My clone (nellie 2) "balsa Fenders"

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sporty
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Re: My clone (nellie 2) "balsa Fenders"

Post by sporty » Sun Jun 09, 2013 7:08 am

Both of the two cars, I have done so far, both have the 1/16th removed for the DFW.

4wheeldrfit-

Yes, Dale mentioned that to me, you do not typically see that for a scout race.

Sporty



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whodathunkit
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Re: My clone (nellie 2) "balsa Fenders"

Post by whodathunkit » Wed Jun 12, 2013 5:32 pm

Well Sporty,
Here it is all painted up with a few of your cool DerbyTalk decals on it.
Image

Thanks for the DT decals
Mark.


What type of automobile can be spelled the same forwards & backwards?

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sporty
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Re: My clone (nellie 2) "balsa Fenders"

Post by sporty » Wed Jun 12, 2013 5:53 pm

:bigups: :thumbup: :bigups: :thumbup: :bigups: :bigups:

Looks very sharp !

Sporty


whodathunkit wrote:Well Sporty,
Here it is all painted up with a few of your cool DerbyTalk decals on it.
Image

Thanks for the DT decals
Mark.



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Re: My clone (nellie 2) "balsa Fenders"

Post by Laserman » Wed Jun 26, 2013 5:13 pm

Hey fellas,

These cars look great!

Do you guys leave the fenders open on the inside to avoid aerodynamic cupping?

Or is it because the air skips past the opening anyway, and so you might as well leave it open to reduce weight?

Thanks.



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sporty
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Re: My clone (nellie 2) "balsa Fenders"

Post by sporty » Wed Jun 26, 2013 5:38 pm

I have not wind tunnel tested this design. I no longer have access to a wind tunnel also.

But testing revealed the typical air flow flowing over and around wheels and ect, like a 1/16th bubble over the actual surface. However the air flow does drop down after the front fenders (on a test of another car back in 2010 with fenders) the air flow drops off and starts to go the the next lowest surface, the down onto the track. It did not seem to ever pick back up to go over the rear fenders (on a different car with rear fenders, " making sure no one gets confused here, that the cars pictures, have not been wind tunnel tested by me anyhow).

So, anyhow, there has been great debate on this, meanign what I seen and found with wind tunnel testing, my air and wind speed was to match and estimate what the air flow was. due to scale size and many testing done with non scale size wind factoring in. And also not running into any wind, unless the track is out doors on a windy day. the only wind push being created is by the car or cars themselves.

I had to exceed the wind speed parameters to see movement of tiny, super light tassels, past the mid point of the car, to see them move at all. or the air to remain up higher and over the rear wheels or rear fenders.

This old info, tho, posted somewhere on here, 3 years ago.

Sporty



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Re: My clone (nellie 2) "balsa Fenders"

Post by 4wheeldrift » Wed Jun 26, 2013 6:50 pm

There's no doubt that having fenders is not going to be a silver bullet. We ran a long wheel based car in the beginner class at the nationals that went up against full fendered cars and won but was also beat by cars that had front and rear fenders. Like others have said, this is probably one of the last places to look for speed. I wanted to do fenders for the big race but had never run them before and was afraid they'd cause me more problems than what I'd probably gain on the track with them.



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whodathunkit
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Re: My clone (nellie 2) "balsa Fenders"

Post by whodathunkit » Wed Jun 26, 2013 8:14 pm

Sporty,
I like how the center section of the fender's on your car are different then mine.

If you look close at the Top Center section of the fenders on Sporty's clone fender car.
You'll see how the fender's start a slow rize in about the middle of the car over the back wheel well.

Take a look at how the center section on mine stay flat with a very steep rize over the back wheel well.
sporty wrote:I have not wind tunnel tested this design. I no longer have access to a wind tunnel also.

But testing revealed the typical air flow flowing over and around wheels and ect, like a 1/16th bubble over the actual surface. However the air flow does drop down after the front fenders (on a test of another car back in 2010 with fenders) the air flow drops off and starts to go the the next lowest surface, the down onto the track. It did not seem to ever pick back up to go over the rear fenders (on a different car with rear fenders, " making sure no one gets confused here, that the cars pictures, have not been wind tunnel tested by me anyhow).

So, anyhow, there has been great debate on this, meanign what I seen and found with wind tunnel testing, my air and wind speed was to match and estimate what the air flow was. due to scale size and many testing done with non scale size wind factoring in. And also not running into any wind, unless the track is out doors on a windy day. the only wind push being created is by the car or cars themselves.

I had to exceed the wind speed parameters to see movement of tiny, super light tassels, past the mid point of the car, to see them move at all. or the air to remain up higher and over the rear wheels or rear fenders.
Sporty
:scratching: I think I missed it on the clone part!
Whodathunkit..


What type of automobile can be spelled the same forwards & backwards?

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