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

[TiGeo]

If a pretensioner fires after your already have it tight, it’s not like it’s going to crush you against the seat. It’s going to draw a straight line between the points, both hips and above the shoulder, which aren’t so much behind you but next to you. It takes a lot of tension to provide perpendicular bracing at the middle of the belt. I would like for the airbag to catch my face, not punch me back into the seat like a 99mph baseball changing direction when it hits the bat.

Hips and shoulders gonna be sore anyway if you take a hit.

As far as collapse, if the roof collapses at those speeds, one won’t be “getting out of the way,” thats going to be fast and out of the persons control. And, the B-pillars will be collapsing with the roof in that case anyway … everything is going to be loosening up.

I learned with a few MTB accidents that once the accident hits, there’s no thinking, controlling, evading or avoidance - it all happens and then is done and you may not have a clue what was happening during - at that point Sir Isaac Newton is driving.

Agree with your comments including the mtb...been there. I do love the "so you can duct out of the way" thing...hilarious. Dude, if you flip you may not even been conscious...haha..as you get tossed around like a rag-doll. Being stationary is good...it's why race cars use harnesses. The HANS just helps reduce the Dale Earnhardt thing.

 

[meep]

Agree with your comments including the mtb...been there. I do love the "so you can duct out of the way" thing...hilarious. Dude, if you flip you may not even been conscious...haha..as you get tossed around like a rag-doll. Being stationary is good...it's why race cars use harnesses. The HANS just helps reduce the Dale Earnhardt thing.

Right? The G-forces alone when a car is hit and flips - and you have no basis of gravity to work against in your seat … wheels off the ground? So is everyone inside!

 

[Ranger83]

I made an aluminum clamp for the lap portion. Before that, zip tie.

 

[TiGeo]

I made an aluminum clamp for the lap portion. Before that, zip tie.

Folks used to use something called a CG Lock...no longer produced.

 

[edyvw]

I do it all the time.
Easier to focus when to shift for example from 3rd to 2nd and not throw car out of balance in 80 degree curve. Just one example.

 

[shortyb]

Folks used to use something called a CG Lock...no longer produced.

Thank NHTSA for that one. Ralph Nader lives on .

 

[Jetronic]

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.

Physics say you will move towards the crushing if not restraint.

 

[Jetronic]

-- "They" say you shouldn't put in a 4-5 point harness without a roll cage because of the whole "your body needs to fold inward, out of the way, of the roof collapsing" thing. There are "boy racers" who put in the harness (because it impresses girls) and are "going to put the cage in later" who draw ire for doing this.

-- If you pre-set the 3-point seat belt to locked, and god forbid get in a wreck doing something fun/stupid, your insurance (car, health, life) might be more willing to pay if they can't fully reconstruct the accident. In other words, it'll look more like an accident, and less like a boy-racer out racing with racing gear on.

-- Car seat mode is achieved by pulling the 3 point all the way out, so it engages a ratchet mechanism on the return to the spool. Return it all the way, and the ratchet is released. There's a fat person on my commuter van who frequently does this accidentally and has to reset it. I highly doubt the driver's position would have this mode.

-- Seat belts are sacrificially stretchy. This helps them be "soft" in a wreck and less damaging to your organs. Pretensioners take away some of this "give" so you don't wind up too far out of place in very serious accidents, while letting the give work during slower speed ones. This is why your owners manual reads to inspect/ replace belts after even minor wrecks.

don't forget that the seat itself is elastic, you're sitting on and against a spring.

 

[CarlB]

Each crash is unique, so there's many that will be survivable or fatal based on happen stance.

Harness and no hans is bad. See Dale Earnhardt
Cage and no helmet is bad. Head bonks on metal.
3point Lap belt and airbag is good. They work together.
Rolling over without a cage has some caveats. Seat backs can collapse and save your spine. Fixed back seats don't. Adding a helmet increases head height. A harness will prevent submarining in a rollover and if roof caves in your having a bad day.

