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carguy123
carguy123 SuperDork
10/31/11 9:11 a.m.

On the front of a car what is the real world net effect difference between how a splitter works and a small wing?

iceracer
iceracer SuperDork
10/31/11 9:59 a.m.

Both create drag and some down force. Other than that I have nothing.

Keith
Keith GRM+ Memberand SuperDork
10/31/11 10:05 a.m.

The splitter keeps air from going under the car, which I'm guessing is going to have an effect both front and rear although mostly at the front. It would probably drop drag, although it will increase the frontal area. It'll also help force air into the radiator which is nice.

A front wing is going to provide downforce on the front only, and will increase drag. I'd work on under-car air first. Dropping the pressure under the car by 0.25 psi has a pretty big effect when you consider how many square inches are involved.

ReverendDexter
ReverendDexter SuperDork
10/31/11 10:19 a.m.

A splitter is what separates the air going over the car from the air going under the car, and an air dam is what keeps air from going under the car.

Splitters are parallel to the ground, air dams are perpendicular to it. Both control how air flows around the car.

carguy123
carguy123 SuperDork
10/31/11 10:22 a.m.

This isn't about any one car or anything I'm doing, I'm just trying to get straight in my head the actual real world differences.

While I realize they both actually DO different things, it seems that the net effect of both is very similar.

I hadn't thought about a splitter forcing air into the radiator.

Hal
Hal Dork
10/31/11 10:28 a.m.
ReverendDexter wrote: A splitter is what separates the air going over the car from the air going under the car, and an air dam is what keeps air from going under the car. Splitters are parallel to the ground, air dams are perpendicular to it. Both control how air flows around the car.

And an air dam is usually required to get the splitter low enough to be effective. Splitters don't work very well if they are 6" off the ground.

Per Schroeder
Per Schroeder Technical Editor/Advertising Director
10/31/11 10:34 a.m.

And to make a front wing that has downforce is kinda tricky, as it needs to be far enough away from bodywork to not interact with the airflow going over/under

Appleseed
Appleseed SuperDork
10/31/11 11:33 a.m.

Careful, or you may get this:

Keith
Keith GRM+ Memberand SuperDork
10/31/11 11:55 a.m.

My bad, I didn't distinguish between a splitter and an air dam very well. I've always viewed a splitter as a way to make an air dam more effective. You can't really have a splitter without an air dam of some sort, and you really should have a splitter on your air dam if possible.

JohnyHachi6
JohnyHachi6 Reader
10/31/11 12:08 p.m.

Here's some basic guidelines for modern aero design that might help answer your question:

  • A car typically needs comparable amounts of downforce at the front and back of the vehicle to handle well.

  • It is usually easier to generate large downforce at the front of the car than at the rear (since you have undisturbed airflow and lots of available area up front). So, to balance the downforce, you typically limit the amount of front downforce based on how much rear wing you can fit on the car.

  • Front downforce can be generated with a wing or splitter/airdam. The wing generates some drag (though small in magnitude) and can lead to issues with cooling since air is diverted upwards over the hood instead of through the radiator (depending on design). The splitter/airdam actually reduces drag on the car, if properly designed, and can produce large amounts of downforce.

  • To take advantage of the splitter/airdam you need to have a smooth underbody extending from the splitter under as much of the car as possible. You can increase downforce with effective sideskirts which contain the under-body air flow.

In summary, a splitter/airdam is preferable to a front wing in most applications. If you have a way to generate huge amounts of rear downforce, or your car is severely lacking in front traction at high speed, then you can supplement the front downforce with the addition of a wing, but do the splitter/airdam first.

JohnyHachi6
JohnyHachi6 Reader
10/31/11 12:10 p.m.

The reason that scion (Appleseed's post) has such a huge front wing is probably related to the fact that it's a high-powered FWD car, which needs unusual biased amounts of front traction, and has a relatively large rear wing. You can see that the wing was only added in addition to the splitter/airdam.

Joshua
Joshua HalfDork
10/31/11 12:30 p.m.
Appleseed wrote: Careful, or you may get this:

With the amount of money and R&D that went into that thing, why wouldn't you just buy a better car? And by better I mean anything but Scion.

92CelicaHalfTrac
92CelicaHalfTrac SuperDork
10/31/11 12:41 p.m.
Joshua wrote:
Appleseed wrote: Careful, or you may get this:
With the amount of money and R&D that went into that thing, why wouldn't you just buy a better car? And by better I mean anything but Scion.

Because sometimes you build for a class rather than buying a better car. (I could have had a nice RX8 for the money that went/is going into my Escort.)

Anyone who races with SCCA knows this.

jerel77494
jerel77494 New Reader
4/15/24 2:27 p.m.

In reply to Appleseed :

Or this:

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