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      07-23-2019, 01:15 PM   #265
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Beyond the Numbers: Parsing some C8 tea leaves

Looking beyond mere calculus gives an indication of Corvette engineers’ priorities


Interesting article written by David Booth, he's an auto journalist and electrical engineer who writes for the National Post in Canada

https://driving.ca/chevrolet/corvett...-c8-tea-leaves

Well, the armchair engineers certainly seemed to be out in force this weekend, didn’t they, questioning pretty much everything about the new mid-engined Corvette, a few of their “How can theys” and “that’s impossibles” sounding like they came from skulking Porsche owners trying desperately not to come out of the closet. (And, lest I be subjected to the human rights crucible, by “not come out of the closet,” I am speaking of brand-concealing jealousy and not any closeting of sexual orientation).

Of particular concern, it seems, are the price — its incredible $69,998 projected Canadian MSRP — and the fact that it manages to accelerate to 100 kilometres an hour in around three seconds flat despite boasting only 495 horsepower. The first, as my original deep dive explained, is actually not all that surprising since the C8 really isn’t that new. Oh, to be sure, the engine is most definitely in a different place and, as a direct result, it sure as shooting looks different. The aeros all had to be redone and one surmises that an extraordinary amount of time was spent computer simulating the suspension calibration. But that’s up front costs and, while the costs of R & D are not to be discounted, they pale in comparison to the billions that it costs to actually build a typical, high-end, low production supercar.

And here the C8 is anything but revolutionary. Underneath that radically revised skin, the new car is so similar to the previous iteration that it could have been badged C7.5. Indeed, the major upgrade in chassis construction — again, not design — are some larger high-pressure castings, the kind of run-of-process improvement that General Motors would almost have incorporated even if the C8 had stayed resolutely front-engined. Other than a rear bumper beam that’s made of carbon fibre, there’s little new in the process of building a Corvette, hence why there’s been such a comparatively small increase — about 7.5 per cent — in suggested retail price.

'HOW IS THE C8 SO BLOODY FAST WHEN IT’S SO DARNED HEAVY?'

As for the much-deliberated subject of the C8’s acceleration abilities, the naysayers are picayuning the wrong Corvette deficiency. The issue they should be questioning isn’t horsepower, but weight. What they really should be asking is: “How is the C8 so bloody fast when it’s so darned heavy?”

The downside of the familiarity of construction is that new Vette is a bit of a lardy beast, its 1,530 kilograms really only outweighed, in the supercar spectrum, by the Acura NSX, which, you’ll remember has no less than three electric motors and two turbochargers to account for. Others, like the McLaren 600LT undercut its avoirdupois by some 230 kilos.

Nor, as those armchair Zora Arkus-Duntovs have proclaimed, is the Corvette’s monstrous acceleration simply the result of superior rear-engined rear weight distribution. Oh, that would account for why it’s quicker than the C7 although it’s some 70 kilograms heavier than that dinosaur, but it does not explain how the plainly heavier and significantly less powerful — 490 hp/465 lb.-ft. versus 710 hp/568 lb.-ft. — Corvette is but a tenth (and a smidge) second slower than Ferrari’s 488.

One hint may be Tadge Juechter’s contention that the new C8 has a monster low first cog, geared, as the chief engineer says, for “hard launches.” But torque multiplication alone can’t account for the C8’s unlikely turn of speed. Indeed, all that power needs to be controlled and therein, I suspect, lies the Corvette’s secret sauce — launch control.

Now there’s nothing special about the concept of launch control; it’s been a supercar staple for almost a decade now. What will be special, I believe, is GM’s application of it.

Chevrolet has, over the last few years, made something of a specialty of electronic traction nannies, its Performance Traction Management Systems (PTM) at the forefront of electronic chassis controls. At least part of the reason the C7 was so controllable on a racetrack was the incredibly judicious intervention — or non-intervention — of PTM into tail-wagging oversteer. The reason Camaro SS could be transformed from sow’s ear into the silk purse the Z/28 became — you don’t really think the Z/28 became 911-baiting as a result of suspension tweaking did you? — is thanks to PTM. Never mind that the reason that The General became so expert in electronic controls is because their basic chassis were so archaic, the reason we’re seeing such an unexpectedly quick C8 is because all that electronic traction nous is finally being applied to a modern frame design. These electronic controllers will also be easier to implement now that Corvette has abandoned both manual and automatic transmissions in favour of a dual-clutch DCT, it being much easier to electronically control a physical clutch than squidgy hydraulics.

