991 GT2RS
07-02-2017, 02:24 PM
#2326
Do we have an facts on the water spray intercoolers? I've heard 3 laps of 'ring before reservoir needs refilled, which at say 21 minutes hard running is borderline annoying on a track day, especially if real-world useage is worse.
Have also heard that it runs down in about the same time as a tank of fuel, which would be a lot better.
Have also heard that it runs down in about the same time as a tank of fuel, which would be a lot better.
07-02-2017, 02:34 PM
#2327
Burning Brakes
Officially going to pass on this. Plenty of turbo cars to choose from, and plenty of 300k cars to choose from as well.
I think real check writing demand will be surprisingly low on this car. Unless porsche throws a # limit or a plaque on it - I just don't see people lining up to throw 335k with tax on a 911. I also think these will be discounted, and depreciate.
It's an impressive piece of engineering for sure, but I think they are crazy trying to make so much margin per car.
I think real check writing demand will be surprisingly low on this car. Unless porsche throws a # limit or a plaque on it - I just don't see people lining up to throw 335k with tax on a 911. I also think these will be discounted, and depreciate.
It's an impressive piece of engineering for sure, but I think they are crazy trying to make so much margin per car.
In today's world of prevalent hybrid, twin-turbo and supercharged technology, achieving a high horsepower is easy. Achieving high horsepower with a naturally aspirated engine that revs high and fast and smooth while retaining a factory warranty is hard. Having that engine in a manual is a bonus. A few cars today have such an engine, but only one of those can be had with a manual transmission (991.2 GT3). I would buy two of those before I would buy one of these GT2RS. Better yet, I can buy a brand new 991.2 GT3 and buy a used 458. Then I will have two awesome engines and two great but different transmissions.
07-02-2017, 03:20 PM
#2329
Does anyone know how different the engine internals are from a regular ttS 3.8L? Is the increase power mostly just a result of bigger turbos/higher boost? In this case is it expected to have a greater turbo lag than the other models? This may lessen the fun of driving this car on the street.
Jim
Jim
07-02-2017, 03:24 PM
#2330
Does anyone know how different the engine internals are from a regular ttS 3.8L? Is the increase power mostly just a result of bigger turbos/higher boost? In this case is it expected to have a greater turbo lag than the other models? This may lessen the fun of driving this car on the street.
Jim
Jim
The source of its natural authority: the six-cylinder, twin-turbo boxer engine at the rear, four-valve technology, variable turbine geometry (VTG) with large turbochargers and newly designed charged air system, direct fuel injection (DFI) and VarioCam Plus. And transmission directly above the rear axle
...
Variable turbine geometry (VTG)
The variable turbine geometry of the twin water-cooled turbochargers arranged in parallel directs the incoming exhaust gas towards the turbine wheel via electronically controlled, moveable vanes in such a way that the ratios of both a ‘small’ and ‘large’ turbocharger can be achieved. VTG therefore largely eliminates the target conflict of a normal turbocharger – and enables optimum aspect ratios to be achieved in every operational state.
At low revs, this results in a high turbine speed and thus a high charge pressure – for increased engine filling efficiency, greater torque and considerably improved performance. The torque curve reaches a higher level much earlier – and then maintains it. At high revs on the other hand, the full potential of a large charger can be utilised by adjusting the vanes – a lower exhaust back pressure for maximum performance. Thanks to the variable turbine geometry, the dynamic build-up of charge pressure produces an improved response.
07-02-2017, 03:32 PM
#2331
From the website:
The source of its natural authority: the six-cylinder, twin-turbo boxer engine at the rear, four-valve technology, variable turbine geometry (VTG) with large turbochargers and newly designed charged air system, direct fuel injection (DFI) and VarioCam Plus. And transmission directly above the rear axle
...
Variable turbine geometry (VTG)
The variable turbine geometry of the twin water-cooled turbochargers arranged in parallel directs the incoming exhaust gas towards the turbine wheel via electronically controlled, moveable vanes in such a way that the ratios of both a ‘small’ and ‘large’ turbocharger can be achieved. VTG therefore largely eliminates the target conflict of a normal turbocharger – and enables optimum aspect ratios to be achieved in every operational state.
At low revs, this results in a high turbine speed and thus a high charge pressure – for increased engine filling efficiency, greater torque and considerably improved performance. The torque curve reaches a higher level much earlier – and then maintains it. At high revs on the other hand, the full potential of a large charger can be utilised by adjusting the vanes – a lower exhaust back pressure for maximum performance. Thanks to the variable turbine geometry, the dynamic build-up of charge pressure produces an improved response.
The source of its natural authority: the six-cylinder, twin-turbo boxer engine at the rear, four-valve technology, variable turbine geometry (VTG) with large turbochargers and newly designed charged air system, direct fuel injection (DFI) and VarioCam Plus. And transmission directly above the rear axle
...
