Useful or usless? You decide.

[M-SPEC]

A fan will never make the down force you are thinking of, it is pretty much physically impossible. Think about the power it takes to turn a set of helicopter rotors and how much lift they have to produce with huge set of rotors just to get the helo off the ground, now if you reverse this concept, what sort of power and rotor (fan) size would it take to create a real down force of 200 - 400 pounds just in that area

a full out F1 car produces enough down force to drive upside down at speed with out any fans ...just ducting, lots of R&D, wings and a whole lot of carbon fibre .... ie, if they drove in a big tube they could drive on the ceiling

[Wants_a_GTR]

A fan will never make the down force you are thinking of, it is pretty much physically impossible. Think about the power it takes to turn a set of helicopter rotors and how much lift they have to produce with huge set of rotors just to get the helo off the ground, now if you reverse this concept, what sort of power and rotor (fan) size would it take to create a real down force of 200 - 400 pounds just in that area

a full out F1 car produces enough down force to drive upside down at speed with out any fans ...just ducting, lots of R&D, wings and a whole lot of carbon fibre .... ie, if they drove in a big tube they could drive on the ceiling

They say that anywayz. The company called Gumpart is going to be actually doing it with there car. They have a tunnel, just need a driver.

[judasentinel]

....and I thought I was the only one with maverick ideas. Way to go, man. Dont let anyone stop you from pursuing what you want to do. Its a very interesting idea, but stuff like that has been tried before with varied success.

On a conceptual level, it is a great idea. Execution will be a different thing. There are a few basic rules of aerodynamics/physics that one will have to take into account:

1. The volume of air flowing IN must not be more than what will be escaping OUT or being consumed, otherwise there will be SEVERE turbulence in the engine bay that will destroy the car's balance and aero efficiency. The system to let the air out from the engine bay will have to be so designed that there is never a BUILD-UP of pressure inside the engine bay. Pressure is force/unit area. And any amount of pressure exerted on a semi-enclosed area BEYOND atmospheric pressure (which varies with temperature) will cause slow but sure damage to the engine bay/hood, firewall, etc..

2. There is a phenomenon in aerodynamics called a VORTEX - a swirling flow of fluid or air. A vortex is inherently more efficient than a straight line flow of a fluid due to its increase velocity and ability to mix well with the environment. Vortexes, however, also can cause physical strain on anything that comes in their way, especially if their velocity is high enough to dislocate stuff. A classic example is a tornado, which moves in a vortex fashion - swirling motion. A fan causes air to move in that fashion. If the fan you install does not cause air to move faster to form a vortex, it will be nothing more than a forced intake that introduces air into the engine bay.

3. Another important thing to consider is the temperature differential between the air coming in and the engine bay temperature. Air temperature rises with its velocity. If the speed of airflow (inflow AND outflow) is not fast enough to dissipate heat when it leaves the engine bay, it can overheat. Again, the velocity of air coming in will determine the incoming air temperature. It is a very fine trade-off - if the incoming air is too fast, it will be difficult to dissipate the heat and release the air without exerting pressure, AND if it is too slow, it wont make much difference.

4. Now let's come to downforce. Air moving laterally UNDER the car will be sucked in vertically up thru the fan, right? That will create increased pressure right under the engine bay/fan, which will cause the car's front to LIFT a little bit, IF the fan is moving slow.

Your idea seems to be geared towards serving three purposes, and please correct me if I am wrong: (a) Increase front downforce and stability; (b) Engine cooling; (c) Increased volume of air available for the turbo(s) to suck in.

If that is what you want to achieve, ANY introduction of a MOVING PART into the scheme of things will ALWAYS bring in the added issues of material strength, angular velocity, and space consideration. What you want to achieve has been achieved with no moving parts not just in F1 cars, but also in our own Skylines/GTRs. Aero kits, front lips, FMICs, ram air intakes, etc., all achieve cooling, increased downforce, and power increase.

