AZ45
June 18th, 2005, 12:35
These are posts stolen from a road racing forum that I thought were pretty informative.
Most of the theory makes sense for off road racing.
Notes On Race Car Harnesses - Design and Installation
-©Michael Henderson. Written for "The Greasy Rag", an Australian vintage racing publication. Reprinted in its entirety and with the author's permission from CSRG News, a monthly publication of the Classic Sports Racing Group.
-During private practice at Amaroo recently, a very quick Sports 1300 went straight on over the hill and down into the earth-filled tire wall outside the sweeper. The car was badly damaged, with most chassis rails bent and the engine/gearbox shifted substantially forwards.
- -The driver, David Williamson, was extensively injured:
-* fractures and dislocations both feet and ankles, necessitating a wheelchair after discharge from hospital;
-* undisplaced fracture of cervical vertebra;
-* fractured ribs, punctured lung;
-* bruised spleen;
-* fractured left lower arm. - -Most of these injuries, if only slightly worse, could have been fatal or caused permanent disability. David has readily agreed to my telling his story. -
-None of us like to think about being hurt in a race car. But while exploring the edge of control is part of the kick we get from racing, it seems reasonable and socially responsible to minimize the risk of being hurt if we crash. I first started analyzing race crashes in 1966, and successfully convinced a skeptical world that it was better to be belted into an open car than to be thrown out of it. My development of the six-point harness with the GQ Parachute Company, taken over later by "Dumbo" Willans, was part of this work. I still analyze crashes, but road cars these days. Knowing my background, David asked me to examine his car and his injuries, to see whether they might have been prevented. -
-This process was so instructive I thought it was worth writing down some of the lessons in the context of what new research is showing about race car harnesses. First, we worked out what happened to him in the crash. The actual speed of impact would be an estimate, but is likely to have been in the order of 100 km/h. The impact was slightly angled, so the speed might have been higher than that. The car was effectively crushed about two-thirds of a meter, and the relatively stiff tire wall probably compressed about one-third of a meter. The total stopping distance of a meter then gives the deceleration force on the car at around 40 g {Note1**[IMG]http://cdn3.race-dezert.com/forum/images/mexico-flag.png[/IMG] [I]ˇAy, caramba![/I]****[IMG]http://cdn3.race-dezert.com/forum/images/mexico-flag.png[/IMG] [I]ˇAy, caramba![/I]**. Now we know from the black box crash recorders in Indy cars that drivers can ride out 40 g crashes with no more than bruising (the limit of human tolerance is being approached at about 50 g). Why not in David's case? -
-The first reason is that David "submarined". Basically, he slid partly underneath the lap belt. As it rode up his stomach to his chest it bruised his spleen, then it went up and broke some ribs, which in turn punctured a lung. His feet were forced down to the footwell, with forces being directly transferred into a collection of vulnerable small bones and joints. -
-Hanging on to the wheel, his arm was broken as he instinctively tried to stop himself going forward. This was not enough to stop him being violently flexed over the lap belt so far that he hit his helmet hard on the steering wheel, bending the rim about 30 degrees forward. The impact was enough to break a bone in his neck, just as it was at full stretch. -
-Because problems with the harness and its installation and use could have contributed to these injuries, we studied it carefully. It was a six-point belt, with two-inch webbing. The shoulder belts had been routed over a transverse chassis rail behind his shoulders and down to a lower rail at the bottom of the car. The crotch straps were joined at a central single latch plate. David confirmed that they were quite loose, and could be clipped into the buckle very easily. -
-The submarining happened because there was little to stop it. Crotch straps are there for two reasons. Not only do they have a direct effect in preventing sliding underneath the lap belt, they also stabilize the whole system. Unlike the tree-point belts in a passenger car, the buckle of a race harness is in the center. This means as soon as the shoulder belts are loaded, they pull the lap belt upwards and the lower part of the body tries to shoot underneath. This killed Jochen Rindt, who told me in 1969 that although he had come to accept a harness in the Lotus, he would never wear crotch straps. In his crash at Monza his lap belt ended up near his neck, rupturing his liver on the way. Australian -child car seats, which also have central buckles, have crotch straps for exactly the same reason. -
