Chevrolet considering twin-turbo V6 for next Corvette

[GoCougs]

The 911 and the Corvette are almost exactly the same size.

It also has a smaller engine, a much more compact drivetrain, and (probably the most important part) commands a 63% premium over the Corvette.



The more you guys insist on comparing the Corvette to cars that cost WAY more than it, the more I think you're beyond bonkers if you believe GM can build this hypothetical Uber-Vette for a reasonable price tag.

Hey dawg you dropped context somewheres along the way.

The point wasn't comparing the two cars in total but countering the assertion that the Corvette's unique features contribute to its being a sports cars ("But its traits as a sports car would be compromised"); other performance cars use more traditional chassis and suspension layouts and perform as well (usually better) whilst being better overall cars.

And like I said look what GM can do for $50k (560 hp Z28) to $60k (560 CTS-V). Take a smaller variant of either chassis for a 2+2 configuration, add AWD, substitute in a V6TT in the 425-450 hp range, and voila, one has in effect an 80th percentile GT-R for about the same cost as a Corvette. It's 100% doable, if GM had both the opportunity and the inclination.

Even the Corvette at $50k is a good example - there is a LOT of unnecessary cost in both design and materials thrown into the space frame chassis, plastic body panels, leaf springs, rear tranny + torque tube. Swap these non-necessities for unit-body chassis, steel body panels, traditional tranny layout and substitute AWD and V6TT and voila redux.

[SVT666]

Hey dawg you dropped context somewheres along the way.

The point wasn't comparing the two cars in total but countering the assertion that the Corvette's unique features contribute to its being a sports cars ("But its traits as a sports car would be compromised"); other performance cars use more traditional chassis and suspension layouts and perform as well (usually better) whilst being better overall cars.

And like I said look what GM can do for $50k (560 hp Z28) to $60k (560 CTS-V). Take a smaller variant of either chassis for a 2+2 configuration, add AWD, substitute in a V6TT in the 425-450 hp range, and voila, one has in effect an 80th percentile GT-R for about the same cost as a Corvette. It's 100% doable, if GM had both the opportunity and the inclination.

Even the Corvette at $50k is a good example - there is a LOT of unnecessary cost in both design and materials thrown into the space frame chassis, plastic body panels, leaf springs, rear tranny + torque tube. Swap these non-necessities for unit-body chassis, steel body panels, traditional tranny layout and substitute AWD and V6TT and voila redux.

Why would you want to ditch the transaxle?  All that engineering is already done.  Besides, if you stuck a traditional tranny back in, the footwells will get smaller and the transmission tunnel will get bigger.

[GoCougs]

No the leaf springs are fine.  The squirrely limit is really mostly seen on the Z06's because of not enough shock tuning and the basic fact that the C5/C6 chassis is now about 15 years old and has a torsional rigidity of about 25hz, while modern sports coupes and sedans are more than twice as stiff (50+hz). 

The leaf springs are very bad. Not only does one spring service both sides of the car, the spring also serves as a secondary anti-roll bar. Thus, one single suspension member is simultaneously bending in torsion + bending on its long axis. This is asking for infinite dynamical issues, and precisely explains the Corvette's excessively squirrely handling and flinty ride.

Expect the C7 and onward to have either coil springs or only leaf-springs + closed loop magnetic particle shocks as standard.

[Tave]

Hey dawg you dropped context somewheres along the way.

No, I think that was you.

The point wasn't comparing the two cars in total but countering the assertion that the Corvette's unique features contribute to its being a sports cars ("But its traits as a sports car would be compromised"); other performance cars use more traditional chassis and suspension layouts and perform as well (usually better) whilst being better overall cars.

While costing twice as much. Where was that context? Oh yeah...

I don't know about a better power band, but pretty much everything else you listed as an advantage is due to the added $$$$$ put into the 911's parts, or the fact that the engine hangs off the back and aids in braking and accelerating.

And like I said look what GM can do for $50k (560 hp Z28) to $60k (560 CTS-V).

Oh, two not-sports cars that use drivetrains sourced from the Corvette. Another bonehead comparo.

