Author Topic: Bockscar 2.0  (Read 464100 times)

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Offline Speed Limit 1000

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Re: Bockscar 2.0
« Reply #15 on: October 05, 2017, 07:17:34 PM »
F=MA.  Reduce the mass and you reduce the force.  I think the benefits of a break away chassis is fairly well understood and adopted in a few different forms of motorsports.

Stainless, Bockscar has always been one of my favorite cars for as long as I could remember - Ben Jordan was an early and great influence on me and my brother.  I'm glad you're bringing it back and hope you can maintain a majority of it's original form.  Looking forward to seeing it out on the salt again.

Ben Jordan changed our lives in a very positive and lasting ways :cheers:
« Last Edit: October 05, 2017, 07:20:13 PM by Speed Limit 1000 »
John Gowetski, red hat @ 221.183 MPH MSA Lakester, Bockscar #1000 60 ci normally aspirated w/N20

Offline tortoise

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Re: Bockscar 2.0
« Reply #16 on: October 05, 2017, 08:44:43 PM »
Actually, it is just the opposite- the heavier pieces have more energy; that must be dissipated so they tumble down the course further.

Regards, Neil  Tucson, AZ

If they go further, starting from the same speed, then they are decelerating more slowly. Speed doesn't kill, it's the deceleration.

I have a feeling that it's a more nuanced question, and am not entirely convinced by my own argument. You guys may be right, but the case has not been made. A relevant question, which perhaps some of you may be able to answer, is in a fatal accident on the salt, is it more likely caused by deformation of the cage, or subjecting the driver to massive accelerations within an intact cage?
« Last Edit: October 05, 2017, 08:51:04 PM by tortoise »

Offline Interested Observer

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Re: Bockscar 2.0
« Reply #17 on: October 05, 2017, 09:12:23 PM »
Since you are embarking on a clean- or near clean-sheet build, one might consider the following:

Some years ago, on the long drive home from Speed Week, a particular team fell to discussing the various vehicle configurations then extant on the salt.  In due course Jim Feuling’s streamliner came up for consideration.  Recall, front wheel drive, engine in front of the front axle, necessary bits in the middle, driver in the rear.  This was seen to offer a number of advantages and only one disadvantage (which could be lived with).
   Predominant weight on the driving and steering axle
   CG well in front of the CP
   Ready access to engine and driveline
   Superior driver sightlines
   Possible tapering profile

Offline ggl205

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Re: Bockscar 2.0
« Reply #18 on: October 05, 2017, 09:48:13 PM »
Actually, it is just the opposite- the heavier pieces have more energy; that must be dissipated so they tumble down the course further.

Regards, Neil  Tucson, AZ

If they go further, starting from the same speed, then they are decelerating more slowly. Speed doesn't kill, it's the deceleration.

I have a feeling that it's a more nuanced question, and am not entirely convinced by my own argument. You guys may be right, but the case has not been made. A relevant question, which perhaps some of you may be able to answer, is in a fatal accident on the salt, is it more likely caused by deformation of the cage, or subjecting the driver to massive accelerations within an intact cage?

If a roll structure is still in tact after a crash, I would submitt it is sudden deceleration G's that kills. My first encounter with a high profile racer killed by sudden deceleration was Mark Donahue. After a high speed crash into a chain link fence, Mark walked away looking quite normal only to collapse and die within minutes after the crash. I am not sure if I understand exactly the cause but it has to do with sudden deceleration tearing brain connections from the skull. So, anything that can lessen deceleration G's, the better chances are of survival.

John

Offline Speed Limit 1000

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Re: Bockscar 2.0
« Reply #19 on: October 05, 2017, 09:50:11 PM »
Since you are embarking on a clean- or near clean-sheet build, one might consider the following:
   
   Superior driver sightlines
   


In the Bockscar the motor in the back is about at the drivers sight level
John
John Gowetski, red hat @ 221.183 MPH MSA Lakester, Bockscar #1000 60 ci normally aspirated w/N20

Offline Stainless1

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Re: Bockscar 2.0
« Reply #20 on: October 06, 2017, 01:42:28 AM »
Nathan, don't worry, you will be able to recognize it when we are done...

We probably won't build it to break apart in a crash... I would be afraid the rough salt might make it come apart prematurely... Besides I'm not that smart  :roll:

IO, semi clean sheet... unfortunately if we made it front engine that minimal sight line we have would become nonexistent....

As the picture shows, the build table is getting closer, all the fixture pieces have been squared, leveled and welded on.... the kiln has been disassembled for new quartz tubes and heating elements.... Yep Jerry, that is some of the non-race related stuff I do to keep the home owner association (Linda) happy. 

With any luck I will get the tube stops cut and fitted tomorrow
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline BHR301

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Re: Bockscar 2.0
« Reply #21 on: October 06, 2017, 03:54:54 AM »
Question, with a break away chassis wouldn't that leave the cockpit area without a chute?

Bill

Offline ggl205

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Re: Bockscar 2.0
« Reply #22 on: October 06, 2017, 07:43:39 AM »
Question, with a break away chassis wouldn't that leave the cockpit area without a chute?

Bill

Bill, at that point, the chute is useless.

