Stupid Question

[Spuds]

Originally Posted by Tcoat

It is basic physics. I thought engineers understood such but guess I was wrong.

in case you aren't just trolling I'll try to explain briefly.

In rolling motion, you have two types of velocity, translational and angular. Angular is always perpendicular to the radius, while translational is a constant in the direction of travel. To get the velocity of any point on the wheel, you add both of these velocities together.

First, break down the angular velocity into it's horizontal and vertical components. This is typically done through basic trigonometry, but to spare you the math we will look at 4 easy points to visualize. At the bottom of the wheel is as negative (backwards) as it is going to get. At this point all of the angular velocity is horizontal. At the top of the wheel it is as positive (forwards) as it is going to get, again the velocity is 100% horizontal. At the front and the back (relative to the car) of the wheel, the horizontal velocity is 0, meaning those points are traveling vertically. Don't believe me? Have someone swing a weight on a string and watch it from the side.

Knowing that, the best chance for a rock to be flung straight back is if it were flung from the bottom of the wheel right? However, we know that the bottom of the wheel, in contact with the ground, has to be moving at the same speed as the ground, otherwise it would be slipping. Which means that the bottom of the wheel must be moving at a horizontal velocity of 0kph.

As discussed before, the bottom of the wheel is the most negative angular velocity you can have. So if the point of the wheel with the most negative angular velocity is traveling at an total (angular+translational) velocity of 0, then all other points on that wheel must have a positive total velocity.

Therefore something which at one point matches the actual velocity of the wheel and is then thrown off can only be going forward or remain stationary.

[Spuds]

Originally Posted by Tcoat

Are you really this obtuse all of a sudden or just siding with the alleged "engineer" because he is saying what you want to hear?

When the wheel rotates mud, sand, and stones can stick to it. As you pick up speed the centrifugal force will eventually overcome the adhesion and they will fling off. They can do that at any point in the rotation. A surprising amount will fly forward and down with some serious velocity. The corner of the rocker below the front of the wheel well liner is ungiving metal. If nothing protects it then it will eventually (some times rapidly depending on where you live) get blast like a sand blaster. This leads to rust and structural damage. The rubber or plastic can absorb the impacts without degrading as quickly as solid steel protecting your rocker corner. You are not fucking protecting the wheel from splashes you are protecting the rocker from the wheel. In most of the real world this is a very important feature but I get that Californians and Hawaiians are confused by such things.


You saw the fucking picture I posted of mine do you think I packed crap in there on purpose? Do you think almost every manufacturer that calls it a shield or guard had a translation issue? For that matter do you truly think that the top automotive manufacturer in the world farms out their tech writing to some almost illiterate translator? Are you really that gullible?

Yes the little rubber flap will have a slight aero effect but that is not the only or even main purpose.

I swear people on here are getting fucking stupider every day.

You don't need a flap hanging down from the body of the car to do that. The wheel well is plastic. If you look at the design of the part on the car, it is one piece that wraps completely around the section you were referring to, and then adds a random flap hanging out there. The flap section is for aerodynamics. I'll be willing to believe it's a dual purpose part on certain specific cars, and they picked one of the purpose for the name. However, the flap itself is an aerodynamic feature.

[JD001]

Originally Posted by Tcoat

Are you really this obtuse all of a sudden or just siding with the alleged "engineer" because he is saying what you want to hear?

When the wheel rotates mud, sand, and stones can stick to it. As you pick up speed the centrifugal force will eventually overcome the adhesion and they will fling off. They can do that at any point in the rotation. A surprising amount will fly forward and down with some serious velocity. The corner of the rocker below the front of the wheel well liner is ungiving metal. If nothing protects it then it will eventually (some times rapidly depending on where you live) get blast like a sand blaster. This leads to rust and structural damage. The rubber or plastic can absorb the impacts without degrading as quickly as solid steel protecting your rocker corner. You are not fucking protecting the wheel from splashes you are protecting the rocker from the wheel. In most of the real world this is a very important feature but I get that Californians and Hawaiians are confused by such things.


You saw the fucking picture I posted of mine do you think I packed crap in there on purpose? Do you think almost every manufacturer that calls it a shield or guard had a translation issue? For that matter do you truly think that the top automotive manufacturer in the world farms out their tech writing to some almost illiterate translator? Are you really that gullible?

Yes the little rubber flap will have a slight aero effect but that is not the only or even main purpose.

I swear people on here are getting fucking stupider every day.

Erm.. May I ask? Did someone nick your splatter guard?

