Z06 tested in new SAE horsepower rating procedure

[Jason C]

Detroit - General Motors has become the first manufacturer to certify its horsepower and torque rating using the new Society of Automotive Engineers (SAE) test procedure J2723. The 7.0L LS7 engine for the 2006 Corvette Z06 is the first to be certified under the new test procedure at 505 horsepower @ 6300 rpm and 470 lb-ft @ 4800 rpm.

"The new voluntary SAE power and torque certification procedure ensures fair, accurate ratings for horsepower and torque as it uses third-party certification," said Jim Queen, GM vice president, global engineering and the general chair for the 2005 SAE World Congress. "SAE technical standards level the playing field and this certification procedure is just the latest example of the value SAE has offered over the past century."

"We're very proud to be the first to certify engines with the new procedure and pleased with the LS7 certification results," said Tom Stephens, group vice president of GM Powertrain. "Going forward, GM will certify its engines to the new procedure as we want customers to have accurate information when they make a purchase decision. GM encourages all manufacturers to do the same."


From what I can tell of the press release, the only major difference is that it uses a third-party to obtain the figures. Nice that the Z06 gained 100hp from one generation to the next.

:bigpimp:

http://a5.cpimg.com/image/B7/B3/46161335-11f2-02000154-.jpg

[Jason C]

From some guy that actually attended (edited for clarity):

Now my notes from the Corvette technical sessions:
The LS7 produces 505hp @ 6300 rpm
and 470 lb-ft @ 4800 rpm
400 lb-ft is available from 2000 rpm
This is the first engine tested under SAE standard J 1349 revised
All GM engines will be tested under this standard from now on. This standard basically requires a third party certified SAE representative to certify the horsepower. All other manufacturers will probably use this standard soon as well.

The C6 was the first 400hp car that did not require the gas guzzler tax and they are hoping the C6 Z06 will be the first 500 hp car without the gas guzzler tax. This is not in the bag but preliminary results look promising.

On one presentation by Tadge Jeuchter (assistant vehicle chief engineer) he listed price versus power to weight. The price was between 65 and 70K. The power to weight ratio was better than the Ford GT and the Ferrari 360.

The aluminum frame saved 136 lbs
Magnesium roof panel saved 6.6 lbs
Carbon Fiber floors and wheel housings saved 7.5 lbs
Magnesium engine cradle saved 12 lbs
Carbon Fiber fenders saved 11.7 lbs

The frame was engineered to match steel frame physical and functional interfaces.
First time a frame engineered in steel has been reengineered for aluminum. Their basic goal was to make the production process at Bowling Green no different than with the steel frame.

The reason for CF fenders instead of hood is mainly the fenders had to be changed anyway to accommodate the wider tires and the hood is a carryover part from the C6. More on that later.

The shared panels between the C6 and Z06:
Hood, Roof Skin, Doors, Hatch, Rear Facia

Unique parts:
Front Fascia, Fenders

The 2005 clutch was designed for the Z06 output so the clutch is the same used on the base C6

The LS7 is actually 11 mm narrower than the LS2.

The intake on the LS7 is 25% less restrictive than the LS2
Same restriction as LS6 but with 23% higher airflow at peak horsepower.

Cylinder Heads flow 40 % more than the LS6 on intake 25% more on exhaust.

Valve angle went from 15-12 degrees due to racing experience.
Rocker ratio went from 1.6 to 1.8
Lift on Cam is 15mm or .591"

The titanium valves and con rods are coated for thermal protection.
Titanium intake valve (56mm) is 26% lighter than LS2
Sodium filled exhaust valves (41mm) are 18% lighter than LS2

LS7 has 37% lower back pressure than LS2.

Crankshaft is 4140 steel w/ undercut and rolled filets
Piston: floating pin with polymer coated skirts
Rods are tapered on piton pin end to reduce mass
Engines are balanced, hot tested, and shipped to Bowling Green

Z06 gear ratios: 2.66, 1.78, 1.3, 1, 0.74, 0.5
C6 Z51 ratios: 2.97, 2.07, 1.43, 1, 0.84, 0.57
Does not reduce Z06 top speed but the Z06 will probably not reach 200 mph. It will top out above 190 though.