-The excessive flexion of the upper part of David's body started when he finally got held up by the loose crotch straps, by which time his feet were mashed in the footwell. The flexion was allowed by the geometrically loosened shoulder belts and increased by the stretching allowed by the long length of the straps. -
-General Motors has been doing Indy car crash simulation (sled) testing, using dummies, for about five years. We now know far more than we did about the details of what happens in this kind of crash. It turns that what we thought was right in the beginning, was later proved to be pretty right all the time. -
-At impact, the whole body moves forwards until lap and crotch straps restrain the hips. Then the torso rotates 30 degrees until the shoulder belts stop the rotation. Most of this movement is due to changing belt geometry and shape changes to the body within the belt, even with the mounting points just behind the shoulder. High-speed movies of a correctly-restrained dummy reclining at 45 degrees show forward shoulder movement of about 250 mm in a 40 g crash. About 20% of this forward motion is due to belt stretch, working out to about 50 mm. -
-This confirms two things for us. First, to restrain body movement within the confines of the shoulder straps, the belts must be as tight as possible throughout the crash sequence. And that means tightness in both the shoulder and crotch straps, which balance each other. Second, the shorter the shoulder belts, the less the total stretch. In David's Sports 1300, fibers in the shoulder belts were melted as the webbing stretched over the chassis rail. -
-Not only do slack belts allow more movement - or "excursion", as we call it in the trade - but they also directly increase forces on the neck and chest because the body's deceleration is more violent. The body slams into the belts at the pre-crash speed of the car, instead of riding the crash with the car as it collapses. Loose shoulder belts are a threat to the neck. -
-It's very important to get the shoulder belts loaded as soon as possible in the crash. The best way to arrange this is to place the mounting points so that the belts leave the shoulders at about 90 degrees to the spine. If you sit bolt upright, take the belts straight backwards; but when reclining, the mounting points should be below the shoulder but not so as to take the belts back along a line 40 degrees below the horizontal. When the diver is reclining, horizontal shoulder belts don't get fully loaded until well into the crash, by which time the shoulders will have moved well forward. -
-Whatever the car, lap belts should be anchored near vertically (say, 80 to 90 degrees), with the webbing passing over or in front of the hip bones. -
-In a 40 g crash, an 80 kg driver will be loading the belt system with a 3,200 kg force, about twice the weight of a fully-laden Falcon. The more widely that load is distributed, the lower the risk of belt-induced injury. That's why three-inch (75 mm) belts, with reasonably stiff webbing, are far better than belts with two-inch straps. They'll soon be mandated by the FIA. -
-Crotch straps can't be made of three-inch webbing, but in any event they should bear on the bones of the pelvis between the legs. This allows them to be really tight without discomfort, and puts crash loadings into strong (and hard) body parts rather than weak (and soft). Crutch straps take a heavy beating in a crash. A friend recently stuffed a March very hard into an earth bank at Oran Park, and two days later - without other injuries - had two jet-black bruise lines across the top fronts of his legs. -
-To get the right geometry the crotch straps must be widely separated as they approach the lap belt, just like a parachute harness. Easily the best way to do this is to take them up through D-rings on the lap belts. Every Formula One car has this kind of system. Taking the twin crotch straps (or, worse, a single one) via a single latch plate to the bottom of the buckle is a compromise aimed at cutting cost and adding convenience, mainly for Sedan cars. -
-Only a few race harnesses comply with my criteria: three-inch webbing, D-ring crotch straps, a central rotary buckle of course, and details such as spring-loaded anti-slip adjusting buckles.
