New supercharged Corvette.

Status
Not open for further replies.
Joined
Oct 1, 2010
Messages
8,361
Location
Michigan
From a GM news release this morning:

DETROIT – The all-new 2015 Corvette Z06 is the most powerful production car ever from General Motors and one of a few production cars available in the United States that delivers more than 600 horsepower.

The Z06’s LT4 supercharged 6.2L V-8 engine is SAE-certified at 650 horsepower (485 kW) at 6,400 rpm and 650 lb-ft of torque (881 Nm) at 3,600 rpm.

“The LT4 Small Block sets a new benchmark for power and torque at GM,” said Steve Kiefer, vice president, GM Powertrain Engineering. “The engine also puts the new Corvette Z06 on par with the most powerful supercars offered in America, while delivering performance with impeccable manners that make it suitable for daily driving.”

Compared with other supercar engines, the LT4 is a veritable fountain of low-end torque, producing 457 lb-ft (619 Nm) just off idle and 625 lb-ft (847 Nm) by only 2,800 rpm. The V-12-powered Ferrari F12 Berlinetta, for example, produces about 28 percent less torque than the Z06, despite offering about 12 percent more horsepower – and its peak torque isn’t achieved until 6,000 rpm. The LT4 maintains 90 percent of its peak torque, or 592 lb-ft (802 Nm), from 2,500 to 5,400 rpm.

The new LT4 engine eclipses the Porsche 911 Turbo S engine’s peak power levels by 90 horsepower (67 kW) and 134 lb-ft of torque (182 Nm).

“Torque is the pulling power of an engine and the LT4’s abundance of it at every rpm in the engine’s speed range helps the 2015 Corvette Z06 accelerate quicker and respond nearly instantaneously,” said Jordan Lee, chief engineer for Small Block engines. “It’s the very definition of power on demand.”

The new Z06 engine produces 40 percent more peak torque (180 lb-ft / 244 Nm) than the previous-generation’s 7.0L LS7 engine – and 7.5 percent more than the supercharged 2013 Corvette ZR1’s 604 lb-ft (819 Nm). At 3,200 rpm, the new LT4 surpasses the LS7 by 208 lb-ft of torque (252 Nm). On the horsepower side of the graph, the LT4’s 650-hp rating is 29 percent greater than the LS7’s 505 horsepower (376 kW), and 12 horses more than the ZR1’s LS9 engine.

“The new LT4 engine builds on the design strengths of our previous supercharged engine and leverages the technologies introduced on the Corvette Stingray – direct injection, cylinder deactivation and continuously variable valve timing – to take Corvette performance to an all-new plateau,” said Lee. “Our new, very compact supercharger also helps the engine make power more quickly, and perhaps more importantly, it helps produce more torque earlier in the rpm band.”

“It’s also worth mentioning that the LT4’s supercar performance numbers are achieved with an engine that is nearly the same size as the very compact LT1 engine introduced in the 2014 Corvette Stingray,” Lee said. “The power density of the LT4 makes it one of the smallest and lightest 650-hp engines in the industry.”

LT4 details

The new LT4 engine is based on the same Gen 5 small block foundation as the Corvette Stingray’s LT1 6.2L naturally aspirated engine, incorporating several unique features designed to support its higher output and the greater cylinder pressures created by forced induction, including:

Rotocast A356T6 aluminum cylinder heads that are stronger and handle heat better than conventional aluminum heads
Lightweight titanium intake valves
Machined, forged powder metal steel connecting rods for reduced reciprocating mass
High 10.0:1 compression ratio – for a forced-induction engine – enhances performance and efficiency and is enabled by direct injection
Forged aluminum pistons with unique, stronger structure to ensure strength under high cylinder pressures
Stainless steel exhaust manifolds and an aluminum balancer that are lighter than their LT1 counterparts
Standard dry-sump oiling system with a dual-pressure-control oil pump.
A new 1.7L supercharger spins at up to 20,000 rpm – 5,000 rpm more than the supercharger on the Corvette ZR1’s engine. The rotors are smaller in diameter, which contributes to their higher-rpm capability – and enables them to produce power-enhancing boost earlier in the rpm band. That boost is achieved more efficiently via a more direct discharge port that creates less turbulence, reducing heat and speeding airflow into the engine.

“The Small Block’s cam-in-block design heritage has always enabled very high performance and responsiveness in a small, compact package – an attribute amplified by the performance of our new supercharger’s design,” said Lee.

The LT4 is assembled at the new Performance Build Center at GM’s Bowling Green Assembly Plant and at GM’s Tonawanda engine plant in New York. It is matched with a standard seven-speed manual transmission or an all-new, paddle-shift eight-speed automatic transmission built in Toledo, Ohio.

Designed to deliver shift responses on par with the world’s best dual-clutch transmissions, it is the first automatic offered in a Z06. It also makes the Z06 one of the few cars this powerful to offer the choice of a conventional manual transmission or an eight-speed automatic.

The 2015 Corvette Z06 goes on sale in the fourth quarter of 2014.
 
Yep, it may be old news but it is GOOD news!

