b16

Problem is people have died at the track in this car too. :\

Ingenieur

no concrete poles or curbs at a track
the pole sheared the car in half

the reason is the same at both: over estimation of ones ability or under estimating the speed of the car, usually both

the car is safe, the driver was not
an accident for walker, negligence for the driver

http://www.caranddriver.com/reviews/...a-gt-road-test

Achieving the desired bedrock chassis stiffness Porsche wanted in an open car required adding extra material to the chassis. Hölscher wouldn't quote any numbers but said it's probably the stiffest car on the road today. After our brief drive, we think he might be right.

Thoughts of ride quality quickly faded as we barreled into a tight hairpin at 135 mph. Here's where we'd like to brag about our abilities to keep this flailing beast on the track. But we can't—the GT's excellent manners and tremendous grip make difficult maneuvers seem easy.

It wasn't the outright speed that floored us. We expected that. It was the easy controllability. Those rigid suspension mounts may be a bit annoying on the road, but on the track they provide a stream of tiny signals that impart confidence. We tried, but we never found a way to upset the chassis. It's simply glued to the road.


http://www.autoweek.com/article/20050502/FREE/505020719
You can hammer the GT an awful lot harder than you thought you could, and it won’t hurt you. I eased on too much throttle coming out of a tight corner, for instance, and found the rear stepping out. No problem, I just backed off and the rear came back. Same with lifting too suddenly going into a corner. Time and again the GT stayed in line where old 911s would have spun off into the grass and Armco.

Chris Harris http://www.pistonheads.com/news/defa...?storyId=29008

Thericker

Let's reflect on the positive..

b16

Concrete walls though.

Don't get me wrong, I'm not defending anyone here. Just saying it is hard to judge without being there yourself.

dremorg

Knock it off guy. I gave you the article. The track is where you drive reckless, not the street.

Ingenieur

The walls actually are set-up to make it safer, to control your path and dissipate energy. The pole cut the car (and passengers) into pieces.

It's not that hard: The car is very strong, amazing handling and brakes. Speed was the sole factor and was excessive, my guess, >100 mph. It doesn't take Einstein or an accident reconstruction expert to figure this one out.

the black boxes will yield much data...
hopefully the tox reports are negative for the driver

From what I've read he was a good guy. I didn't personally know him, but from the information presented I can draw that conclusion. The same goes for his accident: don't have to have first hand knowledge, the aftermath can paint an accurate picture.

It's sad, but we just lost a chock (6 to be precise) of soldiers in 'Stan and it didn't get hardly any press, and has been already forgotten by most.

Our priorities as a Country seem askew.

b16

So you're the patron saint of driving the speed limit.

dremorg

It's not about whether or not "I" obey the speed limit. This isn't about me. I simply gave you the article. The first thing you said was "people have died on the track in this car too"...the place where it's safe to drive with excessive speed. You're trying to defend. When you were told there are no trees or poles on the track you come back with "Concrete walls though" They're the investigation experts.

jrcart

Coroner report was released today. He said vehicle was traveling well over 100mph and cause of death was combination of "Trauma and Thermal Injuries"(burned to death). No drugs or alcohol were found in blood labs.

http://movies.msn.com/movies/article.aspx?news=845678

Ingenieur

over 150 ft/sec or a football field every 2 sec

stopping distance from 100 mph? 300'?
1 sec reaction + system lag + distance ~ 500' and 6-7 sec

in a business park
stupid and shows a complete lack of understanding of the physics of the inertial reference frame

the report is on-line
the impact occured at >100 mph
he had already scrubbed off significant speed
the drivers side hit the tree & pole first and spun the car 180 and the passenger side then hit the tree
they were both alive briefly and died in a 'pugilistic' stance, what ever that means
it was so hot it cracked his bones

jrcart

Pugilistic Stance: A ‘defensive’ position fancifully likened to that adopted by pugilists (boxers), which is typically seen in severely burned bodies, characterised by flexion of elbows, knees, hip, and neck, and clenching of hand into a fist; it is caused by high-temperatures in fire, resulting in muscle stiffening and shortening; it occurs even if the person was dead before the fire.

Kinda gross and morbid...

ghiaguy

sobering. stay safe out there guys

Alexbenz

Was it ever determined if either of them was alive after the crash and or suffered pain from burning alive?

vdubpower

never had i heard of or seen heat cracking bones....him bracing for the impact would cause the radius and ulna to fracture....

Ingenieur

yes
walker had soot in his lungs meaning he was breathing smoke/fire for a time

sounds like the driver died quickly, his side sheared the concrete pole almost splitting the car in two, it sounds like his head hit the pole

such a stupid waste of life

people need to realize you need 500' to stop from 100 mph, that is a long way
speeding on secondary roads is absolutely stupid
at least on a divided interstate you have some room for margin of error
none on a secondary road

I think the actual police accident report, ie, cause and specifics of the accident, (vs the coroner report, cause of death, etc.) will show he was travelling closer to 130-150 range, and slowed to 100+ before impact
a damn shame

jrcart

500ft?? Lol my Ford Raptor can stop from 100mph in under 500ft. My SLS BS can do it in 266ft and a CGT can do it in 275ft. Maybe you meant to say 300ft

Ingenieur

that is once the brakes are applied
reaction time and system lag time (pedal travel, build up some prssure, pads to engage)

the numbers I've seen for Porsches with PCCB were 310 range
couldn't find a specific number for the CGT and this is under testing conditions: on a wet or road with any debris, paint stripes, worn tires, etc, you will be much further...a couple 32's of tire wear can increase the distance significantly, as much as 20% according to Bosch Automotive Engineering Handbook...