However, having said all that, I still believe that you MUST try your idea out. There is NOTHING more important than following your heart in life, and there is no greater loss in life than wasted talent. Go for it!! See how it works. Just be careful to not cause any damage to your wonderful GTR

I hope you wouldn't take my comments as criticism but as potential pitfalls to work around. If you can take care of them all and still achieve increase in downforce, it would be great.

[Bossman]

I see, you mean like the Brabham BT46B "Fan car" that was design by Gordon Murray except you have a filter? I would leave the filter out because I don't think the City workers' union would approve you of cleaning the streets instead of them.

[Shadao]

also... where is this fan gonna fit? have you been under your car lately? there isnt much room for a skid plate let alone a fan and a filter thick enough to do anything..

great idea, but i think it will take alot to make it work with our cars, now if you designed a car around this idea it would make more sense... but to add something like this i dont see it being a very effective thing

[SxyBeast]

Judasentinel:

Amazing wealth of information there my friend. Thank you for the help and advice, and also bringing this into perspective. It will take way more than just building it to archieve this. It will take lots of testing and trial and error. But I am up for it. If all is well maybe I can experiment this winter.

But ultimatelly a few people here have confirmed my fear of invention/innovation in the auto sector. Because its just all been done before.

Okay so all my questions pretty much have been delt with but one problem that is still here is fueling the fan. Everything else can be played with through R & D and trial and error but I have no idea whatsoever how this thing can be powered. Obviouslly an electric motor is out of question, and belt drive is aswell. The race cars that imployed these fans ran off drivetrain, but they were usually at the back of the car. Can something like this be done at the front of the car? Like perhaps running off the front diff, or any moving parts connected to front wheels? It would however be better to somehow run off engine RMP's like the racing cars. They said that at idle out of gear when reved the cars would squat, thats how much downforce they had. This would be the ultimate senario as the fan would increase low speed downforce.

PS sorry if I have stupid ideas of how this can be done, I'm not that mechanically inclined.

[judasentinel]

The ONLY thing that will be stupid about you is the questions that you dont ask.....you are on track to learning, my friend. No worries.

I was thinking about your idea and was contemplating how the front downforce, if increased, would impact the driving of the car. A basic idea is as follows:

Downforce is inversely proportional to top speed. The higher the downforce, the lower the top speed and acceleration.

Front downforce is not enough for better car control. You need rear downforce too, which is in fact many times more important than front downforce for straight line stability. Generally speaking, front and rear downforce-inducing components work on the air that works with both - for example, the front lip or bumper divert the air around them to a certain direction. That air then comes in contact with the rear spoiler, which gets pushed down due to airflow above it, and that creates rear downforce.

So if you were making your system, and ignored the rear downforce in such a way that the air that your system used to create front downforce does not flow backwards to create rear downforce, you will be seeing a highly unstable car no matter what you try. And I will tell you why. Front and rear downforces have to be determined in such a way that there is an overall stability in the car. Too much front downforce increase turning stability, but also can cause oversteer. Too much rear downforce increases staright line stability, but can cause understeer. And if your front downforce increase causes a reduction in rear downforce, you will see the car fishtailing and the rear end will go all over the place. Have you ever seen an F1 car go AS SOON AS it loses its rear wing? It goes into the wall spinning. That is because the increased front downforce cause the car to spin and the rear wing is not there to oppose it.

And it is also important to note that if you increase the front downforce a lot, you pretty much have to make sure that the airflow out of your system does not become a speed bump for the car (due to turbulence), AND that it flows backwards to stabilize the rear end as well.

Now let's come to the issue of powering the thing. How about NO POWER AT ALL? Ever heard of windmills? The old dutch country is filled with those - they were power BY AIR that rotated their blades. What if you could come up with a very lightweight but strong material to make the louvers or wings of the fan that moved faster and faster with the increase in speed? And I say this also to counter one comment you made - you do not need ANY downforce at idle, man. You need downforce at increased speeds, not at low speeds. The whole concept of downforce is that you need it AFTER the force of gravity and tire friction have given their all to keep a car glued to the driving line it is taking. If a car had unlimited friction on tires, it wouldnt move, and so it is true for gravity. But both have their limits. And so cars need to play with the BIGGEST hurdle for speed - AIR resistance. I could reach 300 mph with an 80 hp car if there were NO air resistance and unlimited distance to reach that speed. Downforce is the art of using the resistance to increase stability. It is pretty much like saying that WE ARE AT WAR TO ENSURE PEACE, lol. Downforce, to counter the negative effects of air resistance that slows lap times down.