I was more interested in the transmission, as GM has been planning this one for a long time and I can't wait to see how it enhances an already great Vette...
 
I know it hasn't exactly been a big secret, but this is the first that we've heard a definite Horsepower number. The last I heard, they were having trouble matching the old ZR1 power number. Now they have exceeded it, so that's a nice surprise. I would have been perfectly fine with 620 HP in that car. They have to leave room at the top for whatever a new ZR1 will put out.
wink.gif
 
Originally Posted By: SteveSRT8
Yep, it may be old news but it is GOOD news!

I was more interested in the transmission, as GM has been planning this one for a long time and I can't wait to see how it enhances an already great Vette...



Yeah, my dad is really interested in the 8-speed Stingray. He drove the 6-speed this past weekend and liked it, but the 8-speed sounds even better. I'm skeptical of the PDK performance claim they make, but if they can match or come close to the ubiquitous ZF 8-speed, it will be a winner.
 
Originally Posted By: SteveSRT8
Yep, it may be old news but it is GOOD news!

I was more interested in the transmission, as GM has been planning this one for a long time and I can't wait to see how it enhances an already great Vette...



Not only the tranny but this power plant includes cylinder deactivation.
Combine that with the incredible bottom end torque and lots of gears and I bet this car will get 35+ mpg on the highway with cruise set at 70mph.


I wonder how many forum posts we will see concerning oil consumption. If any chev engine with afm is going to consume oil this one would be it with the high compression numbers AND forced induction.

Now for the most important question......
What grade oil does it spec? Is it gonna be the 5w-30 as per usual or will this bad boy need a 40 grade ?
Or is chev gonna shock us and specify a dexos 20 grade?

I wonder why they are using a supercharger instead of turbos for boost? Is it a packaging issue or what's that about?
And all this from a cam in block pushrod engine.
Looks like old tech is still proving to be the way to go,which kind of surprises me.
With all the options available to GM I'm surprised to see them taking this route.
It must be the dohc heads are too bulky to fit in the engine bay,I assume.
 
Originally Posted By: Drew99GT
Ok, this is the new ZO6; do they have plans to bring back the ZR1 with even more power??


A very good question. My guess is that the ZR-1 code will go dormant for a while, probably until (if) the Viper pulls a bigger rating than the ZO6. All my previous kidding about this setting the bar, the Hellcat may very well pop out with a competitive or even higher rating... BUT its in a totally different size/weight/class of vehicle. People who compare Corvettes and Challengers need a good forehead smack, they're just too different by design. Even if the Challenger gets 670 horses, its still going to perform very differently than a C7, and so GM has no reason to go higher in the Corvette.

If the Viper surpasses it on the other hand.... but the Viper is already in danger of falling short of the Hellcat.
 
Originally Posted By: Clevy
Originally Posted By: SteveSRT8
Yep, it may be old news but it is GOOD news!

I was more interested in the transmission, as GM has been planning this one for a long time and I can't wait to see how it enhances an already great Vette...



Not only the tranny but this power plant includes cylinder deactivation.
Combine that with the incredible bottom end torque and lots of gears and I bet this car will get 35+ mpg on the highway with cruise set at 70mph.


I wonder how many forum posts we will see concerning oil consumption. If any chev engine with afm is going to consume oil this one would be it with the high compression numbers AND forced induction.

Now for the most important question......
What grade oil does it spec? Is it gonna be the 5w-30 as per usual or will this bad boy need a 40 grade ?
Or is chev gonna shock us and specify a dexos 20 grade?

I wonder why they are using a supercharger instead of turbos for boost? Is it a packaging issue or what's that about?
And all this from a cam in block pushrod engine.
Looks like old tech is still proving to be the way to go,which kind of surprises me.
With all the options available to GM I'm surprised to see them taking this route.
It must be the dohc heads are too bulky to fit in the engine bay,I assume.


Exactly. There is the primary reason that the regular Vette has the lowest CG of any vehicle ever tested. If anyone could ever see one of the last gen Vette engines with the "dry" sump setup like the ZO6 you would see it is an incredibly compact and lightweight engine design despite its apparent lack of technical sophistication.

I would expect a 40w oil spec. We'll see, eh?
 
Originally Posted By: 440Magnum
Originally Posted By: Drew99GT
Ok, this is the new ZO6; do they have plans to bring back the ZR1 with even more power??


A very good question. My guess is that the ZR-1 code will go dormant for a while, probably until (if) the Viper pulls a bigger rating than the ZO6. All my previous kidding about this setting the bar, the Hellcat may very well pop out with a competitive or even higher rating... BUT its in a totally different size/weight/class of vehicle. People who compare Corvettes and Challengers need a good forehead smack, they're just too different by design. Even if the Challenger gets 670 horses, its still going to perform very differently than a C7, and so GM has no reason to go higher in the Corvette.

If the Viper surpasses it on the other hand.... but the Viper is already in danger of falling short of the Hellcat.






Hey 440.

