11-15-2004, 05:05 PM
This was posted on the sr20forum (<!-- m --><a class="postlink" href="http://www.sr20forum.com/showthread.php?p=868561#post868561">http://www.sr20forum.com/showthread.php ... post868561</a><!-- m -->), and I figured anyone that races with a trunk mounted battery may be interested in this:
"Yesterday at Buttonwillow, John Lindsey's #46 SE-R cup car was destroyed in a very violent end over end crash. Fortunatly the stout cage allowed by SE-R cup rules, a good seat, harness and Hans device allowed John to walk away from the accident with only minor bruses and soreness.
What was scarey was what happend to the battery. The battery was a lightweight Hawker dry cell. The battery was trunck mounted in a Summet Racing battery box bolted to the floor of the car and held down with a typical metal braket inside the box. This mounting conformed in its holdown to every sanctioning body set of rules I have ever seen and was sanitary with large washers, etc backing up the bolts. The battery box was also retained by a sturdy nylon strap, it all looked safe and sano
The accident was violent with the car flipping up to 20 feet in the air and tumbling end over end 4 times. The car's safety equipent performed flawlessly, the cage was not even bent although the car was crushed around it. However, the battery mounts tabs pulled through the hold down bracket, the battery came loose, the battery box shattered into many small pieces and the battery was flinging around in the car attached to the cables!
The ground cable eventualy tore off and the only thing that prevented the battery from becoming a 15 lb projectile with the lone remaining postive calbe which fortunatly held. Emagine what would happen if this was a conventional 30 lb lead acid battery full of sulfuric acid! The battery was probably the most hazardous thing in the accident!
I think we really need to look at the mounts for trunk mounted batteries, first off, I think never run a stock lead acid battery. Run a lightweight gell cell battery, the lighter the better, like a hawker or baker racing battery. A lighter battery has less potential energy to bust out of its moorings and the gell electrolite is less caustic. The battery should be held down by a wrap around large bracket of at least 10 gauge held down by 4 grade 5 bolts or better, backed up by really big washers. The box should not have any sort of retention fucntion.
Remember in a crash, the battery can generate spike forces of over 100 lbs and hit you at speeds of 50 mph. It could crack your head open helmet or not. Also look at your fire bottle mounts. This accident was terrible and it makes me sick to my stomach to look at John's car but there are important lessons to be learned here that might save some of us later.
Lastly, I think a neck restraint might be critical. John was wearing a Hans device which probably spared him a bit of injury. The Hans device did give him a pretty good bruse on his back, an indication of how much force it prevent his neck from absorbing.
Lastly don't skimp on your cage, seat harnesses, window nets, drivers suits, helmits, fire systems etc. Buy the best made, not nessesarly the best you can afford.
This accident was one of the most violent I have seen in club racing, because of good car prep and good safety equipment, the driver was able to walk away. John is an excellent, fast and expericanced veteren driver that had a bit of bad luck. We all need to learn from this. My car is going to have many changes to its safety systems in the off season because of what I learned."
"Yesterday at Buttonwillow, John Lindsey's #46 SE-R cup car was destroyed in a very violent end over end crash. Fortunatly the stout cage allowed by SE-R cup rules, a good seat, harness and Hans device allowed John to walk away from the accident with only minor bruses and soreness.
What was scarey was what happend to the battery. The battery was a lightweight Hawker dry cell. The battery was trunck mounted in a Summet Racing battery box bolted to the floor of the car and held down with a typical metal braket inside the box. This mounting conformed in its holdown to every sanctioning body set of rules I have ever seen and was sanitary with large washers, etc backing up the bolts. The battery box was also retained by a sturdy nylon strap, it all looked safe and sano
The accident was violent with the car flipping up to 20 feet in the air and tumbling end over end 4 times. The car's safety equipent performed flawlessly, the cage was not even bent although the car was crushed around it. However, the battery mounts tabs pulled through the hold down bracket, the battery came loose, the battery box shattered into many small pieces and the battery was flinging around in the car attached to the cables!
The ground cable eventualy tore off and the only thing that prevented the battery from becoming a 15 lb projectile with the lone remaining postive calbe which fortunatly held. Emagine what would happen if this was a conventional 30 lb lead acid battery full of sulfuric acid! The battery was probably the most hazardous thing in the accident!
I think we really need to look at the mounts for trunk mounted batteries, first off, I think never run a stock lead acid battery. Run a lightweight gell cell battery, the lighter the better, like a hawker or baker racing battery. A lighter battery has less potential energy to bust out of its moorings and the gell electrolite is less caustic. The battery should be held down by a wrap around large bracket of at least 10 gauge held down by 4 grade 5 bolts or better, backed up by really big washers. The box should not have any sort of retention fucntion.
Remember in a crash, the battery can generate spike forces of over 100 lbs and hit you at speeds of 50 mph. It could crack your head open helmet or not. Also look at your fire bottle mounts. This accident was terrible and it makes me sick to my stomach to look at John's car but there are important lessons to be learned here that might save some of us later.
Lastly, I think a neck restraint might be critical. John was wearing a Hans device which probably spared him a bit of injury. The Hans device did give him a pretty good bruse on his back, an indication of how much force it prevent his neck from absorbing.
Lastly don't skimp on your cage, seat harnesses, window nets, drivers suits, helmits, fire systems etc. Buy the best made, not nessesarly the best you can afford.
This accident was one of the most violent I have seen in club racing, because of good car prep and good safety equipment, the driver was able to walk away. John is an excellent, fast and expericanced veteren driver that had a bit of bad luck. We all need to learn from this. My car is going to have many changes to its safety systems in the off season because of what I learned."
