Author Topic: Miniature Streamliners  (Read 7407 times)

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Offline Sumner

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Re: Miniature Streamliners
« Reply #15 on: November 26, 2018, 12:16:09 PM »
2018 book still says 1 1/2x.095 for G to K unless record is over 175, then the larger tube applies.

... and all the G to K streamliner records in BFS, FS, BGS, GS are over 175 I believe so one has to go to the larger dia. tubing or to the appropriate square tubing size,

Sumner

Offline Milwaukee Midget

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Re: Miniature Streamliners
« Reply #16 on: November 27, 2018, 10:55:21 AM »
Let me also bring up this point.

CURRENTLY the rule calls for 1 5/8" diameter tubes at these speeds.

Most cars of this type take years to get to the point where they're ready to race, and in that time frame, RULES CHANGE.

Next year, the car may be done, but if the rules change, it might not be compliant.

We almost lost a MAJORITY of motorcycle streamliners due to a proposed tubing size rule change a number of years back.  I believe it was only because of the popularity of the class that the change was re-examined.  I doubt small-bore special construction classes would garner the type of internal institutional support that the more popular, high-visibility MC streamliners did, if a change in basic construction were to be re-examined.

Nobody's got a crystal ball on this stuff, but while the rules permit 1 5/8" for the speeds I run, when I put the cage in the Midget, I went to 1 3/4"

Overbuilding now can go a long way toward not rebuilding later.
« Last Edit: November 27, 2018, 12:57:20 PM by Milwaukee Midget »
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Offline Stainless1

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Re: Miniature Streamliners
« Reply #17 on: November 27, 2018, 11:07:31 PM »
Actually the rules would let you run 1.5 x .095, but a heavier duty cage won't hurt .... and you probably want to survive if something untoward happens  :-o
 :cheers:
Stainless
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Offline fordboy628

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Re: Miniature Streamliners
« Reply #18 on: November 28, 2018, 03:09:35 AM »
Let me also bring up this point.

CURRENTLY the rule calls for 1 5/8" diameter tubes at these speeds.

Most cars of this type take years to get to the point where they're ready to race, and in that time frame, RULES CHANGE.

Next year, the car may be done, but if the rules change, it might not be compliant.

We almost lost a MAJORITY of motorcycle streamliners due to a proposed tubing size rule change a number of years back.  I believe it was only because of the popularity of the class that the change was re-examined.  I doubt small-bore special construction classes would garner the type of internal institutional support that the more popular, high-visibility MC streamliners did, if a change in basic construction were to be re-examined.

Nobody's got a crystal ball on this stuff, but while the rules permit 1 5/8" for the speeds I run, when I put the cage in the Midget, I went to 1 3/4"

Overbuilding now can go a long way toward not rebuilding later.

Structurally speaking . . . . .  allow me to add this:

Structural strength in tubing is raised significantly by increases in diameter, approximately 1/8" to 1/4" increase in diameter.
Structural strength is only raised modestly by small increases in wall thickness, say from .095' to .120"/.125".

Check any strength of materials table from any tubing manufacturer.   Note also that there are differences in strength in tubing manufacturing, ie: ERW Vs Seamless Vs DOM; as well as strength differences in material specification.

And all of this does not consider quality of fabrication or welding or any post welding heat treatment/stress relieving . . . . .

Going toward the "cheap end" on any safety equipment, not just roll cages/structures, might not be the "insightful" thing to do, certainly from a long term planning view, as MM points out.

Also, you might want to have a dialog with a competitor who has survived a "ferocious crash" in a vehicle with an "overbuilt" safety structure.   Finding a surviving competitor from a crash of an "underbuilt" safety structure might be "more challenging" . . . . . and is the reason why safety structure requirements are "upgraded".

And finally, if you do not possess the ability to calculate the amount of energy that would need to be "dissipated" in an "unfortunate incident", at record speed in the vehicle you propose to build, and the ability to calculate the structure required to "protect" the driver/occupant", you really need to stick to the "overbuilt side" of the rule book.

Once you are "crashing", you are no longer a driver.   You are just a bb in a pail, hoping your pail is strong enough to withstand the "beating".

 :cheers:
Fordboy
« Last Edit: November 28, 2018, 03:12:15 AM by fordboy628 »
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Offline stay`tee

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Re: Miniature Streamliners
« Reply #19 on: November 28, 2018, 04:31:55 AM »
Also, be aware of where your tubeing/steel is manufactured,, I recently purchased some tubeing (pipe) from a National Retail Hardware supplier here in Australia, using a hydralic tube bender the stuff crinkled up in the throat of the bend, my understanding is that the tubeing was manufactuted in a very large country to the north of us,, I then purchased some tubeing from a reputable Australian Steel house who manufacture and sell their own product, no problems with the forming of the bends  :-)
First Australian to ride a motorcycle over 200mph at Bonneville,,,

Offline NathanStewart

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Re: Miniature Streamliners
« Reply #20 on: December 05, 2018, 11:09:12 AM »
Why are you guys telling him any of this?  He's a fabricator (or at least owns a welder and tubing bender), has a rule book and apparently has been once or twice so he already knows everything.  He was just wondering if A) the rules don't actually mean anything (certainly the SCTA is pretty flexible on its rules about roll cage tubing size, right guys?) or B) the rules don't apply to him (certainly they'll let me deviate from the rules because I'm special, right guys?).   :roll:

Son, you've not been on this forum or in our world remotely long enough to start calling people dicks.  You can pack up that attitude and find your way to the door as far as I'm concerned.  Come back when you get over your jack-hole attitude and realize you don't know squat and actually want to learn something. 
El Mirage 200 MPH Club Member

Offline 4-barrel Mike

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Re: Miniature Streamliners
« Reply #21 on: December 05, 2018, 12:02:22 PM »
He was last on the site on November 25.

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Offline bob

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Re: Miniature Streamliners
« Reply #22 on: December 05, 2018, 05:08:01 PM »
no fooling , I wish I had taken the dicks suggestions a bit more seriously at the beginning of my build, then I wouldn't have dicked of time and dicked away money. its dicking tough building one of these. so to all the dicks out there that have replied to my questions and offered advice --- thank you --- love every minute of this.