And the fan will not increase slow speed downforce for any benefit, because (a) you dont need increased downforce at slow speed - it will kill the lap time, and (b) it wont be able to generate downforce at slow speed unless you power the fan with an alternative source that keeps it moving at high angular velocity.

My point is, that downforce is important at high speeds, not low speeds. And at high speeds, the speed and sheer pressure of air touching the fan could itself be a source to move it to at least bring a bit of cooling and extra air for the turbo(s). However, in order to generate increased downforce up front, an air-powered fan rotating at around 200 rpm may not be enough. There are ways around it, but you need a wind tunnel to understand my point.

[FITZY_07]

TOTALLY OFF TOPIC,

BUT,

on the bottom left diagram where it says take the dumb test...... I Did...


I am F*Cking DUMBBBBBBB!!!! LMFAO!

[Skym]

I was reading the post's again and thinking. The idea of a fan in front is standard on our cars (engine fan). But from what I understand it's connected to the motor and is driven by a belt. The fan uses a clutch type of device in the middle of fan that recieves hot air from radiator to engage clutch more and more thus spins fan faster (up to I think is idle rpm) when radiator gets hotter.

Also from what I can remember the engine fan works till around 3000rpm. At 3000+ rpm, there's enough air being rammed into front of car, so the fan is not needed.

It makes me think, was the fan on the back of F1 car (engine is in the rear) driven by a belt of the crank???

Here's a videoclip of the fan F1 car (closeup and in motion from about 2:22)-

http://www.youtube.com/watch?v=1d7iR72UVh4

Closeup of the fan, etc -

http://www.carspace.com/neil733/Albums/Goodwood%20Festival%20of%20Speed%2003/DSCF2275.JPG/page/photo.html

Another interesting fact I found, the orginal fan car was built for the 1970 CanAm series by Jim Hall (Chaparral 2J) -

http://www.motorsportcollector.com/CHAPARRALPHOTOS2/2Jp2.jpeg

Found it here -

http://www.f1db.com/forums/showthread.php?t=2663

Some info on the prototype Chaparral cars that were built by Jim Hall -

http://en.wikipedia.org/wiki/Chaparral_Cars

Chaparral 2J -

http://www.youtube.com/watch?v=rWzUsW18k3c

http://www.youtube.com/watch?v=0XFjBV1sWRM&feature=related

http://www.youtube.com/watch?v=hxBiIDvbYUc&feature=related

[SxyBeast]

The ONLY thing that will be stupid about you is the questions that you dont ask.....you are on track to learning, my friend. No worries.

I was thinking about your idea and was contemplating how the front downforce, if increased, would impact the driving of the car. A basic idea is as follows:

Downforce is inversely proportional to top speed. The higher the downforce, the lower the top speed and acceleration.

Front downforce is not enough for better car control. You need rear downforce too, which is in fact many times more important than front downforce for straight line stability. Generally speaking, front and rear downforce-inducing components work on the air that works with both - for example, the front lip or bumper divert the air around them to a certain direction. That air then comes in contact with the rear spoiler, which gets pushed down due to airflow above it, and that creates rear downforce.

So if you were making your system, and ignored the rear downforce in such a way that the air that your system used to create front downforce does not flow backwards to create rear downforce, you will be seeing a highly unstable car no matter what you try. And I will tell you why. Front and rear downforces have to be determined in such a way that there is an overall stability in the car. Too much front downforce increase turning stability, but also can cause oversteer. Too much rear downforce increases staright line stability, but can cause understeer. And if your front downforce increase causes a reduction in rear downforce, you will see the car fishtailing and the rear end will go all over the place. Have you ever seen an F1 car go AS SOON AS it loses its rear wing? It goes into the wall spinning. That is because the increased front downforce cause the car to spin and the rear wing is not there to oppose it.

