Ground Effects: How to Spot Them, How They Affect Aerodynamics

November 6, 2013

Ground effects are typically found in racing cars, and they look great, but can they be added to to non-racing cars?

Skid Marks On The Ground

Putting ground effects on your car can help its performance, but it can also give it a cool look. If you're into aftermarket body kits, there are some ground effects out there that take the car to a whole new level. The problem is that a lot of times, that level is down a few notches from the stock vehicle. If you want high quality ground effects, you have to know what to look for. Here are some tips to help you get started.

Know Who You're Working with
Whether you're buying online or in person, you need to be able to trust the company selling the ground effects. If the company is trustworthy, the products usually are. For online experiences, you can always look at review sites to see what others have said about a certain site or manufacturer. Make sure that all of the transactions are run on a secure server. If they are, you are less likely to lose your personal information through the purchase. For local businesses, simple word of mouth will help you determine if the place is good or bad.

Look at the Materials
Materials impact the ground effects a lot. Carbon fiber is used a lot, but it will cost more to buy. With that in mind, it is lighter than other alternatives and can increase your performance. Polyurethane and fiberglass are other alternatives, but if you see materials beyond those, you may want to seek the advice of a performance mechanic or body shop to ensure the piece will work well with your car. Also make sure that whatever you get can be easily painted over so it matches the rest of your car.

Think about the Style
Make sure that your body kit actually looks like it suits the car. Fit and finish mean everything, so analyze both the performance and the aesthetics you will get from the ground effects. If they seem so off the top that they would hurt the car, chances are that's true. Then again, the worst looking kits can sometimes be the most helpful, so you must be diligent in your selections.

Ask for Help
Seek out the opinions of someone more knowledgeable than yourself. A lot of body shop owners that install ground effects on a daily basis know what companies to work with and what styles actually produce results. You can post questions on online forums as well. You can get real advice from real people who may have the same concerns you do.

How Ground Effects Affect Car Aerodynamics

In many cases, particularly with racing cars, ground effects are seen as a good thing. These light and aerodynamically designed vehicles move so quickly that they have the tendency to want to rise up off of the ground. Naturally, is not advisable to have the vehicle body lifting off of the ground, particularly in racing cars that are moving exceptionally fast. Therefore, an increase in the ground effects helps to tie the vehicle down to the ground.

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In larger, non-racing cars, ground effects are seen as something to be avoided. While they can help lighter vehicles to avoid lifting off of the ground, they often encumber larger, heavier cars by making it more difficult for them to turn and to steer. Thus, the ideal ground effects compromise is somewhere in between, depending upon the exact type of car and its weight and structural design.

How Designers Make Use of Downforce
In racing cars, the idea is to have a higher level of ground effect in order to keep the vehicle tied to the ground and to increase the downforce on the car, which pushes it towards the earth. This increases the handling of the car and makes it less likely that it will lose control as it goes around fast turns. In order to achieve this, designers aim to make a vehicle that naturally has higher air pressure over the top portion of the car and lower air pressure underneath. The difference in pressure helps to trap the vehicle down to the ground. Ground effect body kits make use of a law in physics called Bernoulli's principle, and encourage air to move slowly through the underside of the car and quickly over the top, thereby lowering the pressure in the underside space.