[Vinsanity]

I don't care much for the leaf spring setup myself, but I think the space frame, fiberglass body, and especially the rear transaxle is worth keeping around. They all serve to keep the car lightweight and purpose-built. Ditch those things, and watch the weight go up, and performance suffer. Yes, the M3 is approaching the performance/value realm of the Corvette, but the M3 is the ultimate iteration of the 3-series; the point at which the Corvette is just getting started. The ultimate iteration of the Corvette? The ZR1.

If anything, I'd say that AWD, a turbo V6, and 2+2 seating configuration would be worthless on a Corvette.

[GoCougs]

I don't care much for the leaf spring setup myself, but I think the space frame, fiberglass body, and especially the rear transaxle is worth keeping around. They all serve to keep the car lightweight and purpose-built. Ditch those things, and watch the weight go up, and performance suffer. Yes, the M3 is approaching the performance/value realm of the Corvette, but the M3 is the ultimate iteration of the 3-series; the point at which the Corvette is just getting started. The ultimate iteration of the Corvette? The ZR1.

If anything, I'd say that AWD, a turbo V6, and 2+2 seating configuration would be worthless on a Corvette.

Right - and yet the M3 uses traditional construction and layout - no space frame, no plastic body panels, no rear tranny + torque tube, no goofy leaf springs. Or, alternatively, if the M3 employed those construction techniques it'd be a much more expensive vehicle.

If BMW had the economies of scale and scope of GM (especially in the power plant) and cheaped the interior down to the level of the Corvette, I betcha we'd easily see the $58k M3 at $48k (= base MSRP Corvette).

(See that Tave?)

[Vinsanity]

My point was that the Corvette's design gives it potential for true supercar performance in the ZR1, whereas the M3 is close to, if not at its max potential, being based on the 3-series sport coupe/sedan.

[sportyaccordy]

As much as it pains me to say it, Cougs makes a great point. For $60K would you rather a used Z06 or a new M3? To me the choice seems obvious.

However, the base Corvette is no slouch. I'm pretty sure it's faster in all directions than an M3, which still makes it a great performance bargain (unless I'm mistaken), and is really more in line with what the Vette is about. It's still faster than a lot of more expensive cars (the most important one being the 911), which is what the Vette has always been about. This 2+2 twin turbo ATTESSA-PRO spaceship could not do the same.

[Tave]

(See that Tave?)

Yes, I see you, as well as 565, comparing the Vette (sports car) to a compact sedan which weighs 500 pounds more, costs more, is slower, and doesn't corner as well.

And yes, I also see you saying stuff like, "if only BMW had the advantages of economy of scale of GM," not realizing of course, that the 3-Series enjoys so many advantages in economy of scale over the Corvette that it isn't even funny.

[GoCougs]

My point was that the Corvette's design gives it potential for true supercar performance in the ZR1, whereas the M3 is close to, if not at its max potential, being based on the 3-series sport coupe/sedan.

Okay, I see, and one thing for sure we'll never see a 638 hp M3 from BMW's factory!

[GoCougs]

Yes, I see you, as well as 565, comparing the Vette (sports car) to a compact sedan which weighs 500 pounds more, costs more, is slower, and doesn't corner as well.

And yes, I also see you saying stuff like, "if only BMW had the advantages of economy of scale of GM," not realizing of course, that the 3-Series enjoys so many advantages in economy of scale over the Corvette that it isn't even funny.

The only person comparing the Corvette and 911 is you.

Nah, remember I said both economies of scale and scope;  I seriously doubt that BMW could build the C6 for ~$48k.

[SVT666]

Sure they could.  But BMW would put in good seats, aluminium or carbon fibre bodywork, a DOHC V8 with 8 throttle bodies, iDrive, coilovers, and a quality interior.  If BMW didn't do any of that they could easily sell it for $48K.

[Tave]

The only person comparing the Corvette and 911 is you.

Come again? We're talking about the M3 v. Corvette.

Right - and yet the M3 uses traditional construction and layout - no space frame, no plastic body panels, no rear tranny + torque tube, no goofy leaf springs. Or, alternatively, if the M3 employed those construction techniques it'd be a much more expensive vehicle.

