Car Forums Spoilers, what are they good for.
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 12-26-2004, 06:08 AM #1 DSMer CF Extraordinaire     Join Date: Jun 2004 Location: Chicago, IL Posts: 1,639 Spoilers, what are they good for. It seems to me that in the "import community" the bigger your spoiler the badder your car is. While I find that way of thinking to have the utmost stupidity put behind it, I can only lead to one conclusion. Why? Well people see SCCA racers in their M3's, Audi S4's, and Acura RSX's with extremly large spoilers and I guess they believe that adding a spoiler to their Civic, Integra, Eclipse will aslo work in the same fashion as it does on a race car. Well..... Yes and No. A spoiler works by creating downard force on the car as the vehicle travels forward. This is also known as "donwforce". Downforce is generated by the difference in air pressure over and under thw wing. If we have a spoiler and non turbulent air flowing through it (straight flowing air that has not allready been interrupted by other objects), there is a higher pressure on the top side of the spoiler that flows at a high velocity and a lower pressure on the bottom side of the spoiler that flows at a lower velocity. The higher velocity of the air traveling over a spoiler causes a downward force/pressure to be generated. Mathematicly, the formula for the fucntioning of a spoiler would look like this: Cl=L / ((1/2)r(V^2)A) Cl= Lift Coeficient L= Lift(Downforce) r= Density of Air V= Velocity A= Wing Area One big factor of the lift force that will be genmerated is the angle of attack(The angle at wich the wing if facing when the air flow hits it). Generally the larger the angle of attack(without going so large that you're creating a wall that blocks the air) the more downward force that will be created. Again turbulence in the air will factor into this equation. Now that you know how a spoiler works and what makes it work better you next question may be. Well how can we conculde if we have turbulent air flowing into the spoiler. Lets take a 95 Honda Civic. It has a streamlined flow but after the rear of the roof the air becomes turbulent. If you've ever seen a car in a wind tunnel, white colored air is emmitied at the middle of the car in the front and it flows over the car. If it flows over the entire car without intertuption this would be a engineers dream. For air to flow over an entire car without turbulence. However, this is'nt true in a honda. After the air leaves the hood it becomes turbulent. The flow of the air becomes unpredictable and can even flow backwards from the oposing force of the air. This make the spoiler useless and infact creates unnesicary drag on the car and slows you down. One factor that people seem to not accept is that the spoilers mointed on the SCCA race cars are really high in the air. Yes it looks rediculous but if the spoiler is mounted high enough into free flowing non turbulant air it becomes more efficient than if trapped beneath a pocket of turbulent air. This is why airplanes shake in turbulence! So actaully the people you see with taller spoilers( I mean like 2 feet in the air almost) actually have a more efficient spoiler than the ones that are smaller. Is'nt that a bitch? __________________ ...Everyone is entitled to their own opinion. It's just that yours is stupid...
 12-26-2004, 06:46 AM #2 Godlaus UnFedFat in Disguise     Join Date: Dec 2004 Posts: 1,697 NOICE!!!!!!! yeah, it's a bitch, but they didn't get the spoiler for that reason, and I think it's best if we don't tell them, because it gives them ammo. I suppose the only other thing i can add/ask, is, at what speed do spoilers become effective and is it really necessary at that speed? In what I've heard, spoilers only come into noticable effect at roughly 70-80 mph. And, if you're car is still burning out at 70-80 mph, you've got an insane car, which you need for racing, not everyday driving. so, spoilers being unnecessary. But, there are some cases in which I see spoilers to be necessary. (Like on some cars, such as the skyline). They just look a lot better. Truthfully, any spoiler over 1 foot high schould be banned. But, take in the cosmetic effect also. Because almost nobody buys a spoiler for the actual aerodynamic effect. Good use of real-world knowledge!!!!!!!!!!!!! __________________ I am everything you want to be
 12-26-2004, 06:58 AM #3 DSMer CF Extraordinaire     Join Date: Jun 2004 Location: Chicago, IL Posts: 1,639 Spoilers are in effect everytime the car moves. So long as air is flowing over the car and the car is moving the spoiler is having some effect on the vehicle. I think what you're asking for is when do spoilers become an advantage and yes that is arround 60+ mph. You'll hardly notice any downward force on your car unless you are traveling at higher speeds than any normal road would allow you. Will it give you an advantage at 100mph, no not really. Will it make your car 10 miles faster, no not really. However in a competetive event where every millisecond counts it just may give you the upper hand. __________________ ...Everyone is entitled to their own opinion. It's just that yours is stupid...
 12-27-2004, 10:35 PM #5 DSMer CF Extraordinaire     Join Date: Jun 2004 Location: Chicago, IL Posts: 1,639 Good one ChrisV. I thought about explaining the difference between a spoiler and a raised wing, but I thought that would have made the article alot longer than I was willing to commit in those 20 minutes. Yes, good addition... I think this about wraps up rear end spoilers and wings. However if you touched it breefly but if you'd care to explain a little about front end downforce generated by front bumpers and aftermarket front bumpers. I think thats why NIRA drag cars have a sloped front end with no openings to allow air to move over the hood of the car thus pushing it down. __________________ ...Everyone is entitled to their own opinion. It's just that yours is stupid...
 12-27-2004, 11:26 PM #6 Ki2AY CF's Pond Scum     Join Date: May 2004 Location: San Francisco CA. Posts: 708 although i dont respect your attitude dsmer i do respect your knowledge and i enjoy reading each thread you post, therefore i dont hate you thx for the info __________________