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The C&D article is correct. It will be a NA flat plane crank motor. Even the Corvette race teams were hinting around at it at the races. Weight reduction will be a huge priority.
Well, that's interesting. What does that mean in the real world?
1. If N/A and FPC, it will be the largest displacement production FPC motor ever. I had the second largest, the 5.2 FPC in my '17 Shelby GT350. How did that work out for myself and a few of my friends who bought them? Hint, there were NO happy endings with this car. You see, an FPC and a large displacement get along with each other about as well as...well nothing. Which is why you do not see large displacement engines coming out from Ferrari, McLaren, Lambo, etc. With my GT350, it was gutless under 3400 RPM, and trips to the gas station were often to check the gas and fill the oil. Two of my five friends who tracked their GT350s, blew their VooDoo engines. The C&D long term GT350 tester quaffed oil like a camel who had not had access to water for 10 days after departing the last oasis.
2. Weight reduction will be a huge priority. That's great to hear. Please tell us how. The new base C8 is bigger and heavier than the C7 Stingray. The new C8 Z06 will have a heavier DOHC engine (heavier than the small block pushrod motor) It will also have a higher CG, but we won't dwell on that here as it is not a weight issue in of itself. It will have larger wheels and tires, a stronger (heavier) DCT, bigger (most likely) heavier brakes. more cooling capacity (heavier). So if weight reduction will be a huge priority (GREAT!) how will that be achieved at a price point that will fit into the oft referenced $85k entry level for a C8 Z06. Remember, even now the base C* can be optioned out well into the $90k range. Hmmm, let's see - ok, carbon fiber wheels (such as those found on the GT350 R) . What will that option run as a set - $8k to $10k)? Massive changes to the C8 frame - say replacing many parts with titanium? Unlikely, due to material and reengineering expenses. Changing the dimensions of the C8 to make it smaller? Again, not realistic. Severely de-contenting the car to make a "R-Spec option?" Possible, but the realistic audience size of buyer for that car will be a small percentage of Z06 buyers.
3. Yep - so what does all this mean in the new world. Especially now with severe world-wide dislocation further reducing the potential pool of $85k - $120k toy buyers.
Last edited by NineVettes; 05-04-2020 at 11:33 AM.
Weight reduction will be a huge priority. That's great to hear. Please tell us how.
Hmm, guess you're just not reading the posts but no one said anything about Titanium! Every deal with titanium fabrication??
The discussion was magnesium replacing aluminum casting. I speculated that may be why GM went to large aluminum castings, mostly bolted together versus welded aluminum parts as in the C7. This is a simple comparison quoted from the net:
Magnesium vs. Aluminum
Imagine a car made entirely of die cast aluminum parts. Now imagine that exact same car made from die cast magnesium parts. The magnesium car would be 1/3 lighter in weight than its aluminum cousin. The magnesium die cast parts outperform aluminum ones in so many ways. The advantages include:
33% lighter than aluminum.
Similar or greater mechanical properties.
Lower working temperatures extend die life and reduce energy consumption during production.
Machining is faster and easier and machining tools last significantly longer.
Superior thin-walled near net shape casting of larger, more complex parts so there are fewer components and less assembly required.
Greater general corrosion resistance.
It's also alloy and design dependent. My "Guess" is the current aluminum castings in the C8 may well be a minimum bending (flexure) design (like why high strength steel is often NOT used on many bridges) and NOT strength limitation so the 33% lighter may be accurate. There are more castings in the C8 than just the large ones from Bedford.
^^^
Not the whole frame! Yep magnesium had been used years for wheels and other car parts! That's NOT new!
Yep the C6 frames that were made from aluminum were particularly inefficient as they used hydroformed side rails that had the same thickness front to back where the max was only needed in a specific area. GM brought that frame into Blowing Green versus buying from a Tire 1 supplier for the C6. It optimizes strength along the side frame rails only were needed. Now they have gone to large (and small castings!)
Not the whole frame! Yep magnesium had been used years for wheels and other car parts! That's NOT new!
The frame isnt very heavy. Not much savings there.
C6Z frame was 285lbs. C7 heavier. C8 probably heaviest? Lets say mg saves ~30%... that is MAYBE 100lbs?
