How NOT to drive a STI Type R!
09 June 2004, 03:57 PM
#32
Scooby Regular
Join Date: Aug 1999
Posts: 7,957
Likes: 0
Received 0 Likes
on
0 Posts
in light all the number of posts I have seen like this, is anyone keen to fit that removable roll cage that performance drivers were selling? it never really took off, but with T5NY's crash too, I am getting more and more tempted all the time.
09 June 2004, 04:37 PM
#33
Scooby Regular
Join Date: May 2004
Posts: 252
Likes: 0
Received 0 Likes
on
0 Posts
Adam
Be careful on this. It is a very VERY difficult call.
Full roll cages are carefully designed to take impacts from all angles and to protect the main areas of the cabin. The points at which they are bolted / welded to the body of the car are very carefully selected in order to strengthen the entire shell. In addition, the shell is seam welded.
If you fit a full roll cage badly, it can actually be more of a danger than not having one at all.
So...
with all of that in mind, having a roll cage, that by it's very design is detachable, *seems* dangerous to me.
Then add to that, the fact that it is not a full cage, then on top of that, the fact that having something made of solid metal in the car when you're flapping about inside it is not exactly the most comforting thought, and I am put off.
Remember, that roll cages in rally cars depend on the seam welded shell, the correct installation, different designs for each car, full race harnesses, race seats, helmets, etc, etc.. all of this is taken into account.
---
IMPORTANT : I am not saying that you will be safer or less safe with one of these roll cages or any roll cage, as it is impossible to tell until you have that specifc accident how it will all handle it and whether you will fly towards it, away from it, or in between it.
All the best
Simon
Be careful on this. It is a very VERY difficult call.
Full roll cages are carefully designed to take impacts from all angles and to protect the main areas of the cabin. The points at which they are bolted / welded to the body of the car are very carefully selected in order to strengthen the entire shell. In addition, the shell is seam welded.
If you fit a full roll cage badly, it can actually be more of a danger than not having one at all.
So...
with all of that in mind, having a roll cage, that by it's very design is detachable, *seems* dangerous to me.
Then add to that, the fact that it is not a full cage, then on top of that, the fact that having something made of solid metal in the car when you're flapping about inside it is not exactly the most comforting thought, and I am put off.
Remember, that roll cages in rally cars depend on the seam welded shell, the correct installation, different designs for each car, full race harnesses, race seats, helmets, etc, etc.. all of this is taken into account.
---
IMPORTANT : I am not saying that you will be safer or less safe with one of these roll cages or any roll cage, as it is impossible to tell until you have that specifc accident how it will all handle it and whether you will fly towards it, away from it, or in between it.
All the best
Simon
09 June 2004, 05:35 PM
#34
Scooby Regular
Join Date: Aug 1999
Posts: 7,957
Likes: 0
Received 0 Likes
on
0 Posts
simon,
I wouldnt use one of these cages without harnesses and a helmet.
from what i saw the cage was behind the seat and is anchored to the sill of the car and the suspension turrets which are the strongest structural points on the monocoque.
To my knowledge it isn't designed for crash proection, it is designed for rollover protection, I would have though in a crash it would provide you with some deal of protection on the basis that it should be stronger than the b pillar and force the car to bounce off the impacting object which on a road car would be worse but if harnessed in, would be better.
The aim of the item from what I can tell is to prevent the roof caving in in the event of a roll. I can't see how this wouldn't happen since the roll hoop is a structurally strong piece, the sections of the cage are braced in the same way as a space frame relying on triangles its rigidity.
In short the free standing cage is structurally incredibly strong when freestanding, if bolted to the strongest parts of the car, I can't see how its structural integrity could do anything other than strengthen the cars resistance.
It can't break out the car due to its, it can't puncture the doors etc, it can't brak the car by transferring load as it is braced to the strongest parts, and if it did somehow, that would be in the event of a major crash in which case you would want the load transferred away from the driver and passenger area and preferably to the rear turrets.
To put it more logically, I understand your concerns but don't see how they can't be explained away easily.
The fixed rollcages are bolted to the strongest points in the car too the safety ones not the full structural ones. they are welded to the seems and to brackets on the suspension turrets.
The removable cage is bolted to the seat belt take off points which also have to be structurally very sound and after normally in the same location as the weld points for the roll cage.
They were also iirc made by safety devices and I can't imagine a company with the leading reputation in roll cages putting their name and trademark to something which will do more harm than good.
