ZR1

[Rich Z]

http://www.autoweek.com/apps/pbcs.dl...735513721/1065


After four years of denials, innuendo, spy shots, "wink-wink" confirmations and strategically choreographed "surprise" appearances, Chevrolet has released details of its worst-kept secret.

The 2009 Corvette ZR1--referred to during those many months of development as Blue Devil, Sting Ray and Corvette SS--will go into production next summer at the Corvette assembly plant in Bowling Green, Kentucky, and will go on sale in fall 2008. Chevy will not complete official horsepower and torque certification until spring, but Corvette assistant chief engineer Tadge Juechter says to expect at least 100 hp per liter. That equals 620 hp to go along with approximately 600 lb-ft of torque from an all-new, 6.2-liter aluminum-block LS9 V8. Juechter dismissed long-standing online forum speculation that the engine--built at the GM Performance Center in Wixom, Michigan--might produce as much as 700 hp, pointing out that 100 hp per liter is about the maximum for a reliable supercharged engine fit for everyday use.


This is the heart of the ZR1--the LS9 6.2-liter supercharged V8 is make at least 620 hp and 600 lb-ft of torque.
Bore is 4.06 inches, and stroke is 3.62 (as on the LS3 used in Corvette coupes and convertibles). The LS9 has a lower 9:1 compression ratio than both the LS3 and the Z06's LS7. A new forged-steel crank, steel cylinder liners, titanium connecting rods and intake valves and sodium-filled hollow exhaust valves are all LS7 features, too, but these actual parts are unique to LS9. Twelve-millimeter head bolts (versus 10 millimeters for the LS7) and piston-cooling oil squirters are LS9-only. Pistons are forged aluminum, whereas the LS7's are cast. Valve lift remains 14 millimeters, but overlap decreases slightly in the name of refinement.

"This is not 'Z06-plus'; it's a different kind of car," Juechter said. "Z06 is kind of a lean track machine; this offers all of the performance but also everything else. It's very sophisticated and not purely for track use. It will post faster times at any track than the Z06 will, but it's also a lot more comfortable. It's for the guy who wants it all."


The ZR1's interior is similar to that used in the Corvette Z06.
An Eaton Roots-type supercharger breaks new ground. The sixth-generation twin-rotor design uses four lobes on each rotor (versus three on the previous generation) and also twists each lobe 160 degrees (versus 60 degrees). The net effect is a far more efficient blower that requires less power to turn, takes up less space under the hood and weighs less. Spinning at the same speed, the new unit produces 20 percent more airflow with about 35 percent less parasitic drag on the engine. Another benefit is a reduction in induction/supercharger noise.

Rather than using a typical single heat exchanger/intercooler setup mounted directly above the engine's centerline, LS9 uses two outboard-mounted heat exchangers and intercoolers--packaging that eliminates the need for an enormous hood bulge.

With the engine mounted slightly lower than in other Corvettes and the intercoolers' location, the hood bulge is only about an inch high and should not interfere with forward sight-lines. A polycarbonate window exposes the top of the cast-aluminum intercooler cover.

Overall styling does not depart radically from that of the Z06, but several obvious visual cues differentiate the ZR1. The supercharger alone adds about 100 pounds to the car's nose, so engineers offset that somewhat with a carbon-fiber hood and front fenders that feature dual-gill air outlets behind the front wheels. The rear spoiler is new, designed to balance downforce produced by a large front splitter.


The ZR1 gets a redesigned rear spoiler to balance downforce from the large front splitter.
Loads of unpainted carbon fiber distinguish the ZR1, including the splitter, roof and its supporting "bow," and rocker-panel extensions. Because ultraviolet light degrades unpainted carbon fiber, General Motors bought a $60,000-per-gallon UV-blocking clear-coat additive that's used in the circuit-board industry. Juechter said carbon-fiber breakdown would have been unacceptable in a car that almost certainly will sell for $100,000 to $125,000.

Chevy skipped the carbon treatment on the rear end, partly because of weight distribution. While the Z06 comes in at 50/50 distribution, the ZR1 is in tune with the base car's slightly more front-heavy 52/48, making traction a concern. Curb weight should be about 3350 pounds, depending on equipment, roughly 200 pounds heavier than the Z06.