[JD001]

Originally Posted by Spuds

You don't need a flap hanging down from the body of the car to do that. The wheel well is plastic. If you look at the design of the part on the car, it is one piece that wraps completely around the section you were referring to, and then adds a random flap hanging out there. The flap section is for aerodynamics. I'll be willing to believe it's a dual purpose part on certain specific cars, and they picked one of the purpose for the name. However, the flap itself is an aerodynamic feature.

I am currently killing time in Chatteris, waiting for Fensport to sort out the suspension on my BRZeeeeee. It was crazy low, I think I may have worn out the splatter guards... BTW, I will be posting photos of my car alongside Fensport's Track prepped Yaris...

[Grady]

Here is a novel idea, you know some times a part can do more than one function.

[WNDSRFR]

Originally Posted by Tcoat

Are you really this obtuse all of a sudden or just siding with the alleged "engineer" because he is saying what you want to hear?

When the wheel rotates mud, sand, and stones can stick to it. As you pick up speed the centrifugal force will eventually overcome the adhesion and they will fling off. They can do that at any point in the rotation. A surprising amount will fly forward and down with some serious velocity. The corner of the rocker below the front of the wheel well liner is ungiving metal. If nothing protects it then it will eventually (some times rapidly depending on where you live) get blast like a sand blaster. This leads to rust and structural damage. The rubber or plastic can absorb the impacts without degrading as quickly as solid steel protecting your rocker corner. You are not fucking protecting the wheel from splashes you are protecting the rocker from the wheel. In most of the real world this is a very important feature but I get that Californians and Hawaiians are confused by such things.


You saw the fucking picture I posted of mine do you think I packed crap in there on purpose? Do you think almost every manufacturer that calls it a shield or guard had a translation issue? For that matter do you truly think that the top automotive manufacturer in the world farms out their tech writing to some almost illiterate translator? Are you really that gullible?

Yes the little rubber flap will have a slight aero effect but that is not the only or even main purpose.

I swear people on here are getting fucking stupider every day.

Jeez,

Take it easy, it's just a rubber flap.

[gen3v8]

So at 60mph does mud/roks fling down the skirts/sills off the tires OR is the mud travelling vertically and the sills are hitting the mud at 60mph. Similar impact but one is the mud/rocks moving the other is the car.

[JD001]

Originally Posted by JD001

I am currently killing time in Chatteris, waiting for Fensport to sort out the suspension on my BRZeeeeee. It was crazy low, I think I may have worn out the splatter guards... BTW, I will be posting photos of my car alongside Fensport's Track prepped Yaris...

As promised snap of my BRZeeeeee with the Yaris race car..

https://www.ft86club.com/forums/show...&postcount=859

[NoHaveMSG]

Originally Posted by JD001

As promised snap of my BRZeeeeee with the Yaris race car..

https://www.ft86club.com/forums/show...&postcount=859

Did you ask Fensport what they call that part?

[JD001]

Originally Posted by NoHaveMSG

Did you ask Fensport what they call that part?

Noooo... Stopped myself from popping the question as I felt a bit stupid asking... However, once the dust (or the rocks) have settled I will ask.. I am planning another trip to Fensport to get the poly bushes installed..

[FR-S2GT86]

My old lady just calls it "...that flappy thing down there...".

[Sapphireho]

Originally Posted by FR-S2GT86

My old lady just calls it "...that flappy thing down there...".

We're talking about cars.

[Clipdat]

Originally Posted by Tcoat

Are you really this obtuse all of a sudden or just siding with the alleged "engineer" because he is saying what you want to hear?

When the wheel rotates mud, sand, and stones can stick to it. As you pick up speed the centrifugal force will eventually overcome the adhesion and they will fling off. They can do that at any point in the rotation. A surprising amount will fly forward and down with some serious velocity. The corner of the rocker below the front of the wheel well liner is ungiving metal. If nothing protects it then it will eventually (some times rapidly depending on where you live) get blast like a sand blaster. This leads to rust and structural damage. The rubber or plastic can absorb the impacts without degrading as quickly as solid steel protecting your rocker corner. You are not fucking protecting the wheel from splashes you are protecting the rocker from the wheel. In most of the real world this is a very important feature but I get that Californians and Hawaiians are confused by such things.


You saw the fucking picture I posted of mine do you think I packed crap in there on purpose? Do you think almost every manufacturer that calls it a shield or guard had a translation issue? For that matter do you truly think that the top automotive manufacturer in the world farms out their tech writing to some almost illiterate translator? Are you really that gullible?

Yes the little rubber flap will have a slight aero effect but that is not the only or even main purpose.

I swear people on here are getting fucking stupider every day.

They sure are. Thank you for so eloquently demonstrating that.

[vindiesel]

It’s actually a tuna sandwich with crust