Using seat-belt inertia lock to stay put for performance driving....how can't this be safe?

[TiGeo]

Ok BITOG-Kollective.....what say you? I know someone here is an expert...

When I go to the track, I use "the seatbelt trick" to keep myself more situated in my seat so I can focus on driving vs. bracing in higher G turns - using the inertial lock. You can see my process here:



This is the same procedure you use when you install a car seat in a car that doesn't have LATCH brackets. This is the same inertial lock that tightens your belt when you stab the brakes driving. So here, I am pre-engaging it. This is analagous to me driving, slamming on the brakes to avoid a crash and hitting a car - in that scenario the inertial lock will be engaged to keep you from moving before the crash. Many folks in the online track event world seem to think this is dangerous and defeats the car's safety system. I say that is not true. Many cars haver pyrotecnic pre-tensioners that fire when the air bags go to keep you even more situated. There seems to be a prevailing thought that you need to be able to move all over in the event of a crash or you will be injured (say in a rollover...you should read some of the comments! "You need to be able to move out of the way of the roof collapsing" etc.....that is exactly the opposite of what is safe, staying put is what keeps you safe in the research I've read. I reached out to the NTHSB as well as a known/trusted motorsport safety vendor. NTHSB had no data and was careful (duh!) of what they said but they didn't say it was dangerous. I reached out to VW - same. Motorsport safety guy said "no issue". Why would this be availalbe to you as a driver if doing it negated the entire safety system? The only reason your 3-pt belt allows movement is for comfort - for pure safety a harness would be the safest system. Then the folks will say you need a HANS or you'll snap your neck...I have had folks say that about this setup with the inertial lock. Craziness to me at least. What say you BIOTOG keyboard warriors?

 

[wings&wheels]

"You need to be able to move out of the way of the roof collapsing" etc.....

That is right up there w/ my Uncle once telling me back in the day that seatbelts are "..dangerous, you need to move if you get t-boned..". I was probably the only regular seatbelt wearer in the family then. Always wanted to ask how you manage to control your 160lb self enough to move out of the way of a crushing roof or door while in the midst of a collision...where you gonna go?

IIRC, some did this a car control clinic I attended. Also, wasn't there a device that would do the same? Seem to remember Bavarian Autosport and others selling something, but I could be wrong.

 

[racer12306]

I feel like if you're on your lid, the inertia lock is already active.

Also, if you're flailing around inside of a rolling car, your neck can break regardless of what's restraining you.

 

[BornSlippy]

What speeds are you hitting on the track?

 

[Rand]

if its good enough to secure a child seat why would engaging it make it inherently unsafe for an adult?
Seems to be a falloff in the logic of the "its bad" argument.

 

[dnewton3]

I would agree with TiGeo. Being more secure is a good thing; to improve control and limit movement in case of an accident. Using the inertia lock can help achieve this. I don't see a downside.

The only risk would be if the pyrotechnic charge tightens the belt so much that it may cause tissue damage. But if you're in an accident that bad, bruising around the pelvis is probably a given anyway.

 

[TiGeo]

What speeds are you hitting on the track?

Can reach 140 mph. At that speed all bets are off anyway w/r to your car's designed-for crash systems....it's pray at that point.

 

[BornSlippy]

A seat belt's job is to keep you in your seat. I don't see how your method is compromising the seat belt's job of keeping you in your seat.

 

[dnewton3]

I would add this concept as well. In dedicated race cars, there are no "pretensioners" or pyro-charges. They use either 4 or 5 point belt systems (and maybe HANS). The belts in those race cars are cinched TIGHT right before the race starts. When I used to race karts, I wanted to be pulled in tight; helped me control the inputs (steering and pedals).

I agree that at 140mph in a civilian based car, there's not much hope if you get into an accident, especially if you strike a hard barrier. But maybe being in better control (by being cinched in tight), perhaps you can avoid that crash, or at least reduce the severity?

Being strapped in tight can't hurt in a macro sense. It can only help.

 

[Kira]

Many folks in the online track event world seem to think this is dangerous and defeats the car's safety system. I say that is not true.

