TRAKCAR

^^^ pffff

Spyder Man

A bigger turbo is more volumetric efficient and will generate less heat than a smaller turbo because

1. Bigger turbo will move more airflow with less heat generated during the compression stage

2. Once the air is combusted and turned into exhaust, a turbo with a bigger turbine wheel induces less exhaust backpressure. The less backpressure on the exhaust side, the more air that can be pumped through the engine at any given boost pressure

Heat soak is a technical issue that all high performance car engineers need to resolve. Utilising water injection is a crude way to deal with this technical challenge. Bugatti Veyron and Chiron's engine generates heaps more heat than the GT2 but they never need to resort to water injection to solve the heat soak issue and nor did any other hypercar/supercar manufacturers

tcsracing1

Picture a GT3RS that sounds like a Turbo S.

BrntRubber

£265k GBP makes no sense to me considering the competition and the reported performance numbers the car will be achieving. GT2s 640ish hp vs the new Mclaren's 720hp, carbon tub and all new ground up design. A 720s with nice spec/options is £260k.

Maybe it is being produced in limited numbers. That would start to make sense.

ScottKelly911

Might as well order them with the *** seats
Hahhaah I was actually in it as an extra
Absolutely a must! Yes they may all appreciate, but just ask the people who didn't order the CF Fenders on the 997 GT2RS. It's absolutely going to make a difference.
I'll have to disagree with you. Like I said above, regardless of miles, cars with the CF fenders on the 997's always command considerably more all things being equal and I know of several collectors who wont even consider a non CF Fendered car as well as must have the Sport Buckets as opposed to the *** seats. So it's fair to to believe that the 991 GT2RS's with Weissach package will be more sought after than non-WE cars. This is true even dating all the way back to the 1973 Carrera RS. Just look to see how much the original 500 Lightweights go for over the additional Touring cars. If you want to go even further back, look at the 356 Speedsters that had the 4-cam engines vs. non 4-cams. There is quite a precedent set for the collector market. That being said, they'll all be collectable either way, but WE's will definitely be more.

qbix

I recon like 100x more than fuc*ed up McLarens that need to be towed back 10kms after they leave dealership.

RennOracle

Water injection is the better solution for the GT2 RS. Porsche is trying to make a reliable tracktool, like they did with the GT3 RS, but turbo. Turbos bring new challenges and there isn't a better solution for homogeneous IATs than Water injection.

I'm actually glad they did this, this is not a crude way, this should have been the way for cars of this nature for a long time.

Plus this will only be used when the IAT is at big temperature, taking away the need for repetitive cooldown laps like every turbo cars ends up needing and it will provide a constant power delivery at every condition and instance.

Hell, they should even provide a mode for water methanol, now that we are at it.

GrantG

Might be interesting to make these cars Flex Fuel compatible, so we could fuel them with E85. Makes big power/torque without as many temp issues... And 106 octane fuel costs $1.85 per gallon.

The 2.0L motor in my Daily Driver Evo makes 425hp and 435 ft-lbs on the original stock turbocharger with E85 fuel and runs cool as can be. A 3.8L motor would nearly double those figures with similar stress (my motor is not breaking a sweat at all - built Evos commonly make 700hp).

TRAKCAR

What happens if you just throw E85 in it?

Nizer

Everything rots.

GrantG

The ECU has to be able to work with E85. It burns at a very different mixture than gasoline. Flex Fuel vehicles can determine exactly the Ethanol concentration in the fuel and automatically adjust mixture and boost settings appropriately. So, don't try it

My Evo isn't a Flex Fuel vehicle, but I have ECU maps that I can load for either E85 or 91 Octane gasoline with a Cobb Accessport. I also have a manual boost controller that I change depending fuel (24psi boost for E85).

GrantG

Modern fuel systems generally hold up very well (since most gasoline has 10% Ethanol now anyway). My Evo has had no issues whatsoever without any change to fuel system - besides higher capacity fuel injectors and fuel pump). 11 years and 90k miles...

Old cars generally hate alcohol in fuel (even the E10 that is everywhere) - they have many rubber lines and fittings that disintegrate). But any car newer than 10 years typically does not suffer from this.

dariog

Hi

I guess yesterday's announcement Porsche has made us giving some insight about possible specification of 991 GT2RS (better) and pricing (higher):

https://newsroom.porsche.com/en/prod...and-13806.html

if the pricing (MSRP) will be over 300K EUR in Europe we should expect GT2RS to be even higher number for base variant...

Any thoughts?

Petevb

I like the water injection.

Making power is the easy part- drop compression, big turbos, crank the boost and you'll make virtually whatever power figures you'd like- keep in mind that old school two valve, air cooled Ruf and 993 GT2 Evos were capable of ~600 hp at the wheels back in the 90s. The conundrum, however, is that the more power you make the more power delivery and driveability matters.

All wheel drive (as in the 991 Turbo S, Veyron, etc) helps deal with an unexpected surge of turbo torque by distributing it to all four wheels- corning attitude is relatively unaffected. The same delivery with RWD will leave you with an arm full of lock and a cold sweat. There's a reason GT2s developed a widow maker reputation, and now we're approaching 60% more power than the original.

Water injection isn't being used for more power, it's letting them increase the compression to make the same power more consistently and with better delivery. One could argue that the using the 4.0's longer stroke crank would have been just as effective with less complexity, though water injection will likely mean more consistent performance on hot track-days.

One can argue that scary is part of the GT2's character, and hence more lag isn't a bad thing. Certainly dealing with that power delivery was a core part of the 1M's flawed charm for me. At near 700 hp, however, I'll personally take as little turbo lag as I can get.

MaxLTV

You need a much bigger fuel pump and a very broad adjustability range to adjust for the fuel that 1) requires much more fuel for the same engine volume; 2) burns cooler and detonates less, and thus needs very different ignition timing to work properly.

Also, corrosiveness, but I think they solved it because of ethanol in normal fuel anyway.

But ethanol is magic for high-boost turbos. I've seen some tests, and even on mildly tuned turbo cars, 91 E10 is making more power than 94 non-ethanol gas, while in NA applications 94 non-ethanol works better (with exception of heat soak situations).