Regardless...the amount of weight added by going to the new engine and additional coolers will not be fully offset by going mg. There is a lot more to getting a car around a track than overall weight though...
Last edited by Apocolipse; 05-04-2020 at 12:17 PM.
The frame isnt very heavy. Not much savings there.
C6Z frame was 285lbs. C7 heavier. C8 probably heaviest? Lets say mg saves ~30%... that is MAYBE 100lbs?
Regardless...the amount of weight added by going to the new engine and additional coolers will not be fully offset by going mg. There is a lot more to getting a car around a track than overall weight though...
Yep wish the C8 was as light as my 1st car, a '41 Ford Coupe I stuffed an Olds engine into in 1959 or even my 1974 260Z! But cars do get heavier with govenment regs etc. I built my street rod that doesn't have to meet any regs weights 3000 lbs and with it's set back 502 cid BB has 53% of it's weight on the narrowed Ford 9 inch Currie rear with a 4 bar link suspension and 16.5 inch section width Mickey Thompsons rear tires.
I find the C6Z comparison humorous as it is what Tadge said caused their realization the finally needed a ME! This is his statement in the 1 hour Autoline interview:
"He said they knew they had pushed the FE as far as they could when they had difficultly getting the C6 ZR1 in 2006 with it’s supercharged 638 hp supercharged 6.2 liter engine and they were concerned they would not be able to match the 0 to 60 times of the 505 hp Z06 because of limited traction of that 52 front/ 48 rear weight distribution! He said they baily squeezed by using very sticky special tires! They saw the handwriting on the wall."
He said they had Pratt & Miller define with their race car design software etc the optimum configuration for Vette! They said 60% rear weight and an ME with low moment of inertia!
Tadge also said every time they were solving a C8 design problem they would say, "It would be easy if we weren't constrained by money." I'm sure the envy Ferrari with their new SF90 Stradale's 996 hp hybrid that weights 3500 lbs!
Hmm, guess you're just not reading the posts but no one said anything about Titanium! Every deal with titanium fabrication??
The discussion was magnesium replacing aluminum casting. I speculated that may be why GM went to large aluminum castings, mostly bolted together versus welded aluminum parts as in the C7. This is a simple comparison quoted from the net:
Magnesium vs. Aluminum
Imagine a car made entirely of die cast aluminum parts. Now imagine that exact same car made from die cast magnesium parts. The magnesium car would be 1/3 lighter in weight than its aluminum cousin. The magnesium die cast parts outperform aluminum ones in so many ways. The advantages include:
33% lighter than aluminum.
Similar or greater mechanical properties.
Lower working temperatures extend die life and reduce energy consumption during production.
Machining is faster and easier and machining tools last significantly longer.
Superior thin-walled near net shape casting of larger, more complex parts so there are fewer components and less assembly required.
Greater general corrosion resistance.
It's also alloy and design dependent. My "Guess" is the current aluminum castings in the C8 may well be a minimum bending (flexure) design (like why high strength steel is often NOT used on many bridges) and NOT strength limitation so the 33% lighter may be accurate. There are more castings in the C8 than just the large ones from Bedford.
Yes, I read them and a lot of other papers re the use of magnesium alloys in car frames. Within my self-imposed 30 minute lunch window, (work is busier than ever) I meant magnesium not titanium in my earlier post. However, that said, all of the articles I have read pertaining to use of magnesium allow to build the entire car frame may be coming technology but not quite here yet. And when it is here, will save about 33% or so, probably not enough to offset all of the other weight gains associated with the Z06 higher performance model.
And, given what we see of current pandemic issues - I would not be surprised to see the reveal of that car put off to late '21 with sales in '22 - the pool of people comfortable with spending that level of money on a toy is definitively reduced. THey can make '21 the year of the production Vert intro, since what is left of the '20 model year is rapidly slipping away. And if the new Z06 is powered by that 5.5 liter N/A FPC, I will not be buying it based upon my prior experiences with larger displacement FPC. Nope. No thanks, nada. If I get tired of my '19 M7 Z (which now weighs in the vicinity of 3470 lbs with fuel) and running around 685 r/w hp, there could be a Sebring Orange ZR1 in my future. Or, one of another few cars I am researching.
I noticed in your reply you clearly avoided addressing any of the concerns I expressed with FPC and larger displacements. And their gutlessness under 3400 RPM.
