changing the topic back to the rear wing for a second... is there a significant functional difference between the real FRPP Cobra R wing and the Steeda race wing? Steeda wing I'm talking about is this one:
also, the front splitter, is it worth it for mostly hill climb racing and some open track events or should I just leave the 03-04 cobra front with Mach1 chin spoiler?
The Cobra R front works assuming you make it stiff enough to handle the forces being applied to it. It is the only front airdam I would buy that I would have confidence in.
As for the Steeda race wing, I assume it's just as good as the Cobra R (seeing as it's a clone) but I prefer the FRPP one, as we have hard data on it, and not the Steeda R wing specifically. I am not super crazy with how the Steeda wing is so curved. The FRPP R wing is a straight horizontal line, but the wing has been contoured specifically to produce downforce. That Steeda wing has such a large curve, and I can't see a good view of the profile of the wing. The Steeda wing would catch more clean air as it's higher than the FRPP R wing, but I'm not sure how the profile is. Until we get more information or data, I'd stick with the SVT designed and proven FRPP R wing.
Here is a cut and paste I did on a different board about Mustang Aerodynamics. I think you could benefit from it, though it's not super technical.
Ok, this is just full of misconceptions and misinformation. Since you seem to genuinely believe what you have written and are not coming off as a huge prick I'm going to be nice and just correct what is wrong. Which is a lot.
The rear spoiler on any stock Mustang (other than the Cobra R) are purely aesthetic. The wing is too low above the decklid to have any "clean" usable air to influence. The roof of the Mustang is very typical and the airflow goes straight over the rear window and if following the curve hit somewhere about a foot past the end of the car. This is not to say no air moves over the car, high pressure (it's high pressure because the air is traveling slower than the air above it, as the air above it must cover more distance in the same time, creating a lower pressure to do so) air literally "rides" above it and just stays on top. A good example is with truck beds. To get optimum efficiency of the truck, the tailgate must be up, as it traps a bit of air and forces it to create a small turbulent cyclone in the bed of the truck, just aft of the cab. This again creates a difference in pressures and forces the air going over the cabin to "ride" over the cyclonic air in the bed. This in turn reduces resistance, increasing efficiency. This principle is generally the same with the Mustang, however not as dramatic.
For the spoiler to be effective it must be raised and placed into the path of the low pressure air to take advantage of it. When the air is divided by a properly designed wing, the upper part of the wing travels a farther distance than the lower part of the wing, and it creates a difference in pressure. The pressure going the farther distance is has to speed up to meet the bottom air at the same time (think of 2 different radii on a moving record). Because it speeds up the pressure drops. In a properly designed wing on a plane the longer distance traveled is on the top of the wing. The bottom, slower air is a higher pressure and pushes up because the faster moving air on the top has a lower pressure. By the Natural Gas Laws (and it seems nature/physics in general) the air wants to become neutral, so it tries to equal the differences in force by pushing up on the low pressure. With enough upward force, we have lift, and the ability to fly. The faster to go, the more lift you achieve (to a point it seems, as then the air will start to react different. Take for instance supersonic aircraft. The wings of the aircraft have to be angled against the body like that for the air to have a direction of flow. As you approach (and surpass) the sound barrier the aircraft is moving so fast that it's pushing so much air forward with it at the leading edge of the wing (you are looking at the nose of the plane to the back, now look at the wings) it builds up air and again creates different pressure zones. This in turn destroys the efficiency of the wing and will cause the plane to break apart from vibrations and other failures. With an angles wing now commonplace on modern supersonic aircraft, the air at the leading edge of the to flow to the edges of the wing and be purged into the rest of the ambient air, instead of building up on the wing.