Larger wheels and tires also aid traction and differentiate the ZR1 from its brethren. Custom Michelin Pilot Sport 2 run-flats measure 285/30R-19 in front and ride on 10-inch-wide, one-piece Speedline 20-spoke rims; rears measure 335/25R-20 on 12-inch-wide Speedlines. The bigger wheel-and-tire combination weighs more than the Z06's, but total unsprung weight decreases, thanks to the standard carbon-ceramic Brembo brake system. Monoblock six-piston front calipers stop ridiculously large 15.5-inch front rotors, developed originally as front brakes for Ferrari's FXX multi-millionaire track-day special. Rear calipers use four pistons to clamp 15-inch rotors lifted from the Ferrari Enzo's front brakes. Stopping power should be incomprehensible, as the Brembo setup offers twice as much pad/rotor contact area as the Z06's to go along with the typical benefits of carbon-ceramic discs.


A low profile intercooler was designed to sit on top the ZR1's supercharger--hood height is raised only about 1 inch.
As Juechter said, Chevy wants the car to appeal beyond the ultra-hard-core set. Standard magnetic selective ride control, which offers both touring and sport modes, is a key fundamental difference from the Z06. The adjustable suspension allows for reduced spring rates and a more coddling ride, with larger antiroll bars providing enough stiffness to produce racetrack-appropriate handling in sport mode. Corvette's familiar four-mode traction/stability system remains.

Other hardware changes include steering with a mechanically variable ratio, from 17.1:1 on-center to 14.6:1 as you wind on lock. Compared with the Z06's 2.78 turns lock-to-lock, only 2.54 turns are needed. A new 260-millimeter twin-plate clutch handles the engine's torque, as do stronger prop-shaft couplings, driveshafts, ring and pinion and billet-machined steel limited-slip differential housing. The Tremec six-speed manual gearbox is strengthened internally and is a much closer-ratio box than usual for Corvettes. A tall gear allows for speeds higher than 65 mph in first, while top speed is achieved in a relatively short sixth gear rather than fifth, as is the Corvette norm. Chevy has not released performance numbers, but 0-to-60 mph should be less than 3.5 seconds--if you can put the power down efficiently. Expect a quarter-mile time in the low-11-second range, with a top speed between 200 and 205 mph, although 214 mph is theoretically possible, according to Juechter.

GM plans to build ZR1s at a max volume of approximately 2000 per year for the remainder of the C6's life cycle--about four more years--plenty of time for it to stake its claim as the all-time Corvette king.

[Rich Z]

Wow! 200 pounds HEAVIER than the Z06? That's even with the lighter carbon fiber body panels? Yeah, I know the supercharger adds about 100 pounds all by it's lonesome, but I'm surprised at the extra fat (or is it muscle?) thrown in.

On one hand I think I would like to get one of these, but on the other I think not. Not real crazy about the clear plastic bubble on the hood. It will look like crap when it eventually gets hazy looking.

I found it interesting that GM went with the LS3 block instead of the LS7. I read somewhere that the engineers were concerned that the cylinder walls on the LS7 were too thin to hold up under a boosted application. Sure puts a wrinkle in my idea of maybe getting a C6Z06 one of these days and going the boosted route with it. Already heard concerns over the strength of the pistons in the LS7, but at least they are replaceable.

So I guess the question is, does the ZR1 justify the cost difference over the Z06 based on what you are getting for those dollars? People are talking about dealer gouging of maybe $20K over the MSRP price of about $100K. Is the new LS9 (which is really just a reworked LS3 with a blower on top of it) really that much more expensive to offer than the LS7?

So who does GM consider to be their main competitor in the market that would be interested in buying a ZR1? And how does the price/performance ratio stack up in comparison? Right off hand, I think top of the list would be the Dodge Viper. Right off the showroom floor, performance specs are apparently REAL close. With a MSRP base of $86K, I think it's going to be a tough call for someone not married to the Corvette. Having $10K still sitting in the pocketbook after the purchase of a Viper to put into performance mods could sway a lot of people to that direction.

Heck, for that matter, I think a moderately used Ferrari will catch someone's eye when they get up into the price range of the new ZR1.

Not to mention that the economy is real sluggish lately, so people are going to be a bit more circumspect of how they spend their money.

The argument that the Corvette has a LOT of bang for the buck doesn't hold a much water when the buck goes too high in relation to the bang. Someone looking for simply the bang can spend their bucks more wisely than having to have the newest toy on the block.

So, I'm thinking maybe GM overshot the mark on pricing on this guy. Or maybe they just changed their marketing strategy to point towards a different target market.....

[Gary S]

I'm interested to see what the car ends up selling for in relation to MSRP.