Variable turbine geometry (VTG)
The variable turbine geometry of the twin water-cooled turbochargers arranged in parallel directs the incoming exhaust gas towards the turbine wheel via electronically controlled, moveable vanes in such a way that the ratios of both a ‘small’ and ‘large’ turbocharger can be achieved. VTG therefore largely eliminates the target conflict of a normal turbocharger – and enables optimum aspect ratios to be achieved in every operational state.
At low revs, this results in a high turbine speed and thus a high charge pressure – for increased engine filling efficiency, greater torque and considerably improved performance. The torque curve reaches a higher level much earlier – and then maintains it. At high revs on the other hand, the full potential of a large charger can be utilised by adjusting the vanes – a lower exhaust back pressure for maximum performance. Thanks to the variable turbine geometry, the dynamic build-up of charge pressure produces an improved response.
Jim
07-02-2017, 03:48 PM
#2332
A turbo engine can't hold a candle to a NA one in purity of sound. Yes, the GT2 won't sound bad by itself, but back to back, the difference will be obvious. The GT2 sounds uninspiring, with a low pitch, and like it revs really low as well. Nothing compared to even a Cayman GTS (which has PSE), let alone a high-revving GT3. BUT all turbo cars are like that. The good news is it doesn't sound like a vacuum cleaner, like the Turbo S does.
And VTG improves turbo lag, but doesn't eliminate it, especially at almost 190 HP/liter. As somebody mentioned, I much rather own a 991.2 GT3. The new GT2 seems more like a Turbo SS than a true RS. Also curious if internals are beefed up vs the Turbo S. With the difference in HP, I say it has to. And at that output per liter, hopefully it won't turn into another GT3 engine fiasco. We'll find out soon enough
.
And VTG improves turbo lag, but doesn't eliminate it, especially at almost 190 HP/liter. As somebody mentioned, I much rather own a 991.2 GT3. The new GT2 seems more like a Turbo SS than a true RS. Also curious if internals are beefed up vs the Turbo S. With the difference in HP, I say it has to. And at that output per liter, hopefully it won't turn into another GT3 engine fiasco. We'll find out soon enough
.
Last edited by JCtx; 07-02-2017 at 04:35 PM.
07-02-2017, 04:05 PM
#2333
Race Car
Originally Posted by Footsoldier
Do we have an facts on the water spray intercoolers? I've heard 3 laps of 'ring before reservoir needs refilled, which at say 21 minutes hard running is borderline annoying on a track day, especially if real-world useage is worse.
Have also heard that it runs down in about the same time as a tank of fuel, which would be a lot better.
Have also heard that it runs down in about the same time as a tank of fuel, which would be a lot better.
07-02-2017, 04:23 PM
#2334
Former Vendor
07-02-2017, 04:33 PM
#2336
Addict
Rennlist Member
Rennlist Member
A turbo engine can't hold a candle to a NA one in purity of sound. Yes, the GT2 won't sound bad by itself, but back to back, the difference will be obvious.
And VTG improves turbo lag, but doesn't eliminate it, especially at almost 190 HP/liter. As somebody mentioned, I much rather own a 991.2 GT3. The new GT2 seems more like a Turbo SS than a true RS. Also curious if internals are beefed up vs the Turbo S. With the difference in HP, I say it has to. And at that output per liter, hopefully it won't turn into another GT3 engine fiasco. We'll find out soon enough.
And VTG improves turbo lag, but doesn't eliminate it, especially at almost 190 HP/liter. As somebody mentioned, I much rather own a 991.2 GT3. The new GT2 seems more like a Turbo SS than a true RS. Also curious if internals are beefed up vs the Turbo S. With the difference in HP, I say it has to. And at that output per liter, hopefully it won't turn into another GT3 engine fiasco. We'll find out soon enough
.The difficulty of running 700hp with VTGs has always been the heat management and Porsche have gradually used technology to win this battle, the expansion intake system, bigger turbos and of course the intercooler water sprayer have made 700hp a reality.
07-02-2017, 04:55 PM
#2339
Former Vendor
RS's turbos have apparently bigger turbines than previous models, just using 991 turbo S's units and just increasing boost would rise backpressure and thus also EGT and IAT. IC water spray could be added because IC placing is (has always been) far from optimal, limiting both size and flow across them. Of course there's aerospace quality ICs (used in racing), but €10k+/pair can be limiting factor even in high end car like this one.
07-02-2017, 05:06 PM
#2340
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The unapologetic brutality of the GT2 RS is appealing. For a properly rich person who likes this sort of car, seems a no brainer to get one. I certainly would - makes me drool.
But for those who need to care about the cost and can't afford a fleet of cars like this, I suspect that the next GT3 RS is going to be a better proposition: much less cost, lap time not far behind, NA sound and response, etc.
But for those who need to care about the cost and can't afford a fleet of cars like this, I suspect that the next GT3 RS is going to be a better proposition: much less cost, lap time not far behind, NA sound and response, etc.
