991 Turbo
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Racer
Joined: Apr 2008
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From: Omaha, NE
991 Turbo
Stopped by the Porsche dealership today to pick up a few things. Asked the manager if he knew of anything new on the 991 front. Told me that, when he was in the Canary Islands for the international unveiling of the new Boxster, he had a discussion with some factory reps.
The new turbo will have 3 (yes 3) turbos - 2 large ones and one smaller one. He didn't know how the set-up works yet. Producing 540HP.
Any ideas on how a three turbo set-up will work. Obviously the large ones are set-up similar to the twins - but the third is what? Kicks in at higher RPM.
Theories?
The new turbo will have 3 (yes 3) turbos - 2 large ones and one smaller one. He didn't know how the set-up works yet. Producing 540HP.
Any ideas on how a three turbo set-up will work. Obviously the large ones are set-up similar to the twins - but the third is what? Kicks in at higher RPM.
Theories?
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Smaller turbos spin up faster and produce power more quickly than larger ones, resulting in less turbo lag. While I don't know how the engine will actually be plumbed for 3 turbos, it makes sense that the small turbo would be designed to provide initial boost with the bigger ones kicking in for ultimate power output as they spool up.
Burning Brakes
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Smaller turbos spin up faster and produce power more quickly than larger ones, resulting in less turbo lag. While I don't know how the engine will actually be plumbed for 3 turbos, it makes sense that the small turbo would be designed to provide initial boost with the bigger ones kicking in for ultimate power output as they spool up.
The triple turbo 991 rumor has been kicking around for a while.
Wordsmith
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I read the patent filing was discovered and that's about the full extent of information outside the factory.
Just google Porsche tri-turbo and you'll see links to autocar.co.uk and other sites. I didn't see the patent itself or any diagram, so hopefully someone can sleuth that down.
On the glass half full side (which I struggle to see as the turbo becomes heavier and more luxurious and the GT2 RS just didn't get the standing ovation it deserved, perhaps solely because of the ridiculous price gouge) I'd say we could be looking at ball bearing turbos, ceramics, carbon intakes, titanium exhausts, an upside down engine with lower C-of-G, clutch-slipping PDK and potentially for a high displacement 3.8 or 4.0 engine reaching above 600 neddies in future versions. Glass half empty, the turbo is fated to be a luxurious executive express, adorned with froufrou cabin trim and gadgets and laden with emissions technology to appease red tape merchants as they rearrange the deck chairs on the SS Climate Titanic.
With three turbos, there's not too many realistic alternatives for Porsche and a flat six. One small, two small or even three small could work. One small electric one. One huge exhaust driven one and two small electric ones. Separate left-bank, right-bank with electric and no need for intercoolers (or at least, much smaller, potentially heat-exchangers to a refrigerant) and one big Bertha and its own intercooler and single waste gate to single cat. If this were the GTR going to triples, any amount of techno-gasm could be warranted, but for Porsche, I can only hope for clean, simple, elegant, devilishly clever.
The design could be predicted by guessing the priorities of their objectives with the engine. We already see in the 991 that priority nummer eins is emissions and fuel efficiency. That means the exhaust temps have to build quickly to light off the catalytic converter stage and boost has to build with as few variables to create as few contingencies for lean, clean burning.
I believe BMW went with an electric auxiliary compressor to the intake. That could be good if they've designed a system that keeps the engine thinking it's always 10 feet under water, so to speak. And a "small" 3.6 that revs to "only" say 7000-something rpm doesn't necessary exceed flow from some clever hairdryer thingamajig.
Given the likelihood of the 911 Turbo going to electric front drive at some point in the future, there's going to be ample amps around the thing to spool up a clever little variable vane compressor without the weight of an impeller hot side.
Would they seriously roll out that much technological OMG in the first 991 or leave it for a subsequent model once the 991 loses its cachet?
Would they reserver the tech bling for the 918 or is its day already passed and buyers have spoken with their shoes and walked?
I doubt they're ready to put electric anything in the 991 just yet -- they've already got enough to worry about and VW wants profits before all else, so any boardroom level "guidance" would be along the lines of "sell what you got" and the tri-turbo impetus is purely politics and complying with absurd government (worldwide) emissions standards -- which should be based on unit volume sales, not a one-size-fits-all "revenue through taxes and penalties" scheme to artificially burden niche auto-makers while the giants can do their CAFE offset shenanigans with econo-boxes, tax credits and a grand, fake bankruptcy to jettison their lifetime employee retirement fund liability.