John

Offline jacksoni

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Re: Bockscar 2.0
« Reply #23 on: October 06, 2017, 08:30:04 AM »
Question, with a break away chassis wouldn't that leave the cockpit area without a chute?

Bill

Bill, at that point, the chute is useless.

John
I was going to question this as well. Need two chutes, one for the engine, one for the driver and surround........ :roll: :roll: :?
Jack Iliff
 G/BGS-250.235 1987
 G/GC- 193.550 2021
  G/FAlt- 193.934 2021 (196.033 best)
 G/GMS-182.144 2019

Offline NathanStewart

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Re: Bockscar 2.0
« Reply #24 on: October 06, 2017, 03:14:07 PM »
F=MA.  Reduce the mass and you reduce the force. 

F=MA. Reduce the mass and you increase the acceleration. Lighter vehicles are easier on things they run into, but that's not the issue here.

Okay, maybe I was lazy with my physics reference but it's about reducing energy.  The more mass and velocity an object has, the more kinetic energy it's going to have.  Having parts shed away during a crash gives the benefit of releasing energy to remove those parts and then reducing the energy of the parts the driver is still attached too.  The driver is going to have momentum and will want to keep moving while the chassis is slamming into the ground.  If you can reduce the chassis's momentum by reducing it's mass, less energy is going to get transferred to the driver.  You highlight this point above.  If a lighter vehicle is "easier" on things they run into then it has the same affect on being easier on those inside the vehicle. 

Bockscar is a fairly small and lightweight car so it's kinetic energy is already going to be much less anyways. 

El Mirage 200 MPH Club Member

Offline CNC-Dude

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Re: Bockscar 2.0
« Reply #25 on: October 06, 2017, 04:20:21 PM »
  I am not sure if I understand exactly the cause but it has to do with sudden deceleration tearing brain connections from the skull. So, anything that can lessen deceleration G's, the better chances are of survival.

John
[/quote]

Yes, that and other internal organs continuing to stay in motion when your body is stopped suddenly and tearing loose internally causing exsanguination .

Offline tortoise

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Re: Bockscar 2.0
« Reply #26 on: October 06, 2017, 06:58:53 PM »
  If a lighter vehicle is "easier" on things they run into then it has the same affect on being easier on those inside the vehicle.

A heavy vehicle at 100 mph hits, say, a house. It goes through 3 walls before the coming to a stop. A lighter vehicle just breaks through the outer wall before coming to a stop. All other things being equal, which vehicle has subjected the driver to higher acceleration?


Offline WhizzbangK.C.

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Re: Bockscar 2.0
« Reply #27 on: October 06, 2017, 07:32:59 PM »
 If a lighter vehicle is "easier" on things they run into then it has the same affect on being easier on those inside the vehicle.

A heavy vehicle at 100 mph hits, say, a house. It goes through 3 walls before the coming to a stop. A lighter vehicle just breaks through the outer wall before coming to a stop. All other things being equal, which vehicle has subjected the driver to higher acceleration?



It seems to me that on a good LSR course, there are no houses, or other solid objects, to hit. In this venue the forces generated during an incident mostly result from tangential contact with the ground. The higher the mass of the object involved, the longer it will take to stop, resulting in more impacts. The lighter the mass the quicker the deceleration and the sooner you come to a stop, minimizing the number of hits you take in the process. Think of it this way, would you rather tumble and roll 5 times or 25?
« Last Edit: October 06, 2017, 07:35:26 PM by WhizzbangK.C. »
Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of.  Douglas Adams

Offline tortoise

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Re: Bockscar 2.0
« Reply #28 on: October 06, 2017, 08:04:17 PM »
It seems to me that on a good LSR course, there are no houses, or other solid objects, to hit. In this venue the forces generated during an incident mostly result from tangential contact with the ground. The higher the mass of the object involved, the longer it will take to stop, resulting in more impacts. The lighter the mass the quicker the deceleration and the sooner you come to a stop, minimizing the number of hits you take in the process. Think of it this way, would you rather tumble and roll 5 times or 25?

That may indeed be correct. My last post addressed only the argument presented by the post I was responding to.

Are post-crash analyses in SCTA events ever made public?

Offline WhizzbangK.C.

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Re: Bockscar 2.0
« Reply #29 on: October 06, 2017, 09:13:30 PM »
It seems to me that on a good LSR course, there are no houses, or other solid objects, to hit. In this venue the forces generated during an incident mostly result from tangential contact with the ground. The higher the mass of the object involved, the longer it will take to stop, resulting in more impacts. The lighter the mass the quicker the deceleration and the sooner you come to a stop, minimizing the number of hits you take in the process. Think of it this way, would you rather tumble and roll 5 times or 25?

That may indeed be correct. My last post addressed only the argument presented by the post I was responding to.

Are post-crash analyses in SCTA events ever made public?

As far as I've been able to see, they do not make the analyses public. Not just the SCTA, but all the sanctioning bodies seem to operate the same way. The only results that the general public can see are the rule changes that come down, and even then they usually don't directly reference the incident that brought about the change. Most times that is pretty obvious from circumstantial evidence, but they rarely state it explicitly.
Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of.  Douglas Adams