Do you have any idea why the v10 doesn't use a hemi head? Or does it? I don't know why dodge wouldn't incorporate it into the viper.
The hemi head really shines once the rpm hit 2500 and more,so I would imagine that head is ideal in a performance ,high revving application.
Unless of course it uses a twisted wedge head or something and using a hemi head would be going backwards from a performance stand point.
Any ideas 440? I'm not being a jerk here, I'm genuinely interested so if you know any of the vipers intimate details I'd appreciate it very much if you shared that info,please and thank you in advance.

My biggest question is why doesn't dodge just kill the v10 and put something like the hellcat engine into it,or is viper and that extremely long front end/v10 just have to go together?
 
Originally Posted By: Clevy

My biggest question is why doesn't dodge just kill the v10 and put something like the hellcat engine into it,or is viper and that extremely long front end/v10 just have to go together?


You're asking the questions I've been asking for several years. Its been pretty easy for guys to get Viper-topping numbers out of the Hemi for a while now, albeit with aftermarket parts and no warranty to worry about. I think part of it is the sound and feel of the V10 being synonymous with Viper. The V10 is, as far as I know, still a 2-valve wedge-head. But it got a huge amount of updating at the last generation (when I expected it to be replaced with a Hemi, by the way) that I'm not really familiar with since I'm not a huge Viper fan. So I don't really know if its being limited by its head design, or just by typical Mopar conservatism. And another big question is how that pattern of conservatism will affect the rating finally selected for the Hellcat- it wouldn't surprise me if they did NOT go after the ZO6 rating with it, but instead came in around 620-640. We should know soon, though.
 
Originally Posted By: 440Magnum
Originally Posted By: Clevy

My biggest question is why doesn't dodge just kill the v10 and put something like the hellcat engine into it,or is viper and that extremely long front end/v10 just have to go together?


You're asking the questions I've been asking for several years. Its been pretty easy for guys to get Viper-topping numbers out of the Hemi for a while now, albeit with aftermarket parts and no warranty to worry about. I think part of it is the sound and feel of the V10 being synonymous with Viper. The V10 is, as far as I know, still a 2-valve wedge-head. But it got a huge amount of updating at the last generation (when I expected it to be replaced with a Hemi, by the way) that I'm not really familiar with since I'm not a huge Viper fan. So I don't really know if its being limited by its head design, or just by typical Mopar conservatism. And another big question is how that pattern of conservatism will affect the rating finally selected for the Hellcat- it wouldn't surprise me if they did NOT go after the ZO6 rating with it, but instead came in around 620-640. We should know soon, though.





Thanks 440.

I'm puzzled as to why they won't take their premiere sports car to the next level.
I think a hemi head would give significant midrange gains over a twisted wedge however I don't know if low rpm drive ability would be negatively affected.

The new vette is pretty hot though.
I'm betting it'll put down Better fuel economy numbers than most v 6 family sedans.
And I love that they incorporated afm into the engine. It shows that they believe in the system whole heartedly.

Thanks again for the info 440
 
Only 104hp/L even with a supercharger? What garbage! Honda beat them long ago! hurrrr GM can't even beat that in 2015, GM can't even into OHC durrr stuck in the cretacious period! My CRV has pretty good resale value!!!
lol.gif


hahah jk jk

very nice job!

I like this part “Torque is the pulling power of an engine and the LT4’s abundance of it at every rpm in the engine’s speed range helps the 2015 Corvette Z06 accelerate quicker and respond nearly instantaneously,” said Jordan Lee, chief engineer for Small Block engines. “It’s the very definition of power on demand.”

That meaty torque courtesy of Direct Injection, what's been like a renaissance for stock SBC performance.
thumbsup2.gif
 
Originally Posted By: jrustles
Only 104hp/L even with a supercharger? What garbage! Honda beat them long ago! hurrrr GM can't even beat that in 2015, GM can't even into OHC durrr stuck in the cretacious period! My CRV has pretty good resale value!!!
lol.gif


hahah jk jk

very nice job!

I like this part “Torque is the pulling power of an engine and the LT4’s abundance of it at every rpm in the engine’s speed range helps the 2015 Corvette Z06 accelerate quicker and respond nearly instantaneously,” said Jordan Lee, chief engineer for Small Block engines. “It’s the very definition of power on demand.”

That meaty torque courtesy of Direct Injection, what's been like a renaissance for stock SBC performance.
thumbsup2.gif




My M3's 4.0L NA V8 is doing 103.5hp/L, and that's assuming you trust the conservative power rating. If you go based on what actual owners dyno, it's more like 109hp/L.

Though I do somewhat agree. Even with a mild tune, the supercharged Audi 3.0TFSI V6 is doing 135hp/L. The more aggressive but still streetable tunes are doing 150hp/L+ with nothing else other than an exhaust.
 
Cool car.

But the Porsche will still munch it with acceleration because its AWD.

GM's right at the limit of what RWD can do HP wise, I bet that car is a handful on anything but warm dry roads.

Ferrari and Mercedes are in the same boat, which is why all the new AMG's are AWD.


GM needs to spend some money on the Corvettes transmission as well, they need a dual clutch like the PDK. Now they are pricing them around the $100k mark which is still a bargain but they need to update some of their running gear.
 
Last edited:
Status
Not open for further replies.
Back
Top