^^^
Applaud you reading and posting off work hours! I have the luxury of being retired 20 years with a part time internet business that has me on my desktop, laptop or large iPad much of the day. (The small orders that go into PayPal justify the “stuff” I buy for my car toys! When it builds sufficiently, I buy something!) I can justify (to myself) spending time on the forum etc.
I agree a reduction in chassis weight, although helpful will not offset the performance issues with the leaked Z06 power info. I didn’t comment on the flat crank as from what I read, no need for the Z06 to have one to meet IMSA regulations. And no question the vibration, which is tolerable in a race car is not in a DD! Will have to see just what they use.
Titanium use on the Corvette is not new. I had a titanium exhaust on my 2001 Z06. Why not again? Titanium springs? Carbon fiber wheels? Smaller wheels? Lighter, non powered, non ventilated seats. 2-5 speaker stereo system. Air gapped duel pane polycarbonate back “glass” (maybe not legal OEM). Lots of choices, some more expensive than others.
Titanium use on the Corvette is not new. I had a titanium exhaust on my 2001 Z06. Why not again? Titanium springs? Carbon fiber wheels? Smaller wheels? Lighter, non powered, non ventilated seats. 2-5 speaker stereo system. Air gapped duel pane polycarbonate back “glass” (maybe not legal OEM). Lots of choices, some more expensive than others.
If the C8 mule, which many expect is the Z06, is any indication... the wheels will not only be larger in width, but also larger in diameter than the Stingray. The mule I’m referring to looked to running a 20”/21” combo with camo wheel covers to hide the assumed carbon fiber wheels of the Z06.
If the C8 mule, which many expect is the Z06, is any indication... the wheels will not only be larger in width, but also larger in diameter than the Stingray. The mule I’m referring to looked to running a 20”/21” combo with camo wheel covers to hide the assumed carbon fiber wheels of the Z06.
The constantly larger and larger wheels is the stupidest thing I have seen over the years in terms of performance. Larger wheels are heavier, and heavier at the worst possible point, exactly where it will have the worst impact on inertia. It hurts braking and acceleration. Please stop the insanity.
I understand this point, however, Carbon wheels solve that issue. A Carbon 20/21 set up will weigh less than a standard 18/19 set up from the base C7. My issue is not having enough tire sidewall personally.
In case anyone has forgotten, these are screenshots from the leaked North American Engine Forecast document that was posted in November of 2017, then promptly pulled. Really no way of knowing the crankshaft type or aspiration, but if there is a 5.5L variant and it is N/A, I believe it's safe to say the TT LT7 we've seen leaked is likely a 4.2L engine. I don't have it saved but I think the 5.5L gave an estimated 8xxhp on the document.
I think the difference is Porsche isn't afraid to use more expensive lighter weight materials. They know their customers will pay for $145k for a GT3 not sure how many Z06 owners and up for paying that much.
Porsche is using less expensive materials, plain aluminum casting with high instance of porosity and thickness variations for strut towers.
Hence the many strut tower failures
Weight is good, weight is strength, c8 Vette will not turn into a bucket of bolts over time no Matter the abuse.
I love flying over curbs on track and not have a strut tower poke through the hood
In case anyone has forgotten, these are screenshots from the leaked North American Engine Forecast document that was posted in November of 2017, then promptly pulled. Really no way of knowing the crankshaft type or aspiration, but if there is a 5.5L variant and it is N/A, I believe it's safe to say the TT LT7 we've seen leaked is likely a 4.2L engine. I don't have it saved but I think the 5.5L gave an estimated 8xxhp on the document.
It makes crazy logic that the street Vett engine would be flat plane and reduced in displacement from 5.5 lt to handle the vibration issues of the flat plane with TT to increase the power level. Flat plane for bragging? Or for weight issues to meet racing rules of "within 10% of production weight" for the racing crank. Oh well, we'll see.
Last edited by Kodiak Bear; 05-08-2020 at 01:23 PM.
05-04-2020, 11:27 AM
I have the luxury of being retired 20 years with a part time internet business that has me on my desktop, laptop or large iPad much of the day. (The small orders that go into PayPal justify the “stuff” I buy for my car toys! When it builds sufficiently, I buy something!) I can justify (to myself) spending time on the forum etc.