So the Porsche 911 Turbo "three way" whether you want one or not -- and I think most drivers, man or woman, would argue there's a "good" three-way and there's a "WTF?! No way never!" bad three-way -- is coming in the form of an additional conventional turbo mounted above the engine and the existing twin turbos will be, if anything, mounted even higher or potentially above the engine, too. As we've already seen, Porsche is intent on heat escaping from the top of the engine, away from underlying, weighty batteries. Perhaps they've already bitten the bullet and reconfigured the flat six to have intake from below and exhaust out the top, the gases go out the back through the bumper and heat (and blistering turbo housings) are above the engine. I doubt they go the whole hog, but I expect at least a significant incremental move towards a "hot top" design. The turbo and GT2 already get cold air from the flanks, so I imagine with the extra space of the 991, they've incorporated a design to route cold air intakes beneath ("behind") the engine and the exhaust to be in front and above, perhaps with a distinctive, high-mount exhaust rather like the Scuderia (which claimed the exhaust is now participating in the aero like their F1 cars ... maybe so.) Again, that would be impressing engineering, but I just don't see why the bean counters would green light that kind of R&D heavy lifting or burden the 991 with all those incremental gains in the first model year rather than being phased in over the usual five years plus or minus.
I loathe the complexity, weight and downright assbackwardation of it all as the engine becomes more and more characterless, linear and bland, but I can still respect the engineering heavy-lifting going on. Imagine the nightmare for the aftermarket tuners to get past all the defensive lock-outs on these new tri-turbo engines. So much for a quick flash and 100 hp thank you very much.
Ironically, with PDK mated to a turbo, there's less concern for lag and more desire for outright oomph -- the PDK can slip the clutch to momentarily increase torque, it can instantaneously slip a downshift any number of cogs to get right to where the engine is best able to respond to the throttle input and it doesn't need to retard the engine on upshifts. For a manual box driver, maybe the lag is still an issue of sorts, but I think their real "customer" is the average bozo that just wants to mash the throttle and feel the instant neck-snap acceleration.
As for design layout to meet emissions, one small conventional turbo to get the ball rolling would make sense, funneling exhaust and back-pressure through a single path out to build exhaust temps quickly with nearly zero coolant circulation other than to keep head temps even to prevent warping forces.
Anything is possible. In simple terms, the way I see it, you'd want one small turbo to spool up quickly from both banks and then feed both banks (arguably, it could feed selective cylinders as it built intake pressure, but this would involve valve actuation or throttles ... just more weight and complexity.) A more practical solution is two small turbos feeding each bank, left and right, as separate, but the current solution is one turbo per bank feeding both banks per a common intake plenum chamber, which Porsche has retained since the 993 over a decade ago, so I doubt they've found reason to drop that today. Two small screws could remain spooled up (by-passed and recirculated, never reaching the catalytic converter stage) and one honking great turbo could provide mid range oomph through a downstream ducted/throttled intake that would achieve boost all the way to the rev-limit, then its waste gate would go into the cat stage. This could potentially result in the "front" muffler of a three muffler scheme with one big cat that gets hot quickly rather than two cats and two gas flows (or even three if things were really ugly. They could even run a heating element on the cat to get it fired up. Let's hope there's no thought of EGR to the single turbo to reduce emissions.
No matter the architecture, we have to brace ourselves for an invisible or gawd awful ugly engine bay for the turbo from here on.
While I love the 993 Turbo and would never part with it, and I'm still tempted by the GT2 RS (though Porsche sort of gave it an unflattering "old maid" treatment by improving upon it with the GT3 RS 4.0 in terms of painted carbon panels) the 997.2 Turbo is just not my cup of tea -- those bulging running lights are such a cheap, nasty, last minute "make it more distinctive" grasp at failure, I'd literally want to cut them off with a spoon before driving the car.
Here's hoping the 991 Turbo improves upon the 991 Carrera styling:
* distinctive, subtle LED headlights instead of the bulbous "aero" headlights
* simple bumper designs, exhaust like the Carrera GT through the bumper
* engine intakes through the rear quarters shaped into the fender metal, not plastic stick-on bits that are cheap and easy
* Targa style hatch access through the rear window to all that rear shelf space (for all 991's)
* recessing the wipers so they're hidden behind the hood/bonnet
* a headlight washer design without having shiny plastic nipples ... recessed or pop-up design
* heads-up display
* monolithic carbon brake rotors instead of kitchen cabinet laminate
* curb weight around 3200 lbs instead of I fear 3800 lbs ...
Just google Porsche tri-turbo and you'll see links to autocar.co.uk and other sites. I didn't see the patent itself or any diagram, so hopefully someone can sleuth that down.