-The best harnesses don't cost a lot more that the worst, and less than a couple of tires these days. Fitting and wearing them properly is free. As David told me when I was writing his story, if only one driver's pain is prevented by better understanding, then it makes his own pain worth while. -
-BIOGRAPHICAL NOTE -
-Michael Henderson M.D. is a physician and internationally-known motor vehicle crash researcher. He has also been an auto racer since 1960. He was the author of the seminal "Motor Racing in Safety" in 1968, and influential in turning round Formula One and other open-wheel racers to acceptance of full harnesses. His first prototype harness became the Willans, now used world-wide. He currently drives a Lola T560 Formula Atlantic in vintage races, and also has a Lotus Eleven (Dick McGovern?'s old car), Elva-BMW and a Ralt RT4. in June, Michael was involved in a major crash with the Elva-BMW, the car was a write-off, but Michael came through it with "limited"; injuries, and will be racing again soon. -
-{Note 1**[IMG]http://cdn3.race-dezert.com/forum/images/mexico-flag.png[/IMG] [I]ˇAy, caramba![/I]****[IMG]http://cdn3.race-dezert.com/forum/images/mexico-flag.png[/IMG] [I]ˇAy, caramba![/I]**
-Calculate 40 g from velocity and time:
-dV = -100 km/h
-dt = Crash Distance / Avg Crash V = (1m*3600sec/hr)/(0.5*100km/h = 0.072 sec
-Deceleration = dV/dt = (-100,000m/3600sec)/0.072sec = -385.8meters/sec^2
-Deceleration g's = (-385.8meters/sec^2)/(9.802meters/sec^2/g) = -39.4g =~ -40g
+At impact, the whole body moves forwards until lap and crotch straps restrain the hips. Then the torso rotates 30 degrees until the shoulder belts stop the rotation. Most of this move
-----------------------------------------
In car safety-
I got this from a rallying friend regarding in-car safety issues. More and more, it is leading me toward replacing my sub belt with a 6 point style submarine belt. After seeing the film shown by Jim Downing at VIR last year and now this I plan to make the change as soon as I can.
" .. safety seminar put on by Detroit Region earlier this year, right after Earnhardt's death:
The main speaker was Dr. John Melvin, a bio-mechanics expert, who headed GM's racing injury research team from 92 to 98 and is now a consultant to all the major racing sanctioning bodies. They spent most of their time analyzing Indy car crashes, but their findings are of importance to all who race/rally. Here are some highlights:
1. The HANS device is the ONLY safety item that prevents the basil skull fracture that keeps killing our friends in NASCAR, for example. The big problem is the cars are now so stiff that the energy level transmitted to the driver is much higher than it used to be. Indy cars are even stiffer but all the flying carbon fiber dissipates a lot of that energy.
The mechanics of the event have the torso stopping from belt tension but the head keeps moving forward until it stops; that is when the neck and spine are rotated parallel to the impact direction and it stretches tight (OUCH!!). What has saved many drivers lives before the advent of the HANS was the steering wheel...yes that's the key. The head will hit the steering wheel and stop before the belts have completely stopped the torso. This prevents the whipping effect. His best guess as to the Earnhardt episode was that the broken lap belt (improperly installed) caused his body to rotate right and his head MISSED the wheel. The whip got him... He also said that in production type racecars like ours, the crumple effect really reduces the likelihood of hitting hard enough to be the recipient of this type of injury. In rally, we tend to have lower speeds and "semi-movable" impact objects like trees. Hitting a concrete barrier @ 100+ mph has much greater energy implications. Having said that, I still think that a HANS might be a good idea in rallying. Check with Mark Utech to see how he liked his.
2. Belt lengths should be kept as short as possible! I specifically asked John about this one because I see all the WRC guys with the 3 mile long belts. What people need to understand is the darn belts stretch a bunch even when they are short! You should have seen the belt stretch on the Indy tub lab crashes John showed. Long belts have other implications. If you hit hard forwards your body will be off the seat a bunch and if you then roll, your body will not be properly supported which can cause other injuries. Think about it. Just because the WRC is the pinnacle of the sport does not mean they truly understand this stuff. John said some of the worst belt mountings he has ever seen were in F1 cars. He also said he doesn't understand why the WRC guys do it that way.