There's no "best" setup.

Ultimately it's always compromises when using a street prepped vehicle to drive on track. It's why these are just driving events and not racing events. Insurance and sanctioning bodies have minimal safety required for timed events. Fire suppression, cage, harness, hans, fire suits.

 

[Ranger83]

Folks used to use something called a CG Lock...no longer produced.

All kinds of competition products get dropped due to insurance liability concerns. We developed a motorcycle camera mount with a piezo gyro to keep the camera level. Realized we would never be able to get insurance….

If you take two pieces of aluminum bar stock, drill them at each end, and get bolts with wing nuts, easy to make and works fine. Had access to a milling machine so milled a slot in one end so the top could swivel.

For that matter the zip tie worked fine.

 

[TiGeo]

Each crash is unique, so there's many that will be survivable or fatal based on happen stance.

Harness and no hans is bad. See Dale Earnhardt
Cage and no helmet is bad. Head bonks on metal.
3point Lap belt and airbag is good. They work together.
Rolling over without a cage has some caveats. Seat backs can collapse and save your spine. Fixed back seats don't. Adding a helmet increases head height. A harness will prevent submarining in a rollover and if roof caves in your having a bad day.

There's no "best" setup.

Ultimately it's always compromises when using a street prepped vehicle to drive on track. It's why these are just driving events and not racing events. Insurance and sanctioning bodies have minimal safety required for timed events. Fire suppression, cage, harness, hans, fire suits.

I think that the rollover/roof collapse issue is over-risked in modern cars but the risk is there at some level for sure. I see plenty of folks being ok with Vettes and a Bray-Krause harness bar w/fixed backs b/c apparently the Vettes have v. stout rollover protection (?). I believe you are still safer in a crash with a fixed back/harness/HANS than a 3-point only just based on likelihoods of the various consequences.

 

[CarlB]

I think that the rollover/roof collapse issue is over-risked in modern cars but the risk is there at some level for sure. I see plenty of folks being ok with Vettes and a Bray-Krause harness bar w/fixed backs b/c apparently the Vettes have v. stout rollover protection (?). I believe you are still safer in a crash with a fixed back/harness/HANS than a 3-point only just based on likelihoods of the various consequences.

They just accept risks or don't understand them.

The Corvette roof isn't enough to support it. Track driving is generally dealing with speeds/situations very different to a road crash. Dip some tires with tons of gload, or hit tire barriers at speed. It's just something you either accept the risks or build a car with rollover protection in mind.

 

[BHopkins]

Each crash is unique, so there's many that will be survivable or fatal based on happen stance.

Harness and no hans is bad. See Dale Earnhardt
Cage and no helmet is bad. Head bonks on metal.
3point Lap belt and airbag is good. They work together.
Rolling over without a cage has some caveats. Seat backs can collapse and save your spine. Fixed back seats don't. Adding a helmet increases head height. A harness will prevent submarining in a rollover and if roof caves in your having a bad day.

There's no "best" setup.

Ultimately it's always compromises when using a street prepped vehicle to drive on track. It's why these are just driving events and not racing events. Insurance and sanctioning bodies have minimal safety required for timed events. Fire suppression, cage, harness, hans, fire suits.

Shouldn't that read "A 5-point harness will prevent submarining . . ."

My understanding of submarining is when an occupant slips under the lap portion of a seat belt, with the hips and legs going towards the IP. You mention a harness preventing submarining in a rollover. I guess I'm missing something on the physics that happen in a rollover. How is submarining a thing in a rollover?

 

[CarlB]

Shouldn't that read "A 5-point harness will prevent submarining . . ."

My understanding of submarining is when an occupant slips under the lap portion of a seat belt, with the hips and legs going towards the IP. You mention a harness preventing submarining in a rollover. I guess I'm missing something on the physics that happen in a rollover. How is submarining a thing in a rollover?