On the glass half full side (which I struggle to see as the turbo becomes heavier and more luxurious and the GT2 RS just didn't get the standing ovation it deserved, perhaps solely because of the ridiculous price gouge) I'd say we could be looking at ball bearing turbos, ceramics, carbon intakes, titanium exhausts, an upside down engine with lower C-of-G, clutch-slipping PDK and potentially for a high displacement 3.8 or 4.0 engine reaching above 600 neddies in future versions. Glass half empty, the turbo is fated to be a luxurious executive express, adorned with froufrou cabin trim and gadgets and laden with emissions technology to appease red tape merchants as they rearrange the deck chairs on the SS Climate Titanic.
With three turbos, there's not too many realistic alternatives for Porsche and a flat six. One small, two small or even three small could work. One small electric one. One huge exhaust driven one and two small electric ones. Separate left-bank, right-bank with electric and no need for intercoolers (or at least, much smaller, potentially heat-exchangers to a refrigerant) and one big Bertha and its own intercooler and single waste gate to single cat. If this were the GTR going to triples, any amount of techno-gasm could be warranted, but for Porsche, I can only hope for clean, simple, elegant, devilishly clever.
The design could be predicted by guessing the priorities of their objectives with the engine. We already see in the 991 that priority nummer eins is emissions and fuel efficiency. That means the exhaust temps have to build quickly to light off the catalytic converter stage and boost has to build with as few variables to create as few contingencies for lean, clean burning.
I believe BMW went with an electric auxiliary compressor to the intake. That could be good if they've designed a system that keeps the engine thinking it's always 10 feet under water, so to speak. And a "small" 3.6 that revs to "only" say 7000-something rpm doesn't necessary exceed flow from some clever hairdryer thingamajig.
Given the likelihood of the 911 Turbo going to electric front drive at some point in the future, there's going to be ample amps around the thing to spool up a clever little variable vane compressor without the weight of an impeller hot side.
Would they seriously roll out that much technological OMG in the first 991 or leave it for a subsequent model once the 991 loses its cachet?
Would they reserver the tech bling for the 918 or is its day already passed and buyers have spoken with their shoes and walked?
I doubt they're ready to put electric anything in the 991 just yet -- they've already got enough to worry about and VW wants profits before all else, so any boardroom level "guidance" would be along the lines of "sell what you got" and the tri-turbo impetus is purely politics and complying with absurd government (worldwide) emissions standards -- which should be based on unit volume sales, not a one-size-fits-all "revenue through taxes and penalties" scheme to artificially burden niche auto-makers while the giants can do their CAFE offset shenanigans with econo-boxes, tax credits and a grand, fake bankruptcy to jettison their lifetime employee retirement fund liability.
So the Porsche 911 Turbo "three way" whether you want one or not -- and I think most drivers, man or woman, would argue there's a "good" three-way and there's a "WTF?! No way never!" bad three-way -- is coming in the form of an additional conventional turbo mounted above the engine and the existing twin turbos will be, if anything, mounted even higher or potentially above the engine, too. As we've already seen, Porsche is intent on heat escaping from the top of the engine, away from underlying, weighty batteries. Perhaps they've already bitten the bullet and reconfigured the flat six to have intake from below and exhaust out the top, the gases go out the back through the bumper and heat (and blistering turbo housings) are above the engine. I doubt they go the whole hog, but I expect at least a significant incremental move towards a "hot top" design. The turbo and GT2 already get cold air from the flanks, so I imagine with the extra space of the 991, they've incorporated a design to route cold air intakes beneath ("behind") the engine and the exhaust to be in front and above, perhaps with a distinctive, high-mount exhaust rather like the Scuderia (which claimed the exhaust is now participating in the aero like their F1 cars ... maybe so.) Again, that would be impressing engineering, but I just don't see why the bean counters would green light that kind of R&D heavy lifting or burden the 991 with all those incremental gains in the first model year rather than being phased in over the usual five years plus or minus.
I loathe the complexity, weight and downright assbackwardation of it all as the engine becomes more and more characterless, linear and bland, but I can still respect the engineering heavy-lifting going on. Imagine the nightmare for the aftermarket tuners to get past all the defensive lock-outs on these new tri-turbo engines. So much for a quick flash and 100 hp thank you very much.
Ironically, with PDK mated to a turbo, there's less concern for lag and more desire for outright oomph -- the PDK can slip the clutch to momentarily increase torque, it can instantaneously slip a downshift any number of cogs to get right to where the engine is best able to respond to the throttle input and it doesn't need to retard the engine on upshifts. For a manual box driver, maybe the lag is still an issue of sorts, but I think their real "customer" is the average bozo that just wants to mash the throttle and feel the instant neck-snap acceleration.
