Nellie Faye Fenders and Air shields vs ???

[bryan]

I'm designing a 1/4 chassis car with balsa Nellie Faye style fenders and air shields inside the wheel. Is there a reason the fenders shouldn't be constructed 1/16 thicker to cover the inside of the wheels fully? The air shields could be skipped, and the airflow would be even cleaner. Right? Why isn't this a popular option? What am I missing?

 

[HurriCrane Racing]

Even with the fender 1/16" wider than the wheel, the air would still tumble into the wheel cavity.
You will also increase your frontal exposure.

If you are racing a scout event, you may not need the wheel covers. Much will depend on the level of competition in you pack. If you plan on racing league, you'll need every bit of speed you can find. Why leave speed on the table and give the competition an advantage?

One thing about the Nellie Faye fenders, It forces you to drill the rear axle farther forward than what is optimum. They also cover the top of the wheels which will make cleaning and removing your wheels more difficult.

Good luck.

 

[bryan]

Even with the fender 1/16" wider than the wheel, the air would still tumble into the wheel cavity.
Good luck.

This would be league racing. I meant to say the entire upper interior of the wheel would be completely covered. The extra width would extend over the wheels. I have access to a laser cutter and could cut just about any shape and layer it together.

 

[Dennis]

This would be league racing. I meant to say the entire upper interior of the wheel would be completely covered. The extra width would extend over the wheels. I have access to a laser cutter and could cut just about any shape and layer it together.

I had that idea last year and tried to make a few fenders to that design. Never came out how I wanted. Would be interested to see what you come up with using your laser cutter.

Air would still get into the wheel well. It seems like it would be less air then what’s being caught by a completely exposed wheel. Also thought about making the fender a little wider than the face of the wheel and putting some tape over that part to completely block the air from getting in from the outside.

 

[B_Regal Racing]

This is just my opinion...

Nellie Faye style fenders cover the top of the wheel yield more frontage than standard fenders. Making them a bit wider to cover the inside cavity of the wheels only increases the frontage. While I do not have any personal experience with Nellie Faye style fenders (never raced them in the league), I do believe the extra frontage will create more drag than will traditional fenders and air shields. While you can argue that traditional fenders and air shields will create more turbulent air than will Nellie Faye style fenders, I believe the drag of the Nellie Faye style fenders is more detrimental to speed than are traditional fenders and air shields. As stated above, there are also additional challenges cleaning the wheels and re-prepping the car. Nellie Faye style fenders, however, do look awesome. Best of luck....