Chin spoiler and tire spats

[kach22i]

Originally Posted by rainagain

Lawn edging, what a great idea!

It is, I've used the larger stuff on my truck. Link in signature below.

[Cd]

Sometimes tire spats that seem as though they would help the Cd count, really don't do much of anything.

When these spats were tested on this '80 Camaro, they didn't do anything for the Cd despite shielding those wheels sticking out into the wind.



Car Aerodynamics - A2 Wind Tunnel - Wind Camp Tech Theory
Here, Eaker is examining the stock Z28-type side spats, which did not alter the Cd but added 40 pounds of rear downforce. He thought they may be more helpful in yaw but says testing 0 degrees to the airflow gives you 75 percent of the data you'd need at slight yaw. We also tested the Moon discs, which reduced drag by two to four counts. The farther the wheels are from the outer edge of the fender, the less the discs matter. View Related Article


Read more: Chevy Camaro Aerodynamics Side Spats Photo 8

Aerodynamics can be puzzling sometimes. Truly unpredictable !

[California98Civic]

Originally Posted by Cd

Sometimes tire spats that seem as though they would help the Cd count, really don't do much of anything.

Very useful article. Thanks. Odd that they don't note a kamm back as a certain aero benefit in their list. The article PaleMelanesian posted has some interesting info on the placing and shaping of the spats, which apparently can make a lot of difference: Autospeed Modifying Under-Car Airflow. Maybe these spats on the camaro might have been shaped differently and had better effects?

Originally Posted by Peter7307

California98Civic,
Nice job on the mods.
I would easily take them as being factory if you had not pointed out the changes you had made.

Peter.

Thanks Peter. I'm going to need to rebuild them when I lower the car soon.

[Cd]

Originally Posted by California98Civic

Very useful article. Thanks. Odd that they don't note a kamm back as a certain aero benefit in their list. The article PaleMelanesian posted has some interesting info on the placing and shaping of the spats, which apparently can make a lot of difference: Autospeed Modifying Under-Car Airflow. Maybe these spats on the camaro might have been shaped differently and had better effects?

Spats certainly do make a difference. I was just showing the unpredictability of aero mods. Personally, I would have bet money ( and lost money ) by looking at the spats on that Camaro.
The area of the wheel sticking out in the wind is enormous ! I would have thought the spats would have dropped the Cd quite a bit.

While we are on the subject of that car, just look at the huge gaping wheel wells around that back tire ! No wheel skirts, yet a .201 !
And stock door handles and misaligned window trim as well !
That car LOOKS like an aero nightmare.

[Frank Lee]

Like that boxy yet sleek old Lexus sedan, whatever that was.

[aerohead]

Originally Posted by Cd

Sometimes tire spats that seem as though they would help the Cd count, really don't do much of anything.

When these spats were tested on this '80 Camaro, they didn't do anything for the Cd despite shielding those wheels sticking out into the wind.



Car Aerodynamics - A2 Wind Tunnel - Wind Camp Tech Theory
Here, Eaker is examining the stock Z28-type side spats, which did not alter the Cd but added 40 pounds of rear downforce. He thought they may be more helpful in yaw but says testing 0 degrees to the airflow gives you 75 percent of the data you'd need at slight yaw. We also tested the Moon discs, which reduced drag by two to four counts. The farther the wheels are from the outer edge of the fender, the less the discs matter. View Related Article


Read more: Chevy Camaro Aerodynamics Side Spats Photo 8

Aerodynamics can be puzzling sometimes. Truly unpredictable !

Without a wrap-around front airdam as wide as the width of the spat,the approaching air would be colliding with the tire face,spoiling an opportunity for the spat to function.
The Trans Am Firebird used 'leading' streamlining to clean up the flow for this region of the body.

[tru]

Originally Posted by aerohead

Without a wrap-around front airdam as wide as the width of the spat,the approaching air would be colliding with the tire face,spoiling an opportunity for the spat to function.
The Trans Am Firebird used 'leading' streamlining to clean up the flow for this region of the body.

I think ur confused, as was i on first inspection. the spat is on the front side upstream on the rear tires.

[66sprint6]

I took a crack at some innitial planning and designing last night at a buddies shop. We did a ton of thinking, messed with a few different materials he had layin around and eventually got to work on puttin together a simple "prototype to test out made of aluminum. I didnt want to go too low with the stuff and scrape it all the time so I went 3" below the stock bumper which is enough to cover all the "nastiness" as we call it thats previously left hangin in the wind LOL. We didnt have enough time to finish but the design looks alot like a stock chevy chin spoiler that is only in the front and doesnt wrap around. Im not sure I like it very much but might test it out when we finish and see what happens. Im thinkin I might grab some of that lawn edging and do one more like I wanted, where it wraps all the way around the bumper like the lower chin on the boxy Jettas and Golfs. We messed around with tire spat ideas as well, real simple like the old Prius used to have but will finish the spoiler first. No pics yet, but when I get the bracket together Ill post some up and get yall to critique it!
Matt

[aerohead]

Originally Posted by tru

I think ur confused, as was i on first inspection. the spat is on the front side upstream on the rear tires.

I guess my reaction would be similar.Aft-body mods cannot function if the air to them is turbulent.
In the absence of an airdam and rocker panel extensions flush with the outside edge of the tires,the flow to the rear spat could be real 'trash',negating its effect.

[Cd]

Originally Posted by aerohead

Without a wrap-around front airdam as wide as the width of the spat,the approaching air would be colliding with the tire face,spoiling an opportunity for the spat to function.
The Trans Am Firebird used 'leading' streamlining to clean up the flow for this region of the body.

I'm puzzled because the smooth wheels helped the drag yet the spat did nothing for the drag.

It sounds as if you mean that the front airdam keeps air from colliding with the tire, spoiling an opportunity for the spat to function, yet the wheel covers ( Moon discs ) functioned as they did, so plenty of air was getting to that area.