Depends, the schroth 4 points are anti-sub without having a 5 or 6 anti-sub strap. If the roof collapses on your non-caged car, you want to have the seat fail or occupant submarine. If you are harnessed into a non-caged car and the roof collapses, then the chances of spinal damage dramatically increase over a 3-point.

Again, it's impossible to predict the circumstances to every crash, but running a harness without; cage, hans, etc is introducing new risks with each variation.

 

[TiGeo]

They just accept risks or don't understand them.
View attachment 277895

The Corvette roof isn't enough to support it. Track driving is generally dealing with speeds/situations very different to a road crash. Dip some tires with tons of gload, or hit tire barriers at speed. It's just something you either accept the risks or build a car with rollover protection in mind.

I agree, you just accept risk to track your car at some level. I do see that folks often over-risk things however by always assuming the worst case scenario vs. the most plausible worst case scenario. It's typical in safety culture when doing risk assessments for many to do this e.g. fatality isn't always the consequence (risk = liklihood x consequence with all controls in place). There are also pics of Vettes that flipped that don't like like the one you have and in that case, even with a stock seat you may have been screwed regardless. Risk assessment is v. personal for sure and we just have to choose what we are comfortable with as long as it fits in the group/club/whatever's rules.

 

[TiGeo]

Depends, the schroth 4 points are anti-sub without having a 5 or 6 anti-sub strap. If the roof collapses on your non-caged car, you want to have the seat fail or occupant submarine. If you are harnessed into a non-caged car and the roof collapses, then the chances of spinal damage dramatically increase over a 3-point.

Again, it's impossible to predict the circumstances to every crash, but running a harness without; cage, hans, etc is introducing new risks with each variation.

The Schroth ASM 4-points cause a lot of drama online with folks in these discussions for sure. I think it's a cool product IF they have one certified for use in your particular vehicle. Some clubs still won't allow them based on, IMHO, not understanding the product and testing that was done on them.

 

[CarlB]

I agree, you just accept risk to track your car at some level. I do see that folks often over-risk things however by always assuming the worst case scenario vs. the most plausible worst case scenario. It's typical in safety culture when doing risk assessments for many to do this e.g. fatality isn't always the consequence (risk = liklihood x consequence with all controls in place). There are also pics of Vettes that flipped that don't like like the one you have and in that case, even with a stock seat you may have been screwed regardless. Risk assessment is v. personal for sure and we just have to choose what we are comfortable with as long as it fits in the group/club/whatever's rules.

Yeah, personal risk acceptance key. I don't mind HPDE'ing something without cage+harness that carries more straight speed than many racecars. But I understand the risk of death and disability is far higher. Meanwhile the risk of driving to the event is the highest.

The Schroth ASM 4-points cause a lot of drama online with folks in these discussions for sure. I think it's a cool product IF they have one certified for use in your particular vehicle. Some clubs still won't allow them based on, IMHO, not understanding the product and testing that was done on them.

I've used one before, but only on a car where the rollover protection was at cage level. I can respect any sanctioning body not allowing them when the safety would end up being totally case by case. They don't want to see anyone eating through a tube.

 

[TiGeo]

Yeah, personal risk acceptance key. I don't mind HPDE'ing something without cage+harness that carries more straight speed than many racecars. But I understand the risk of death and disability is far higher. Meanwhile the risk of driving to the event is the highest.

I've used one before, but only on a car where the rollover protection was at cage level. I can respect any sanctioning body not allowing them when the safety would end up being totally case by case. They don't want to see anyone eating through a tube.

They get used typically in daily-driven street cars in leu of your 3 points so no cage but that shouldn't be an issue/per its design b/c of the ASM. The clubs I've heard of having issues get hung up on the tail strap angle being steep vs. traditional harness where it's at a v. shallow angle. That's why Schroth uses the seat back strength test as a litmus for their use in a particular vehicle. I always chuckle that folks trust Schroth, a world-leader motorsport safety for harnesses...except those