Spoiler aerodynamics

[dsekovski]

Is the top spoiler aerodynamic to improve performance and mileage or just for aesthetics?

[drunkenmaxx]

much like the cord tom green taped to his stomach in "freddy got fingered" it's put there for fun.

[redlava]

Purely for looks.It is way to small and blocked by the roof rack, the Vibe is front-wheel drive, and I don't think it will go fast enough for it to even be remotely effective.

[Bobtronique]

Agreed!

[BOZACK]

Who cares! It looks really cool! I so want one!

[Bobtronique]

I know, I know! But who asked the question first?

[ColonelPanic]

Spoilers don't make much of a difference until they're mounted on a race car of some description and you're traveling at speeds far in excess of anything you are allowed on normal roads. Or it does add horsepower for certain models, see attachment. Otherwise, not much use other than make people say "hey, that looks good." The mid spoiler is highly functional though, gives you a place to sit your beer.

Attached files

[northvibe]

you mean you guys dont go 130mph constantly? ...pssshhhh me either, but i might need that spoiler to do that i wanna get them eventuaally i think they are pretty cool, know that mid gate + beer.. = kick freakin (removed) get it.

[scherry2]

Quote, originally posted by redlava »It is way to small and blocked by the roof rack, the Vibe is front-wheel drive, and I don't think it will go fast enough for it to even be remotely effective.this statement is for vibes with there cross bars removed:has anyone here taken their vibe with rear top spoiler into a wind tunnel? everyone here is saying that if you put a spoiler on there will be no difference. I don't think thats true. get in your vibe pull out into the road and put your hand out the window fingers forward and hand flat horizontal, as you drive faster tell me what is happening to your hand and your hand is really small. the spoiler acts much the same way. the air going over the spoiler pushes down just like an airplanes wings but on a smaller scale. no, the vibe is never going to fly or go fast enough to cause such a down force that the vibe will stick to the road but it will make a difference in the areodynamics of the vibemy $.02 please prove me wrongfront wheel drive has nothing to do with aerodynamics.

[vibebob]

would/does the spoiler affect the rain/mist from getting on the rear window ? wuote Bobtronique -- I know, I know! But who asked the question first? unquote.I thought WHO was on first.

[tnpartsguy]

It's a pretty, doesn't affect the rear window, in fact, might be worse since I added my top spoiler....but it sure hasn't helped at all.....the ones that help are normally angled down to make the air blow across the window.

[heha]

just please be aware that when you decide to drive home that you should take the beer off the mid spoiler, nobody likes seeing a perfectly good beer go to waste because of stupidity.hehe

[drunkenmaxx]

Quote, originally posted by heha »just please be aware that when you decide to drive home that you should take the beer off the mid spoiler, nobody likes seeing a perfectly good beer go to waste because of stupidity.heheyeah, and if that happens, don't let me find out. there will be hell to pay!

[MadBill]

It's actually pretty easy to see if there's a substantial effect on drag. All you need is a stopwatch and an empty straight and level road. o After driving 10 miles or so to warm up tires, lubricants, etc., accelerate to the highest speed you find safe/legal, put it in neutral and time the interval to coast down to perhaps 45 MPH. o Repeat at least 4 to 5 times in each direction. o Discard the fastest and slowest times and average the rest. o Fit or remove the spoilers and repeat. If you can't clearly see the difference, it is negligible for all practical purposes.I did some front air dam development this way on my old Pontiac Firefly (Geo Metro clone) and picked up about 3 MPG!

[mcgusto82]

ha ha ha hathe post here are quite funny.spoilers work on low preassure spot on top ofthe vihicle. they in turn turn that negative preassure lifting the vihicle up and turns it into a lower preassure are below the spoiler. spoilers don't create the down force by the air bing pushing it dow, intead byt the negative preassure cause byt the difference.in the picture here, the spoiler is maintaining the wind speed above the wing, while the low preassure is causing the wind to slow down and therefore suck the wing down. thus, downforce. while yes, there is force pushing down on the spoiler. the greater force is low preassure below.the image on top is a venturi channel. most high power vehicle have them. a clear cut example of how downforce is created by slower moving lower preassure air moving below. as you see, ther is no flap pushing surface below, yet the downforce is there.back to topic. the spoiler on the in all favoriteness, it creates the down force a small baby riding in the car would. (maybe if that)the fact that the roof is one of those low preassure points created by the windscreen would only slow the air flow on the roof. thus creating no preassure indifference below the spoiler surface. even if you go faster on our cars. the screen, the front incline degree is to great to create smooth high preassure flow towards the rear where the spoiler is. if anything with that high degree incline, there would be turbulance instead.but like others have said, i can always use another hand to hold my beer. studies have shown a beer stays cooler put down than on a hand.

