Z06 Flat plane crank?
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 24,017
Likes: 634
St. Jude Donor '10
lots of manufacturers are embracing the flat plane crank. most are in the 3.8 to 4.0 size and use some pretty exotic rotating parts to make it work
ford used quality parts, but the big displacement is harder to tame with a larger stroke Once gm makes a dohc tt vette, I'm in.
ford used quality parts, but the big displacement is harder to tame with a larger stroke Once gm makes a dohc tt vette, I'm in.
Last edited by SurfnSun; Jan 25, 2021 at 09:23 AM.
Burning Brakes
Joined: Aug 2019
Posts: 1,085
Likes: 582
Not really it has a very cool design. Where the cylinder heads are reverse. The turbos are in the valley of the engine. And the injectors are where the exhaust ports are. A awesome design, because the turbos are so close to the exhaust ports. Quicker spool up, and more power. I can not understand why no one came up with this smart design.
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 24,017
Likes: 634
St. Jude Donor '10
Not really it has a very cool design. Where the cylinder heads are reverse. The turbos are in the valley of the engine. And the injectors are where the exhaust ports are. A awesome design, because the turbos are so close to the exhaust ports. Quicker spool up, and more power. I can not understand why no one came up with this smart design.
Le Mans Master
Joined: Jul 2000
Posts: 6,559
Likes: 4,501
From: North Dallas 40 TX
The production engine can be whatever size they can make in the same block. As a matter of fact, a leaked GM North American Engine plan document showed a 4.4 liter DOHC as well as a 5.5 liter DOHC. IIRC correctly they were both listed at TT.
I believe the race and production engines are based on small block Chevy bore centers. I have no confirming information other that one post that described as a Gen 6 small block. One thing that has not changed across all generations of the small block has been the bore center spacing.
Le Mans Master
Joined: Jul 2000
Posts: 6,559
Likes: 4,501
From: North Dallas 40 TX
Not really it has a very cool design. Where the cylinder heads are reverse. The turbos are in the valley of the engine. And the injectors are where the exhaust ports are. A awesome design, because the turbos are so close to the exhaust ports. Quicker spool up, and more power. I can not understand why no one came up with this smart design.
Burning Brakes
Joined: Aug 2019
Posts: 1,085
Likes: 582
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 24,017
Likes: 634
St. Jude Donor '10
I think getting 440rwhp and 575rwtq from a Callaway Twin Turbo might qualify as experience. What turbo cars have you owned? I also understand what the stock turbos were listed at.
Last edited by SurfnSun; Jan 25, 2021 at 06:10 PM.
Burning Brakes
Joined: Aug 2019
Posts: 1,085
Likes: 582
Then there was my 94 Supra turbo. 320 stock hp. I completely built that car from top to bottom. Too much to explain. Google performance auto sound September 2007. That will explain that car. Magazine cover.
I now have a 2020 civic si. Put down pipe cold air and larger inner cooler. And I did a k tune. I had a few more turbo cars. 05 sti. A old conquest.
So yes I have had a lot of turbo cars. I did a lot of Supra stuff in years past. I’ve owned a auto shop for 25 years. So I know a little about turbo cars.
Last edited by the lark; Jan 26, 2021 at 06:29 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Le Mans Master
Joined: Jul 2000
Posts: 6,559
Likes: 4,501
From: North Dallas 40 TX
A lot. First one was a 81 turbo trans am. 301 motor. Not much to do with that. I was 17. Gutted the cats. And installed a vacuum tee that could adjust the waste gate. Allowing more boost. Also had a 87 grand national. 230 stock hp. Do the same with that. But way better results. Did a few more mods to that.
Then there was my 94 Supra turbo. 320 stock hp. I completely built that car from top to bottom. Too much to explain. Google performance auto sound September 2007. That will explain that car. Magazine cover.
I now have a 2020 civic si. Put down pipe cold air and larger inner cooler. And I did a k tune. I had a few more turbo cars. 05 sti. A old conquest.
So yes I have had a lot of turbo cars. I did a lot of Supra stuff in years past. I’ve owned a auto shop for 25 years. So I know a little about turbo cars.
