Magazine article

[BluEyes]

Anyone interested in aero should go pick up a copy of the March 2007 "Hot Rod" magazine. (wait, March? Yeah, the mag industry has a wierd calendar)

Not the usual reading for guys here, but turn to page 112 and they have a nice article on wind tunnel testing a car for racing at Bonneville. They took a Camaro from a .497 Cd to .201 with some aero tricks! Definately worth a read, IMO.

[Matt Timion]

Anyone interested in aero should go pick up a copy of the March 2007 "Hot Rod" magazine. (wait, March? Yeah, the mag industry has a wierd calendar)

Not the usual reading for guys here, but turn to page 112 and they have a nice article on wind tunnel testing a car for racing at Bonneville. They took a Camaro from a .497 Cd to .201 with some aero tricks! Definately worth a read, IMO.

Whoa... that sounds awesome. I think i'll pick that up later.

[TomO]

It be great if someone could scan that article and post it up here.

[MetroMPG]

Is this it?

http://www.hotrod.com/techarticles/hdrp_0609_aero_tricks_tips/

[Matt Timion]

http://www.hbo.com/alig/img/bios/img_borat6_s2.jpg

NIIICE!

http://www.hotrod.com/techarticles/113_0510_aero_13_z+aerodynamic_tips_tricks+dragste r_rear_wing.jpg

[white90crxhf]

it sounds like i need to buy that jdm or edm spoiler for my crx now :)

[The Toecutter]

I can't find that camaro.

[rh77]

In the article, there's mention of relieving air pressure in the fender wells. Some models have "brake cooling" tendencies with flow into the well, but I wonder if letting air flow out the rear of the area would provide a better overall flow of the vehicle?

Salt/Sand and grime may be harsh on the body or frame, but I'm thinking about how a notch or hole in the often-plastic shield behind the tire would help with improving air-flow. Maybe something that runs the air out and perhaps down under the car. That is, unless you have the area covered :) Maybe the front wheel wells could benefit most...

RH77

EDIT: Excellent article, BTW (as I read it again)...

[BluEyes]

Is this it?

http://www.hotrod.com/techarticles/hdrp_0609_aero_tricks_tips/

No, they don't tend to put the newer articles online (have to make money somehow). The article I read they were actually testing cars in a wind tunnel.

Regarding flow in the fender wells, alot of fendered race cars have vents in the top of the fender to let out pressure. Not sure how it affects drag, but it can probably reduce front end lift. The front wheels seem to be terrible for aerodynamics no matter how you cut it. Pressure in the wheel well, turbulence, disrupted flow... I wonder what effect front fender skirts have on lift tendencies? They might trap in pressure, but might also reduce flow through the area and encourage it to go elsewhere?

[rh77]

On some newer cars, I've noticed a small lip extension (about 3-4" wide and 2" tall) just before both the front and rear wheels on the Kia Spectra, Prius, and TSX (I'm sure more have them).

I searched but couldn't find a pic -- I may have to get under the TSX to snap some shots myself.

They often have cut corners similar to a half-octagon shape. IIRC, this also helps with directing flow around the wheels (not sure about the exact rationale :confused: )

RH77

[kwtorbe]

If you notice on a '69 Dodge Charger Daytona's there are two scoops facing the back of the car on the front fenders. These scoops hide the holes on the tops of the fenders that were used to release the air that got trapped in the fenders at high speeds. Dodge told Nascar they were for tire clearance to prevent ford and chevy from using their idea. They came up with these from extensive wind tunnel testing. New cars don't have the open inner fenders though like the old cars so I can't see how it would benifit most newer cars to cut holes in the tops of the fenders.

I read that posted link in hot rod a long time ago. Pretty sweet.

[BluEyes]

Anyone else who read the article? It's still not up on their website, being as it is in the current issue.

I've been thinking alot about notch angle lately and what angle/height of lip spoiler would help my car out. As the article defines it, notch angle is the angle between horizontal and a line drawn between the tip of the trunk or spolier and the back end of the roof.

For those not familiar with a LeBaron, my car looks like this:
http://images.intellichoice.com/used/92180LeBaLX%5B%5B%5D%5D%5B%5B%5D%5D4552.gif

I'm sure the line of the rear glass is not helping me at all which is why I am interested in a spolier. The glass is nearly vertical and I notice that once I am above 45mph or so, any water droplets on the rear glass stay stationary. I'm pretty sure that this is indicating flow seperation, and if I could get a spolier back on the trunk to increase the pressure on the rear window without significantly lowering the pressure behind the trunk, I ought to see something.

[kwtorbe]

I'm sure the line of the rear glass is not helping me at all which is why I am interested in a spolier. The glass is nearly vertical and I notice that once I am above 45mph or so, any water droplets on the rear glass stay stationary. I'm pretty sure that this is indicating flow seperation, and if I could get a spolier back on the trunk to increase the pressure on the rear window without significantly lowering the pressure behind the trunk, I ought to see something.

Interesting.....I hope it works.

[red91sit]

Try a little one first, that is what I'm going to do on the lincoln. (simalar box on box profiles)

[brelandt]

Lucky me. I found a copy of the mag at my local Winn-Dixie. Was suppose to be displayed until Feb 13, but as luck would have it somebody failed to remove it!

The article was really good! Answers a few of my questions. Actually a lot of them....

The big one for me was the front air dam. The addition of a HUGE air dam which is what I will have to install outweighs the additional frontal area. That's great news.

The other biggie for me is the convertible top. What to do to smooth it out? I'm leaning on placing a 2" tall edge on the top of the windsheild. Will act the same as the air dam under the front bumper. If it works to keep air turbulence under the car it should do the same for the top? However, without thousands of dollars to rent the wind tunnel????

Lots of things they said that I didn't know was the use of speed tape. Tapeing the seams did nothing to the CD as well as making a flare in front of the rear tire. It only added 40 pounds of down force but no improvement in CD's.

Anyhow, great reading!!!!!!

[BluEyes]

I really doubt that air dam will work on top of the vehicle though. The air dam works for the underbody because the air cannot 'fill in' behind it very effectively due to the ground being there. The reduction in turbulence is just because there is less air there.
I think a better fix for a convertible top would be to have it adjusted (if possible) so that it's not loose and flapping in the breeze. Or find a hardtop to replace the fabric.

[brelandt]

I really doubt that air dam will work on top of the vehicle though. The air dam works for the underbody because the air cannot 'fill in' behind it very effectively due to the ground being there. The reduction in turbulence is just because there is less air there.
I think a better fix for a convertible top would be to have it adjusted (if possible) so that it's not loose and flapping in the breeze. Or find a hardtop to replace the fabric.


I actually thought about that "AFTER" I opened my dumb mouth! LOL!
Since a hard top would cost $1000 and my truck is only worth $500 there is no way I'm going that route.

Thinking more along the lines of using metal flat bars. Place 3 or so from front to back may do the trick.