3. Racing seats should laterally support your shoulders, NOT your ribs. Your ribs are not meant to take the punishment of a sideways input. Good seats support your shoulders and put the lateral load in there. That means all you guys with the aluminum seats that only have rib support could seriously hurt yourselves under the right conditions. He had nothing good to say about them. There is still a lot of debate over mounting to the cage or not. Depends on the situation.
4. NEVER use 5 point harness. Use a 6 point with the anchors mounted rearward of where your buckle ends up. The best way is to lay the sub belt on your seat and mount it to the same place as your lap belts. The idea of the sub belt is not really to keep you from submarining. It's real use is to stop the forward motion of your torso. To do this the sub must be stretched opposite to the direction of the force (the idea that you can't push a wet noodle). The closer you mount the belt to the horizontal direction, the sooner the system tightens up and stops your body. By actually sitting on the sub like I mentioned, it acts like a parachute sling making the belts very effective. I have tried this on the Supra and found it a little uncomfortable at first, but I got used to it. Of course I then crash tested the set-up and found that my belts held me in place very well, even hanging upside-down!
5. The cheapo $3.00 roll bar padding is only good for soaking up blood after an impact. It is too soft to absorb any serious impact. The only kind to use if SFI approved stuff that goes for $15 for 3 ft. It has a much higher density and hurts when you pound your fist into it. But it is designed for the kind of impacts that you have it there for in the first place. I redid all of mine and it cost me about $120. Cheap insurance.
6. Steering wheels should be deformable. Any of you guys running a Grant or similar "dune buggy" style wheel that has a steel rim under foam padding are destined to break your forearms/wrist/hands. I know you are out there because I have seen them myself. Get rid of it and spend $150 on something decent that will not hurt you! Nuf said.
Whew. I feel better now. I can only hope that you guys take some of this stuff to heart. I'm no safety expert, but I am an engineer. Everything this guy said made sense and could be backed up with science. I have changed a bunch of things on my car and feel good about it. I just wish all of you could have been there to hear the good doctor. The sport would be a safer place.
-- brad barber peace. love. track.
Most of the theory makes sense for off road racing.
Notes On Race Car Harnesses - Design and Installation
-©Michael Henderson. Written for "The Greasy Rag", an Australian vintage racing publication. Reprinted in its entirety and with the author's permission from CSRG News, a monthly publication of the Classic Sports Racing Group.
-During private practice at Amaroo recently, a very quick Sports 1300 went straight on over the hill and down into the earth-filled tire wall outside the sweeper. The car was badly damaged, with most chassis rails bent and the engine/gearbox shifted substantially forwards.
- -The driver, David Williamson, was extensively injured:
-* fractures and dislocations both feet and ankles, necessitating a wheelchair after discharge from hospital;
-* undisplaced fracture of cervical vertebra;
-* fractured ribs, punctured lung;
-* bruised spleen;
-* fractured left lower arm. - -Most of these injuries, if only slightly worse, could have been fatal or caused permanent disability. David has readily agreed to my telling his story. -
-None of us like to think about being hurt in a race car. But while exploring the edge of control is part of the kick we get from racing, it seems reasonable and socially responsible to minimize the risk of being hurt if we crash. I first started analyzing race crashes in 1966, and successfully convinced a skeptical world that it was better to be belted into an open car than to be thrown out of it. My development of the six-point harness with the GQ Parachute Company, taken over later by "Dumbo" Willans, was part of this work. I still analyze crashes, but road cars these days. Knowing my background, David asked me to examine his car and his injuries, to see whether they might have been prevented. -