[spiceman]

Originally Posted by Rich Z

http://www.autoweek.com/apps/pbcs.dl...735513721/1065


After four years of denials, innuendo, spy shots, "wink-wink" confirmations and strategically choreographed "surprise" appearances, Chevrolet has released details of its worst-kept secret.

The 2009 Corvette ZR1--referred to during those many months of development as Blue Devil, Sting Ray and Corvette SS--will go into production next summer at the Corvette assembly plant in Bowling Green, Kentucky, and will go on sale in fall 2008. Chevy will not complete official horsepower and torque certification until spring, but Corvette assistant chief engineer Tadge Juechter says to expect at least 100 hp per liter. That equals 620 hp to go along with approximately 600 lb-ft of torque from an all-new, 6.2-liter aluminum-block LS9 V8. Juechter dismissed long-standing online forum speculation that the engine--built at the GM Performance Center in Wixom, Michigan--might produce as much as 700 hp, pointing out that 100 hp per liter is about the maximum for a reliable supercharged engine fit for everyday use.


This is the heart of the ZR1--the LS9 6.2-liter supercharged V8 is make at least 620 hp and 600 lb-ft of torque.
Bore is 4.06 inches, and stroke is 3.62 (as on the LS3 used in Corvette coupes and convertibles). The LS9 has a lower 9:1 compression ratio than both the LS3 and the Z06's LS7. A new forged-steel crank, steel cylinder liners, titanium connecting rods and intake valves and sodium-filled hollow exhaust valves are all LS7 features, too, but these actual parts are unique to LS9. Twelve-millimeter head bolts (versus 10 millimeters for the LS7) and piston-cooling oil squirters are LS9-only. Pistons are forged aluminum, whereas the LS7's are cast. Valve lift remains 14 millimeters, but overlap decreases slightly in the name of refinement.

"This is not 'Z06-plus'; it's a different kind of car," Juechter said. "Z06 is kind of a lean track machine; this offers all of the performance but also everything else. It's very sophisticated and not purely for track use. It will post faster times at any track than the Z06 will, but it's also a lot more comfortable. It's for the guy who wants it all."


The ZR1's interior is similar to that used in the Corvette Z06.
An Eaton Roots-type supercharger breaks new ground. The sixth-generation twin-rotor design uses four lobes on each rotor (versus three on the previous generation) and also twists each lobe 160 degrees (versus 60 degrees). The net effect is a far more efficient blower that requires less power to turn, takes up less space under the hood and weighs less. Spinning at the same speed, the new unit produces 20 percent more airflow with about 35 percent less parasitic drag on the engine. Another benefit is a reduction in induction/supercharger noise.

Rather than using a typical single heat exchanger/intercooler setup mounted directly above the engine's centerline, LS9 uses two outboard-mounted heat exchangers and intercoolers--packaging that eliminates the need for an enormous hood bulge.

With the engine mounted slightly lower than in other Corvettes and the intercoolers' location, the hood bulge is only about an inch high and should not interfere with forward sight-lines. A polycarbonate window exposes the top of the cast-aluminum intercooler cover.

Overall styling does not depart radically from that of the Z06, but several obvious visual cues differentiate the ZR1. The supercharger alone adds about 100 pounds to the car's nose, so engineers offset that somewhat with a carbon-fiber hood and front fenders that feature dual-gill air outlets behind the front wheels. The rear spoiler is new, designed to balance downforce produced by a large front splitter.


The ZR1 gets a redesigned rear spoiler to balance downforce from the large front splitter.
Loads of unpainted carbon fiber distinguish the ZR1, including the splitter, roof and its supporting "bow," and rocker-panel extensions. Because ultraviolet light degrades unpainted carbon fiber, General Motors bought a $60,000-per-gallon UV-blocking clear-coat additive that's used in the circuit-board industry. Juechter said carbon-fiber breakdown would have been unacceptable in a car that almost certainly will sell for $100,000 to $125,000.

Chevy skipped the carbon treatment on the rear end, partly because of weight distribution. While the Z06 comes in at 50/50 distribution, the ZR1 is in tune with the base car's slightly more front-heavy 52/48, making traction a concern. Curb weight should be about 3350 pounds, depending on equipment, roughly 200 pounds heavier than the Z06.