I wouldnt use one of these cages without harnesses and a helmet.
from what i saw the cage was behind the seat and is anchored to the sill of the car and the suspension turrets which are the strongest structural points on the monocoque.
To my knowledge it isn't designed for crash proection, it is designed for rollover protection, I would have though in a crash it would provide you with some deal of protection on the basis that it should be stronger than the b pillar and force the car to bounce off the impacting object which on a road car would be worse but if harnessed in, would be better.
The aim of the item from what I can tell is to prevent the roof caving in in the event of a roll. I can't see how this wouldn't happen since the roll hoop is a structurally strong piece, the sections of the cage are braced in the same way as a space frame relying on triangles its rigidity.
In short the free standing cage is structurally incredibly strong when freestanding, if bolted to the strongest parts of the car, I can't see how its structural integrity could do anything other than strengthen the cars resistance.
It can't break out the car due to its, it can't puncture the doors etc, it can't brak the car by transferring load as it is braced to the strongest parts, and if it did somehow, that would be in the event of a major crash in which case you would want the load transferred away from the driver and passenger area and preferably to the rear turrets.
To put it more logically, I understand your concerns but don't see how they can't be explained away easily.
The fixed rollcages are bolted to the strongest points in the car too the safety ones not the full structural ones. they are welded to the seems and to brackets on the suspension turrets.
The removable cage is bolted to the seat belt take off points which also have to be structurally very sound and after normally in the same location as the weld points for the roll cage.
They were also iirc made by safety devices and I can't imagine a company with the leading reputation in roll cages putting their name and trademark to something which will do more harm than good.
09 June 2004, 06:36 PM
#35
Scooby Regular
Join Date: May 2004
Posts: 252
Likes: 0
Received 0 Likes
on
0 Posts
I wouldnt use one of these cages without harnesses and a helmet.
--
Like I say Adam it's a difficult call, and I am not saying it will definitely be bad, and not saying it will definitely be good. But..
playing devil's advocate on your comments (not meaning to do the whole quoting thing, this is purely just to show the there are potential holes in everything - for the sake of this discussion alone)...
from what i saw the cage was behind the seat and is anchored to the sill of the car and the suspension turrets which are the strongest structural points on the monocoque.
Remember, that you as a driver are NOT the strongest and most anchored down point of the car. So this means that (big time devils advocate), you could have a full head on with a wall, then entire front of the car crumple up and crush you against the (now) rigid back end of the car?? Possibly before, the car would have crumpled in a completely different way??
The aim of the item from what I can tell is to prevent the roof caving in in the event of a roll. I can't see how this wouldn't happen since the roll hoop is a structurally strong piece, the sections of the cage are braced in the same way as a space frame relying on triangles its rigidity.
In short the free standing cage is structurally incredibly strong when freestanding, if bolted to the strongest parts of the car, I can't see how its structural integrity could do anything other than strengthen the cars resistance.
It can't break out the car due to its, it can't puncture the doors etc, it can't brak the car by transferring load as it is braced to the strongest parts,
and if it did somehow, that would be in the event of a major crash in which case you would want the load transferred away from the driver and passenger area and preferably to the rear turrets.
The removable cage is bolted to the seat belt take off points which also have to be structurally very sound and after normally in the same location as the weld points for the roll cage.
---
All I'm saying is.. just because it's called "roll cage", don't necessarily think it's going to be safer.
Cheers
Simon
10 June 2004, 04:43 PM
#36
Scooby Regular
Join Date: Aug 1999
Posts: 7,957
Likes: 0
Received 0 Likes
on
0 Posts
good points simon, all of them.
but I do wonder how much you underestimate the strength of the standard sill where the seat belts are anchored.
If a crash is strong enough to rip the seat belt bracing backwards by virtue of pushing the cage rearwards (without breaking it) I can't see how anyone could survive the crash in any event.
The belt may be designed to be string in tension, but there is no question that the sill is structurally rigid in all directions. thats why the weight of the car can be jacked at all points along it.
with regard to crush zones, these are there because increasing the force experienced byt he driver is the rate of change of momentum. If you increase the time over which the vehicle slows down,the peak force is reduced. This helps protect you from injury from seat belts etc.
This is mostly because they aren't particularly well supported. A famous idiot whose name escapes proved that the human body can withstand incredible forces if incapable of moving. It is the movement within the seat that causes the problem. He strapped himself rigidly to a rocket sled along a tracked and then effectively stopped dead from 600mph. It produced a famous video which pioneered proof of the sturdiness of the human body. The key thing here was the harness. When in a full race harness there is no give, no inertia reel to enable you to move around comfortably with one lap strap and shoulder strap holding you in. Race harnesses are not about comfort they are about security.
