Petevb

I understand that perspective, and it absolutely does come to the result. But the "how" and "why" can be interesting, and occasionally even tell you something about the "what"...

neanicu

The recipe has definitely changed! Before you had freshly cut potatoes and carefully fried in olive oil. Now you have frozen and already cut potatoes from a bag. The result is the same : French fries.

ipse dixit

Even though my head just exploded, thanks very much for the info, Petevb.

MM3.9GT3

Pete, thank you for the incredibly detailed analysis. I agree with your perspective on Porsche's GT cars. They need to be special, and if Porsche claims that the suspensions, and engines are vastly different from the "regular" Porsches, then they need to be held to a high standard, and not a "marketing" standard.

Great job.

bronson7

Lot's of interesting and informative material to digest. Great work in pulling it all together Pete.

Petevb

Porsche publishes an online "PET" for most models. PCNA has them on their site through 2010. Others have versions that are current through today, though I'm not certain they are supposed to be public. I'm hesitant to link in case they are not, but search and they are out there...

golfnutintib

+1 here...but kudos to OP nonetheless

997s07

Cars are special to their owners for many reasons. Some want a true race engine and some want a driving experience.

The 991 engine AFAIK is not being raced in official FIA races, I could be wrong. To some this is important.

FORENN

Really? Wow. Somewhere in your Internet surfing, you must have taken a wrong turn. This is Rennlist. Yes, people care about such things here.

To the OP, thanks for such an interesting and useful explanation.

<3mph

I'm astounded at the expertise of guys like you Pete. I'm happy to try and soak up knowledge by reading your posts. Thanks so very much!!

montoya

Another: Thanks Pete! Awesome work!

djcxxx

Thanks for the clarity of your diagrams and analysis. IMHO the substantial interest (concern?) in the similarities between the standard engine and the GT3 is a reflection of the post M96/Mezger era where the base Carrera engine could not be used for the GT3/Turbo/Motorsport applications. Prior to the M96 the basic Porsche flat six was the foundation for all applications not just the road cars as we all know. Unfortunatley the "failure" of the M96 (and M97) in this regard has left many enthusiasts w/ a jaundice eye with regard to the capabilities of the modern Porsche engines found in the standard sports car series. A motosport effort for the current GT3 engine (or a reasonably close derivative) would be welcome reassurance that this 9K capable engine will not spotaneously grenade after 30-40K miles of combined street/track use.

Just in time

These are interesting findings. The Automobile Mag on the GT3 states, however, that the engine shares only a few components with the regular flat six. What gives? Where are the journalists getting their info? Is Porsche feeding them this info? Maybe there is a significant difference on how engine/components is defined. All I can think is that if both engines are quite similar that either: 1)the regular 911 engine could be easily unleashed to do a lot more (something that has not been seen as of yet) or 2) the GT3 should blow up very quickly given that it is essentially a regular 911 engine pushed to the extreme. While we saw those two fires we have not heard of other catastrophic failures afterward.

In conclusion something does not jive.

neanicu

Yeah,your conclusion definitely does not!

You've used 2 scenarios and taken them to the extreme :

The Carrera engine can't be " unleashed " into a GT3 engine and the GT3 engine certainty won't blow up,but it is not motorsport proven either. Read the whole post carefully and examine the pics. Take your time.

Just in time

I certainly did take my time. I am not an an engineer but can follow drawings. Something certainly does not jive. I am not taking issue with Pete' s analysis. Contrary, what I am trying to understand is why if the two motors are that similar why is their performance so dissimilar? I stand by my two observations but can add a third: that the parts that are different are really critical to performance and the ones that are the same are either over engineered or not as critical. So maybe the motors are similar in a number of parts but very dissimilar in a number of very very important ones. One could argue that it is not how many parts/components are similar/dissimilar but which ones. Absent that what gives?

The fact that it is not motorspots proven is a separate issue altogether. What this requires is a ceteris paribus analysis to see what causes "essentially" similar motors to have such different performance.

Finally how come we see the motorspots press continue to make reference to what, at least numerically, could be shown to a fallacy?