Tires were developed by Goodyear and feature Goodyear patented technology developed on the C5-R called DTS.
DTS= dynamically tuned solution.
It basically features an asymmetrical trade pattern so tires “lean” into turns.

Tires: C5 Z06 - C6 Z06
Front: 265/40ZR17 - 275/35ZR18
Rear: 295/35ZR18 - 325/30ZR19

Wheels
Front: 17x9.5 - 18x9.5
Rear: 18x10.5 - 19x12

Brakes
C5 Z06:
2 piston front
1 piston rear
2 pads per caliper

C6 Z06:
6 pistons front
4 pistons rear
1 pad per piston (all same part number)

Rotors: C5 Z06 - C6 Z06
Size(mm) weight(lbs) - Size(mm) weight(lbs)
Front: 325x32 8.2 - 355x32 11.5
Rear: 305x26 6.3 - 340x26 8.9

Exhaust went from 2.5” nominal diameter to 3”

Aerodynamics:
Drag coefficient 0.34


Added Mass vs. saved Mass (compared to normal C6)
Brakes +27.5 lbs
Dry sump oil +17.6 lbs
Exhaust +11.7 lbs
Rear battery +8.8lbs
High capacity Axle +8.8 lbs
Engine Oil Cooler and diff cooler +7.7 lbs
Wheels and tires +6.2 lbs

Aluminum Frame -136 lbs
Interior and acoustics -33 lbs
Magnesium front cradle -11.9 lbs
Carbon Fiber fenders -11.7 lbs
Carbon Fiber floors and wheel housing -7.5 lbs
Fixed roof -6.6 lbs

Totals:
88.3 lbs added - 206.7 lbs removed



Some power to weight ratios (lbs per hp)
Enzo 4.53
Saleen S7 5
Carrera GT 5.03
Z06 6.26
Ford GT 6.31

Weight distributions: Front% - Rear%
C6 Z06 50.6 49.4
C6 coupe 52.3 47.7
C5 Z06 53.6 46.4

Z06 is capable of 205 in 5th gear although it won’t hit 200 mph due to aerodynamics.
60 mph in 1st gear


Power and efficiency
Same chart as in back of the book C6 and in the April issue of Automotive Engineering International so I won’t post everything

Power Fuel Economy Index:
Z06 505 hp 20.7 mpg (conservative) 10,500
C6 400 22.6 9040
911 GT2 477 18.2 8681
Viper SRT-10 500 15.5 7750

Reason Ceramics were not used for Rotors –affordability (duh)

Aerodynamics
Nf / N @ 300 kph 0.48 Normal Force Distribution
Ram FEAF 48.9 Cooling flow
Powered FEAF 63 powered cooling flow

300 lb reduction in lift at 186 mph
Side mirrors actually produce downforce

Part reduction in drag
Splitter - 202 lbs
Wheel opening leading edge extension - 22 lbs
CHMSL - 80 lbs
Total: 304 lbs

Brake flow @ 80 kph (50mph)
C5 Z06 - C6 Z06
Front 2 cmm - 10 cmm
Rear 1 cmm - 2 cmm

Dual durometer front air dam is common to XLR, C6, and Z06
Consists of stiff upper section to keep its shape at speed and softer lower section to reduce scraping on curbs.

Still being worked on is a brake duct incorporated into front splitter

They actually brought in a 360 modena to test it’s aerodynamics because Ferrari claims it actually produces downforce. The Corvette guys were not able to duplicate that in the lab but said it is possible that it may produce a little downforce.