And finally, it appears, as was much speculated, there is room to fit some (small) electric motors to the C8’s front end. That means, again as has been much speculated (with great encouragement from GM insiders, I might add), that a hybridized, all-wheel-drive variant of the Corvette is possible, if not probable. It almost certainly won’t be a Porsche 918-like plug-in, however, there being precious little space to fit a significant — i.e. 20 kilowatt-hour — battery into the current chassis. And, no folks, GM is not going to load 100 kilograms of lithium ion into either front or rear trunk, not when they went to such trouble to reduce weight — that aforementioned carbon-fibre bumper beam — at the polar extremes of the car.

In fact, I suspect that before we see a fully-electrified Vette, some form of mild hybrid — where an extra powerful alternator feeds a little power into the engine via an extra sturdy belt — will find its way into the C8’s engine bay. The General was once the leader in such systems — they called it their Belt-Alternator-Starter, or BAS system — and has much expertise that would benefit a gas hog like the C8. Wouldn’t it be interesting — and now this is me playing armchair engineer — if GM combined its BAS mild hybrid engine electrified support with real electric motor hybridization? More power, all-wheel-drive, as well as enhanced coasting and shut-off from the big, gas-guzzling V8.

And finally, there is perhaps the most ignored aspect of all the reports of Chevy’s new C8, namely Juechter’s contention that the centre of all that newly redistributed weight is concentrated right at the driver’s inside hip. That would be mighty impressive seeing as a significant portion of the feedback the driver receives from a supercar’s chassis is through their posterior. Having the car feel like it’s resting directly beneath your buttocks is always a whole bunch better than trying to pilot a car at its limit based on feedback from the trunk.

The 2020 Chevrolet Corvette C8 interior Chevrolet
It also gives us some glimpse into Chevrolet’s priorities in designing the C8. They were obviously not too worried about overall weight or high-rpm horsepower; hence their reliance on, for supercars, somewhat archaic aluminum frame construction and the ubiquitous small-block V8. They did, however, seem to care enough about weight distribution to take the time to design that aforementioned carbon-fibre bumper beam — which, by the way, is completely hidden, negating any potential “marketing” value — which would reduce the car’s polar moment of inertia. In other words, they didn’t spend their hard-to-come-by research dollars worrying about weight, but rather where it was to be placed.

So, here’s my last words to all you naysaying nabobs of negativism (more commonly known as Porsche 911 owners). It would seem that the C8’s handling could turn out to be even more impressive than its turn of speed. Be afraid. Very afraid.
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      07-23-2019, 03:08 PM   #266
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Haha...yeah there is some haters on the Porsche forums, but most have been pretty excited about it.

Kinda liking the blue....


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      07-23-2019, 04:24 PM   #267
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Starts at under 60k. M2 competition is destroyed. Supra is destroyed
Time to buy American again!
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      07-23-2019, 04:29 PM   #268
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Quote:
Originally Posted by Grumpy Old Man View Post
Chevrolet has, over the last few years, made something of a specialty of electronic traction nannies, its Performance Traction Management Systems (PTM) at the forefront of electronic chassis controls. At least part of the reason the C7 was so controllable on a racetrack was the incredibly judicious intervention — or non-intervention — of PTM into tail-wagging oversteer. The reason Camaro SS could be transformed from sow's ear into the silk purse the Z/28 became — you don't really think the Z/28 became 911-baiting as a result of suspension tweaking did you? — is thanks to PTM. Never mind that the reason that The General became so expert in electronic controls is because their basic chassis were so archaic, the reason we're seeing such an unexpectedly quick C8 is because all that electronic traction nous is finally being applied to a modern frame design. These electronic controllers will also be easier to implement now that Corvette has abandoned both manual and automatic transmissions in favour of a dual-clutch DCT, it being much easier to electronically control a physical clutch than squidgy hydraulics.
Good stuff. Thanks GOM.

Please note: The Performance Traction Management system is part of the FE4 upgrade (option) to the Z51 Performance Package. You need Z51 plus FE4 to get this system.
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      07-23-2019, 04:34 PM   #269
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Quote:
Originally Posted by glennQNYC View Post
Good stuff. Thanks GOM.

