That's not what you posted originally.

This is what you originally posted in response to my post, which had nothing to do with economies of scale:

"So you think that out of a total of maybe 200,000 or so C8s that we can expect to be built, only 3,000 or so will be TT and the rest will all be NA or NA hybrid??? I'm not trying to be condescending, but in an industry where virtually all high performance cars are going FI, you think GM is only going to make roughly 1.5% of their C8s TT over the next 5 or 6 years??? Do you really believe this or is this some crazy kind of theory you have in order to convince yourself that the Z is going to be NA?"

We already know the ZO6 will be NA for reasons that have already been discussed ad nauseam. The economy of scale factors in because the twin turbo LT7 will be based on the LT6.

If you want an example of GM applying this in practice then check out the ATS and the ATS-V. The V was powered by a 3.6 L V6TT, the LF4, and only produced in small numbers. It was a new iteration of the LF3, which powered a CTS V-Sport and was also produced in small numbers. Cumulative LF3 and LF4 production would have been around the number of ZR1s produced, I can't find the exact figures online but they were tiny. I don't know if it was profitable but the engines were based on GM's ubiquitous 3.6L NA V6 LFX.

Similarly we can expect the LT7 to essentially be an LT6 with a pair of turbos and liquid intercoolers attached. The LT6 is a variant of GM's Gen VI DOHC V8 architecture which obviously will be produced in massive numbers. All of the R&D regarding the new block and DOHC heads can be amortized over all the trucks it will power, with the Corvette being a fraction of that cost. The twin turbo R&D? I would expect all that was learned from the twin turbo V6 engines was applied to the LT7 so it won't be akin to desiging the engine from a blank sheet. We'll see.

How GM can make it all work from the perspective of bean counters I don't really know. What I do know is that the ZO6 is based on the NA LT6, and that is not based on "magazine propaganda" as you say, though one part of the puzzle is that the few car magazines and blogs that I find credible are unanimous in their reports of the ZO6's NA engine. We also have at least one forum member with inside knowledge of the head design, an acoustic analysis of the ZO6's exhaust note, hours of video with audio, some of my own overheard info locally, and as the coup de grace we have John's report that the redline will be 8500 rpm.

Mass produced twin turbo engines aren't designed to rev so high because it isn't necessary to meet power goals. An NA engine's torque output with commercially available tech is largely limited by displacement so the only way to get more power is to increase the revs, but with with forced induction one need simply to turn up the boost. GM's twin turbo V6 and V8 engines all have low rpm redlines (6500 or less) and feature flat torque curves with minimal lag and I wouldn't expect the LT7 to be much different. With an 8500 rpm redline the turbos would have to be too large and the engine would be gutless at low rpm. Variable geometry turbos could work but that adds cost and complexity while reducing reliability. Not GM's style, nor that of any other mass market automaker. An 8500 rpm redline for the ZO6 is confirmation that it will feature the NA DOHC FPC V8, otherwise known as the LT6.

 

Three questions::
a) does it fit
b) can you drive it
c) does it perform

Naturally asperated:
a) yes
b) yes
c) yes

Turbo
a) yes
b) yes
c) yes

Super
a) yes
b) no
c) it would if you could drive it.

You see the access to the front end of the engine is where almost all superchargers get the power to charge the intake air.
The room between the front of the engine and the back of the firewall is a few millimeters.
Thereby the belt does not fit and you have to get the drive from between the engine and the transmission.
Good luck with that (0 millimeters).
I guess you could use an electrically driven supercharger............

 

NA NA NA, remember that I posted it’s a NA!

 

The Mustang would like a word with you.

Note: Outside of Corvette a Camaro, Chevy now sells a grand total of TWO cars. Neither of which I'd want, especially the Spark.

My understanding is Ford got out of the "car" business for very sensible reasons. People want trucks, SUVs and cross overs. Look at Chevy: 7 SUVs (ironically, same as Ford).

I agree that trucks will continue to go with smaller engines and FI. I just think at some point those engines will get so small and provide so much less power and torque that most will switch to diesel, even the brodozers. Hell, especially the brodozers. Ever since I got my TD I've said I'd never go back (especially given my use case). Sure, if I were to step down to a 1/4 or 1/2 ton truck, I might consider a gas engine, but highly likely I'd prefer a TD for the torque and fuel economy benefits.

And not sure where you are, but the vast majority of trucks in my area diesels, including the brodozers. I just wish the brodozers didn't run around with their tuners set to "roll coal" 90% of the time. But that largely seems to be a Dodge thing.

