One of the helpful elements used is called a bumper canard or dive plane. As seen on the DTM Touring Car above, the bumper canards are just above the front splitter and below the Dunlop sticker. These canards serve to add more downforce at the front increasing overall car balance in cars that have excessive rear downforce. This allows the car to be setup to maximum downforce without having to compromise the cars handling .

Also in prevalent use is the vortex generator. These devices create a venturi effect that keeps the air flowing closely together. This compressed flow allows the air to be directed much more accurately and in higher volume. You can see these devices on both the Mitsubishi Lancer Evolution MR (pictured) and the Subaru Impreza WRX STi. In these cars, the vortex generator sends more air over the rear wing, thereby increasing its efficiency.

In the past, other unusual designs were used to increase overall downforce. The most famous of these odd designs was the Brabham BT46B Formula 1 car, otherwise known as “the fan car”. This car had been designed by Gordan Murray to use a fan attached to the engine to suck air from underneath the car. This lead to a vacuum effect being created underneath the car which allowed it to stick to the road like glue. Niki Lauda and John Watson went on to pilot the fan car for only one race: the 1978 Swedish Grand Prix at Anderstorp. Watson DNF’d and Lauda went on to win comfortably. The fan car ended up being banned shortly thereafter.

This concludes our look at modern car aerodynamics. Please leave a comment to discuss your thoughts or opinions on this piece. Let us know what you’d like to hear about next time.

The diffuser works in two ways. First, it reduces the turbulent airflow.  Second, it slows down and pressurizes the air as it comes off the car.

Turbulent airflow is always problematic to aerodynamic efficiency. The diffuser reduces this turbulence. When the air hits the front splitter and is forced underneath the car it speeds up and decreases in pressure. When it enters the diffuser the air is allowed to expand and slow down increasing pressure to equate to the normal atmospheric pressure of the surrounding air. This is where the airflow is smoothed to decrease turbulence. If the air were to blast into the normal airstream at its high velocity, low pressure state, parasitic drag is created. This is air needing to fill the void left by the moving object it follows. The diffuser serves to eliminate the creation of parasitic drag and the air is replaced in the same state as the surrounding air.

The second function of a diffuser is a suction effect created by the pressure difference between the fast moving air under the car and the slow moving air in the diffuser. As the air slows, it decreases in pressure. This low pressure area will create a vacuum effect. This vacuum sucks the rear of the car closer to the ground (seeing as the it cannot really move the ground up to meet the car, all relativistic physics aside). It should be noted that most of the effectiveness of the diffuser is lost if there is too much clearance between the road and the underbody.

Come back next week for a look at the rest of the miscellaneous canards and fins that are also common in aerodynamics today.

Although not the first to dabble in aerodynamics in racing, Chaparral Cars is widely considered the first to do it successfully.  Jim Hall would race through the 60′s and 70′s radical new cars that he designed using his engineering background and an impressive hand behind the wheel of  a race car. His cars featured movable wings and, in one of his last cars, fans to suck air out from underneath the car. Hall’s cars were extremely successful in the Can-Am series and lived on in legend to this day.

Today, rear wings are a huge part of the aerodynamic success of vehicles simply because they can create huge amounts of downforce. Put together with the downforce created by the front splitter, at speed the car can have thousands of pounds of artificial weight added to it. This balance is very important because just like adjusting the suspension to account for handling, the aerodynamic elements will play a large role in the overall stability at speed. Having too much front downforce will cause the car to be very loose and vice versa. Also there is the element of drag to consider. The rear wing will cause massive amounts of downforce but also cause lots of drag, slowing the car down and making higher speeds much harder to attain. This balance between top speed and handling must also be considered when setting the car.

Next week: the venerable diffuser.

The leading edge of a car is generally called a splitter. This is due to the fact that at this point the air is split, with some of it having to go over the car and some under. This is important because of the differential in pressure that is created in this process. The air flowing underneath the car speeds up creating low pressure. The air flowing over the car encouters a surface with a high angle of attack and forces the car into the ground. The low pressure area under the car sucks it down and the high pressure area above pushes the car into the ground.