Please note: The Performance Traction Management system is part of the FE4 upgrade (option) to the Z51 Performance Package. You need Z51 plus FE4 to get this system.
I'm looking forward to seeing one in a showroom up close and personal.
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      07-23-2019, 05:27 PM   #270
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Quote:
Originally Posted by Grumpy Old Man View Post
Quote:
Originally Posted by glennQNYC View Post
Good stuff. Thanks GOM.

Please note: The Performance Traction Management system is part of the FE4 upgrade (option) to the Z51 Performance Package. You need Z51 plus FE4 to get this system.
I'm looking forward to seeing one in a showroom up close and personal.
When do we think that will be possible?
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      07-23-2019, 05:32 PM   #271
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Couldn’t resist.
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      07-23-2019, 05:43 PM   #272
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Bottom Line... This C8 is a f****** Game Changer... Period.

Pricing. Power. Performance. Curbside Appeal. Are ALL on point! I am a diehard European Auto fan. But I am giving props where they are do.
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      07-23-2019, 05:56 PM   #273
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Originally Posted by The HACK View Post

Should be able to walk in and do the same thing I did, offer a local dealership 25% off of MSRP and walk out with a brand new Corvette on the same day without negotiation.
What dealer did you go into to buy a new base C7 for less than $42k.

I want to talk to them, because I'll go ahead and buy one.
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      07-23-2019, 06:47 PM   #274
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What dealer did you go into to buy a new base C7 for less than $42k.

I want to talk to them, because I'll go ahead and buy one.
You can check most of the big national dealers, MacCulkin, Les Stanford, Bachman in Louisville etc. they’re ALL offering 15-18% off MSRP plus $3,000 loyalty as of July on existing inventory.

But I bought mine at a local dealer in So Cal, and it wasn’t a base model. It was a loaded Grand Sport, MSRP $88K with 3LT trim and Z07 package. $23K off the sticker was what I offered a year ago and they accepted with little to no negotiations (just had to get authorization to sell it to me at that price from the owner of the dealership).
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      07-23-2019, 07:05 PM   #275
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I think the car is good looking from most angles; the question is this: Well put together? I had one a long time ago and hoping it is better.
The heat factor: in the old Vettes, your foot might burn up a little-will your back and rear feel the engine heat to a ridiculous point?
Could be like "sweatin to the oldies". Looks nice-hoping it is fun to drive as it looks.


there is no such thing as what you speak of anymore. I have a c7z, the entire car was a huge leap from the c6.. sit in one if you can.
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      07-23-2019, 07:17 PM   #276
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When do we think that will be possible?
I haven't really seen anything about when they'll be available but I suspect it's a few months out yet.
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      07-23-2019, 07:27 PM   #277
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Silver w/ silver stripes kinda catches my eye...
THAT........is sexy
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      07-23-2019, 08:23 PM   #278
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Silver w/ silver stripes kinda catches my eye...
THAT........is sexy
Agreed.
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      07-23-2019, 09:05 PM   #279
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When do we think that will be possible?
Check with your local dealer..... called mine today and was told to come in this Thursday as they will be having a special showing from 4-8
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      07-23-2019, 09:09 PM   #280
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The car looks good and is very intriguing...I really look forward to the various magazines reviewing the car and a 40,000 mile test by C+D.
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      07-23-2019, 10:09 PM   #281
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Looking beyond mere calculus gives an indication of Corvette engineers’ priorities


So, here’s my last words to all you naysaying nabobs of negativism (more commonly known as Porsche 911 owners). It would seem that the C8’s handling could turn out to be even more impressive than its turn of speed. Be afraid. Very afraid.
Although I appreciate what the C8 is offering for only $60K but I wouldn't be so fast dissing on the 911 owners. To be fair, the 911 and R8 and other supercars either are using unibody frame or outright carbon tub (McLaren) therefore they have an advantage in term of chassis responsiveness because they are inherently stiffer. The Corvette uses effectively an space frame so it may not have the chassis stiffness of the unibody.

In term of engine, I've driven the LT1 before and although it's effective in its output, it's not exactly the most inspiring motor in the world. And being driven 8K rmp red line DOHC engines in the M3, the LT1 6.5K rpm redline is somewhat a frustration. I suspect the LT2 won't be that different from the LT1. And of course being a mid engine car is not going to change that.

Also the Corvette rear suspension uses upper/lower control arm which is more or less a carry-over from the C7 and. I think Porsche 5-link mutilink suspension is probably more effective.

