Originally Posted by Whoopsy

Just divide output by displacement. and it's 132.7hp/liter. Slightly better than the 918's 132.2hp/liter.



Actually they don't. Ferrari's engines are all dyne-ed at the factory to make at least what they published.

As with all engines, there will be variations, for the 918 engines, each one of them are tested to make at least 608, but all of them make more, some much more than others, the exact number is top secret and only Porsche knows which engine is the ringer and is in which chassis. I had asked them about the dyno numbers on my own car's engine and they still wouldn't tell me.

In Ferrari's case, they could reserve the high output engines and put them in press cars, hence the sometimes unreal numbers from them.

For the weight, Ferrari uses dry weight, which is already a couple hundred pounds lighter than 'wet' kerb weight. Then on top they would put every single lightweight carbon fibre options on the car and perhaps go as far as replacing all the leather with light weight alcantara and use that lightest possible weight as the published weight. This is completely 'legal' and not really cheating. One can put like 100k worth of carbon fibre options on a ordered car and through the Tailor Made program and replace all the leather with light weight alcantara too. The sky is pretty much the limit on how much one wanna spend on a car with Ferrari.

Originally Posted by Petevb

I doubt we'll see significantly more revs. Measured by corrected piston speed the 991 GT3 is already a high point in production cars, meaning it likely has more stress on the rods, crank and pistons than any street engine that has come before it (918, Audi RS5, S2000, etc). It's quite a feat that they were able to achieve 9k with this stroke; even 200 rpm more would be huge.

On the other hand I do suspect the can find another 30 hp with the 9k limit if they go looking. Friction and pumping losses have gone way down vs the 997 RS 4.0: lighter valve springs due to both solid lifters and finger-follower cams, lower pumping losses due to half the oil volume getting pumped around, etc. Power should also be up due to a higher compression ratio with direct injection, etc, but the new engine still makes "500 hp". I suspect that's intentional, and Porsche is limiting the GT3's output to allow for future expansion. I would not be shocked if they go for the Speciale's record, but all that said I agree 550 hp seems out of the question.

Originally Posted by Petevb

I'd guess that a milder cam profile is most likely, though that could be in combination with any number of restrictions such as throttle body or a less finished head.

Porsche has been tuning the powerband for feel over numbers for a long time. The "rush to redline" is only possible because they artificially limit low-end and midrange torque, which is difficult to do smoothly and without losing response.

The new multi-stage intake manifold of the GT3 actually makes noticeably less low and mid-range torque than the old 997 RS 4.0 in places (according to the published power curve) but it's less lumpy and a more linear build of torque. They limited torque in favor of power on the 4.0 Mezger by massively over-sizing the intake (which likely made some of those lumps harder to tune out). I suspect the smoother build of the 991.2 was largely the result of having more margin in hand and hence more ***** to turn to get the feel they were looking for.

If you have power in hand (and the math says they should) then de-tuning is the easy part. I'd probably try to design for everything the same except for a cam and ported/ polished heads for maximum parts commonality if I were them.

Originally Posted by porscheflat6

9500 would be amazing. I think they would increase compression before RPM.

Originally Posted by GrantG

They did already add compression - higher than 991.1 GT3, 911R, and 991 RS...

Originally Posted by fxz

Unless a 4.2 L...

Originally Posted by Guest89

How do you think they will manage power increases over time?

10-15 bhp increments?

Originally Posted by Guest89

Speciale compression is IIRC 14:1; what is .2 GT3?

Originally Posted by TRAKCAR

991.2RS 4.0 525HP @9200, (I still think 4.2 and 535HP)Ring 7:15 September intro first shipping March. Maybe shipping couple months later? $190 MSRP, more if 4.2.

GT2RS 700HP Ring 6:58 Goodwood and Sept intro, not a LE numbers car. Also early 2018 shipping $250 MSRP

Porsche will build 991 GT cars in multiple quantities over the 996 and 997 as already shown by the 991.1RS, 7400 worldwide.

That sound about right?

So call it 7500 GT3RS and 2500 GT2RS on top of 7500 .2GT3' will pretty much guarantee that by late this year all GT3's are MSRP. And all RS will be once all are build.

Great way to fight the flippers Porsche.

Originally Posted by Petevb

I would say more than that, depending on price increase. I need to referesh some of the numbers I did a few years ago, but Porsche's trend has been consistent (light blue are all Porsche models from 2015):

Originally Posted by rosenbergendo

Does Motorsport have the capacity for that many cars? 2500 GT2RS seems way high!

Originally Posted by TRAKCAR

991.2RS 4.0 525HP @9200, (I still think 4.2 and 535HP)Ring 7:15 September intro first shipping March. Maybe shipping couple months later? $190 MSRP, more if 4.2.

GT2RS 700HP Ring 6:58 Goodwood and Sept intro, not a LE numbers car. Also early 2018 shipping $250 MSRP

Porsche will build 991 GT cars in multiple quantities over the 996 and 997 as already shown by the 991.1RS, 7400 worldwide.

That sound about right?

So call it 7500 GT3RS and 2500 GT2RS on top of 7500 .2GT3' will pretty much guarantee that by late this year all GT3's are MSRP. And all RS will be once all are build.

Great way to fight the flippers Porsche.

Originally Posted by jo_ker

Petevb - honestly: You would be exactly the right guy to try this one:

Originally Posted by jo_ker

i donīt think motorsport will built those.
or to say in another way: I think that the GT2RS are built on the same line as the GT3 and GT3RS.

Anyhow the correct question will be - do they have the capacity for 17.500 units?

Based on peterīs numbers which i think are good: 7500 GT3RS and 2500 GT2RS on top of 7500 .2GT3'

I heard from two cleaning ladies that group emission is the base of all the limitation. Same with Cayennes where buyers are pushed to Diesel... i canīt or donīt want to believe it. Chaosoul what do you know?

Originally Posted by rosenbergendo

Does Motorsport have the capacity for that
many cars? 2500 GT2RS seems way high!

Originally Posted by jo_ker

i donīt think motorsport will built those.
or to say in another way: I think that the
GT2RS are built on the same line as the
GT3 and GT3RS...
Chaosoul what do you know?