The angle and design of the wing is not particular great so even if the wing was put into "clean air" it would probably create more lift than downforce. Also, even if it did create downforce it would not be enough to make a significant amount of force pushing the rear of the car down and thusly it will not affect the airflow enough to put a significant change in force pushing the car down other than gravity. The Cobra R wing, miscellaneous APR wings, and wings from Apexi and other reputable companies are the only ones that are high enough to put the wing (well, it's more of an inverted wing) into the "clean" air and are properly designed to give downforce, not lift. Moving the stock wing back does not change anything in the car's aerodynamic profile as it's ineffective from the drawing board and not even close to the proper airflow needed to achieve real downforce. Also covering the holes is not a big deal. They are so small, again out of the clean air, and even if they were in the path of clean air, the internal pressure inside the decklid is significantly higher than that of the air moving over the hole, it would actually suck air out rather than be an obstruction. Essentially it's a rudimentary NACA duct, and real NACA ducts are excellent ways to provide air intakes without sacrificing aerodynamic efficiency (there is a lot of science and calculations behind them as well to make really effective NACA ducts).
The chin spoiler is again not anywhere near as effective as you believe. What I think you are think of is that it the chin spoiler is acting too much like a true front splitter. The mach chin spoiler is too small, nowhere near long enough, and too flimsy. To get the affects of a real splitter you have to lower the car significantly (2+ ideally more). Also the length of the underside of splitter has to be extended. The purpose of a front splitter is somewhat the same as a wing. It works off of a difference of pressure, but it does it slightly different. with a splitter you move air under a flat plate essentially and constrict it. In doing this, you speed the air up (Bernoulli Principle) and you lower the pressure (Bernoulli again). on top of the spoiler, the air hits the front of the car and essentially slow down significantly. This creates a high pressure zone, and now mirroring a wing the High pressure zone pushes down on the low pressure and you have downforce. The length forward of the front edge of the car, the length going back under the car, and the height of the underside of the splitter to the ground all play significant roles in the effectiveness of the front splitter. too short and it doesn't have enough area to produce a high pressure zone and you don't create as much downforce as you could. If the splitter is too high, it will not constrict the air enough and you won't create as much downforce, and if the splitter doesn't go far back to at least a minimum of the beginning of the oil pan (generally for the Mustang). You want this distance to keep the air "trapped" under the car thus keeping the air at a lower pressure and the further you go back, the more areas like the windshield and front of the hood push down because the air going over them is higher pressure than the air going under the car. This is why you see full flat bottom race cars. They utilize the entire car as a wing to produce downforce, and is how it's possible to create hundreds of pounds of downfoce. The other thing you are thinking of is that the chin spoiler is pushing more air aside reducing air under the car. Again it's so small and flimsy it doesn't do anything at all really.
You are not creating enough of a change in the engine's dynamics to warrant 3 mpg with just a cat-back and CAI (though it is a possibility mind you). You are allowing a very small amount of air more through the intake, but with the stock manifolds/heads it's not even arguable really. The exhaust is the same way. You are allowing the exhaust gasses to scavenge a little better through out the exhaust and possible helping create a ever so slight increase in suction when the exhaust valves are open, but I'm not going to say it is worth it. I'd guess 2 mpg in a healthy car tops, but this has so many variables I cannot give a "real" answer.
K-member, A-arms, tubular sway bars. always good to lighten up
Coil-overs to lower the car for long trips. Again, sound thinking. It works as less air travels under the car. Lowering can actually create a mini underbody affect as it can change pressures enough to be noticeable. Lower a car and it should achieve a faster top end assuming same power and only wind resistance was stopping it.
Adding a hood scoop to the car does nothing but induce drag. Even opening it up and "routing" it into the intake, which I assume you didn't do as you said you just opened it to "blow on the intake". I'm guessing it's "blowing" on the upper intake. That does nothing. The air will not cool the intake enough to get any benefits and routing the intake doesn't work either. With our intakes there are too many bends to try and take advantage of true RAM air. Only the air channel ducts directly into the intake/runners and has minimal to no bends will it work. Also the hood scoop will create drag even opened up. This causes a fluctuation of pressures in the engine bay (which is normally stagnant) and will most likely rip itself off unless secured properly.