reaction time, even if you can assess the situation/need to brake and make the move in 1 sec, unlikely, you still have travelled 150 ft
even if it's only 2 seconds to see a deer, kid, stopped vehicle you'll have travelled 300'
trained gun fighters require that much to assess and fire, and they are locked and loaded and anticipating the shot...
'surpise' adds a lot to reaction time, you don't drive on the edge of anticpation of emergency/unexpected braking (like you do when you know a corner is approaching)

according to Bosch and Volvo the system lag may be 0.1 to 0.3 sec, 15 to 45 ft

500' for the total distance = reaction + system lag + braking distance is not unrealistic, and probably conservative

from a highway design manual
To make highways reasonably safe, the engineer must provide a continuous sight distance (see the stopping sight distance module) equal to or greater than the stopping sight distance. As an integral part of the stopping sight distance, a value for the brake reaction time must be assumed. Extensive research has shown that 90% of the driving population can react in 2.5 seconds or less. The brake reaction time normally used in design, therefore, is 2.5 seconds. The distance traveled during the brake reaction time can be calculated by multiplying the vehicle's initial speed by the brake reaction time.

on a bell curve 80% will be 2 sec +/- 0.1 sec



Here's a simple example. Suppose a person is driving a car at 55 mph (80.67 feet/sec) during the day on a dry, level road. He sees a pedestrian and applies the brakes. What is the shortest stopping distance that can reasonably be expected? Total stopping distance consists of three components:

1. Reaction Distance. First. Suppose the reaction time is 1.5 seconds. This means that the car will travel 1.5 x80.67 or 120.9 feet before the brakes are even applied.
2. Brake Engagement Distance. Most reaction time studies consider the response completed at the moment the foot touches the brake pedal. However, brakes do not engage instantaneously. There is an additional time required for the pedal to depress and for the brakes to engage. This is variable and difficult to summarize in a single number because it depends on urgency and braking style. In an emergency, a reasonable estimate is .3 second, adding another 24.2 feet.
3. Physical Force Distance. Once the brakes engage, the stopping distance is determined by physical forces (D=S²/(30*f) where S is mph) as 134.4 feet.

Total Stopping Distance = 120.9 ft + 24.2 ft + 134.4 ft = 279.5 ft

Merc63

^ way too much free time. Almost fell a sleeping reading all that.

Ingenieur

too short attention span or narcolepsy you probably sleep at the wheel too, 5 second reaction time for you
it's mostly cut and paste
took a whole 2 minutes to put together, a lifetime for you to comprehend

actually, can one have too much 'free time'?
should they work all the time?
or is it better to make alot of money in a short time
$20 hr x 2500 hrs or $200 x 1000 hrs?

the guy with walker fell asleep at the wheel
he may have been 'awake', but he sure as hell wasn't making conscious or rational decisions
I can say with certainty he'd like a 'do over' or would have liked a wake up call, like 'slow the hell down before you kill us or someone else!'

Ingenieur

killing more of my free time (as opposed to restrained time?)
or is free time non-productive time?

good info http://www.4n6xprt.com/Braking_Effec...her_Speeds.pdf
an article that postulates (and imho makes a good case) braking efficiency does not diminish with speed, car stops with the same efficiency from 60 as 100, ie, the g force is ~ the same...it has distances for many cars compiled from many magazine sources

people don't realize when driving they are a ballistic object bound by laws (other than traffic) Newton's, friction, etc.

how many people can determine stopping distance for a given speed if they know 60-0 is say 100'? what is it at 100 mph? 275' = (100/60)^2 x 100'

or stopping time from 60 mph if the know decel is 0.9 g (in line with the test results)
2.5 ~ t = v/a = 88/(0.9 x 32) ~ 2.5 sec

the more you understand the equipment/system, the better (as in safer) driver you will, and will better exploit the potential of the system

that is why the technical savvy F1 drivers seem to be more successful on average...they can converse technically with their engineers and optimize the package...

in Europe they used to have cut-away cars to train drivers on mechanics, it was required to get a license...
here the gym teacher, or dad who can't drive for crap, teaches you how to 'park', not drive, lol

Merc63

You sound like a guy with zero friends.

Euler

All that and nothing about a fire. Cumon engineer tell us how stuff burns.

Alexbenz

He could have been unconscious??? I'd hate to drown or burn alive...such a horrible way to go

Euler

Are you the author of the referenced article? It has a similar pedantic and condescending tone.

otakki

You play with fire and you get burnt. That's the way it is.

There are some good angles from v6s_stink's comment on worldcarfans.com Paul Walker article yesterday:

"I don't have mixed feelings about the deaths, those were sad tragedies, period. As the original post stated, it is about much of the response generated. I haven't driven but a few miles in a car above 100 MPH on public roadways, and then on an isolated western USA road where there was multiple miles of unobstructed visibility for 180 degrees around and in front of me. I have ridden high end superbikes at speeds over 100 MPH for hundreds of miles under the same wide-open conditions. That does feel very natural quickly once speed is reached. I am pretty sure that 100MPH on an urban boulevard, between buildings and past entrances, is much less natural and should trigger some feelings about personal and public safety. My plus 100 MPH motorcycle jaunts were actually legal as my state's speed limit was once "safe and reasonable for existing conditions" and court tests during the time were consistent with conditions I carefully considered as appropriate for speed. I could have died too as physical laws will not be broken, but the risk to self and the public was infinitesimally lower. If a vehicle, animal or pedestrian approached I probably had several times the amount of reaction and braking time necessary to completely stop the bike. Can we say that these guys had enough time to cut even 50% of their speed if something got in their way. The video of the scene doesn't appear that way."