boostdfd3s

The bottom of the Ferrari Enzo is a totally SMOOTH surface, not necessarily flat. A smooth surface will reduce turbulence because the air has a uniform surface to flow against. Now the enzo has shaped venturi tunnels that actually suck the air up and away from the rear of the car, causing a low pressure area under the car and creating downforce. At the front it also has the F1 style nose to direct airflow as well as motorized flaps to control the amount of downforce at the front of the car. So flat underbodies help *to some extent*, but its the venturi tunnels that REALLY make the biggest differences.



EDIT: This is why the diffusers you can buy for the rear of our cars are actually quite pointless. Those diffusers only smooth out the last 12" or so of the air flowing underneath the car. Now if someone would integrate that RE diffuser into a totally flat underbody with ribs to direct the airflow, im sure wind tunnel testing would show a lot of improvement in downforce and Cd.



-Zach

boostdfd3s

hes right on the money with this. F1 cars do have ducts to evacuate some of the air UPWARD, which also adds to the downforce, but also eliminates the problem of having too much air underneath the car. I was also watching this show on SPEED about the death of an F1 driver (i forget his name), but he entered a corner at normal speeds, but went STRAIGHT and into the wall. They found out that the car actually was TOO low to the ground, stopping the airflow underneath the car and it caused an aerodynamic stall and a loss of almost all his downforce, which made the F1 car act like a civic at 160mph going into a turn. So if someone is going to make an underbody tray/diffuser/venturi tunnels for the FD...dont drop it too low!!! *phew*.....back to the topic folks!

Srce

You're talking about the great Ayarton Senna, I have the vid of that crash, totaly ghostly.

boxrs4sale

ha ha.. we already know your shallow

Sinful7

As I was telling Martin, a flat underbody panel would help. The air under the stock chassis is turbulent as it spills over the various protrusions. If you smooth out that surface, then the turbulent air will be reduced, and thus encourage laminar flow and an increase in flow velocity.

A wing lifts because the air travelling above the wing is moving faster than the air below the wing. The result is a lower pressure on top, and the air below pushing the wing up.

So what happens if you decrease the flow ratio by simply increasing the flow rate below the wing? You get less lift.

I would concede that given certain vehicle shapes, it might be possible to increase lift because the underbody tray would create more of a wing effect. However! If you couple the underbody tray with a rear diffuser and a good sized wing on the rear, I would be inclined to think that your downforce would be largely increased over that of a stock-body car, and I think it is due in large part to the lowered cd and the increased airflow of a flat-bottom car. Also, (akin to F1 cars)any lift effects could be largely negated by the allowance of air to move from the bottom to the top of the car.. Maybe in the form of an aerodynamic inlet in the underbelly, and a corresponding vented hood.. But I most definetly digress..



Wind tunnel testing is very a expensive and time consuming venture. Most reputable aftermarket companies will simply track test their car. It's pretty easy for a trained driver to feel the subtle differences in handling that are changed by aerodynamic effects. I would most definetly trust someone who has successfully maintained a high rate of speed in real world conditions, rather than that of a wind tunnel tested model..



Oh, and on another note, sideskirts are funtional. They serve two main purposes. The first, is to create a more aerodynamic design by disallowing air coming from around the side of the nose to re-enter the underbody portion. Secondly, it is designed to reduce turbulent airflow leading from the nose and front tire over the back of the vehicle to cfeed the wing. when coupled with a wing that hangs over the side of the vehicle, the sideskirts can do more than you'd think!



Same goes for the popular rear diffusers. The accomplishment there is two fold; acceleration of the air to decrease pressure (And increase downforce), and to smooth the air as it joins the post-wing flow.

Turbulence at the rear of the car is a significant cause of drag and could potentially contribute to the ineffectiveness of a wing.

boostdfd3s

....he just used bigger words than me

Sinful7

Right! And on another interesting note, did you know that the shape of a bodykit can have different reactions with a vehicles performance? If the nose of your car is more aerodynamically efficient, your coefficient of drag is lower and will allow a higher topspeed and faster high-level acceleration. Conversely, a blunt, squared front end will cause better handling, manifested in a faster turn-in response. The effect is distinctly pronounced on F1 cars - on the canard, a lower angle of attack (read: more aerodynamic) will result in a slower turn-in (understeer). Increase the angle of attack (read: more blunt), the better the turn in response. Of course, there's always a balance, and if the angle of attack is too compromised, turbulent air will destroy the effects of the canard.. It is, however safe to assume for a street application, high speed turn in response will be increased (paralleled by drag) with a blunt front end.

BlueDragon871

i got sum pics of the front bumper ill post em in a sec

sidewinderx7

its been more than a sec.

boxrs4sale

its been like a day now