I don't want to come off as the "know-it-all" who wet blankets a conversation or question, but......Could it be you just read another example of internet noise?
People say things automatically now-a-days without regard for accuracy.
In fact, they say wacky, stupid and irresponsible things just to get readers, clicks or attention.

Gluing yourself into a fast car's seat seems real elementary to me too.
I love automotive velour seats because the wee bristles hold on to your rumpus.

 

[DuckRyder]

Agree my only concern would be the pretensioners.

 

[4WD]

I would agree with TiGeo. Being more secure is a good thing; to improve control and limit movement in case of an accident. Using the inertia lock can help achieve this. I don't see a downside.

The only risk would be if the pyrotechnic charge tightens the belt so much that it may cause tissue damage. But if you're in an accident that bad, bruising around the pelvis is probably a given anyway.

Allot of folks are not aware of the charges - and when they might actuate.
Wife was hit from behind in our 2017 Tahoe - side curtains deployed - seatbelts fired - fuel supply shut - electrical system shutdown … (OnStar called LEO’s)
The belt assemblies were one of the more expensive parts …
(have to be OEM) …

 

[TiGeo]

I would add this concept as well. In dedicated race cars, there are no "pretensioners" or pyro-charges. They use either 4 or 5 point belt systems (and maybe HANS). The belts in those race cars are cinched TIGHT right before the race starts. When I used to race karts, I wanted to be pulled in tight; helped me control the inputs (steering and pedals).

I agree that at 140mph in a civilian based car, there's not much hope if you get into an accident, especially if you strike a hard barrier. But maybe being in better control (by being cinched in tight), perhaps you can avoid that crash, or at least reduce the severity?

Being strapped in tight can't hurt in a macro sense. It can only help.

I think you hit on it - this would be the only concern, being "over tensioned" and bruising/broken ribs but you have other more pressing (pardon the pun) issues in these situations and even without this setup I do, many folks have severe bruising and broken ribs etc. from crashes from factory 3-point belts. I did some research on this topic and everything points to....not moving is safer and meanwhile, the collective online track safety folks often think that you will "move out of the way" of a crushed in roof etc. and that this is safer...no way. The injuries sustained in high-speed crashes are often from you flailing around, and that's backed by research, not internet myth.

I also wear a HANS device - there is one made my Simpson called the "Hybrid S" - it's the only one that is compatible with a 3-point belt. Your neck/head are teathered to your torso with these so no harness needed.

https://www.simpsonraceproducts.com...k_restraints/hybrid/hybrid_s/parts/HYSMED11PA

 

[shortyb]

I don't want to come off as the "know-it-all" who wet blankets a conversation or question, but......Could it be you just read another example of internet noise?
People say things automatically now-a-days without regard for accuracy.
In fact, they say wacky, stupid and irresponsible things just to get readers, clicks or attention.

Gluing yourself into a fast car's seat seems real elementary to me too.
I love automotive velour seats because the wee bristles hold on to your rumpus.

This.

First off, the goal of tightly strapping yourself in is the PREVENT movement. In a racing scenario this keeps you in the same position so you can control the car properly and consistently. Ever try to turn the steering wheel accurately in a high G turn while you have slid to the other side of your seat? You get the idea. Plus it keeps you located in the interior exactly where it was designed to keep you most protected. Airbags were invented to not only lessen the severity of injury, but also keep occupants that didn't wear seatbelts in place, hence the name "passive restraints".

Secondly, you are not "defeating" the safety system, you are just activating it early. Crashes involve decelerations. These decelerations cause unsecured objects (like occupants) to keep moving (inertia). The inertial lock on a standard 3-point is the outside force that stops the unsecured objects movement when deceleration happens. It is also surprisingly strong as your body weighs like a bazillion pounds (NOT accurate ) when the vehicle is suddenly stopped and you keep moving. That lock keeps those bazillion pounds put.

I did EVOC training for many, many years and first thing I did, whether I was left or right seat, was to activate the inertial lock. My fellow instructors thought I was a bit dramatic until, one by one, they were involved in some sort of E-ticket ride by a nervous, unskilled driver that flung them all over the place when the laws of physics went past bending at 100MPH+. I also wore a helmet every time and incorporated a HANS device when they came out. The latter because I developed cervical injuries as a result of my melon being accelerated way faster than what it was attached to during those many thousands of hours of seat time. If you race, I would suggest you do the same if you don't already.

