unless you live in a very windy city, drag is not really a factor at low speeds. rear downforce at high speeds is depend on upon which rear spoiler you get. of course the soft-top doesn't do much of a job of maintain non-turbulent airflow over the roof of the car.

 

Adding a rear spoiler for downforce purposes is pointless for a street car except for looks. You will never get fast enough for it to make a noticable difference, unless you track the car at high speeds. Certainly the OEM spoiler does not create any downforce whatsoever at any speed, nor any drag.

 

Do the spoiler such as the Mugen SS or the C-WEST add extra drag at low speeds? So basically adding a spoiler dosn't hurt or effect the cars speed and handling? Thanks

 

Depends on what you mean by low speeds. At "low" speeds, you could take Anna Nicole Smith and strap her to your trunk and get no drag. On the other hand, her weight will kill your fuel economy.

 

Effectiveness of spoiler (downforce and drag) is typically quoted at 100 mph, where it can be significant consideration on the larger aftermarket wings.

Less speed = much less effect. Remember aerodynamic drag is a squared function ( 2x speed gives 4x the drag).

The stock piece looks OK but too small to manage airflow, except to keep dirt off the bumper.

I read a while ago that the OEM type spoilers in general NEVER pay for themselves (in fuel savings) over the life of the car. Might be different if you do a LOT of high speed driving (75+mph).

Bottom line - buy one if you like the look.

 

Can a big aftermarket wing actually create too much downforce and slow you down? Thanks for all the replys

 

I think, for the most part, "spoilers" are the "pin stripes" for the new millenium. The reason dealers put them on is that they are fashionable and high profit. The reason people buy them is that they "look good" because we expect them. For most of us, they serve LESS function than the pin stripes. The major manufacturer designers windtest car without spoilers. I think most spoilers DECREASE gasoline efficiency by making the cars less slippery.

I'm talking about the add-on spoilers like the OEM S2000 spoiler, the factory spoiler on my Prelude, and OEM spoiler on the Accord.

Every '03 Accord Coupe sold in Sheridan, Wyoming (unless special ordered) will have a $450 spoiler added "because it finishes the look." If I buy a new RSX-S or Accord V6 Coupe, I'll have no spoiler.

For those who drive over 100 mph competitively spoilers probably make some sense. I assure you that for the very few times I take the car over 100 mph it will be on a long straight sunny road with no obstacles or traffic or competition. Having a spoiler for those very few or never times doesn't make any sense for me.

If you like the looks, get it. If you don't, don't. End of story.

I just spent $75 for my '93 Prelude to buy Honda wheel covers for my ugly black steel winter wheels. I know it is a total waste of money, but I like the look better than naked steel wheels. Cosmetics matter.

 

Shadow_S2K, what's your goal here? If the goal is going fast in a straight line, then don't get anything. Most any spoiler or wing you find will probably just increase drag, not to mention weight.

But if you're looking beyond the straight line...

It's difficult to come up with anything for sure in aerodynamics without actually building/installing a part and testing it. For instance, there's an SAE paper that studied the effects of a small decklid spoiler on a big American sedan. They found a 1" spoiler actually reduced the overall drag of the car, while slightly reducing the car's lift in the rear at speed. At 2", drag was the same as having no spoiler, but now there was a marked reduction in rear lift.

Of course, you can't generalize that the effects would be the same on all cars. However, I wouldn't be surprised if the S2000's OEM spoiler provided benefits similar to the 1" spoiler in the SAE's testing.

I ran a spoiler like this about 10" in height, and noticed it immediately when I first got on the freeway. On the street, the car felt more settled and planted at speeds above 60. On the track it was amazing, making the car much more stable under heavy braking, and lending extra assurance in high-speed corners. Of course this spoiler was a bit extreme and had looks "only its maker could love".