-This process was so instructive I thought it was worth writing down some of the lessons in the context of what new research is showing about race car harnesses. First, we worked out what happened to him in the crash. The actual speed of impact would be an estimate, but is likely to have been in the order of 100 km/h. The impact was slightly angled, so the speed might have been higher than that. The car was effectively crushed about two-thirds of a meter, and the relatively stiff tire wall probably compressed about one-third of a meter. The total stopping distance of a meter then gives the deceleration force on the car at around 40 g {Note1**[IMG]http://cdn3.race-dezert.com/forum/images/mexico-flag.png[/IMG] [I]ˇAy, caramba![/I]****[IMG]http://cdn3.race-dezert.com/forum/images/mexico-flag.png[/IMG] [I]ˇAy, caramba![/I]**. Now we know from the black box crash recorders in Indy cars that drivers can ride out 40 g crashes with no more than bruising (the limit of human tolerance is being approached at about 50 g). Why not in David's case? -
-The first reason is that David "submarined". Basically, he slid partly underneath the lap belt. As it rode up his stomach to his chest it bruised his spleen, then it went up and broke some ribs, which in turn punctured a lung. His feet were forced down to the footwell, with forces being directly transferred into a collection of vulnerable small bones and joints. -
-Hanging on to the wheel, his arm was broken as he instinctively tried to stop himself going forward. This was not enough to stop him being violently flexed over the lap belt so far that he hit his helmet hard on the steering wheel, bending the rim about 30 degrees forward. The impact was enough to break a bone in his neck, just as it was at full stretch. -
-Because problems with the harness and its installation and use could have contributed to these injuries, we studied it carefully. It was a six-point belt, with two-inch webbing. The shoulder belts had been routed over a transverse chassis rail behind his shoulders and down to a lower rail at the bottom of the car. The crotch straps were joined at a central single latch plate. David confirmed that they were quite loose, and could be clipped into the buckle very easily. -
-The submarining happened because there was little to stop it. Crotch straps are there for two reasons. Not only do they have a direct effect in preventing sliding underneath the lap belt, they also stabilize the whole system. Unlike the tree-point belts in a passenger car, the buckle of a race harness is in the center. This means as soon as the shoulder belts are loaded, they pull the lap belt upwards and the lower part of the body tries to shoot underneath. This killed Jochen Rindt, who told me in 1969 that although he had come to accept a harness in the Lotus, he would never wear crotch straps. In his crash at Monza his lap belt ended up near his neck, rupturing his liver on the way. Australian -child car seats, which also have central buckles, have crotch straps for exactly the same reason. -
-The excessive flexion of the upper part of David's body started when he finally got held up by the loose crotch straps, by which time his feet were mashed in the footwell. The flexion was allowed by the geometrically loosened shoulder belts and increased by the stretching allowed by the long length of the straps. -
-General Motors has been doing Indy car crash simulation (sled) testing, using dummies, for about five years. We now know far more than we did about the details of what happens in this kind of crash. It turns that what we thought was right in the beginning, was later proved to be pretty right all the time. -
-At impact, the whole body moves forwards until lap and crotch straps restrain the hips. Then the torso rotates 30 degrees until the shoulder belts stop the rotation. Most of this movement is due to changing belt geometry and shape changes to the body within the belt, even with the mounting points just behind the shoulder. High-speed movies of a correctly-restrained dummy reclining at 45 degrees show forward shoulder movement of about 250 mm in a 40 g crash. About 20% of this forward motion is due to belt stretch, working out to about 50 mm. -
-This confirms two things for us. First, to restrain body movement within the confines of the shoulder straps, the belts must be as tight as possible throughout the crash sequence. And that means tightness in both the shoulder and crotch straps, which balance each other. Second, the shorter the shoulder belts, the less the total stretch. In David's Sports 1300, fibers in the shoulder belts were melted as the webbing stretched over the chassis rail. -