The math: D = 1/2 (WS x H x AoA) x F x ρ x V^2

Expressed as a sentence, it reads downforce is equal to one half of the width of the wing times the height of the wing times the angle of attack, the sum of which is multiplied by the coefficient of drag of the wing, times the air density, times the velocity of the airflow squared.

Unfortunately, there is more to a car than just airflow. Radiators, oil coolers, brake ducts, and ram air intakes are a few of a cars components that require airflow to provide cooling. In the picture above, cooling ducts account for a majority of the leading edge of that 911. So in many cases, figuring out a way to cool a car sufficiently and keep aerodynamic efficiency is of prime concern for a designer.

Next week: the rear wing.

First, every car guy needs to be able to drive, and common wisdom says that if the DMV has revoked your license you can’t do just that. So the car gods blessed us with the greatest tool to avoid speeding tickets: the Valentine 1 radar detector. This baby is awesome. It will detect radar emissions long before the competition as well as the police are able to see that you are speeding. On top of the normal band and strength indicators that you get with any other detector you get directional arrows to tell you where the signal is coming from as well as a signal counter to detect if you are seeing more than one radar beam. Its ability to detect laser is hotly debated but I will say this: it is, without a doubt, the best product of its kind on the market. Period.

Grab it for $399 at the Valentine 1 store.

For the wash and wax crowd there are a handful of wonderful car washing accessories for the car guy’s garage. The one most often overlooked, though, is an orbital buffer/polisher. It is a work of wonder that helps eliminate pesky paint swirls that will accumulate over time with regular hand washes. The orbital polisher is great to ensure a beautifully polished wax job and an amazing looking clear coat for years. The importance of having a quality orbital sander is due to the volatile nature of machine buffing. If you have a circular buffer that rotates too fast, you run the risk of burning the paint. Orbital polishers work in such a manner that you can buff your car with virtually no risk of damage. The name we turn to for the best in these machines is the Porter Cable 7424. It is the orbital polisher of choice for both professional detailers as well as us hobbyists.

Pick one up from Tools Plus for $109 plus shipping.

Another wonderful gift is a car cover. Simple and effective the car cover really helps keep a car clean while it sits waiting for the weekend. On top of that, it is helpful in reducing nicks from accidents in the garage. They really are very useful and many car guys will love them. I recommend California Car Cover as they have been producing quality car covers for years and have many other great implements on their site, like the water blade which Brian and I swear by.

Sort through a bunch of options for your car cover or just get a gift certificate at California Car Cover’s website.

Back to washing and waxing, if your car guy is running at all low on cleaning products or doesn’t have all of the fun specialty products, its time to give him or her the car care kit of all car care kits. Brian and I have always been Meguiar’s guys because they have the best products known to cars. Barry has given us a great kit with everything you need to cover your bases, from clay bar to tire care. The Meguiar’s Complete Car Kit is the one to have.

Get if from Amazon for $45 and get free shipping.

Another great gift is a couple of tickets to your local car museum. Good ones are located in many cities all over the world and we in Los Angeles just so happen to have one of the best: the Peterson Automotive Museum. This is a great opportunity to let your car guy delve into the history and lore that surround the car and it’s culture. On top of that, you will probably have a good time too, if you go with him.

Pick up a $60 annual membership to the Peterson for yourself and your car guy at their website.

A stocking stuffer that every car guy appreciates is a subscription or renewal to a car magazine of his or her choice. Obviously, you are going to want to find out what that magazine is by snooping around the coffee table (or, God forbid, the bathroom). If your car guy doesn’t have a subscription to any magazines you can get him a subscription to a generic one like Car and Driver, Road and Track, or Automobile Magazine (the best of the three in my opinion). If you are looking for a magazine about a specific car, you might be better off just signing your car guy up for the car club associated with it. Many car clubs happen to put out the best publications specific to their marks. Take, for instance, BMWCCA and Roundel, Porsche Club of America and Panorama, and Ferrari Owners Club and Pilota. On top of the magazine subscription for a club you also get many services and amenities that can be quite helpful.

