P-car fan

Trust when I say that "push to pass" is much more than that, it's definitely well worth it!

Key Left

The latest PCA magazine describes the 992 to be specially engineered to be finally Turbo-lag-free.
Now, that sounds worth more than any financing deal, period.

Dewinator

Doesn't sound that special to me, they've been making turbo-lag-free 911s for over 50 years.

Quadcammer

Yeah but these will actually have some torque unlike the anemic motors they had for 50 years

Lawsofpower

precisely.

mac10

I think it's hysterical that people are already discussing and contemplating what they are going to do in 2 years with the release of the next gen car.

seattle_sun

Umm, it is impossible for a Turbo to be lag free. The way a Turbo works makes it mandatory for there to be some lag. Obviously, turbo design, engine design, etc can make this lag smaller or less perceptible.

simplex

Unless they use an electric turbo. Their corporate cousins at Audi have some experience in that.

seattle_sun

Good point...

Dewinator

Agreed. Whatever they're doing in the base 911 and one-step-up-from-base-911 at a given moment is amazing and everything previous is anemic.

911boy

My 991.2 doesnt have much if any perceptible lag. My 2.7 Audi MT sure did 15 years ago.

capedsegwayrider

Porsche filed a series of international patents in 2014 on a quad turbo six cylinder engine. These filings are quite expensive and many of Porsche's past filings of this type have been for components of production vehicles. The timing of the patents also fits with the 992.

I think it's possible that this is the new engine tech they are referring to, however, it's not clear from the patent whether the filing is for a diesel or petrol engine, and whether it's for a V6 or a flat six.

From the complexity of the new engine layout this is probably something that's at the higher end of their product range.

Here are links to two of the patents:

https://patents.google.com/patent/DE...after=20100101

https://patents.google.com/patent/GB...0100101&page=1




What the two patents describe is a new type of dual sequential turbo layout similar to the quad turbo V6 layout in the diesel engine of the new BMW 750d. However, there are some significant differences that are detailed in the second patent.

The differences are seen in the very complex layout of the exhaust and intake lines. In particular, each combustion chamber has two parallel exhaust lines, one from each exhaust port. These parallel lines are connected to the two turbos via a series of intersecting ducts that are controlled by valves.

Porsche's patent explains that in conventional sequential turbo setups, a limitation is that at the high end of the power range, both turbos cannot be operated at max efficiency. However, with the use of the 2 parallel exhaust lines and the complex control scheme, Porsche's sequential turbos can both operate at max capacity at the top end of the power range, giving very high boost pressures.

Lower down in the RPM range, either turbo or both can operate at full or partial efficiency by dynamically changing the valve configurations. Also, the exhaust lines are configured to keep both turbos spinning even when they are not contributing to compression. This minimizes turbo lag associated with the need to overcome rotational moment or inertia starting from a stationary state.

This means that Porsche's sequential turbo scheme gives maximum anti-lag benefit but also max boost pressure.

Each pair of sequential turbos is assigned 3 cylinders, giving 4 turbos for a six cylinder engine.

Another hint regarding the nature of the engine: direct discussion of "economy" and "sport" operating modes, and a torque curve plot where the speed of the engine goes to n=8000 and the torque m goes to >600. If "n" stands for RPM then this is clearly not a diesel.




Regarding electric turbos and hybrid technology, Porsche has also filed at least one patent for a way to use the turbo as an electric generator for charging of the electrical system using exhaust gas:

https://patents.google.com/patent/DE...after=20120101

One could imagine that this would be a compact and light weight solution that could fit a sports car. The stored energy could then spin an electric supercharger to help with turbo lag. However, this system might be for the new 919.

Drifting

What are you smoking? No one has been making anything close to lag free turbos for the past 50 years.

Anyone with a functioning nervous system knows this.

The 488 and the 991.2 carreras are important vehicles because they are the first turbo cars with minimal lag, that are actually tolerable to drive, but no one has made a lag-free regular turbo production car recently and they certainly weren't making lag free turbos 50 years ago, or even 10 years ago.

dflowerz

I think the remark alluded to Porsche making turbo-lag free non turbo engines for 50 years

It will be interesting to see what is new with the 992, while in the meantime enjoying the hell out of my 991.2

I still find it incredible that the 991.2 turbo C2s makes 420 hp. That is the "s" version of the base 911. Not bad!

Drifting

I take back my previous comments if that was the intention, to refer to NA engines. Just the absurdity of the previous comment got to me, if it was indeed meant regarding many of the old porsche turbo engines, where lag could be measured in several seconds.

The regular 991.2 C2S has so much power and torque. I've driven a friends .2 C2S extensively. Super impressed with the power and the minimal lag. That and the 488 are the best turbos I've ever driven or would ever drive.

To be honest, I'm not sure why people feel the need to get a GTS these days. There is so much power and torque in a 991.2 C2S, that you can't really use on the road.

Only if you plan to visit the track regularly as well, does it make sense to spend more for the GTS.