-Not only do slack belts allow more movement - or "excursion", as we call it in the trade - but they also directly increase forces on the neck and chest because the body's deceleration is more violent. The body slams into the belts at the pre-crash speed of the car, instead of riding the crash with the car as it collapses. Loose shoulder belts are a threat to the neck. -
-It's very important to get the shoulder belts loaded as soon as possible in the crash. The best way to arrange this is to place the mounting points so that the belts leave the shoulders at about 90 degrees to the spine. If you sit bolt upright, take the belts straight backwards; but when reclining, the mounting points should be below the shoulder but not so as to take the belts back along a line 40 degrees below the horizontal. When the diver is reclining, horizontal shoulder belts don't get fully loaded until well into the crash, by which time the shoulders will have moved well forward. -
-Whatever the car, lap belts should be anchored near vertically (say, 80 to 90 degrees), with the webbing passing over or in front of the hip bones. -
-In a 40 g crash, an 80 kg driver will be loading the belt system with a 3,200 kg force, about twice the weight of a fully-laden Falcon. The more widely that load is distributed, the lower the risk of belt-induced injury. That's why three-inch (75 mm) belts, with reasonably stiff webbing, are far better than belts with two-inch straps. They'll soon be mandated by the FIA. -
-Crotch straps can't be made of three-inch webbing, but in any event they should bear on the bones of the pelvis between the legs. This allows them to be really tight without discomfort, and puts crash loadings into strong (and hard) body parts rather than weak (and soft). Crutch straps take a heavy beating in a crash. A friend recently stuffed a March very hard into an earth bank at Oran Park, and two days later - without other injuries - had two jet-black bruise lines across the top fronts of his legs. -
-To get the right geometry the crotch straps must be widely separated as they approach the lap belt, just like a parachute harness. Easily the best way to do this is to take them up through D-rings on the lap belts. Every Formula One car has this kind of system. Taking the twin crotch straps (or, worse, a single one) via a single latch plate to the bottom of the buckle is a compromise aimed at cutting cost and adding convenience, mainly for Sedan cars. -
-Only a few race harnesses comply with my criteria: three-inch webbing, D-ring crotch straps, a central rotary buckle of course, and details such as spring-loaded anti-slip adjusting buckles.
-The best harnesses don't cost a lot more that the worst, and less than a couple of tires these days. Fitting and wearing them properly is free. As David told me when I was writing his story, if only one driver's pain is prevented by better understanding, then it makes his own pain worth while. -
-BIOGRAPHICAL NOTE -
-Michael Henderson M.D. is a physician and internationally-known motor vehicle crash researcher. He has also been an auto racer since 1960. He was the author of the seminal "Motor Racing in Safety" in 1968, and influential in turning round Formula One and other open-wheel racers to acceptance of full harnesses. His first prototype harness became the Willans, now used world-wide. He currently drives a Lola T560 Formula Atlantic in vintage races, and also has a Lotus Eleven (Dick McGovern?'s old car), Elva-BMW and a Ralt RT4. in June, Michael was involved in a major crash with the Elva-BMW, the car was a write-off, but Michael came through it with "limited"; injuries, and will be racing again soon. -
-{Note 1**[IMG]http://cdn3.race-dezert.com/forum/images/mexico-flag.png[/IMG] [I]ˇAy, caramba![/I]****[IMG]http://cdn3.race-dezert.com/forum/images/mexico-flag.png[/IMG] [I]ˇAy, caramba![/I]**
-Calculate 40 g from velocity and time:
-dV = -100 km/h
-dt = Crash Distance / Avg Crash V = (1m*3600sec/hr)/(0.5*100km/h = 0.072 sec
-Deceleration = dV/dt = (-100,000m/3600sec)/0.072sec = -385.8meters/sec^2
-Deceleration g's = (-385.8meters/sec^2)/(9.802meters/sec^2/g) = -39.4g =~ -40g
+At impact, the whole body moves forwards until lap and crotch straps restrain the hips. Then the torso rotates 30 degrees until the shoulder belts stop the rotation. Most of this move
-----------------------------------------
In car safety-
I got this from a rallying friend regarding in-car safety issues. More and more, it is leading me toward replacing my sub belt with a 6 point style submarine belt. After seeing the film shown by Jim Downing at VIR last year and now this I plan to make the change as soon as I can.