If BMW had the economies of scale and scope of GM (especially in the power plant) and cheaped the interior down to the level of the Corvette, I betcha we'd easily see the $58k M3 at $48k (= base MSRP Corvette).

To recap, the M3, which is a compact sedan (or coupe) is 500 pounds heavier, costs more, is slower, and corners worse than the Vette, which is a sports car. Why does that sound familiar? Oh yeah:

Yes, I see you, as well as 565, comparing the Vette (sports car) to a compact sedan which weighs 500 pounds more, costs more, is slower, and doesn't corner as well.

Nah, remember I said both economies of scale and scope;  I seriously doubt that BMW could build the C6 for ~$48k.

This is a meaningless argument. No other company on Earth besides GM can build a Corvette for 50 grand, because no other company has put the backwork into building Corvettes.

[565]

However, the base Corvette is no slouch. I'm pretty sure it's faster in all directions than an M3, which still makes it a great performance bargain.

The difference is marginal at best, or in the M3's favor depending on how you look at things.

From the latest tests from Car and Driver.

C6 GrandSport.

http://www.caranddriver.com/reviews/comparisons/10q2/2010_chevy_corvette_grand_sport_vs._2010_lotus_evora_2010_porsche_cayman_s-comparison_tests/2010_chevrolet_corvette_grand_sport_page_3

0-60: 4.3 seconds
1/4mile:  12.6 @ 115mph
0-130:  16.4 seconds
70-0: 154 ft
Skidpad: .98G
Lanechange: 63.3mph

BMW M3

http://www.caranddriver.com/reviews/comparisons/10q3/2011_audi_rs5_vs._2010_bmw_m3_2011_cadillac_cts-v-comparison_tests/2010_bmw_m3_page_4

0-60: 3.9 seconds
1/4mile: 12.4 @ 114mph
0-130: 16.5 seconds
70-0:  153 ft.
Skidpad: .96G
Lanechange: 70.4mph (previous test)


Seriously, even as a current Vette owner, I cannot see a reason to buy the Vette from a performance point of view.  Considering the cars start within 5k of each other, the value equation is the same.  Add to that BMW offers 5 years of free maintanence, a premium dealership service, far greater build quality and refinement, more usable room and practicality, I cannot justify buying the vette at all anymore.


A show of hands.  Who here would actually buy the Grand Sport over the M3 with their own cash?  I certainly would not, and that's worrying because I once easily choose the C5 vette over the E46 M3 (and the rest of the world).

[sportyaccordy]

Those handling #'s seem incredibly low; I have seen slalom speeds of ~70 or so for the Vette

I personally would def get the M3 of course, but simply because I have no use for a 2 seater car. If the Vette had 4 seats (???) I would go for that. The M3 is at the threshold of its performance capabilities, and would take significant investments to push further. The Vette can get significant performance increases with mild mods like an exhaust, etc. To that end there's some added appeal + value.

I think it's less of a matter of the Vette not stepping it up as it is the M3 stepping it up incredibly. The M3 benefited tremendously from being able to use the M5 engine architecture. From there it was easy peasy.

In any case the Vette 3000GT MR-4 would not work.

[GoCougs]

That M3 has the auto-clutch manual option which is a significant price adder. With the 6sp M/T the M3 is in a dead heat acceleration-wise with the C6.

I'm having trouble seeing the "potential" the C6 has above the M3. What is it exactly? The M3 is at its performance peak simply because BMW has other cars above it, like the M6.

[SVT666]

That M3 has the auto-clutch manual option which is a significant price adder. With the 6sp M/T the M3 is in a dead heat acceleration-wise with the C6.

I'm having trouble seeing the "potential" the C6 has above the M3. What is it exactly? The M3 is at its performance peak simply because BMW has other cars above it, like the M6.

If you put enough money and engineering into a car, you can make it really fucking fast, but the M3 is at the peak whereas the Vette is just a camshaft away from blowing the doors of the M3.

[sportyaccordy]

I'm having trouble seeing the "potential" the C6 has above the M3. What is it exactly? The M3 is at its performance peak simply because BMW has other cars above it, like the M6.