Yeah, the brakes and 17'' wheels did hurt a bit, but I'd gladly take the trade off for better stopping power. I can get into how the wheels and unsprung weight rotating around a central point vary on how the weight is distributed but I don't feel like doing that right now.
I doubt your 35 mpg, but your 32 seems possible given a low, low car and proper driving. I got about 28 in my stock (catback, 17'' rims, CAI) 98 singleport, but I also have a better gear ratio for highway (2.73 for me, 3.27 for you.)
True, there is a "dead space" (like I mentioned above with the truck etc.) but the moving the wing back will not affect the air as much as you think. Like I mentioned earlier, most of the air is going over the window/decklid due to the pressure difference, not because the air is bing pooled in front of the wing. Moving the wing back will change the airflow slightly, but nothing significantly because the stock wing is a bad design, in a bad location, and and a majority of the influence comes from the shape of the cabin, not the stock rear wing.
The air dam and rear wing on the 2000 Cobra R was intentionally put in place of the clean air to influence difference in pressures and create downforce. The stock wing doesn't do that, and the chin spoiler is too flimsy to even keep it's shape with the real pressures of a true splitter. The rule of thumb for just a home-made splitter is you should be able to stand on the edge without breaking. This is why real, true splitters are made of CF and other composites and even combinations of them. To keep them light and strong. This is also why front splitters are long as it help distributes the front load a bit.
You used a Tornado? Ok, this conversation is now over, but for the sake of real information I will persevere.
CAIs don't cool the air. Unless you're running a Water/Methanol injection kit, Nitrous Oxide sprayers, or Co2 sprayers you don't cool the incoming air. A CAI just allows you to take in ambient air, which is cooler than the engine bay air (for obvious reasons). Intake spacers are a debatable topic and I'll leave it at that. I've seen some evidence against it, but more for them. I believe they work. Blowing air on the intake from opening up the hood scoop won't net any power. You aren't channeling the air in properly and it's really turbulent. Also you are not giving the air an exit. To be effective you must duct air over the intake and let it leave without being able to disperse inside the engine bay. This will allow the air to pick up heat and leave it without being disturbed and slowing down. If you really want to cool things down just grab a Cowl hood or come up with a more elaborate and effective ducting system to cool the upper intake. Also, the air traveling into the upper intake won't see as great of a temperature change as you believe. Remember that the air going in is ambient and not very hot to begin with. Most cooling times are differential equations and are not constants. The hotter something is that is exposed to a cooler source it will cool rapidly quickly, but it will slow down. It's a straightening curve basically. In short the air isn't hot enough in the intake, or in the intake long enough to exchange enough heat with the Aluminum metal to notice any change.
The reason cars "feel at home at certain speeds" is due mostly to the engine and shape. It's a two point graph. Where the two meet is the speed it's most efficient. Yes they car may be aerodynamically efficient enough to cruise at 80, but the engine might be better suited to move the car through the air at 70 due to it's power curve. mostly the point where the engine is producing the most power for the least amount of fuel is where it likes it best. Most of the older cars because they had such a small gear selection were limited in fine tuning the rpms. We have the ability with a 5-speed tranny to be more exact at speed and have 3 gears to select what speed we want the engine to be at for a certain velocity, whereas with an older 4-speed it's 1 less. This let's us be more precise. Also since we have a fifth gear it's an overdrive. In a normal transmission 4th gear is the 1:1 ration. The drive shaft moves at the same rpms as the motor. In fifth, the ratio is lower (I'm not certain on the T-5) and this allows the drive shaft to make more rotations per minute than the engine.
Air resistance is a squared function. Double the speed, square the resistance.
Most of my rebuttals for this one are covered in my previous explanations (which should be obvious if you read my post), but you do have valid points in this one.
I could get into the more radical things like diffusers, sealing the engine bay, dive planes, vortex generators etc. If anyone wants to know, just ask.
Just to see if anyone read this all the way through http://i233.photobucket.com/albums/ee311/AnaheimElectronics/GemmaBikini.jpg?t=1212557440
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