" .. safety seminar put on by Detroit Region earlier this year, right after Earnhardt's death:
The main speaker was Dr. John Melvin, a bio-mechanics expert, who headed GM's racing injury research team from 92 to 98 and is now a consultant to all the major racing sanctioning bodies. They spent most of their time analyzing Indy car crashes, but their findings are of importance to all who race/rally. Here are some highlights:
1. The HANS device is the ONLY safety item that prevents the basil skull fracture that keeps killing our friends in NASCAR, for example. The big problem is the cars are now so stiff that the energy level transmitted to the driver is much higher than it used to be. Indy cars are even stiffer but all the flying carbon fiber dissipates a lot of that energy.
The mechanics of the event have the torso stopping from belt tension but the head keeps moving forward until it stops; that is when the neck and spine are rotated parallel to the impact direction and it stretches tight (OUCH!!). What has saved many drivers lives before the advent of the HANS was the steering wheel...yes that's the key. The head will hit the steering wheel and stop before the belts have completely stopped the torso. This prevents the whipping effect. His best guess as to the Earnhardt episode was that the broken lap belt (improperly installed) caused his body to rotate right and his head MISSED the wheel. The whip got him... He also said that in production type racecars like ours, the crumple effect really reduces the likelihood of hitting hard enough to be the recipient of this type of injury. In rally, we tend to have lower speeds and "semi-movable" impact objects like trees. Hitting a concrete barrier @ 100+ mph has much greater energy implications. Having said that, I still think that a HANS might be a good idea in rallying. Check with Mark Utech to see how he liked his.
2. Belt lengths should be kept as short as possible! I specifically asked John about this one because I see all the WRC guys with the 3 mile long belts. What people need to understand is the darn belts stretch a bunch even when they are short! You should have seen the belt stretch on the Indy tub lab crashes John showed. Long belts have other implications. If you hit hard forwards your body will be off the seat a bunch and if you then roll, your body will not be properly supported which can cause other injuries. Think about it. Just because the WRC is the pinnacle of the sport does not mean they truly understand this stuff. John said some of the worst belt mountings he has ever seen were in F1 cars. He also said he doesn't understand why the WRC guys do it that way.
3. Racing seats should laterally support your shoulders, NOT your ribs. Your ribs are not meant to take the punishment of a sideways input. Good seats support your shoulders and put the lateral load in there. That means all you guys with the aluminum seats that only have rib support could seriously hurt yourselves under the right conditions. He had nothing good to say about them. There is still a lot of debate over mounting to the cage or not. Depends on the situation.
4. NEVER use 5 point harness. Use a 6 point with the anchors mounted rearward of where your buckle ends up. The best way is to lay the sub belt on your seat and mount it to the same place as your lap belts. The idea of the sub belt is not really to keep you from submarining. It's real use is to stop the forward motion of your torso. To do this the sub must be stretched opposite to the direction of the force (the idea that you can't push a wet noodle). The closer you mount the belt to the horizontal direction, the sooner the system tightens up and stops your body. By actually sitting on the sub like I mentioned, it acts like a parachute sling making the belts very effective. I have tried this on the Supra and found it a little uncomfortable at first, but I got used to it. Of course I then crash tested the set-up and found that my belts held me in place very well, even hanging upside-down!
5. The cheapo $3.00 roll bar padding is only good for soaking up blood after an impact. It is too soft to absorb any serious impact. The only kind to use if SFI approved stuff that goes for $15 for 3 ft. It has a much higher density and hurts when you pound your fist into it. But it is designed for the kind of impacts that you have it there for in the first place. I redid all of mine and it cost me about $120. Cheap insurance.
6. Steering wheels should be deformable. Any of you guys running a Grant or similar "dune buggy" style wheel that has a steel rim under foam padding are destined to break your forearms/wrist/hands. I know you are out there because I have seen them myself. Get rid of it and spend $150 on something decent that will not hurt you! Nuf said.
Whew. I feel better now. I can only hope that you guys take some of this stuff to heart. I'm no safety expert, but I am an engineer. Everything this guy said made sense and could be backed up with science. I have changed a bunch of things on my car and feel good about it. I just wish all of you could have been there to hear the good doctor. The sport would be a safer place.
-- brad barber peace. love. track.