Then there was my 94 Supra turbo. 320 stock hp. I completely built that car from top to bottom. Too much to explain. Google performance auto sound September 2007. That will explain that car. Magazine cover.
I now have a 2020 civic si. Put down pipe cold air and larger inner cooler. And I did a k tune. I had a few more turbo cars. 05 sti. A old conquest.
So yes I have had a lot of turbo cars. I did a lot of Supra stuff in years past. I’ve owned a auto shop for 25 years. So I know a little about turbo cars.
Racer
Joined: May 2016
Posts: 407
Likes: 321
It seems to have worked out for Mercedes with the AMG GT models. And the new black series adds a flat plane crankshaft for 720hp and 590 ft lbs.
Racer
Joined: May 2016
Posts: 407
Likes: 321
What will be costly is all the sales GM is going to lose if they go with an NA FPC making about 600/475 instead of a TT setup making 675/675.. A lot of folks, like me, want no part of a high strung/high maintenance race motor that's way down on power from it's C7 counterpart and is going to go for a $30k premium over a Stingray. GM sold about 5k C7 Zs a year, GM will be lucky to sell half this amount with a small displacement, low torque, NA FPC. With every other manufacturer moving away from FPCs and NA, I have a hard time believing GM is stupid enough not to know this. For these, and many other reasons, I think the NA FPC is a head fake and that GM will go with a TT setup, but that's just my opinion and only time will tell.
If they do go TT, I hope the torque is lower than your figure. I'd rather see 560 ftl-lbs or so. Higher numbers make the car that much trickier and you dont really need more to perform like crazy.
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 24,017
Likes: 634
St. Jude Donor '10
Modern ball bearing turbos spool fast, Id much prefer a traditional turbo layout that has the ability to put out huge numbers. Of course, if GM never gives anyone computer access, downpipes and exhaust may be all you get.
Le Mans Master
Joined: Jul 2000
Posts: 6,559
Likes: 4,501
From: North Dallas 40 TX
If it is optimal, why aren't they using it in F1?
Racer
Joined: May 2016
Posts: 407
Likes: 321
Do you know the engineering and packaging reasons they did that? Without that, you don't know if it was an optimization for power or compromise for packaging, or low speed throttle response to offset the low end torque. What we do know is the C8 was designed with twin turbos on the outboard side of the block. We have CAD images from GM to prove it. Hot V engines do not have room to include a free flowing tubular exhaust pre turbo, unless you want to mount the turbo well clear of the engine like they do on some Truck Pulling designs. Not optimal for a street car. It is not an a design for optimal power in a car with a low hood.
If it is optimal, why aren't they using it in F1?
If it is optimal, why aren't they using it in F1?
Please don't throw out F1 as some holy standard.... it doesn't really apply to street cars. The packaging requirements are very particular in F1, tiny space, very small v6 and a completely different set of parameters. If anything, you would have to consider that the Mercedes F1 engine has been largely dominant for 7 years with the exception of a few Ferrari seasons and you would think that expertise and performance might demonstrate the technical wizardry present throughout the organization.
Burning Brakes
Joined: Aug 2019
Posts: 1,085
Likes: 582
I see the car, but can't read the article. I'll bet it was a big single turbo right? That's the problem, the Supra's design meant you needed a much bigger turbo to make real power. You can't do that with the Blackwing. Some guys may be ok with 550-600hp...many are not.
Modern ball bearing turbos spool fast, Id much prefer a traditional turbo layout that has the ability to put out huge numbers. Of course, if GM never gives anyone computer access, downpipes and exhaust may be all you get.
Modern ball bearing turbos spool fast, Id much prefer a traditional turbo layout that has the ability to put out huge numbers. Of course, if GM never gives anyone computer access, downpipes and exhaust may be all you get.
Burning Brakes
Joined: Aug 2019
Posts: 1,085
Likes: 582
I didn't say it was perfect, I said it worked out well for them. That engine makes big power and torque, has been reliable, manages heat, essentially no lag and sounds absolutely terrific for a turbo engine.... maybe the best out there. But you talk about it as if Mercedes AMG had to use some inefficient design... as if they didn't have the capital to do what they thought was best, lol. Of course they had a set of reasons for choosing it and there are always pros and cons... but they hit a homerun with the design.