 

We've seen a few diagrams from some tuner (I forget who) that showed a solution to that problem that basically consisted of a centrifugal supercharger mounted to the back of the engine being driven by a shaft that ran to the belt system up front. Seemed pretty workable to me. Look at the LT4, the SC on it was driven by a belt that drove other systems as well, no reason that couldn't work here.

That said, I see ZERO chance that Chevy would do it that way.

 

I'll agree the new mustang is a car when Ford admits it's actually a station wagon.

No argument there. It's just common sense to meet market demand.

I'm in Texas. Ironically, most diesels around here seem to be actual work trucks - plain jane farm trucks and company trucks that tow big trailers. Some of the brodozers are diesel, but most seem to be gas. Not sure why - I would think anything that big and heavy would benefit from a diesel engine, but maybe they want to keep the engine stock and just make the truck purty, I don't know. I'm just the opposite - my vette is almost completely stock on the outside. All my mods are on the inside.

 

^there no accounting for brodozer owners. People see my 6" lifted on 37s 3/4 ton and think "brodozer" until they see its hooked up to a 40' gooseneck with a tractor, or actual dozer, or 20k lbs of haybales on it, and it is covered in dirt and mud and realize it isn't what they thought.

 

/\ Procharger has a C8 supercharger system.

 

If we look at the Horsepower per Liter metric and assume that the HP is around 600HP that converts to a 109.09HP/L. There is a certain CF member that insists that GM Powertrain are trying to get 122HP/L or at least that is the goal. Here is a progression of the possible HP ratings where we can estimate a rational outcome. Also is a list of current up to date NA competitor engines for comparison. Note that I have shown the ZO6 as the projected 122HP/L rating. No doubt GM Powertrain will place this within their durability standards which could push it down to 650HP range and still pacify the big HP mongers.

LT6 5.5L
600HP = 109.09HP/L
610HP = 110.91HP/L
620HP = 112.73HP/L
630HP = 114.54HP/L
640HP = 116.36HP/L
650HP = 118.18HP/L
660HP = 120.00HP/L
670HP = 121.82HP/L
680HP = 123.64HP/L
690HP = 125.45HP/L
700HP = 127.27HP/L


654HP = 167.69HP/L Gordon Murray T.50 3.9L
850HP = 141.67HP/L Pagani Huayra R 6.0L
520HP = 130.00HP/L Porsche GT3 RS 991-2 4.0L
502HP = 125.50HP/L Porsche GT3 992 4.0L
671HP = 122.00HP/L Corvette C8 ZO6. 5.5L ???
730HP = 121.67HP/L Pagani Huayra 6.0L
789HP = 121.38HP/L Ferrari 812 Superfast 6.5L
631HP = 121.35HP/L Lamborghini Huracan STO 5.2L
760HP = 116.92HP/L Lamborghini Aventador SVJ 6.5L

 

Very helpful post.

 

Sheesh. It wasn't that long ago that 100 hp/L was considered impossible for a stock engine.

 

What a load of crap...ZERO mention of the #7 Fetzer valve and NONE of this works without the #7 Fetzer valve...geez, EVERYONE knows that.
Don't forget..."It's all bearings today"

 

I know this will be an unpopular comment.. but I'm having a really hard time picturing a NA Chevy powerplant mentioned in the same breath as legitimate supercar engines that cost as much or more than a Corvette.

 

Cost as much to build or sell for as much as a Corvette? What manufacturer replacement parts list for is far in excess of their cost.

 

​​​​​​ZERV..."3 Flavors, LT1, 4.6TT & 5.4TT. LT1 will transition to N/A Dohc at some point down the line." I'm sure you'll be happy with an NA DOHC Stingray someday.

 

Where's that pissing contest emoji when you need it...

 

So you think something like Lamborghini Aventador SVJ's engine costs (specifically to build) the same as the new Z's engine?

 

I just like the “we know” when nobody posting here knows anything related to what actual engine is in the vehicle.

 

Ferrari 348 was 94 HP/L in 1989 (late)
Ferrari F355 was 108 HP/L in 1994 (late)

100 HP/L has not been achieved for a production N/A engine with cam-in-block 25 years later.

On the other hand 200 HP/L has been achieved by several 1.0 L (4-banger) motorcycle engines (8-ish years ago).

HP/L is a RedLine game played out with DOHC, short strokes, and large cylinders.

600cc motorcycles play in the 17,000 RPM RedLine range.
1000cc motorcycles play in the 14,000 RPM RedLine range (BMW S1000RR) and 208 HP/L

 

I didn’t say that. That Lamborghini charges say $60,000, that does mean that it costs Lamborghini 10 times as much to build as it does for GM to build an engine that it sell for $6,000. Their margins are much higher.

Lamborghini is owned by VW also one of largest engine manufacturers in the world. They both pay way less than you would expect for engines.