chaosoul

Nothing concrete.


Word is that they scratched it, then put it on the table again. Many years out.

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.

qbix

And what is Speciale record and how do we know it?
We know for sure that Ferrari are straight cheaters when it comes to their cars' weight and power.

GrantG

Pete - how do you think they're limiting the GT3? They wouldn't do something as cynical as preventing full throttle, as they used to do with the Boxster (to make sure it made 10hp less than equivalent Cayman model)?

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.

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.

rosenbergendo

9500 is def not out of the question!

Petevb

Pass the pipe...

porscheflat6

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

GrantG

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

GrantG

Interesting - makes sense

Petevb

Not cheating? Talk about stretching the truth... Personally I respect Porsche's under-rating far more than Ferrari's overrating- they generally publish numbers an owner can expect to achieve, perhaps because historically they knew a fair number of them would actually get on the autobahn and give it a shot.

I'm pissed enough that Porsche is gaming curb weight by publishing the lightest possible configurator spec (only achieved with smaller fuel tank, radio/ ac delete, lightweight buckets, PCCBs, the lightest headlights, etc). I'd feel completely cheated if they tried to charge another $100k through special wishes to make weight... but I guess it's a question of who's getting fooled- if Ferrari customers are in on it maybe that makes it OK?

CAlexio

So you're saying If they'd offer you 9500r model you'd say "thanks but no thanks.. I'm at my limit"?

Not to mention that 9000rpm and 550hp out of that NA engine is not possible...

Cormid

any word on the 991.2 GT3 PTS window?

fxz

Unless a 4.2 L...