Most supercars now are using active anti-sway bar which would give you a better ride but at the same time has better handling. The Corvette still uses a rather basic, good old anti-sway bar found on a Civic :-)

Also one reason the C8 is fast is because its wheel bass is longer and wider than most but the drawback is if the chassis is not stiff enough, you feel like you're driving a boat. So that is a double edge sword. You can't tell from reading the spec, and only can tell when actually drive the car.

Anyway, like I said before, I need to drive the car to know how it feels like which is something you cannot find on a spreadsheet. No doubt the C8 has incredible value given its performance and cost. But I also have no doubt that the 911, R8, or M4 and definitely Ferrari, McLaren, will still have a richer, more sophisticated feel and driving experience. And that is what the rich people are paying for.
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      07-23-2019, 10:34 PM   #282
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Don't be silly. Rich people don't pay for actual capability. They pay for an image. The C8 will likely clean house at next years C&D Lightning Lap. People will still claim the more expensive cars offer more comfort, more technology or whatever, but fast will always be fast, and the basic C8 is going to be fast.
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      07-23-2019, 11:31 PM   #283
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Quote:
Originally Posted by WestRace View Post
Quote:
Originally Posted by Grumpy Old Man View Post
[SIZE="4"]Looking beyond mere calculus gives an indication of Corvette engineers’ priorities
[/SIZE]


So, here’s my last words to all you naysaying nabobs of negativism (more commonly known as Porsche 911 owners). It would seem that the C8’s handling could turn out to be even more impressive than its turn of speed. Be afraid. Very afraid.
Although I appreciate what the C8 is offering for only $60K but I wouldn't be so fast dissing on the 911 owners. To be fair, the 911 and R8 and other supercars either are using unibody frame or outright carbon tub (McLaren) therefore they have an advantage in term of chassis responsiveness because they are inherently stiffer. The Corvette uses effectively an space frame so it may not have the chassis stiffness of the unibody.

In term of engine, I've driven the LT1 before and although it's effective in its output, it's not exactly the most inspiring motor in the world. And being driven 8K rmp red line DOHC engines in the M3, the LT1 6.5K rpm redline is somewhat a frustration. I suspect the LT2 won't be that different from the LT1. And of course being a mid engine car is not going to change that.

Also the Corvette rear suspension uses upper/lower control arm which is more or less a carry-over from the C7 and. I think Porsche 5-link mutilink suspension is probably more effective.

Most supercars now are using active anti-sway bar which would give you a better ride but at the same time has better handling. The Corvette still uses a rather basic, good old anti-sway bar found on a Civic :-)

Also one reason the C8 is fast is because its wheel bass is longer and wider than most but the drawback is if the chassis is not stiff enough, you feel like you're driving a boat. So that is a double edge sword. You can't tell from reading the spec, and only can tell when actually drive the car.

Anyway, like I said before, I need to drive the car to know how it feels like which is something you cannot find on a spreadsheet. No doubt the C8 has incredible value given its performance and cost. But I also have no doubt that the 911, R8, or M4 and definitely Ferrari, McLaren, will still have a richer, more sophisticated feel and driving experience. And that is what the rich people are paying for.
The C7's rear suspension was a composite transleaf spring. Get your facts straight. It goes back all the way to the C5
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      07-23-2019, 11:48 PM   #284
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The C7's rear suspension was a composite transleaf spring. Get your facts straight. It goes back all the way to the C5
I know. Thanks god the C8 got rid of the leaf springs. But the upper/lower arm control is the same. Maybe some minor change in geometry but the basic setup is the same.
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      07-23-2019, 11:51 PM   #285
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Quote:
Originally Posted by Red Bread View Post
Don't be silly. Rich people don't pay for actual capability. They pay for an image. The C8 will likely clean house at next years C&D Lightning Lap. People will still claim the more expensive cars offer more comfort, more technology or whatever, but fast will always be fast, and the basic C8 is going to be fast.
The current Corvette C7 in GS or Z06 guises already "clean house" and the ZR1 is like second fastest at VIR, so it's not like GM needs the mid engine to be fast.
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      07-24-2019, 12:36 AM   #286
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Quote:
Originally Posted by WestRace View Post
The current Corvette C7 in GS or Z06 guises already "clean house" and the ZR1 is like second fastest at VIR, so it's not like GM needs the mid engine to be fast.
To keep pushing the limits without having to do ridiculous things, they do need the mid engine.
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