ME T/S Turbo Patent

[John]

Thanks to CorvetteBlogger, we have information on a GM patent for a two stage (T/S) turbocharger. While we believe that the first year, 2020 ME will only have a OHV, LT1+ naturally aspirated motor, this patent could easily apply to a 2021+ Z06-equivalent ME, especially so as GM patented, about 1 1/2 years ago, separately, a twin scroll turbocharged motor.

Internal Combustion Engine Having a Two Stage Turbocharger

The next patent details a two stage turbocharger system which is comprised of a High Pressure (HP) turbocharger and a Low Pressure (LP) turbocharger. The system may be configured to operate both turbochargers at low/medium speeds and at high engine speeds, the High Pressure turbocharger is bypassed in favor of the Low Pressure turbocharger. The patent details that turbochargers allow higher engine performances but suffer at low speed or low load. This new two stage system overcomes the deficiencies of turbochargers and provides the engine with a high performance charging system that ensures high efficiency at low operational speed as well as providing lower fuel consumption.






Click here to view and download the patent document for the Two Stage Turbocharger system.


Source:
USPTO.gov[/Quote]

Internal Combustion Engine Having a Two Stage Turbocharger
The next patent details a two stage turbocharger system which is comprised of a High Pressure (HP) turbocharger and a Low Pressure (LP) turbocharger. The system may be configured to operate both turbochargers at low/medium speeds and at high engine speeds, the High Pressure turbocharger is bypassed in favor of the Low Pressure turbocharger. The patent details that turbochargers allow higher engine performances but suffer at low speed or low load. This new two stage system overcomes the deficiencies of turbochargers and provides the engine with a high performance charging system that ensures high efficiency at low operational speed as well as providing lower fuel consumption.







Source:
USPTO.gov[/Quote]

http://www.corvetteblogger.com/2018/...erm=2018-08-22

[John]

Here is the complete text of the T/S Turbo patent:

[Quinten]

I haven't noticed the use of this system in the CAD leaks. The turbochargers reside on opposites sides if the block, fed by separate exhaust manifolds, feeding a single intake manifold from opposite directions. I do think that we'll see this implemented at some point, but It doesn't seem that GM is using it on their new turbocharged V8's.

[John]

Good, fact based, info. Perhaps the patent described set up is not for the first round of ME’s turbo’s.

[Mobius]

Thanks to CorvetteBlogger, we have information on a GM patent for a two stage (T/S) turbocharger. While we believe that the first year, 2020 ME will only have a OHV, LT1+ naturally aspirated motor...

Thanks for posting the patent - an interesting read.

Turbochargers offer a lot of flexiblity wrt power and fuel economy, but the "LT1+" derivative will also be readily tuneable for higher RPM and power.

I like the idea of some head work (lighter valves, ported head, new valve springs, new cam) to bring both RPM and power up in the upcoming LT1+ engine. I think a safe 7500 RPM redline will be achievable.

[John]

As hard as I have tried, I have been unable to get any info on what are the upcoming changes to the C7’s LT1. Not only person is whispering its HP number (at least not yet). All I have heard is the vague term, “updated” to describe the LT1+. Hopefully they would be the very things you have outlined Mobius.

In the pre-C7 reveal process, the motor for the ME was publicly shared (at SEMA) about nine weeks before the C7 was revealed. Wonder if pre-revealing the motor will again be done this time.

But even if so, before that was an October announcement that on 1.13.13 @NAIAS in Detroit), we will reveal “the next generation Corvette,” with nothing further other than the sharing of the C7’s revised emblem, e.g., the tigher Victory Ring.

For more details on the C7’s pre-release taser process, for those who have not seen it:

https://www.midenginecorvetteforum.c...tease-progress

So if GM follow’s a similar pattern on pre-reveal teasing the ME as they did for the C7, we are still a little way away from getting info about the reveal location date and location, even further away from its sharing the LT1+’s motor information. But maybe things would get moved up this time?

[OnPoint]

Nice find. I agree the CAD drawings don't show this, but if packaging constraints don't preclude it, then it may remain a tech option for down the road. The euro spec BMW 750d uses this type of set-up on a V8, dual turbos for each bank - thus quad turbo'd on the V8. Of course they have acres of room to do so under that vast hood.

Will be interesting to see which strategy GM takes to minimize turbo lag on its hp variants.

And then. . . . wait 'til Callaway gets its hands on the LT variant, likely supercharges it (raising its hp by 100+ in usual deadbolt-reliable, warrantied fashion) which won't have any "turbo lag."

The next couple years are going to be a great time to be a Corvette enthusiast.

[John]

As a Corvette friend of mine says, “we live in the golden area of motoring.” All of us here are going to have the most amazing upcoming few years. If only we could each afford to buy one ME every year until ZORA arrives — even if the requirements were to always need to trade in the proceeding year’s one.

I might sign a pact with the devil if I could keep ZORA.

[OnPoint]

Indeed. I think we're going to see the factory stock envelope with the vette pushed farther.

The only trepidation I have as somebody who has modded and raced every Corvette I've owned, is the current state of affairs with the C7 ZR1. Which as of today, is untunable. Nobody has cracked the new ecm with its random/rolling encryption lock. GM stepped up the encryption level substantially on the ZR - clearly signalling it is headed in the direction of locking these down.

My bet is the new ME has the upgraded ecm (or even a successor version), making custom tuning these rigs much more difficult, and possible prevent it altogether. Given Callaway's, Katech's and Lingenfelter's relationships with GM, hopefully there will still be folks allowed into the ecm.

Of course - if GM heads where the rumors indicate it may with regard to power, there may be no need for it anyway. Two-stage turbos (or a turbo set-up with minimal lag), decent hp, and factory warranty. . . heck, I might just leave it like it is.