Please don't throw out F1 as some holy standard.... it doesn't really apply to street cars. The packaging requirements are very particular in F1, tiny space, very small v6 and a completely different set of parameters. If anything, you would have to consider that the Mercedes F1 engine has been largely dominant for 7 years with the exception of a few Ferrari seasons and you would think that expertise and performance might demonstrate the technical wizardry present throughout the organization.
Please don't throw out F1 as some holy standard.... it doesn't really apply to street cars. The packaging requirements are very particular in F1, tiny space, very small v6 and a completely different set of parameters. If anything, you would have to consider that the Mercedes F1 engine has been largely dominant for 7 years with the exception of a few Ferrari seasons and you would think that expertise and performance might demonstrate the technical wizardry present throughout the organization.
Mercedes put there f1 motor in one of there hand built cars. They did but it was very detuned, so it could work on the street. Google it you will find the write up.
Le Mans Master
Joined: Jul 2000
Posts: 6,559
Likes: 4,501
From: North Dallas 40 TX
I didn't say it was perfect, I said it worked out well for them. That engine makes big power and torque, has been reliable, manages heat, essentially no lag and sounds absolutely terrific for a turbo engine.... maybe the best out there. But you talk about it as if Mercedes AMG had to use some inefficient design... as if they didn't have the capital to do what they thought was best, lol. Of course they had a set of reasons for choosing it and there are always pros and cons... but they hit a homerun with the design.
Please don't throw out F1 as some holy standard.... it doesn't really apply to street cars. The packaging requirements are very particular in F1, tiny space, very small v6 and a completely different set of parameters. If anything, you would have to consider that the Mercedes F1 engine has been largely dominant for 7 years with the exception of a few Ferrari seasons and you would think that expertise and performance might demonstrate the technical wizardry present throughout the organization.
Please don't throw out F1 as some holy standard.... it doesn't really apply to street cars. The packaging requirements are very particular in F1, tiny space, very small v6 and a completely different set of parameters. If anything, you would have to consider that the Mercedes F1 engine has been largely dominant for 7 years with the exception of a few Ferrari seasons and you would think that expertise and performance might demonstrate the technical wizardry present throughout the organization.
I brought up F1 because they have different design parameters, and low speed turbo response is not an over-riding parament. They are able to keep their RPMs high throughout the race. That is not good for street drivability. They do not have to worry about startup emissions. Their primary design parameters are producing as much power as possible at a specific maximum boost within the race operating RPM range, on a specific fuel. That gives you a pretty good idea of what types of things are optimized for producing power, excluding limitations for the things Mercedes needs to do for a street engine in one of their cars.
Burning Brakes
Joined: Sep 2006
Posts: 873
Likes: 1,174
To RacerX Point, the F1 cars also use the battery to spin up the turbo and the battery to fill in the turbo lag. The Hot V seems problematic to me because the current car was designed around exhaust on the outside and intake in the ceneter. Not sure what is to be gained in practical terms for the C8 with Hot-V.
I am fairly convinced if the bore centers have to be the same AND if they are the same as a small block, it seems that some variation of 5.5L to 6L makes sense. If the C6Z was 7L and reved to 7K limited by valvetrain and head flow. Some variation of this with DOHC and VVT gets you to 8-9K. Shorter stroke for sure to keep the piston speeds down. FPC or CPC depending on what they can make reliable. Since the Mercury Marine LS7 with DOHC makes 750HP, I assume there will be alot of options that get it done NA for us.
Then the TT will be the ZR1
I am fairly convinced if the bore centers have to be the same AND if they are the same as a small block, it seems that some variation of 5.5L to 6L makes sense. If the C6Z was 7L and reved to 7K limited by valvetrain and head flow. Some variation of this with DOHC and VVT gets you to 8-9K. Shorter stroke for sure to keep the piston speeds down. FPC or CPC depending on what they can make reliable. Since the Mercury Marine LS7 with DOHC makes 750HP, I assume there will be alot of options that get it done NA for us.
Then the TT will be the ZR1