Ferrari's underbody work

[kylebes1]

The Ferrari Enzo is, in my opinion, an awesomely enginered and awesome looking car. Most "super-cars" have to have large amounts of downforce, as they should, to keep stable at high speeds. Well the Enzo as well as it's stablemate the Modena has taken the necessity of a huge rear wing and thrown it to the wind. These two cars, along with many other makes, use smooth underbody panels to control the flow of air underneath the car. Instead of having a rear wing the intire car acts as a wing.

The air under the car travels at a relatively higher speed than that of the air flowing over the car. This makes the pressure under the car realtively less than that of the top side. this causes the car to "suck" to the road.

Now I have seen front spliters and such but I have yet to see a fully implemented underbody panel system.

Now the idea is simple, the underside of the car should be flat. but to reduce lift the panels must continue on a rising sloop form the front to the back of the car. At point B the hieght off the ground must be higher than point A which is closer to the front of the car.

Well does anyone want to attempt this? I certainly do, but I need to know where to buy carbon fiber in panels about 1/4 inch thick.

[e30Matt]

:roll: You're going to do what?

[kylebes1]

IF I can find a place to purcahse carbon fiber panels I would like to design an smooth underbody for my car. I could mock it up with cardboard, then aluminum. and finally CF to make sure that it will work. Aluminum would weigh too much.

[nando]

that would help if the E30 overall wasn't shaped like a barn door.. you're going to lose that undercar turbulence, which is fine, but you'll still have a front end that's shaped like a truck. :)

[kylebes1]

that is true about the front being like a truck. I was also thinking that if you were to creat vents at the rear most part of the hood to allow air to flow freely through the grills and up to the windshield, than that would help the front some would it not?
I am the type where I want my cat to look completely original, or at least factory. Well I was thinking about removing the seal that is at the top of the engine bay that seals the hood and creating the vent I was talking about there. I do not like the idea of hood vents, so this would allow the air to move and no one would ever see that modification.

[Avus_325is]

I'm no engineer, but isn't the underside of the car only smooth on extremely aerodynamic cars because of the lift due to airfoil effect (airplane wing). This is no problem on an e30, so spend your money elsewhere.

[kylebes1]

Well they smooth the underbody to acheive the great aero. I just figured that the underside of the car is alomost half the surface area and every inch would make a difference.
See a rear wing or a spoiler cause drag to create downforce. the smooth underbody creates downforce, or at least cancels lift, for free, with no drag added, in fact this would reduce drag.

[Charlie]

You'd get more of a benefit out of a huge aluminum wing on the back than on an underbody venturi system. The fact that the car is a brick would pretty much negate any possible benefit from reducing the undercar turbulence. It's not exactly the undercar turbulence that gives the car aerodynamic issues.

-Charlie

[elemental]

I would imagine that high speeds 130+ would need to be traveled before such underbody aero would do much

[808BMW]

I would imagine that high speeds 130+ would need to be traveled before such underbody aero would do much

Isn't the whole point of this to achieve stability at those upper speeds?

Also, shot in the dark: How much HP does it take to get a stockish (body wise) e30 to 200 mph?

[nando]

1000+

even cars with lots of horsepower top out around 170, and those are usually 500+hp cars. I think stu said he hit 155, which is moving in our cars!

I don't think it would be a good idea even if you could.

[MattM20]

you could probably gain a nice amount of downforce with a flat underbody, but like others said, the potential of such an idea would go to waste because of the e30's shape. besides, the modena and enzo's aerodynamic efficiency doesnt just come from their underbody design, which isnt completely flat from front to rear. it took hours of wind-tunnel testing to perfect the aerodynamic balance

[NC325iC]

Re: Ferrari's underbody work

The air under the car travels at a relatively higher speed than that of the air flowing over the car. This makes the pressure under the car realtively less than that of the top side. this causes the car to "suck" to the road.

unless im mistaken youve got that backwards
an airplanes wings are curved on top to slow the wind going over them so they can produce an upward suction force.
so if you really wanted to you should put dimpled panels like the new lexus (or whatever it is) to slow the air down and creat a low pressure area under your car.

and im pretty sure in most of the super cars at least the S7 air is channled (i cant spell anything) from under the car upward creating down force

correct me if im wrong

[Nitrox]

Re: Ferrari's underbody work

The air under the car travels at a relatively higher speed than that of the air flowing over the car. This makes the pressure under the car realtively less than that of the top side. this causes the car to "suck" to the road.

unless im mistaken youve got that backwards
an airplanes wings are curved on top to slow the wind going over them so they can produce an upward suction force.
so if you really wanted to you should put dimpled panels like the new lexus (or whatever it is) to slow the air down and creat a low pressure area under your car.

Correct, an aerofoil generally has a larger surface area on the top side to generate additional lift over a flat wing. Since the average car has a similar side profile (flat bottom/curved top) they tend to get 'light' at high speeds. Thus we get into wings (top side) and venturis (underneath) to create downforce.

This is all neat stuff but really next to useless on a street car. Firstly if you are driving at these speeds on public highways you really should be in jail (and lucky to be alive). Secondly, if you are on the track at those speeds you would be really wasting your time modifying an e30 platform.

A lowered stance, a low front airdam, and possibly some lower side skirts would really help keeping air out from under the car and thus generate some downforce. Unfortunately be prepared to lose the bodywork on speedbumps and driveways...

However, unless you have access to a wind tunnel you really dont know what results you're actually going to get.

[kylebes1]

Well you guys have shot me out of the water.
And yes I was thinking of high speed stablity.
i'll be back