Like SVT666 said, you put a little work in a Vette, you have a significantly faster car. Equivalent parts for the BMW would cost 2-4x as much, and still not have as dramatic an effect. Plus the Vette already has the 500lb advantage w/more torque etc...

These things matter to some people. I wouldn't get a Vette over an M3, but I would def consider a CTS-V sedan.

[GoCougs]

Like SVT666 said, you put a little work in a Vette, you have a significantly faster car. Equivalent parts for the BMW would cost 2-4x as much, and still not have as dramatic an effect. Plus the Vette already has the 500lb advantage w/more torque etc...

These things matter to some people. I wouldn't get a Vette over an M3, but I would def consider a CTS-V sedan.

Oh, please please don't go down the "torque" road. The M3 4.0L V8 is a far superior engine, and precisely why with a little less power and moderately more weight the M3 is just as quick (or quicker with the DSG) than the C6.

That same amount of "little less work" on the M3 will yield probably better performance increase simply because the M3 V8 is a much better platform as shown by the spread between peak HP rpm and peak torque rpm:

M3 4.0L V8:
414 hp @ 8,300 rpm and 295 lb-ft @ 3,900 rpm
Spread = 4,400 rpm (!!!)

C6 LS3 V8:
436 hp @ 5,900 rpm and 425 lb-ft @ 4,600 rpm
Spread = 1,300 rpm

The stupefying broadness of the M3's power band! GM is pretty much reaching the max capacity for reliability, durability and emissions with its current N/A V8, and its relative ease of being modified doesn't do much but confirm that it is (very) old technology.

[NomisR]

Oh, please please don't go down the "torque" road. The M3 4.0L V8 is a far superior engine, and precisely why with a little less power and moderately more weight the M3 is just as quick (or quicker with the DSG) than the C6.

That same amount of "little less work" on the M3 will yield probably better performance increase simply because the M3 V8 is a much better platform as shown by the spread between peak HP rpm and peak torque rpm:

M3 4.0L V8:
414 hp @ 8,300 rpm and 295 lb-ft @ 3,900 rpm
Spread = 4,400 rpm (!!!)

C6 LS3 V8:
436 hp @ 5,900 rpm and 425 lb-ft @ 4,600 rpm
Spread = 1,300 rpm

The stupefying broadness of the M3's power band! GM is pretty much reaching the max capacity for reliability, durability and emissions with its current N/A V8, and its relative ease of being modified doesn't do much but confirm that it is (very) old technology.

Looking at those # and you reasonably say BMW engine still has more performance potential and the LS3?  And the LS3 is reaching it's peak in performance and reliability?  I can't read any sarcasm in your remarks

[GoCougs]

Looking at those # and you reasonably say BMW engine still has more performance potential and the LS3?  And the LS3 is reaching it's peak in performance and reliability?  I can't read any sarcasm in your remarks

Look how broad that power band is! 4-valve, OHC, and VVT/L = far far greater ability to move and control air through the engine, which is the most fundamental aspect of engine performance. The whole of the InnerWebs has been down this road a gazillion times before - pooprods, 2-valve, no VVT/L is very very limited in this regard, and why pretty much no one else builds pooprods.

The reason why the ZR1 uses a S/C 6.2L is because the LS7 was at its peak for power, reliability and emissions.  

[hotrodalex]

You know what? Cougs is right. Screw having different cars for different people. We should all have M3's because they are obviously the best. Want a different experience? Too bad, it would be inferior so it sucks.

[sportyaccordy]

Look how broad that power band is! 4-valve, OHC, and VVT/L = far far greater ability to move and control air through the engine, which is the most fundamental aspect of engine performance. The whole of the InnerWebs has been down this road a gazillion times before - pooprods, 2-valve, no VVT/L is very very limited in this regard, and why pretty much no one else builds pooprods.

The reason why the ZR1 uses a S/C 6.2L is because the LS7 was at its peak for power, reliability and emissions.   