And it is also important to note that if you increase the front downforce a lot, you pretty much have to make sure that the airflow out of your system does not become a speed bump for the car (due to turbulence), AND that it flows backwards to stabilize the rear end as well.

Now let's come to the issue of powering the thing. How about NO POWER AT ALL? Ever heard of windmills? The old dutch country is filled with those - they were power BY AIR that rotated their blades. What if you could come up with a very lightweight but strong material to make the louvers or wings of the fan that moved faster and faster with the increase in speed? And I say this also to counter one comment you made - you do not need ANY downforce at idle, man. You need downforce at increased speeds, not at low speeds. The whole concept of downforce is that you need it AFTER the force of gravity and tire friction have given their all to keep a car glued to the driving line it is taking. If a car had unlimited friction on tires, it wouldnt move, and so it is true for gravity. But both have their limits. And so cars need to play with the BIGGEST hurdle for speed - AIR resistance. I could reach 300 mph with an 80 hp car if there were NO air resistance and unlimited distance to reach that speed. Downforce is the art of using the resistance to increase stability. It is pretty much like saying that WE ARE AT WAR TO ENSURE PEACE, lol. Downforce, to counter the negative effects of air resistance that slows lap times down.

And the fan will not increase slow speed downforce for any benefit, because (a) you dont need increased downforce at slow speed - it will kill the lap time, and (b) it wont be able to generate downforce at slow speed unless you power the fan with an alternative source that keeps it moving at high angular velocity.

My point is, that downforce is important at high speeds, not low speeds. And at high speeds, the speed and sheer pressure of air touching the fan could itself be a source to move it to at least bring a bit of cooling and extra air for the turbo(s). However, in order to generate increased downforce up front, an air-powered fan rotating at around 200 rpm may not be enough. There are ways around it, but you need a wind tunnel to understand my point.

Holy crap, exellent point! I never thought about the aerodynamic balance between front and back. Now things are very complicated. What that makes me think about is having an aerodynamic system like ATESSA. Have a fan in rear and front and transfer RPM's between the two as needed like ATESSA does. Now that would be the ultimate handleing car.

Damn that F1 video is crazy. When that thing moves at slow speeds it sucks up rocks and dust! imagine how mad you would make people on the street when you give them cracked windscreens.

Give me some time to think about things now LOL. Thanks again everyone for the input. Maybe its time to show you guys my next idea since everyone helped alot.

PS Judasentinel what do you do for a living? Just curious because it seems like your a mechanical, aerodynamic, and everything else engineer LOL.

[judasentinel]

PS Judasentinel what do you do for a living? Just curious because it seems like your a mechanical, aerodynamic, and everything else engineer LOL.

Did you forget me again, lol? I'm a banker by profession, but look like a rock star from some heavy metal band in the eighties. So, MBA by education, scientist by genealogy, metalhead by music taste and an F1 freak by passion (just like Justin aka CanadianGTR). All of this though comes AFTER my love for a Skyline.

We met at Commerce Gate - Im the guy who doesn't like meets....

[FITZY_07]

Munib is a Janitor.




























Just kidding

[judasentinel]

Munib is a Janitor.

Just kidding

No, you're not............I am Number ONE in the Number TWO business.

[SxyBeast]

Did you forget me again, lol? I'm a banker by profession, but look like a rock star from some heavy metal band in the eighties. So, MBA by education, scientist by genealogy, metalhead by music taste and an F1 freak by passion (just like Justin aka CanadianGTR). All of this though comes AFTER my love for a Skyline.

We met at Commerce Gate - Im the guy who doesn't like meets....

No way man I didn't forget you, how could I forget that sexy pinkish purple gts. I was just curious to what your profession(s) were since you are so knowledgeful. You were also the defining line in my fuel thread. Now I no longer feel gilty about using Shell 91

So I think this idea is pretty much dead for now. But please everyone check out my next thread with my next idea that I will share with you all.

Thanks again to all that commented.