bpproducts

Click on link below for photo
http://www.breathlessperformance.com...ockExhaust.asp

10% Discount for the Forum Members

This version can be used with most all exhaust systems, both 4 tip and 2 tips.

This is a 100% functional lower rear diffuser. A must for track days or that ultimate racing look. Bolts on in about 1 hour.

Weight is about 8.5

It does replace the factory panel.

It is a easy bolt on. Locking tabs on top screws into the factory side mounting holes. and has a brace and bracket that attaches to the lower control arm bolt.

Back up lights are available as a 5 led light incased in the diffuser just above the tips.


Definition of a Diffuser:
A diffuser, in an automotive context, is a shaped section of the car underbody which improves the car's aerodynamic properties by enhancing the transition between the high-velocity airflow underneath the car and the much slower freestream airflow of the ambient atmosphere. It works by providing a space for the underbody airflow to decelerate and expand so that the boundary between the car's airflow and "external" airflow is less turbulent. It also provides a degree of "wake infill" (the wake being a turbulent area of low pressure that is caused by the passage of the vehicle through the air; this can cause pressure drag).

As the air enters towards the front of the car it accelerates and reduces pressure. There is a second suction peak at the transition of the flat bottom and diffuser. The diffuser then eases this high velocity air back to normal velocity and also helps fill in the area behind the car making the whole underbody a more efficient downforce producing device by reducing drag on the car and increasing downforce.

The aft part of a car underbody can be a diffuser. It works to bring the low pressure air below the car back to the ambient atmospheric pressure without inducing turbulence. It uses Bernoulli's principle, such that the pressure increases while the velocity decreases. Since the pressure below the car is lower than on the side and above the car, downforce is produced if implemented correctly. Injecting the exhaust into the rear diffuser can also help extract the air from below the car. The exhaust gasses effectively energize the boundary layer, helping to raise the pressure of the low-pressure, fast-moving airstream back to the ambient atmospheric pressure at the exit of the diffuser. This helps extract the air more efficiently from the underbody.

Note that the front of the car slows down the air without a diffuser making this the ideal place for an inlet. Instead, a splitter is commonly used here. The splitter serves to reduce the pressure below the front of the car and thereby increase the amount of downforce in that region. The airstream is brought to stagnation above the splitter, by an air dam, causing an area of high pressure. Below the splitter, air is accelerated, as stated above, which causes the pressure to drop and create downforce. Some race cars, such as the C6-R Corvette actually use a proper diffuser in this area to help create more downforce.[1]

For drag we perform coast down runs for each setting. Without the above we can only calculate approximate performance levels of each element. IE: front adjustable splitter, rear wing and diffuser. Lap times don’t lie.

Using the formula F= Cl * area we arrive at 3psi for the diffuser which is a total of 480 lbs down force @ 170mph ideally if we were to maintain 2.5“ ground clearance on a smooth track on a standard day. Since the rear ride height is more than that, we have a + rake situation which in itself causes down force because of the ’Wedge effect”. The area and ramp profiles were determined by the space available and no NACA tables were consulted.

The primary reason for the design was to address the unsightly mess Corvette has created at the bottom of the rear valence. Imagine the ZR1 supercar with back up lamps on a fake plastic diffuser. Shucks, this is what we expect from the orient for little city cars. What self respecting V8 has four ugly pipes?

Although it accomplishes the appropriate ’Bling Bling‘ effect, our diffuser also function as designed. If you have all the other necessary elements in place. IE, A proper floor feeder system, droop limits on the rear suspension, ability to adjust total center of pressure, (splitter and rear wing) you will be further able to exploit our new product.

We also have a side feed entry as on the Ferrari Enzo, so we don’t get the full suction peak at entry and the second peak is located at the rear axle. This is because the engine heat is managed down the centre of the car and exits at the opening of the exhaust pipes. This precludes us having a full ’closed in’ floor which would improve the efficiencly of the diffuser considerably.

Our rear wing is designed for engine heat exit over the top of the car as in the factory C6R GT1 cars after which it was designed. There is never the less diffuser energy augmentation caused by the end plates on this design. Since this car is also driven on the street and is used for our product promotion, we elected not to go with a full race car package.

To calculate approximate down force at other speeds at the diffuser we know that lift increases at the square of the velocity. At 75mph we would have 100lbs down force.

With this installation for the street on a stock C6, you will improve your gas mileage at highway speeds because the diffuser allows the air traveling underneath the car a place to expand and decelerate back to road speed as well as providing wake infill. IE: It will reduce total drag.

Dont forget your 10% discount

Can be used on the street or the track!!!

700-253-4T C6 & C6 Z06 Rear Diffuser Price: $1,500.00

700-257 LED Back Up Lights Price $150.00

To order, call us at Breathless Performance at
(954) 925-7725

danl72

Cool.

Nd4spd2

Link doesn't work for me Ernie.

Johnny Utah

j_digi454

Same here.

Eritosthenes

This link should work:

http://www.breathlessperformance.com...ockExhaust.asp

Interesting look. I'm having some initial trouble with the LED backup lights. Probably an acquired taste.

fiveodude

vette6aut0x

Have you done any testing to verify the downforce numbers you quoted, or is it just a SWAG?

LTC Z06

Form following function, I love it, just wish the price was a bit less.

chevyc6z51

it looks like a nice part.. If you guys have one on a c6 non z06 i would love to see pics to see the dif with the smaller wheel size and non wide body makes