I think GM purposely leaves a lot on the table with the LS engines because they know how important responsiveness in the aftermarket is. Plus the motors have been documented as underrated (430HP motor putting down 390rwhp???) Doesn't bode well for the actual performance #s but ultimately dyno #s and strip times are very important to the Corvette crowd; whereas the V8 in the M3 is basically a very expensive black box.

Not to mention (why am I even going here) the simplicity of the LSx motors do wonders for overall engine weight & cost. Again doesn't explain why a Vette costs as much as an M3 (profitability?), but it makes sense from a business standpoint. Sometimes super technology isn't necessary.

[NomisR]

Look how broad that power band is! 4-valve, OHC, and VVT/L = far far greater ability to move and control air through the engine, which is the most fundamental aspect of engine performance. The whole of the InnerWebs has been down this road a gazillion times before - pooprods, 2-valve, no VVT/L is very very limited in this regard, and why pretty much no one else builds pooprods.

The reason why the ZR1 uses a S/C 6.2L is because the LS7 was at its peak for power, reliability and emissions.   

You're forgetting about packaging and weight of the engines.  The pushrod engines can realistically afford to have higher displacement with at lower weight and is more compact than a similarly powered OHC V8.  It also means the components are less stressed and additional room for power increases.  Simplicity is the key. 

[Rich]

You're forgetting about packaging and weight of the engines.  The pushrod engines can realistically afford to have higher displacement with at lower weight and is more compact than a similarly powered OHC V8.  It also means the components are less stressed and additional room for power increases.  Simplicity is the key. 

[GoCougs]

I think GM purposely leaves a lot on the table with the LS engines because they know how important responsiveness in the aftermarket is. Plus the motors have been documented as underrated (430HP motor putting down 390rwhp???) Doesn't bode well for the actual performance #s but ultimately dyno #s and strip times are very important to the Corvette crowd; whereas the V8 in the M3 is basically a very expensive black box.

Not to mention (why am I even going here) the simplicity of the LSx motors do wonders for overall engine weight & cost. Again doesn't explain why a Vette costs as much as an M3 (profitability?), but it makes sense from a business standpoint. Sometimes super technology isn't necessary.

The motors are SAE rated and in general chassis dynos are terrible.

Chevy ain't building a lot of capacity (= $$$) into the motors to cater to the minuscule of buyers who might do something serious to the engine.

I wouldn't call the LSx motors bad but they aren't as (nearly) as good as the competition; anything from the M3's 4.0L, to the Mustang GT's 5.0L, to Toyota's 5.7L, are much better.

[hotrodalex]

How are LSx engines worse? I can't say I've ever heard someone complain about them. They are considered a strength in the Corvette and other top performance cars at GM.

You're forgetting about packaging and weight of the engines.  The pushrod engines can realistically afford to have higher displacement with at lower weight and is more compact than a similarly powered OHC V8.  It also means the components are less stressed and additional room for power increases.  Simplicity is the key. 

At a car show I went to this summer I saw a '32 Ford with a DOHC V8. It was cool, but there was one problem - packaging. The heads stuck out the side of the engine compartment and the builder had to fabricate a special piece to fit over them and it just wasn't ideal.

[sportyaccordy]

The motors are SAE rated and in general chassis dynos are terrible.

Chevy ain't building a lot of capacity (= $$$) into the motors to cater to the minuscule of buyers who might do something serious to the engine.

I wouldn't call the LSx motors bad but they aren't as (nearly) as good as the competition; anything from the M3's 4.0L, to the Mustang GT's 5.0L, to Toyota's 5.7L, are much better.

The engines are good because they get the job done stock at the required cost + weight + size, and leave plenty of room for more. Might not rev to 8K but who cares? It's a good + cheap engine

[SVT666]

The engines are good because they get the job done stock at the required cost + weight + size, and leave plenty of room for more. Might not rev to 8K but who cares? It's a good + cheap engine

Exactly.  Who cares what redline is if you have 430 hp. 

[sportyaccordy]

Exactly.  Who cares what redline is if you have 430 hp. 

W/a lot more available through simple bolt ons. I can't see a Corvette owner complaining about the engine. I could see an M3 owner wanting more torque though.