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goofy idea, fan blades on wheels?


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Guys, I got this weird idea after reading some threads here...what if fan blades(just blades, not powered fans) are attached to each wheel to suck out more air from underneath the car? IIRC fans were used in racing to create vacuum under the car but they were banned outright.

 

The diameter of a stockish Z car tire = 60cm =0.6m (24")

0.6mx Pi = 1.885 meters per rotation

 

As I recall, at 140KPH(87MPH) is when a S30Z become a scary ride? Using that as a starting point for calculation :

 

140kph*1000 = 140000meters/hour

140000meter/hour/60 = 2333.333meters/minute

2333.333/1.885 = 1238 rotations per minute

 

 

140KPH = 1238 tire rotations per minute that means FOUR fan blades rotating at 1238rpm to suck out air from underneath the Z when it is going 140KPH or 87MPH

 

If a Z is to travel at 200MPH(322KPH), there would be 4 fans each working at 2847RPM to create vacuum under the car!!

 

The proper way to prep a Z aerodynamically is as outlined in other aero threads : seal the grill area so air either flow around the car or squeeze thru the radiator. But what if more downforce is needed without adding more wings? I do realize that it costs some power to move air so drivetrain drag will increase. Has this idea been tried? If so what are the results?

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The problem is if you have big brakes filling up your wheels. my rear wheels have a lot of space with the drums in the back but I have some good sized brakes up front. Not huge by any means but they fill up the 13.3" bell in my 15"X8" wheels. I think you would have to count brakes as a big restriction to moving a lot of air up front.

I think it may work on the rear wheels fairly well though.

 

VERY interesting idea!!

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Interesting ideer.

 

This is what you are referring to in the pictures below right? From what I understand, that slot around the perimeter of the rim is the air outlet. Behind that and towards the center of the rim are the vanes, i.e. the wheel itself is a centrifugal air mover evacuating air from behind the wheels. I’m not sure if the purpose was for moving air around the brakes for brake cooling or evacuating air from under the car for down force. Some Datsun race historians here should know for sure.

 

Something to keep in mind, (Helicopter pilots and A&P technicians will understand this), that the wheel is rolling on the ground. As such, the bottom of the tire in contact with the ground is not moving through the oncoming air stream, whereas the top of the tire is advancing into the air stream at twice the speed which the vehicle is traveling. The air flow over the outside of the wheel will have some influence on the wheels “blade” to evacuate air.

 

 

Wheels1.jpg

 

Wheels2.jpg

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wow, I didn't know the idea was/is actually tried, but also commercialized.

Good to know. Thanks for the history and pics.

 

So, those ricer mod spinner wheels were actually a good idea? Who knew.

 

The spinner probably won't have much effect because the spinner is brought up to speed with a bit of friction. The real fan blades are attached solidly to the rims so the fans are forced to spin at the same speed as the tires; solidly mounted fan blades can put down enought work to move decent amount of air to create partial vacuum.

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Hmm..... that REALLY makes me wonder about the 93' cobra rims...

 

Black93Cobra.jpg

 

My brother never fixed his before the car was stolen but the rear set were on the wrong side. How a shop would do that I have no clue, but it was funny who did and didn't notice (mustang fans that wouldn't notice and soccer moms that would...)

 

It's a really interesting idea though. And certainly something worth researching.

 

I want to someone do a 280ZX and put that huge monster of a spoiler on it...

 

You know, I live in the most ghetto of ghetto, and I might... just might think about it. :lol: I'd have to have a cool racey paint job like that though. A primer'ed car that looked like that might be too ghetto, even for me.

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