If you have a race harness, there is a far lower requirement to reduce the forces on the body.
The only vulnerable parts remain the neck/head and limbs, and the force of the crash can normally expect to see arms broken.
Having said that, I can't deny what you have said about being forced back into a rigid loop, I can only tell you an impact which forces the engine so far back that the pasenger cell is breached, thus requiring the passenger to be forced to the rear seat area to avoid the impact from the engine entering the cell, is again not going to be one which any passenger is going to walk out of.
Another thing of note, is that this kit is again intended for track days, not street use. you are talking about head on impact with oncoming vehicles and street furniture, not with tire walls. Thats why the onus in its design is on roll safety protection which is far more likely in a crash occuring on track.
Must admit, that I would like to look into it further. But I trust the name saftey devices to think before they sell something like this, and also the inventor, Mike Peck is one of the most senior pollice accident investigators in the country. I can't think of a better equipped person to have had direct experience of the outcome of car crashes.
Still am glad you ahve made me think as I do tend to accept what I am told without questionning them enough, especially here where my life would be on the line, so thanks for the devils advocate role.
but I do wonder how much you underestimate the strength of the standard sill where the seat belts are anchored.
If a crash is strong enough to rip the seat belt bracing backwards by virtue of pushing the cage rearwards (without breaking it) I can't see how anyone could survive the crash in any event.
The belt may be designed to be string in tension, but there is no question that the sill is structurally rigid in all directions. thats why the weight of the car can be jacked at all points along it.
with regard to crush zones, these are there because increasing the force experienced byt he driver is the rate of change of momentum. If you increase the time over which the vehicle slows down,the peak force is reduced. This helps protect you from injury from seat belts etc.
This is mostly because they aren't particularly well supported. A famous idiot whose name escapes proved that the human body can withstand incredible forces if incapable of moving. It is the movement within the seat that causes the problem. He strapped himself rigidly to a rocket sled along a tracked and then effectively stopped dead from 600mph. It produced a famous video which pioneered proof of the sturdiness of the human body. The key thing here was the harness. When in a full race harness there is no give, no inertia reel to enable you to move around comfortably with one lap strap and shoulder strap holding you in. Race harnesses are not about comfort they are about security.
If you have a race harness, there is a far lower requirement to reduce the forces on the body.
The only vulnerable parts remain the neck/head and limbs, and the force of the crash can normally expect to see arms broken.
Having said that, I can't deny what you have said about being forced back into a rigid loop, I can only tell you an impact which forces the engine so far back that the pasenger cell is breached, thus requiring the passenger to be forced to the rear seat area to avoid the impact from the engine entering the cell, is again not going to be one which any passenger is going to walk out of.
Another thing of note, is that this kit is again intended for track days, not street use. you are talking about head on impact with oncoming vehicles and street furniture, not with tire walls. Thats why the onus in its design is on roll safety protection which is far more likely in a crash occuring on track.
Must admit, that I would like to look into it further. But I trust the name saftey devices to think before they sell something like this, and also the inventor, Mike Peck is one of the most senior pollice accident investigators in the country. I can't think of a better equipped person to have had direct experience of the outcome of car crashes.
Still am glad you ahve made me think as I do tend to accept what I am told without questionning them enough, especially here where my life would be on the line, so thanks for the devils advocate role.
10 June 2004, 05:01 PM
#37
Scooby Regular
Join Date: Nov 2001
Location: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
Posts: 15,239
Likes: 0
Received 1 Like
on
1 Post
but I do wonder how much you underestimate the strength of the standard sill where the seat belts are anchored.
I have replaced the corner of my car and know how thin / weak they are..
The sill is just a box section of thinwalled steel ( it will crush inwards towards the driver with minimal effort however throughout the length it should be stronger..
take a piece of paper and pull the ends apart.. doesnt rip.. put the same force on by pushing the end in, it just bends..
pull again with a little cut in the side.. and very little strength.. it rips..
alter the body in the same way and it could have the same results..
Adam.. try hitting a spot welded panel with a hammer to break the welds.. easy.. fall apart... try it with a properly seam / stitch welded panel.. and you'll be there for a while..
Seat belt mounts are not anything major.. normally a spreader plate / washer to spread the load...
I have rewelded them in when replacing panels before (non scoob)
You would be amazed just how weak the car is with just a few parts removed.