AL space frame:
Total weight of frame - 285 lbs
Steel frame is - 421 lbs


Their goal in developing the AL frame was seamless integration into the assembly process

The aluminum frame increase in effective gage by 1.9 mm
Steel frame gage is 2mm
AL frame gage is 4mm

Aluminum vs. Steel
Bending Stiffness: 22.9Hz - 21.5Hz
Torsional Stiffness: 28.3 Hz - 26.9Hz


As to why they didn’t use magnesium for the rear cradle:
The main goal for the C6 Z06 was weight reduction in the front.
Engineering restrictions would have been basically the same as the front.


Carbon Fiber:

2004 hood was first class A surface CF panel

They plan on building 7000 Z06 a year

Main priority for weight reduction was front parts and high parts to improve weight distribution and center of gravity

Candidates for CF body panels
Hood, Fenders, roof, rear quarters

Structural candidates
Interior and outer wheel house, Tub reinforcement, floor panels, Upper and lower plenum

Rear quarter panels were not chosen even though they had to redesign them anyway because of low priority for weight reduction in the rear. Same for Tub reinforcement.
Hood was a carryover part so cost would have been even more to develop new part out of CF. More later-


Wheel house outers accounted for 22 lbs of weight savings with no increased tooling costs.

The floor panels are Balsa wood sandwiched inside CF (Carbon molding compound to be exact). The continuous random glass strand mat on the C6 is 1.25mm thick top and bottom versus 0.9 mm of CF.

Specific gravity is 1.5 vs 1.9 for fiberglass
1.41 kg saved per panel

Carbon Fiber wheel housing:
2mm thick versus 2.5 mm for normal part
1.1 specific gravity versus 1.4
0.73 kg saved per part

The Z06 will be the highest production volume of Carbon Fiber parts @ 7000 cars per year
2004 Z06 Carbon Fiber hood was largest previously at 2000 parts in a year

Choice of Fenders over hood:
Tooling costs:
Validation complexity because of opening and closing of hood and other reasons.
More Quality improvement for the fenders than the hood.
No bonding or bond readout problems with fenders because of no need for bonding.

Risks with fender:
Complex shape
Die locks

RRIM CF
Specific gravity 1.33 gm/cm 1.58
Thickness 3.5 mm 1.2 mm
Natural Frequency 1st mode 32.4Hz 70.8

$500 k in tooling costs saved in development of Fenders

They are looking at other technologies than glass for rear hatch

Ti exhaust was scrapped pretty much purely for cost reasons but the priority of weight reduction in the front also played a small part.


What I noticed right away: The LS7 could actually be a little smaller than the LS2? Bwahahahaha! Wait till all the mag comparo's/UK TV reviews come out, criticizing it for its "Obsolete, massive 7.0L pushrod motor." :rolleyes: :rolleyes: :rolleyes:

Also, it looks like we have a confirmed price of between $65k-$70k. :thumbup:

7,000 per year. Better get on the list now, if you can swing that kind of change.

[JST]

This is what grabbed my eye (among many other interesting facts):

Weight distributions: Front% - Rear%
C6 Z06 50.6 49.4
C6 coupe 52.3 47.7
C5 Z06 53.6 46.4

So much for the idea that the 7.0L is going to make the C6 Z06 too nose heavy to autocross.

Also, 60 mph in 1st gear.

And 400 lb ft of torque from 2K RPM.

This thing is going to be a frigging monster.

Actually, 7,000 units is quite a bit for a car of this type (and price point). Something in there suggested that the 04 C5 Z06 might have only totaled 2000 units.

It'll be interesting to see if they can actually sell that many. I wouldn't expect dealer gouging to last more than a year or so, but I've been wrong before.

[blee]

The LS7 is actually 11 mm narrower than the LS2.

Bullcrap, the LS7 displaces like 25 liters. It's bigger than the LS2, so tell me how in the world it can be smaller? This whole article is crap. Crappity crap crap. Carp, I tell you.

