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PostPosted: December 5, 2008, 12:51 am 
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The funny thing about aerodynamics is that small things make a HUGE change in drag.

The arms are a big factor in this. In fact, Jack's slightly longer rectangle arms reduce drag big time, despite being bigger, simply because they create better airflow overall. This concept simply expands on that, and for little extra dough.

It is one of the strangest things to work with...aero.

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PostPosted: December 5, 2008, 2:32 am 
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milo wrote:
The streamline tubing is .049 which is about 17 gauge, Jacks are .065 which is almost 14 gauge so it is thinner. I am not sure of the significance of it's thinness.

0.049 is commonly referred to as 18 gauge.
It is exactly 18 gauge in British gauge and a hair under American 18 gauge which is 0.05.

0.065 is exactly 16 gauge in british gauge and just a hair over 16 gauge in American gauge, which is 0.0625.
It is commonly referred to it as 16 gauge.

Moti

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PostPosted: December 5, 2008, 8:40 pm 
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I'm not sure where I got my numbers for that, but they seemed odd. Thanks Moti.


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PostPosted: December 5, 2008, 11:21 pm 
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Not to be a stickler, but every reference I look at tells me that 16 ga CRS steel here in the USA is .0598" nominal. The same "gauge" has a different nominal depending on the material. Sounds funny but true. 16 ga Stainless is .0625 nom. 16 ga aluminum is 0.0508 nom. Since we are talking about tubing here, 16 ga tubing is .065.


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PostPosted: December 6, 2008, 2:16 am 
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Well, with regards to the subject and the tube thickness you quoted, i have to say that I won't build suspension arms with anything less than a 16 ga tube (which is what I'm using on mine).

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 Post subject: Re: Streamline tubing
PostPosted: December 14, 2010, 2:02 pm 
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been thinking on this and did some serious searching...

Found out that one place carries streamline tubing with thicker walls in odd lengths with no minimum order and no processing fees. It definately isn't locost but here is the link anyway

http://secure.chassisshop.com/partlist/5411/

Looks like the largest wall thickness is .065

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 Post subject: Re: Streamline tubing
PostPosted: December 14, 2010, 3:17 pm 
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Aircraft Spruce also has it, http://www.aircraftspruce.com/catalog/mepages/4130streamline.php

I have to wonder though how the expense squares with the small improvement in top speed. Outboard-mounted shocks produce huge amounts of drag in comparison to the tubing, so if higher top speed is really the goal, they need to be moved inboard before fussing with the tubing.

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Last edited by KB58 on December 14, 2010, 3:27 pm, edited 1 time in total.

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 Post subject: Re: Streamline tubing
PostPosted: December 14, 2010, 3:21 pm 
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More importantly, have you checked the gauges section of that site...Nice.
http://www.aircraftspruce.com/menus/in/accelerometers_falcon.html


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 Post subject: Re: Streamline tubing
PostPosted: December 14, 2010, 3:36 pm 
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I believe those G-measuring gauges are for vertical Gs only, of little use to us.

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 Post subject: Re: Streamline tubing
PostPosted: December 14, 2010, 5:42 pm 
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You can mount them with the zero vertical. For the price though you can probably do better with car type stuff though and get your braking and acceleration too. Love mechanical gauges though...

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 Post subject: Re: Streamline tubing
PostPosted: December 14, 2010, 7:34 pm 
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Aerodynamics are for people who can't build engines.
Enzo Ferrari

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 Post subject: Re: Streamline tubing
PostPosted: December 14, 2010, 8:07 pm 
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Enzo Ferrari was also the last builder in Formula to get rid of drum brakes, so he might have been wrong about some things.


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 Post subject: Re: Streamline tubing
PostPosted: December 14, 2010, 8:08 pm 
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FABRIK8 wrote:
Aerodynamics are for people who can't build engines.
Enzo Ferrari

Ironically, that comment was a direct shot at Lotus.

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 Post subject: Re: Streamline tubing
PostPosted: April 19, 2011, 3:00 pm 
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I looked into these, and yes, if you are racing and have the budget, then by all means go aero. I feel lucky to dumpster-dive for Lola scraps that I was able to male my long sway-bar drop-links from aero tubing. It welds (tig) fine using 70s filler rod. These tubes are the "real" deal... some of the aero tubes I found were simply "ovaled" round tubes, and many of the tubes had small inner tube for added strength. Because my life depends on the upper and lower control arms, I invested on tried-and-true chrome molly 1” tubes then plug-welded the bungs with chrome-molly hiem (rod-end) fittings.

All the race car builders I talk with use aircraft spruce for many parts of their build. Then again they have BIG budgets and need to win races. Must be nice.


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PostPosted: July 14, 2011, 12:13 am 
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SR7 Hopeful wrote:
I do like the sound of the above post. Foam and skin them sounds great. Do ppl really think these lil arms will make much of a difference though? We're talking very miniscule would be a fun project though. I love the wheel cover on that Formula car.


Actually the difference is fairly substantial. 160" (or 10" wide wishbones on a locost) of .625" round tubing takes 5.57hp to push along at 100mph. By contrast, the same amount of aero tubing only takes .56hp to push through the air. Effectively freeing up 5hp at 100mph is a bit more than miniscule, though a flat floor, sealed rear and diffuser would probably see larger gains on a locost, but it all adds up.


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