I 100% agree with simon..
ITS weld in or nothing IMHO... and track only.
David
10 June 2004, 07:20 PM
#38
Scooby Regular
Join Date: May 2004
Posts: 252
Likes: 0
Received 0 Likes
on
0 Posts
Adam
Agreed re the reason for "crumple zones", and that rigidity is bad.. this is the whole reason I was making comment on the crumple zones in response to your suggestion that anything that makes the car more strong has to be a good thing.
regarding full race harness. the set-up you describe is not a full race harness as it doesn't have a crotch strap. This kind of set-up is potentially lethal as it allow you to slide down through the belts and potentially decapitate yourself in the way through (especially with a helmet on).
In addition, rally cars have proper competition seats, which restrict the movement of the body you describe. Normal perforamnce car seats are weak and offer very little side support. Race seats offer support for almost every part of the body. They provide a secure zone in which the driver / co-driver sits which is then further protected by a complete cage, which is further protected / supported by a fully seam welded body.
One of the biggest problems with safety equipment is that unless they are used EXACTLY as intended, they can be more of a danger than not having them at all.
A full roll cage is a full roll cage. You will not get anything like the same benefits with a half cage, and in-fact may end up with a worse situation than you had before.
Like I've said in each post... I am not saying they are DEFINITELY bad, or that they are DEFINITELY good, I'm merely saying that you should investigate and consider it very carefully before making a decision.
All the best
Simon
Agreed re the reason for "crumple zones", and that rigidity is bad.. this is the whole reason I was making comment on the crumple zones in response to your suggestion that anything that makes the car more strong has to be a good thing.
regarding full race harness. the set-up you describe is not a full race harness as it doesn't have a crotch strap. This kind of set-up is potentially lethal as it allow you to slide down through the belts and potentially decapitate yourself in the way through (especially with a helmet on).
In addition, rally cars have proper competition seats, which restrict the movement of the body you describe. Normal perforamnce car seats are weak and offer very little side support. Race seats offer support for almost every part of the body. They provide a secure zone in which the driver / co-driver sits which is then further protected by a complete cage, which is further protected / supported by a fully seam welded body.
One of the biggest problems with safety equipment is that unless they are used EXACTLY as intended, they can be more of a danger than not having them at all.
A full roll cage is a full roll cage. You will not get anything like the same benefits with a half cage, and in-fact may end up with a worse situation than you had before.
Like I've said in each post... I am not saying they are DEFINITELY bad, or that they are DEFINITELY good, I'm merely saying that you should investigate and consider it very carefully before making a decision.
All the best
Simon
10 June 2004, 07:28 PM
#39
Scooby Regular
Join Date: May 2004
Posts: 252
Likes: 0
Received 0 Likes
on
0 Posts
PS.
A classic example of a safety device used in such a way as it become dangerous was the tragic incendent with Possum's co-driver Roger Freeth.
The distance between the rear of the seat and the seat belt mounts was long enough that something penetrated the cabin and pulled the belts backwards crushing him fatally.
Since then, tighter regulations have been put in place to insist that the belts are mouted within a certain distance from the rear of the seat and more specific regs on the angle at which they leave the seat.
A classic example of a safety device used in such a way as it become dangerous was the tragic incendent with Possum's co-driver Roger Freeth.
The distance between the rear of the seat and the seat belt mounts was long enough that something penetrated the cabin and pulled the belts backwards crushing him fatally.
Since then, tighter regulations have been put in place to insist that the belts are mouted within a certain distance from the rear of the seat and more specific regs on the angle at which they leave the seat.
11 June 2004, 11:32 AM
#40
Scooby Regular
Join Date: Aug 1999
Posts: 7,957
Likes: 0
Received 0 Likes
on
0 Posts
Simon,
I completely appreciate your concern and can't argue with what you are saying as it makes sense. do still feel that we are talking about track days where the worst thing you could hit is another car, but more likely the tyre wall. With this in mind, I would see the roll protection provided as a good thing, but I would certainly not be so keen to have the roll hoop still in place on the way home after leaving the circuit.
I completely appreciate your concern and can't argue with what you are saying as it makes sense. do still feel that we are talking about track days where the worst thing you could hit is another car, but more likely the tyre wall. With this in mind, I would see the roll protection provided as a good thing, but I would certainly not be so keen to have the roll hoop still in place on the way home after leaving the circuit.
Thread
Thread Starter
Forum
Replies
Last Post