Attached files

[scherry2]

nice comment but man do you need spell check.

[Jaycie685]

So in conclusion, is it beneficial to have a top spoiler?

[mcgusto82]

spell check smell check!!in conclusion, it's just for looks. if you like it, put it on. if you don't, you're not missing out on anything.

[goodvibrations]

I agree with Bozack "who cares" I want one too but I can't bare putting holes in the roof to install one.

[Atomb]

as for aerodynamics and front wheel drive, sherry...i think the issue is the down force on the back of the car is something like putting a heavy weight on your rear bumper (or loading the back of your vibe). This effectively raises the front suspension slightly (or alot?) and reduces the downforce from the weight of the engine on the front powered wheels...

[scherry2]

makes sense, i guess I was thinking of just rear wheel drive cars (being raised on them) and not front wheel drive so a spoiler on the front of the car would be more reasonable on a front wheel drive car.

[binary]

If anyone expects any performance improvements from a factory spoiler - you're just kidding yourself. Its for looks - that's all they were designed for. They have 0 degree angle of attack, which equals zero lift, zero downforce, and very little air drag. If you want more downforce, you could get a wing with a more aggressive angle - but you'll lose top speed, gas mileage, and gain very little downforce until you hit high speeds. Then again, if you were road racing at say >50mph corners - it may help you out.A good set of tires and suspension upgrades would do you better though. As for spell check - I use Google's toolbar. It'll spell check forum posts before you submit them. Works great!

[Atomb]

don't forget a good set of brakes, binary.i'm actually amazed at the amount of upgrades done on this site to make the car go faster/corner harder...but very few ever take stopping better into account!scherry: problem with only front wing is loose tail (quite a bit of that in university )...i'd worry about the opposite effect on the rear wheels (lifting?).But Binary is right, in the case of all cars on the road, the situation is such that it'll most likely NEVER come into play

[scherry2]

Quote, originally posted by Atomb »scherry: problem with only front wing is loose tail wouldn't it also get in the way of your view. (looking at some of the rice spoilers out there)

[Vibe_of_the_thing]

It depends on what the spoiler looks like. If the spoiler is a small lip, then it's theoretically possible that it's there to (get this) improve aerodynamic drag. A spoiler (note that this is different from a wing) will separate the airflow from the car from that point back (hence the name, as it "spoils" the laminar flow). If it is properly placed, it can prevent unstable airflows that attach and detach, or simply choose an advantageous separation point that reduces overall drag or lift. MOST of the time when you see a spoiler on a car it is just to make it look cool and no engineering has been done on it whatsoever. Rarely is a road car designed to produce downforce. If they are engineered, spoilers are usually being added to reduce lift (squint your eyes enough and the general car profile is that of an inverted wing). Porsche put features on the 911 to separate airflow so that the rear profile of the car wouldn't produce enormous amounts of lift. Audi apparently recalled the TT because aerodynamics and suspension settings caused the car to become unstable at Autobahn speeds: http://www.fantasycars.com/Audi_TT/audi_tt.htmlBy contrast, I have read that the spoiler on late-model Mustangs not only increased drag, but actually produced lift as well.These aerodynamics do come into play at any speed, and go up with the square of it, so spoilers are doing SOMETHING out there, but as I say, usually it's not anything particularly well planned out.

[Vibe_of_the_thing]

Binary is right about factory wings generally not serving any purpose. However, spoilers with 0, or even negative degree angles of attack can still serve a purpose (separating the airflow).For fronts, what you are looking for is a splitter. Not very practical for the road where parking medians would be destroying it all the time.