want to see same as those C6 Style on C5 then i'll be interested

damn looks SICK

 

i cant wait to see pics.

 

 

 

i want one, why does this take so long

 

If you guys get any updates from Ernie at Breathless be sure to post them here. I would like to know if he is making a single C5 diffuser style which will work with stock & after market exhausts, or if he is making two styles; a custom centralized exhaust version and a stock/aftermarket exhaust version (like the options for the C6 platform). I heard somewhere that he was building the C5 diffuser around the B&B bullet exhaust (stock/aftermarket exhaust version?). I am more interested in the custom centralized exhaust version as it looks to be more on the functional side. Anyone have any info?

 

What sort of aero benefit will the diffuser generate? What other parts are needed to create correct aero balance with it?

 

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 Toyota GT-One actually use a proper diffuser in this area to help create more downforce.

 

Nice explanation, but let's face it: On the street it just looks

 

yes, and it looks sick

 

I understand the theory. But, if you change any part of an aero package, it affects other parts of the package. If you add large front downforce, you need to balance in the rear, cooling can be affected, you can get odd lifts, etc.

A splitter/board/diffuser with winglets and rear wing create downforce, but you must balance against extra drag, f/r balance, etc. Looks are nice, but I'd want a package that gets X downforce, X drag, is balanced f/r and l/r, and meshes with my cornerweighting and spring rates.

I thought perhaps Breathless had a package with some specs and recommendations.

When you hit 150 down the back straight at Road Atlanta, you don't want your nose getting light and loose, and worse yet, your rear getting light and loose under braking....

 

Yea your right, the diffuser can tell the difference between air on a race track and air on the street. Is it overkill for the street? maybe but i drive like JB does

 

I would buy one.

 

You really think you'll feel much difference when driven at normal street velocities? Even if you drive like a madman, I doubt the performance per dollar invested just ain't there, as compared perhaps to improved tires, shocks, etc. It's all about looks for a street-driven machine.

C'mon, I know you're with me on this.

 

I do drive like a madman but nobody sees it because i do it away from the public. After youve spent all your money on rubber, coilovers, sways, splitter, spoiler... you have to look elsewhere to improve grip performance.

Balance is more important to me than aesthetics right now. If i can get the car more planted at 100+ i will be greatly satisfied. The less speed you have to scrub off coming into a turn the faster your coming out.

But i can agree a lot of sales for such a product will end up on daily drivers, show cars or even weekend warriors. I happen to be the weekend warrior whos car can be driven to work every day. Sure beats the prius im using now for my commute

 

so how are they going to get this diffuser mounted?

 

Yeehaw
http://forums.corvetteforum.com/c5-g...post1569609446

 

Thanks for the update tbrent!

As soon as I get some pics from Ernie at Breathless I will post them up. Hopefully it won't be too much longer. We are still in need of some information regarding price, construction material (carbon fiber, fiberglass, composite material), and exhaust style accommodation/options. An update by Breathless Performance is definitely in order.

 

Looks like we have about a week before pics of the Breathless diffuser will be released. If someone took pictures of the Breathless Performance cars during the Bowling Green Corvette Bash please post them up.

 

As an aero engineering student, i'm interested to see what the actual numbers are for aero benefits. And how the diffuser was designed; if it was a purely CFD-based piece, or if it was a CFD piece validated with wind tunnel tests, etc.

Though a rear diffuser is a bit different from an aero standpoint than attaching a rear wing or front splitter; the diffuser acts to accelerate the flow under the entire underbody, thus making the underbody more efficient as a (low) pressure region. So, by putting on a rear diffuser, I would be less concerned about a force imbalance than if winglets, wings, splitter, etc. were added.

Still... for the hardcore racers out there, I would love to see some wind tunnel numbers!