on the class.
2)I was looking at an old Turbo Magazine one day and i saw a Skyline with a 4 point harness which remined me about this thread. So i decide to look at some other Turbo magazine. 4 Magazines in total, 5 different cars with 4 point harness. And YES these are race cars, not street cars.
M-Speed GT-R 740PS 55.23sec at Tsukuba
Saurus Garage S14 555ps Silvia 57.010sec at Tsukuba
Pan Speed RX-8 298ps 60sec at Tsukuba
Spoon Sports DC-S Integra type r Super Taikyu Race Car 260HP
Tec-Art Toyota Corolla AE86 239ps
Need I Say MORE?
1) If you're driving on the street in a car with no roll cage, use the factory belts.
2) If you're auto-x-ing, a harness and a harness bar are fine, even a good idea.
3) If you're running track-days and don't have a roll bar or roll cage, don't use a harness. Harness bars do nothing to protect your neck in a rollover crash.
There are other issues to consider in the 3pt vs. 4pt debate besides the submarining issue. Please read the posts on this thread for more information.
https://www.evolutionm.net/forums/sh...hlight=harness
Stay safe!
Dave
2) If you're auto-x-ing, a harness and a harness bar are fine, even a good idea.
3) If you're running track-days and don't have a roll bar or roll cage, don't use a harness. Harness bars do nothing to protect your neck in a rollover crash.
There are other issues to consider in the 3pt vs. 4pt debate besides the submarining issue. Please read the posts on this thread for more information.
https://www.evolutionm.net/forums/sh...hlight=harness
Stay safe!
Dave
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From: Atlanta Ga.
1) I dont see how it is possible doing 100Gs. Harness will not save you one bit. You are dead at 100G. 4 tons on a seat belt, yea right. Cite your source.
2)I was looking at an old Turbo Magazine one day and i saw a Skyline with a 4 point harness which remined me about this thread. So i decide to look at some other Turbo magazine. 4 Magazines in total, 5 different cars with 4 point harness. And YES these are race cars, not street cars.
M-Speed GT-R 740PS 55.23sec at Tsukuba
Saurus Garage S14 555ps Silvia 57.010sec at Tsukuba
Pan Speed RX-8 298ps 60sec at Tsukuba
Spoon Sports DC-S Integra type r Super Taikyu Race Car 260HP
Tec-Art Toyota Corolla AE86 239ps
Need I Say MORE?
2)I was looking at an old Turbo Magazine one day and i saw a Skyline with a 4 point harness which remined me about this thread. So i decide to look at some other Turbo magazine. 4 Magazines in total, 5 different cars with 4 point harness. And YES these are race cars, not street cars.
M-Speed GT-R 740PS 55.23sec at Tsukuba
Saurus Garage S14 555ps Silvia 57.010sec at Tsukuba
Pan Speed RX-8 298ps 60sec at Tsukuba
Spoon Sports DC-S Integra type r Super Taikyu Race Car 260HP
Tec-Art Toyota Corolla AE86 239ps
Need I Say MORE?
Show me the the 5th point harness in each of the pics. I dont see it. Look how the pics are taken. 3 out of the 5 pics have the harness bucked up to show off the harness, if there was a 5 point wound't you see them. When you get out of your car do you buck up the seat belt? Probaly not. Just because they have a slot for the crotch strap, it does not mean they have the crotch strap. I can go on all day and look at my magazine an show you not all race cars have 5 point harness. My point is, that a 4 point is as safe, if not safer than a stock 3 point harness.
Last edited by Red Dragon; Aug 3, 2008 at 09:26 PM.
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Posts: 443
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From: Atlanta Ga.
slam on your brakes with a 3pt harness... your belt locks and as you move forward your lap belt tightens prventing you from going down... try the same thing with a 4pt... hmm the belt stretched a little and your lap belt didn't tighten up.
now hit a wall.... see if you slide under the 4 pt, and the 3 pt.....
now hit a wall.... see if you slide under the 4 pt, and the 3 pt.....