what about the RB spoiler???

 

BMW has the second most powerful super computer in europe to do just that. Even then its very much guess work. Aerodynamics is still as much art as it is science. Pringles used the services of another one of the worlds most powerful super computers to engineer the packaging conveyance system for their chips. They used it to calculate the speed at which pringles chips will take flight! It seems kind of silly, but I guess getting all those chips in cans quickly can save them alot of $$. So I think we are still quite a ways off from having desktop simulations of aero packages.

 

Ever notice, with the moon roof open all the way, the 8 feels better?

 

What about the X-men wing?

 

The Audi TT was getting rear lift at high speeds on the autobahn. When the car went around a corner it would go out of control. After all, the TT is shaped like a airplane wing. The rear lip was added to eliminate this rear lift and keep it planted on terra firma.

 

Keep on falling down the stairs.

 

i hear that the downforce cause by the 8's spoiler isn't wasted, its used for regenerative braking, like in a hybrid. That's how it has such stupid-awesome stopping power.


no but really, it's not functional. I hear the MS spoiler is adjustable to be, but not the stock one.

 

Actually there are various methods for desktop aerodynamic analysis. A very board and rough first cut is control volume analysis, but for a shape as complex as a modern automobile that's basically useless. Computational fluid dynamics analysis allows a much more detailed study of a body and works fairly well, especially if it's sitting still. However, spinning wheels and such are quite a nuissance and so in the end there's no substitute for good wind tunnel work, but the simulation packages out there can reduce the work needed to arrive at a solution by a lot.

 

Is this functional?

 

it has been said that the euro lip spoiler for the rx8 does actually lower the cd. i have not seen good pictures of it, but i hear it is very similar to the r-magic lip spoiler. would it be safe to assume that the r-magic would provide a similar benefit? or could even a small change in design actually increase cd?

 

the MS Spoiler was wind tunnel tested.

Does it work ? sure but I think only a bit.

but hey, anything helps ~

 

Actually a spoiler spoils lift by reducing laminar flow. On a plane it is a panel that comes up out of the wing to disturb airflow. On a car it can reduce drag by reducing the low pressure on the back of the car and also reduce the lift produced by the wing like shape a car naturally has. this can lower cd.

A rear wing is like a tail aka as a stabilizer or elevator on an airplane. It has a larger curve on the bottom than the top. It is an upside down wing and produces lift in the downward direction. It also produces "induced drag " which will increase the cd.


John

 

Spoiler?? I thought it was a handle to open the trunk with

 

Many people say that stock spoilers do not decrease drag (cd), a few say they might. Most write on their own authority, a few give technical reasons, sometimes pointing out that finding the answer to this question requires expensive engineering resources.

Mazda developed the RX-8 shape with airflow -- a complicated design problem involving lift, sidewinds, drag, etc., etc. -- and then designed a stock spoiler.

The Mazda RX8, a 191-page bound book published by Mazda and given to early US RX8 buyers, states at page 55:

"The RX-8 attains a respectable drag coefficient of 0.31, the same number as the RX-7. [Note it does not say which generation. Other discussions in the book usually use Gen 3 for comparison with the 8.] An optional rear spoiler lowers it further to 0.30.
"The car's lift coefficients are 0.08 at the front and 0.07 at the rear with the rear spoiler."

Mitch

 

awesome. its good to have numbers.

is it certain that they are talking about the US spec spoiler? the euro lip spoiler is also an OEM part. would anyone happen to know how effective the euro lip spoiler actually is?

 

Interesting point. An earlier Specifications section of the book breaks out European and US figures where different -- mostly in power and transmissions (they have a 5-speed manual as well as the 6), but a slight difference in length as well. That section does not list cd or lift. The language of the book that I quoted doesn't answer your question, but my hunch is that the number is the same or, if different, the US number would be given. No proof of that, thought.

Mitch

 

Interesting info!

 

i dont know anything about fluid dynamics but the US spoiler and the euro lip spoiler are very different in design. i hope someone can tell us about the cd with the euro lip spoiler

 

anybody?

 

that quote is about the "lip spoiler" that is stock on the Euro/UK cars and is why it comes standard there.

 

ohh...so then we are still unsure if the optional spoiler in the US is functional at all then..

 

My RX8 is functional.

 

Most likely US spoiler is for looks but the Euro lip actually improves airflow.

 

Aerodynamics are for people who can't build engines.

-- Enzo Ferrari

(source: http://en.wikipedia.org/wiki/Portal:Cars/Quotes/4)

Personally I liked the look of the spoiler on the car, that's why I opted for it. Weight wasn't a concern ... car is pretty light as it is .... and it was a daily driver (not a track car).

 

I am fully functional