 

[TiGeo]

I don't want to come off as the "know-it-all" who wet blankets a conversation or question, but......Could it be you just read another example of internet noise?
People say things automatically now-a-days without regard for accuracy.
In fact, they say wacky, stupid and irresponsible things just to get readers, clicks or attention.

Gluing yourself into a fast car's seat seems real elementary to me too.
I love automotive velour seats because the wee bristles hold on to your rumpus.

100% what it's based on - folks that don't critically think or research topics. It's a common argument online w/r to this topic - that you either go full-on with a welded in cage/seat/6-point or leave the car as-is bone-stock and don't do anything that is different. There is merit here but there are some great pieces of gear now including ASM (anti-submarine) 4-points that work with specific cars, fixed back seats that work with 3-points, harness bars that are safe, HANS for 3-point, etc. that are trying to improve safety in a situation where the car wasn't really designed for.

 

[TiGeo]

This.

First off, the goal of tightly strapping yourself in is the PREVENT movement. In a racing scenario this keeps you in the same position so you can control the car properly and consistently. Ever try to turn the steering wheel in a high G turn while you have slid to the other side of your seat? You get the idea. Plus it keeps you located in the interior exactly where it was designed to keep you most protected. Airbags were invented to not only lessen the severity of injury, but also keep occupants that didn't wear seatbelts in place, hence the name "passive restraints".

Secondly, you are not "defeating" the safety system, you are just activating it early. Crashes involve decelerations. These decelerations cause unsecured objects (like occupants) to keep moving (inertia). The inertial lock on a standard 3-point is the outside force that stops the unsecured objects movement when deceleration happens. It is also surprisingly strong as your body weighs like a bazillion pounds (NOT accurate ) when the vehicle is suddenly stopped and you keep moving. That lock keeps those bazillion pounds put.

I did EVOC training for many, many years and first thing I did, whether I was left or right seat, was to activate the inertial lock. My fellow instructors thought I was a bit dramatic until, one by one, they were involved in some sort of E-ticket ride by a nervous, unskilled driver that flung them all over the place when the laws of physics went past bending at 100MPH+. I also wore a helmet every time and incorporated a HANS device when they came out. The latter because I developed cervical injuries as a result of my melon being accelerated way faster that what it was attached to during those many thousands of hours of seat time. If you race, I would suggest you do the same if you don't already.

Great info, thanks!

 

[shortyb]

I also wear a HANS device - there is one made my Simpson called the "Hybrid S" - it's the only one that is compatible with a 3-point belt. Your neck/head are teathered to your torso with these so no harness needed.

Good boy. Your neck will thank you in another 20 years.

 

[Kira]

Bunch of new stuff on this thread.
I went to the linked site to see the HANS rigs. I had never heard of them.
Does the "lower head brace" part cradle your head or the helmet?
I assume the helmet and that there is a fastening point at the rear of the helmet to keep your head from going forward.

 

[dnewton3]

TiGeo-
I think you're absolutely on the right track (pun intended) ! What you are trying to achieve is to reduce the quantity and severity of risks. Set the inertial lock. Use the HANS. That about all you can do to reduce the risks. If you want to eliminate the risks, then you have to stop racing.

 

[shortyb]

Bunch of new stuff on this thread.
I went to the linked site to see the HANS rigs. I had never heard of them.
Does the "lower head brace" part cradle your head or the helmet?
I assume the helmet and that there is a fastening point at the rear of the helmet to keep your head from going forward.

If you are talking about the carbon fiber part, that is the back piece that gets strapped aronnd the torso. The tethers then attach to posts on the helmet. This keeps the (helmeted) head in relatively the same position to the body in the event of a crash instead of allowing the head to move forward quickly (whiplash). Dale Earnhardt was probably the most widely known death due to basilar skull fracture when his race car impacted the outside wall at high speed, causing his body to stop, but his unrestrained head not to. Even after Earnhardt's death, several NASCAR drivers still resisted wearing the device until it was mandated in 2001.