OICW

Eactly. The Power is there - 360 rwhp would be easily enough for 180 mph, but the downforce is simply not there for a stable run.

Cobra R front air dam and rear wing might be a good idea for high speed runs.

beabout

[:-] 03/04 Cobra's came with ECM speed limiter set at 155. To go 155 or faster on public roads seems insane at best. But, if you really don't like the car or yourself please take either out without hurting others. Besides as the total number of Cobra's drops the price for existing examples goes up...

03_svt_cobra_22

this guy on svtsnake.com has a cobra with the 3.55 gears and the 6 speed with 470 rwhp and 500ftlbs pulled to 183 in 5th at 6500rpms by using a gps to tell how fast he was goin since we all know the speedo only goes to 160.... neways if he kept pulling through 6th to 6500rpms then the top speed for the svt cobra is nearly 200mph not to shabby for a lil 281

in stock form with the mph and rev limiter off i expect to see 190mph but hope ur tires stick

HornyHornyHippo

Iv only done 145 in my dads car till i ran outa room! Dont worry, safe environment!

pb1302

Mine went 178 on my Eaton setup...... it now wears a Whipple and better suspension. Here are some vids of the pass. We would have gome more, but as you can see on the GPS unit the road turns and there was some cars way agead that were getting closer by the second...... so I let out. I was going for 180...... Whipple whould have that covered...... I am sure it has already topped that but I did not have a GPS unit in the car to confirm.

http://www.pb1302.com/Videos/178%20cobra.MPG

http://www.pb1302.com/videos/Fly_by%20178.avi

Smokin04

This thread made me join this forum because I would like to know where everyone is getting their information from? There are two Cobra's off the top of my head that have eclipsed 200+ with stock aerodynamics. I myself have had mine at 185 and still pulling in 5th gear. The car NEVER felt unstable or out of control even turning at 140+. That was with 540rwhp. I have since went twin turbo and can eclipse 200 quite easily with the stock body. John Buscema (http://www.200mphracing.com) took a STOCK 03 cobra to 203 mph at Bonneville. Steve Benyo drives the Centimark car (http://www.landspeedmustang.com/) to 238.44 at Bonneville and 228 IN THE STANDING MILE at Maxton all with the stock body!

If anything a rear diffuser would really kick *** on a terminator. Here's why:
What I think people should realize is that a diffuser is not for "smoothing out airflow" nor does it "create" any downforce. The word create is thrown around with such little regard. A diffuser is designed to channel (direct) vortices (instances of turbulent air) created by the motion of the vehicle/shape reacting with the air (fluid) it's travelling through. This principle of aerodynamics creates a low pressure zone under the vehicle. Ride height also has a profound affect on under car pressure. The lower the car to the ground, the less airflow (pressure) will be present. Downforce is then "created" when pressure ABOVE the car is greater than the pressure BELOW the car. Poorly designed vehicles with stock ride heights do little to minimize airflow under the car. This creates a pressure under the car (given it's not as great as the top-side pressure, unless the design is not shaped with aero effieciency in mind), but it is pressure none the less, which at high speed will equalize, and lift will occur. A diffuser is beneficial when used with any shape or feature that creates vortices (low pressure) towards the leading edge of the vehicle. (03/04 Cobras have 2 vertical struts in the front bumper cover that create these vortices) The diffuser will then direct the vortices from under the vehicle, which does not allow pressure to build in the rear of the vehicle (trailing edge surface affected by fluid) which in turn builds down force due to the higher pressure already present above the trailing top-side edge.

So with no diffuser, trailing edge pressure will build and less downforce is present at a given speed. With a diffuser, the pressure is not as great, which allows the top-side to be more effective. This can be further enhanced by modifying top-side features (spoilers, splitters) with greater downforce. So all in all, a diffuser is absolutely beneficial. I can compare it to porting heads. Stock heads work, but porting them just makes them more efficient. So a diffuser will enhance the stock aerodynamics of your car which makes the whole picture, more efficient.

Opinions?

Some terms:


Aerodynamics is defined as the study of motion of gas on objects and the forces created. These forces on a car are mainly drag, downforce or lift.

Drag is produced by the air creating certain frictional resistance. It acts towards the rear and tends to slow the car. Drag exists on all car bodies and it increases with the square of speed. Therefore, it determines the car’s top speed and can be as important as the engine power. For road use, drag has a great effect on fuel economy. The reason that a car is designed in a streamline shape is not only for out-looking but more important is to minimize the drag and hence will get good gas mileage.

Downforce is another aerodynamic force and is the same as the lift experienced by airplane wings, only it acts to press down instead of lifting up (see Fig 1). Every object traveling through air creates either a lifting or downforce situation. For racing cars, invent devices such as wings to force the car down onto the track, increasing traction in acceleration, braking and corning. Because aerodynamic downforce does not add centrifugal force in a turn, the effect on the car is higher cornering speeds. Therefore it is good to use some sorts of devices to generate downforce in order to achieve a higher speed in the racing. However, it is not wise to have lift while racing. Lift is an upward force on the body and tends to make any car handle poorly at high speeds. Nevertheless, many road cars tend to create lift rather than downforce due to the body shape. The new VW beetle (see Fig 2) is a classic example of this, developing severe nose lift at high speeds. The body shape is designed as a flat bottom and a rounded top. In doing so, the car body shape itself generates a low pressure area above itself.

Fig 1 Fig 2

Drag Coefficient (Cd) is determined by the shape and smoothness of shape of the car in this instance. Cd and aerodynamic drag have a inextricable link as most of the efforts at reducing aerodynamic drag in racing cars must be directed at improving the coefficient of drag. There are two basic methods to improve Cd. One is to improve the basic shape of the car in order to reduce profile drag and the other is to clean up the detail aerodynamics and reduce parasitic drag. As an example, the following table shows some potential methods to increase Cd of a car and hence minimize the aerodynamic drag of it.
Number
Possible approaches
1 Have a small grill to minimize frontal pressure

2 Have a steeply raked windshield to avoid pressure build up in front

3 Have minimal ground clearance below the grill to reduce air flow under the car as much as possible

4 Have a “Fastback” style rear window and deck to allow the air flow to stay attached

5 Have a converging “ Tail” to keep the air flow attached

6 Have a slightly raked underside to create low pressure under the car

There are also some up to date figures of Cd on passenger and racing cars. The best road cars today manage a Cd of about 0.28. Formula 1 car, with their wings and open wheels (a massive drag component) manage a minimum of about 0.75, which seems inefficient. However, the high downforce and horsepower of the car compensated its weakness of low aerodynamic drag efficiency.

Frontal Area
Drag coefficient as discussed above, by itself is only useful in determining how “slippery” a car is. To understand the full picture, the frontal area of the car needs to be taken into account. For example, one of those new semi-trailer trucks may have a low Cd but a relatively large frontal area. To conclude, combining the Cd with the frontal area is finally obtaining the actual drag induced by the car.

Any questions?

Hegotgame

i have an 03 but the fastest ive gone is 140 in fourth gear.

Smokin04

140 in 4th is getting it done...be careful when you do push it to 5th and definetly if you venture into 6th. Load on the engine increase SIGNIFICANTLY in over drive gears.

MAD SVT

stock is 155, i was told that in the SVT manual, but of course i had to try it. yes 1..5..5

and thats fast enough.

and as far as you guys thinking your going to shift into 6th and get some extra MPH outta it..... bring a wheel barrel to collect your blown motor.
keep it in 5th.

mfj

I believe that I AM THE ONE that first brought up the CentiMark Stang...