At 80mph the wing is tested to put down 80lbs just thought you guys might like to know a fun fact

 

Which wing are you talking about?
There are three.
The SRT wing, the Roadster wing and the Coupe wing. All are different sizes so I would think they had different down force values.

roadster with a stick

 

It would be the coupe limited, base

 

That would be the smallest of the wings. I would then think that my roadster would have proportionaly higher downforce and my SRT would be even greater.

Nice fun fact. Thank for posting.

roadster with a stick

 

Powered by an electric motor, the rear spoiler deploys automatically when car speed rises above 60 mph. Deployment takes less than five seconds and the spoiler generates 356 Newtons of downforce to the rear of Chrysler Crossfire at 80 mph

 

That's a lot of Newtons! How many Newtons when I'm going 150 in the SRT6?

 

I ate a pack of 24 Fig Newtons in my SRT6 over about a 5 minute period while going 80 mph. Not 150 mph, but maybe you can extrapolate?

 

I could have used a little downforce on the front wheels during my drive home from work last night. It is amazing just how badly a Crossfire Coupe with 23,000 miles on the OEM Conti's will hydroplane at 60MPH in a downpour. No problem with the back wheels, though. Time for new tires, I guess.

 

My rears were at the wear-bars at 23K. Time for new ones.

 

Wow, 356 Newtons sounds excessive. 1 Newton is the weight of an average sized apple. Imagine 356 apples on your rear spoiler.

80lbs also sounds like alot too, thats 80 bags of sugar on the rear spolier (here in the UK sugar is sold in 1lb bags).

If anybody want to calculate the downforce, the following formula may prove useful.

Where:

• D is downforce in newtons
• WS is wingspan in metres
• H is height in metres
• AoA is angle of attack
• F is drag coefficient
• ρ is air density in kg/m³
• V is velocity in m/s

 

Read post #17 and #18 from this old thread.
https://www.crossfireforum.org/forum...e-vs-wing.html
They came to the conclusion that 356 Newtons = 40lbs.

 

Every single converter that I used come up with something like this:
1 Newton = 0.224808943 Lbs Force
therefore
356 Newtons = 80.0319826 Lbs Force

Are we questioning the 356 Newtons figure from DC or the conversion to come up with 40 lbs?

 

I thought it only took one Newton and an apple?

 

That there made me laugh.

 

D=?
WS= 2.42 ft= 0.825 m
H= .42 ft (from base of spoiler to center of spoiler) =0.143 m
AoA= 16º
ρ=~1.204 kg/m^3
V=80 mi/hr = 129 km/hr = 35.8 m/s
D= 1/2 [(0.825 m)(0.143m )(16º)] (.09) (1.204 kg/m^3) (35.8 m/s)^2

I got 135 N = ~30 lbs

 

Pounds force and pounds weight are two different units.
Force = m.a (mass x acceleration) and weight is w = m.g where g is gravity.
Newtons are units of force, the equivalent (not equal to) of pounds force.
The down force on the car is about 80 ft.lbs not 80 pounds.

 

A got a similar figure but never posted as I didn't have the actual dimensions of the spoiler at hand so used alot of assumptions.

 

I have an observation regarding the rear spoiler / down force issue. Before I say this, let me qualify it by saying I am not a mathematician, but I do enjoy fig newtons.

Yesterday I found myself at the car wash without having brought my detail kit with me. I live very near the George Bush (boo!) Tollway in Dallas, so my plan was to clean the car, leave it wet, and "air dry" it by driving 90 mph for an extended period of time. We've all done it, so please don't send me a link for microfiber towels!

Anyway, it worked like a champ EXCEPT for the rear glass on the hatch. The water droplets left from the car wash literally did not move an inch and virtually dried in place.

I've looked for some type of wind tunnel test videos on our car to no avail. But because of what I saw, and the fact that the rear wing is directly below and on top of the rear glass, I don't believe that the entire surface of the wing sees an appreciable amount of down force-generating air. I do think that the outside edge might... or maybe the outer half (if you drew a line across it in the center), but not all of it. I would guess the only way to really test this would be to tape multiple one inch long pieces of ribbon all over the rear wing and watch how they move while driving. This will also probably make the car look like a runaway gay pride float, so I probably won't be attempting it.

I could be wrong.

 

The water beads are in the boundary layer, this is a quite thin layer that exists over surfaces that have moving air or water over them in a lamina flow. Increased flow results in the layer getting thinner and turbulence occurring. You just wasn't going fast enough.

The water beads are really evident on the hood, you can see beads just idly wandering rearward at a speed that is a small fraction of the forward velocity of the car.
I had a wasp clinging onto the wind shield yesterday and he had no trouble to stay there at 55 mph. He may have pooped himself though.

This is also an area with less air pressure and air under the car will push the car away from the road.
That's why the wing is there, to disrupt the flow and minimize the low air pressure.

 

Note to self... less fig newtons, more computational fluid dynamics. Check.