[blee]

http://www.sdafs.org/laafs/Amazing%20Fish%20Pictures/Fantail%20Carp.JPG

[blee]

Anyway, back to the topic at hand. The stats are impressive on their own, but anyone who had the chance to see it at NAIAS must agree...it's also stunning. I've never seen a more beautiful post-'67 Vette before in my life. Add to it the ridiculous performance and the fact that it costs less than just about any serious competitor, and it will give any new owner reason enough to smile for every minute behind the wheel.

Let's just hope there aren't a significant number of little glitches at launch, like some of the column lock and saggy body panel issues that kept the new C5 from being a 100% winner out of the blocks.

[Jason C]

The LS7 is actually 11 mm narrower than the LS2.

Bullcrap, the LS7 displaces like 25 liters. It's bigger than the LS2, so tell me how in the world it can be smaller? This whole article is crap. Crappity crap crap. Carp, I tell you.

:lol: :lol: :lol:

You need to put one of these in your car:

http://www.firebreathingfiats.com/Contribute/contact/images/Ricer-excuse-gaugeweb.jpg

[clyde]

Something in there suggested that the 04 C5 Z06 might have only totaled 2000 units.

Not at all. 2004 Z06 production was over 5,600 units. Of those, just over 2,000 had the Z16 option, which was the "Commemerative Edition Package" which included a CF hood, and it was the only way to get the CF hood.

[Jason C]

I like the new media pics, especially when I can zoom them to 2x life size:

http://gm.wieck.com/forms/gm/PV__024262__.jpg http://gm.wieck.com/forms/gm/PV__024277__.jpg
http://gm.wieck.com/forms/gm/PV__024285__.jpg http://gm.wieck.com/forms/gm/PV__024296__.jpg
http://gm.wieck.com/forms/gm/PV__024297__.jpg http://gm.wieck.com/forms/gm/PV__024298__.jpg
http://gm.wieck.com/forms/gm/PV__024303__.jpg http://gm.wieck.com/forms/gm/PV__024305__.jpg
http://gm.wieck.com/forms/gm/PV__024306__.jpg http://gm.wieck.com/forms/gm/PV__024309__.jpg


Stuka's favorite part of the Z06:
http://gm.wieck.com/forms/gm/PV__024295__.jpg

And the part that's going to bug him:
http://gm.wieck.com/forms/gm/PV__024315__.jpg

:eeps: :)

(Btw blee, I zoomed up one of the earlier media pics enough to get a clear look at the center electrode. It looks like the LS7 will come with the ACDelco Iridiums stock.)

[FC]

Awesome. Simply awesome.

"If I were a rich man..."

[JST]

Something in there suggested that the 04 C5 Z06 might have only totaled 2000 units.

Not at all. 2004 Z06 production was over 5,600 units. Of those, just over 2,000 had the Z16 option, which was the "Commemerative Edition Package" which included a CF hood, and it was the only way to get the CF hood.

Ah. I stand corrected.

Still, the new car represents a 1400 per year increase over the old? At a (substantially) higher price? IIRC, there was no problem getting GMS and other discounts on the 04 Z06s. I suspect that will be true of the new ones, as well.

[Rob]

Do you see where that oil filter is? That's what I was talking about in the other thread. Except there is no traditional oil pan on this motor. But you get the picture.

[Jason C]

Do you see where that oil filter is? That's what I was talking about in the other thread. Except there is no traditional oil pan on this motor. But you get the picture.

Yeah, my car is the same. The drainback valve should be in the center return line on the engine block.

[clyde]

Something in there suggested that the 04 C5 Z06 might have only totaled 2000 units.

Not at all. 2004 Z06 production was over 5,600 units. Of those, just over 2,000 had the Z16 option, which was the "Commemerative Edition Package" which included a CF hood, and it was the only way to get the CF hood.

Ah. I stand corrected.

Still, the new car represents a 1400 per year increase over the old? At a (substantially) higher price? IIRC, there was no problem getting GMS and other discounts on the 04 Z06s. I suspect that will be true of the new ones, as well.

Everyone has known for some time that the C6 was on it's way for 06 (actually, as late as early 02 it was thought that it was likely to go on sale as an 05 in the spring of 04). On top of that, everyone expected the Z06 to be replaced (by the same or another historically significant option code) as well. And everyone expected them to be HOT, HOT, HOT.