As for design layout to meet emissions, one small conventional turbo to get the ball rolling would make sense, funneling exhaust and back-pressure through a single path out to build exhaust temps quickly with nearly zero coolant circulation other than to keep head temps even to prevent warping forces.
Anything is possible. In simple terms, the way I see it, you'd want one small turbo to spool up quickly from both banks and then feed both banks (arguably, it could feed selective cylinders as it built intake pressure, but this would involve valve actuation or throttles ... just more weight and complexity.) A more practical solution is two small turbos feeding each bank, left and right, as separate, but the current solution is one turbo per bank feeding both banks per a common intake plenum chamber, which Porsche has retained since the 993 over a decade ago, so I doubt they've found reason to drop that today. Two small screws could remain spooled up (by-passed and recirculated, never reaching the catalytic converter stage) and one honking great turbo could provide mid range oomph through a downstream ducted/throttled intake that would achieve boost all the way to the rev-limit, then its waste gate would go into the cat stage. This could potentially result in the "front" muffler of a three muffler scheme with one big cat that gets hot quickly rather than two cats and two gas flows (or even three if things were really ugly. They could even run a heating element on the cat to get it fired up. Let's hope there's no thought of EGR to the single turbo to reduce emissions.
No matter the architecture, we have to brace ourselves for an invisible or gawd awful ugly engine bay for the turbo from here on.
While I love the 993 Turbo and would never part with it, and I'm still tempted by the GT2 RS (though Porsche sort of gave it an unflattering "old maid" treatment by improving upon it with the GT3 RS 4.0 in terms of painted carbon panels) the 997.2 Turbo is just not my cup of tea -- those bulging running lights are such a cheap, nasty, last minute "make it more distinctive" grasp at failure, I'd literally want to cut them off with a spoon before driving the car.
Here's hoping the 991 Turbo improves upon the 991 Carrera styling:
* distinctive, subtle LED headlights instead of the bulbous "aero" headlights
* simple bumper designs, exhaust like the Carrera GT through the bumper
* engine intakes through the rear quarters shaped into the fender metal, not plastic stick-on bits that are cheap and easy
* Targa style hatch access through the rear window to all that rear shelf space (for all 991's)
* recessing the wipers so they're hidden behind the hood/bonnet
* a headlight washer design without having shiny plastic nipples ... recessed or pop-up design
* heads-up display
* monolithic carbon brake rotors instead of kitchen cabinet laminate
* curb weight around 3200 lbs instead of I fear 3800 lbs ...
Burning Brakes
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From: London, UK
Racer
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From: West Des Moines, Iowa
BMW and or Porsche are going to bring it at some point. 540hp suggested would be loafing and enables tons of future power available. Won't weigh anywhere near 3800 pounds, as it is physically much smaller than the 3850 pound Nissan. Going to get interesting.
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Wordsmith
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The 3800 curb weight "I fear" is my hyperbole more than real concern and a bit of a dig at the ridiculous heft of the GTR. I remember driving the original Godzilla and it was based on a production line car that resulted in all the technology of the day without the "Is there another whole car in the trunk?" result.
Mr Porsche just has to do more than lip service and 50 kilos off the 911 then leave it saddled with mild steel and stamped metal braces. I'm not asking for a monocoque in exotic materials, just a sincere add-lightness effort from the factory.
And I invite them to put their price on it as an option for the 991. They might have a helluva lot of trouble selling a GT2 RS at a quarter million, but I think they'd have hard and fast orders for a 2700lb 911 with the price premium of say the Power Kit (maybe US $30-40K to bring the curb weight down 10%.)
At the cost of being a broken record skipping back to play the same song over and over (you kids won't remember vinyl records, think bad MP3 rip you DL'd off a sketchy torrent and it's like all looped back dubstep, yo ... okay, I have no idea what kids say these days ...)
Imagine the throttle response and apex speeds of a base model Carrera with the 3.4 putting out say 385 hp and pushing around a 2700lb 911 with emphasis on a lightweight unsprung weight and minimal power train "flywheel" inertia.
If there's anyone left at Porsche who really cares and has the power to make it happen, they have to (have to!) deliver a lightweight 911 and get away from all this bull**** of electronics, complexity and everything just gets heavier ... the "analog vs digital" of GT3 RS vs 458 Italia is solid ground that we must hold and reverse the movement of the battle line. In the words of Captain Picard, "This far and no farther!"
http://www.youtube.com/watch?v=cGF1N...tailpage#t=41s
