aharte

Both Autoweek and Motor Trend (and that aero paper) say the drag coefficient is 0.34. The coupe's is 0.29.

Why are you saying a Z06 puts out 460 rwhp? I've seen about 440 hp in tests, and as I've mentioned, it will be significantly less than that in 5th gear.

Here's a dyno test for an M5: http://www.rototestinstitute.org/pop...p?ChartsID=153 The type of machine used connects directly to the hubs, so it is unfortunately hard to compare it directly to standard dynos.

bernrex

One of the Auto Rags claimed it was computer limited to 198 ... but, speculation is it will pull over 200 once computer is 'corrected'.

LTC Z06

That's good to know.

ZeeOSix

I don't think it's 0.34 unless it was re-measured and updated recently. At least originally it was advertised as 0.31 for the Z06 ... and actually the Coupe was 0.289 ... call it 0.29, not 0.28.

http://www.seriouswheels.com/top-200...rvette-Z06.htm

"The aerodynamics of the Z06’s exterior were shaped by the experiences of the Corvette racing program, where high-speed stability and cornering capability are paramount. And while the racecars use large rear wings, the Z06’s elevated spoiler provides sufficient downforce to balance the road-worthy front splitter without adversely affecting aerodynamic drag. The Z06’s Cd is .31."

GM might have a faulse advertising suit coming ...

There are lots of "Sources" out there that say 0.31 also ....
http://www.corvetteforums.com/Corvette-Z06-exterior.asp

Note the root website ... corvetteforums.com ... LOL.

Do your same search with 0.31 instead of 0.35.

LTC Z06

Why wouldn't you believe a SAE written by GM?

From: "The Chevrolet Corvette: New Vehicle Engineering and Technical History" published by Society of Automotive Engineers, Inc. It's a collection of SAE and other papers.

2005-01-1943 2006 Chevrolet Corvette C6 Z06 Aerodynamic Development pages 328-333.

"...develop the 2006 Z06 to provide it with improved high speed stability, increased cooling capability and equivalent drag compared to the 2004 C5 Z06."

EuG

I wish I was. I’d have both Z06 and M5 in my garage


I’m not arguing that it’s not 0.34, however all these sources are hardly reputable.
Most just copy data from one another.
Mags like C/D, MotorTrend etc are not better. They don’t know their *** from their head. I’ve seen them publish total bull$hit data.

When it comes to data like CD, since it’s very hard to measure it, even for a big shot magazine, the only numbers you can trust is official data from GM.

If it’s 0.34 than it’s 0.34

ZeeOSix

Where's that link ... sure I would believe them, but what bothers me is that they have changed the Cd number somewhere down the road. Early number was 0.31.

I'm gonna have to get the official GM sales brochure out and see what it says. If it's different than 0.34 then something has changed, or GM is false advertising.

LTC Z06

I've given you the book that the paper is in, you either buy the book or pay to see the paper on the SAE website.

http://www.sae.org/servlets/productD...PROD_CD=PT-118

SAE Bookstore

The Chevrolet Corvette: New Vehicle Engineering and Technical History

AUTHOR(S):
Daniel J. Holt More publications by this Author


The Chevrolet Corvette: New Vehicle Engineering and Technical History chronicles the development of America's favorite sports car by the designers and engineers who made it happen.

$129.95

ZeeOSix

I don't see an actual Cd number in that quote from the book. Give the quote that shows the Cd number ... "equivalent drag compared to the 2004 C5 Z06" isn't too definitive IMO.

Verrückt

"Specifications subject to change without notice"

I'm sure it says something to that extent somewhere. It always does.

bernrex

I thought we lost the NOTCHBACK style ... so GM could keep the cd close to the older Z's value.

0.34 is not close

ZeeOSix

Of course ... GM lawyers wouldn't have it (typical CYA) any other way.

EuG

Well all those scoops and fat tires don’t help CD
Fat tires also increase frontal area.

C5 Z06 was 0.31, C5 Coupe 0.29

LTC Z06

I already have, .34

But here's the entire quote, "Compared to its 2004 predecessor, the new Z06 is shorter, has larger wheels and tires, large wheel flares as well as features that provide significant lift reduction. These differences are generally associated with a substantial increase in drag. Extensive optimization development resulted in no increase in Drag Coefficient (Cd) with the new Z06 at a Cd of 0.342 vs. 0.342 for the 2004 Z06."

They used over 240 wind tunnel hours. The paper also states that the mirrors were retained because they are used on the race car and actually produce some down force; and are quiet.

John Shiels

I remenber reading they had to work hard to make the new C6 meet the C5's CD never mind the C6Z. Same thing happen on the race car. Downforce is good but can create drag. The more air that passes through a car body the more drag it has. So the large front opening is drag. Like when NASCAR starts to tape up the nose it's to reduce drag and increase downforce. Then it becomes a balancing act with the cooling system.

ZeeOSix

That's more like it ...

I thought the C5 Cd was lower than that to begin with ... at least in the early days of the C5 Zee it was never quoted as being that high -- I think it was quoted as 0.31 (0.29 for the C5 Coupe) in the specs ... will have to dig the info up. Probably another one of those optimistic first cuts by GM bull$hit.

This source says this car has a Cd of 0.34 also ... looks real close to the body shape of the new Zee.
http://en.wikipedia.org/wiki/Chevrolet_Caprice

I see they are way off on the "Chebrolet" Z06 ...
http://en.wikipedia.org/wiki/Drag_coefficient

LTC Z06

I emailed a lot of engineers about the Cd, so far the one that has replied back worked on the AL frame. So I've asked him if the frame can become a vert. We'll see if he replies.

david.k

its just a bragging right. most of us will never go 200. only 0 to 60, 1/4 mile, slalom, and skidpad are important. If even those.

Mako7

I am curious to know why the C6Z does not have the big underbody rear diffuser you see on the Viper, Ford GT, Vision SLR, etc.

My guess is that it was just not needed.

LTC Z06

Bingo! Also, just because a car looks like it has a rear diffuser don't assume that it actually works. I'd be surprised if the Vipers does anything.