The market for new Corvettes is only so large no matter what the pricing (within reason). It took GM almost four years to meet that demand with the C5 (get them into the hands of pretty much everyone that really wanted one and was capable of getting one). The end of that period was when the focus shifted to the C6.

They had trouble moving the end of the run C5s because of the upcoming C6.

Look at the Mustang, the GT in particular, as a smaller scale but larger volume example.

[blee]

I'm curious as well to see how the sales figures for the new Z06 add up. My back-of-the-envelope guess, however, is that Chevy will meet their targets for at least the first year. The real question is whether current or wannabe Z06 owners are willing to step up to the plate and spend significantly more money for the new car. The new Z's superiority over the C6 far outshines the old Z06 compared to the C5, but it was also some $20k cheaper. The well-heeled Corvette buyer probably won't mind so much. There are, however, many Corvette buyers who basically spent the very limit of their car allowance on the C5; people with "regular jobs" who know that the Vette is an extraordinary performance value. I don't know how many of those are out there, and how many would pony up the extra dough. If there aren't enough, then the new Z06 will have to compete against 911 buyers, NSX (hah) buyers, and the like. Whether the perceived or real differences between the Z06 and the rest of that pack is going to put it into a favorable light remains to be seen.

[blee]

BTW, those media pics are fricking beautiful. BEAUTIFUL. I love that stuff.

One observation, though. Why did Chevy not go the final step and cobble up a set of tubular headers for the LS7? Is it possible that they did and just decided to scrap them, in the name of efficiency? Hell, my Focus came with headersssss from the factory.

[Jason C]

BTW, those media pics are fricking beautiful. BEAUTIFUL. I love that stuff.

One observation, though. Why did Chevy not go the final step and cobble up a set of tubular headers for the LS7? Is it possible that they did and just decided to scrap them, in the name of efficiency? Hell, my Focus came with headersssss from the factory.

They did, mostly. The picture just underneath the crank shows a cutaway view of what they designed for the LS7. Headers are an inherent compromise of sorts, the trick is to tune their length so that the exhaust gas pulses will not collide at a certain RPM range. Given that the LS7 redlines at 7000, I'd say they tuned it biased for higher-RPM operation.

[lemming]

I'm curious as well to see how the sales figures for the new Z06 add up. My back-of-the-envelope guess, however, is that Chevy will meet their targets for at least the first year. The real question is whether current or wannabe Z06 owners are willing to step up to the plate and spend significantly more money for the new car. The new Z's superiority over the C6 far outshines the old Z06 compared to the C5, but it was also some $20k cheaper. The well-heeled Corvette buyer probably won't mind so much. There are, however, many Corvette buyers who basically spent the very limit of their car allowance on the C5; people with "regular jobs" who know that the Vette is an extraordinary performance value. I don't know how many of those are out there, and how many would pony up the extra dough. If there aren't enough, then the new Z06 will have to compete against 911 buyers, NSX (hah) buyers, and the like. Whether the perceived or real differences between the Z06 and the rest of that pack is going to put it into a favorable light remains to be seen.

there could be some conquest sales, though. it is in the realm of possibility, either from enthusiasts who are less badge sensitive or viper owners.

but 7k cars per year @ 70k seems......dreamy?

i'm definitely going to wait until spring mountain motorsports gets some z06s (c6) in their inventory to drive one at the limits to see if i still want one.

after this past experience comparing the c5 z06 to the much ballyhooed c6 z51 (you know, the one that gets marginally chosen over the 997S in some cases?), i am really lukewarm on the c6. the interior is definitely not the huge step inside it was said to be, the brake feel is horrible, the steering is numb and even with the z51 there is a whole heck of a lot of body motion going on there.

nice engine, but really muted.

the whole thing made me shake my head. i pity c6 owners who think they bought a sports car. they bought a decent GT.