Prices vary but you are only a short search away.

So there you have my list of good ideas for gifts for your car guy or gal. Let us know if you have something cool as well! Merry Christmas!

So, you’ve been pulled over. Just take your ticket and deal with it later, right? Not for Brian and I. Brian has a pretty unique strategy which has worked for him in the past. When police talk to Brian, he pretends he knows nothing of what he’s done wrong and asks to pay for the ticket up front, right then and there. The reasoning behind this is that the cop, thinking that Brian is just going to pay his fine later on won’t take any notes. This will become crucial later. I, on the other hand, like to start writing down notes and taking pictures right then and there. This is helpful especially when you are far from home. Also, Brian and I are always respectful to police officers and there is no reason you shouldn’t be. They have a job to do and they do it with a certain degree of professionalism most of the time. They slip sometimes, but we don’t go the speed limit every day either. Also, politeness has been known to avoid the ticket all together.

After the incident, its time to do some research. The very first thing to do is to examine the citation thoroughly. The things you should look for are as follows:

• Check to see if the code the officer wrote you up for is quoted correctly. The words next to it have absolutely NO bearing on what the officer is citing you for. The only thing that the court looks at are the numbers. If you have been charged with speeding for example the line should look like this: 22350 Excessive Speed.
• Check the location of the ticket. If the officer has written down the location wrong you can claim you were never there (especially easy if you have pictures of the location you are at!)

• Check your information. If the officer has misspelled your name or anything related to your person, you may be able to claim that it wasn’t you! This is a little harder to do, and generally the court will issue you a corrected violation by mail.

Now, assuming all of that information is right, the next step is to request a continuance. The week of your appearance date, request a continuance either by going online and following the steps or going to the courthouse and speaking with the clerk. The longer amount of time you put between your eventual trial and the date of the violation, the better.

Next, after the continuance period is over it’s time to arraign. To do this go to the courthouse and talk to a clerk. You are going to plead Not Guilty, and request a Trial by Written Declaration. The clerk will then ask you to pay your fine (ugh) and give a form. Feel free to take it home. The Trial by Written Declaration will pit your written testimony against the officer’s written testimony. The hard part is, if the officer submits almost anything, he will win. Judges, for the most part, play on the same team as police. The trick to the written declaration is the hope that the officer won’t submit testimony in which case you win. Brian’s strategy for the written declaration relates back to his “where do I pay the fine” tactic. He in big bold Sharpie writes “NOT GIULTY” (sic) with the reasoning that judges feel bad for the mentally handicapped and don’t fine them. The crazy thing is that this has worked for him. Conversely, I try to collect and exhibit my evidence so that I have a reasonable chance of defeating any of the officer’s testimony. Either way is okay really. Once you turn in your Declaration you will receive the results by mail sometime later. Brian says it takes about a month but I’ve waited as long as three months.

When you receive the results a couple of things could have resulted. The best case is, of course, “All counts have been dismissed.” In that case, you are done. You will receive a refund of your fine by mail at a later date. If you had multiple offenses some may have been dismissed and some may have not. In that case you need to continue to the next step. In the worst case, the officer responded and you lost. Your fine will be forfeited to the State. Alas, all is not lost. A wonderful provision of the Trial by Written Declaration system is that if you do lose your case, you have the right to have a trail in person. You will need to talk to the clerk to exercise this right and schedule an appearance date.

At this point, everyone’s experience becomes a little different. It is all about collecting evidence and proving the officer wrong. All you need to do is prove that the officer’s testimony is flawed and that he doesn’t recall anything correctly. You will then ask the Judge for a dismissal due to lack of evidence. Hopefully, it won’t come to this point and you will have already won, as the trial process takes a lot of leg work in collecting evidence in order to win.

This guide is not intended as legal advice. If you are looking for legal counsel please ask an attorney or contact your local bar association.