Larger wheels and tires also aid traction and differentiate the ZR1 from its brethren. Custom Michelin Pilot Sport 2 run-flats measure 285/30R-19 in front and ride on 10-inch-wide, one-piece Speedline 20-spoke rims; rears measure 335/25R-20 on 12-inch-wide Speedlines. The bigger wheel-and-tire combination weighs more than the Z06's, but total unsprung weight decreases, thanks to the standard carbon-ceramic Brembo brake system. Monoblock six-piston front calipers stop ridiculously large 15.5-inch front rotors, developed originally as front brakes for Ferrari's FXX multi-millionaire track-day special. Rear calipers use four pistons to clamp 15-inch rotors lifted from the Ferrari Enzo's front brakes. Stopping power should be incomprehensible, as the Brembo setup offers twice as much pad/rotor contact area as the Z06's to go along with the typical benefits of carbon-ceramic discs.


A low profile intercooler was designed to sit on top the ZR1's supercharger--hood height is raised only about 1 inch.
As Juechter said, Chevy wants the car to appeal beyond the ultra-hard-core set. Standard magnetic selective ride control, which offers both touring and sport modes, is a key fundamental difference from the Z06. The adjustable suspension allows for reduced spring rates and a more coddling ride, with larger antiroll bars providing enough stiffness to produce racetrack-appropriate handling in sport mode. Corvette's familiar four-mode traction/stability system remains.

Other hardware changes include steering with a mechanically variable ratio, from 17.1:1 on-center to 14.6:1 as you wind on lock. Compared with the Z06's 2.78 turns lock-to-lock, only 2.54 turns are needed. A new 260-millimeter twin-plate clutch handles the engine's torque, as do stronger prop-shaft couplings, driveshafts, ring and pinion and billet-machined steel limited-slip differential housing. The Tremec six-speed manual gearbox is strengthened internally and is a much closer-ratio box than usual for Corvettes. A tall gear allows for speeds higher than 65 mph in first, while top speed is achieved in a relatively short sixth gear rather than fifth, as is the Corvette norm. Chevy has not released performance numbers, but 0-to-60 mph should be less than 3.5 seconds--if you can put the power down efficiently. Expect a quarter-mile time in the low-11-second range, with a top speed between 200 and 205 mph, although 214 mph is theoretically possible, according to Juechter.

GM plans to build ZR1s at a max volume of approximately 2000 per year for the remainder of the C6's life cycle--about four more years--plenty of time for it to stake its claim as the all-time Corvette king.

A few more pic's hence : Blue Devil

[spiceman]

looks very...............usual?

[THOR]

I wonder if this will dilute the Z06 or cause it's demise over time. The stock C6 is getting closer to the stock Z06 and if the C6 keeps improving in performance and upgrades and the Z06 does not, then the Z06 becomes less of a wow factor.

[Rich Z]

Originally Posted by mte.smiles

I wonder if this will dilute the Z06 or cause it's demise over time. The stock C6 is getting closer to the stock Z06 and if the C6 keeps improving in performance and upgrades and the Z06 does not, then the Z06 becomes less of a wow factor.

Yeah.... I found it interesting that GM used the LS3 as the base for the LS9 rather than using the LS7. That is kind of telling me that if you want to buy a C6 to build up, you may be better off starting with the base C6 instead of the Z06.

Wonder what a crate LS9 will be selling for?

[spiceman]

Originally Posted by Rich Z

Yeah.... I found it interesting that GM used the LS3 as the base for the LS9 rather than using the LS7. That is kind of telling me that if you want to buy a C6 to build up, you may be better off starting with the base C6 instead of the Z06.

Wonder what a crate LS9 will be selling for?

I was disappointed in that the orginal ZR1 was a totally different platform.
Thought maybe GM would turn to the cancelled ZR2 platform only instead use the new 572 cu in 720 hp 9.0 liter engine. (has a crate $ of 15K) which is VERY reasonable. Send that off to Kateck, LBP, or MTI to have it really preped correct, and your talking a race car.....not a street car.

Spiceman

[Rich Z]

I guess I'm disappointed, all things considered. I had been SERIOUSLY considering selling off much of my gun collection to buy this new beast. Do the museum delivery and the whole nine yards.

But I really don't think I can bring myself to do it. This car falls short of the mark I think it could have hit.

Too much money but not enough put on the table, IMHO.

Got any more info on that 572 cu in 720 hp 9.0 liter engine?

[85vette]

I've seen the 572 offered on the internet from a dealer as low as $12,999.00. And I read an article (not sure what magazine) where they dyno tested one and the HP was closer to 750. The GM spokesman stated that 720 HP was the minimum acceptable HP output.