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Old 06-17-2004, 11:28 AM   #135
st-anger
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Originally Posted by lakatu
Originally Posted by st-anger
Originally Posted by lakatu
St-Anger excellent write up on the 911 Carrera. I have a question about the relative performance of the current 996 to prior years 300hp 996 model. Sport Auto's Supertest shows the performance of the new 320 hp model recorded the same lap time on the NS (8'12") and was slower on the Hockenheim (1'17.1" verses 1'15.9"). All this despite all the improvements that you eloquently discussed including 20 more horsepower and larger tires and wheels; offset by 68kg more weight. What do you attribute this too? Could normal production variation account for such a difference?

I was wondering if someone who may have read that article may know if Sport Auto discussed why the newer model didn't demonstrate greater performance on the track? The older car seems to outperform the newer version in the corners while slower on the straights. Obviously the greater weight of the newer 996 hurts it in the corners. Also, I don't know the answer to this but the Pirelli's P Zero's the old 996 rode on may be better than the newer 996's Michelin Pilot Sport.
hmmm, you´re right, i´ve looked the lap times up myself again, i´ve both articles, but unfortunately not a single word from the editors why it´s, maybe not slower, but also not faster…
BUT, from what I know about both cars, which i´ve already driven, the old Carrera is a bit more gentle to drive, maybe not because of the 68kg, but i´ll try to explain…
first, we should mention that both cars had been equipped with the optional sport suspension, second, and now we´re talking about the latest Carrera only, the 320hp version not the 300 one, the dynamic vehicle behaviour at the limit has been pushed upwards a bit thus it´s now even more narrow than on the mk1 996 C2 and quite compareable with the handling of the 993… while drag throttle, the C2 has a strong tendency to understeer because of the special axle-geometry and the wide rear tyres, the mk2 C2 has 285, the mk1 “only” 265, both with 225 at the front, so to prevent understeering one´ll go off the accelerator to force the car into load-cycle change, and then again at full throttle, BUT this results in a quite undefined vehicle handling, because the car doesn´t really give the driver a notice when it´s near its limit, so one could easily loose it without some experience and practice…
so i think it´s obvious that such a handling characteristic isn´t very helpful for a good lap time at a narrow and kinda slow track like HHR…
hope this helps a bit….
St-anger sorry to drag up an old post but I have been thinking about a question related to this post for awhile and I am not sure of the answer I have come up with. The question that arose in my mind from your answer was why would Porsche deliberately narrow the dynamic vehicle behavior at the limit?

First let me explain what I think that means. It sounds like the MKI starts to progressively understeer or oversteer gradually as it approaches its handling limits. Whereas the MKII stays neutral without either end sliding and then when it reaches its cornering limits it suddenly transitions breaks traction into a more extreme understeer or oversteering condition.

Assuming I understood this correctly the MKII’s handling behavior seems like it would be less desirable since it would not communicate to the driver where the cornering limit is and thereby prevent approaching as close as possible that limit without exceeding it.

On the other hand I notice from the data that while the lateral acceleration is the same for both cars the slalom speeds and evasive course speeds are higher for the MKII. This would make sense since as long as the driver didn’t exceed the handling limits, the position of the car should not drift as wide allowing a tighter more precise line and therefore faster speeds. Here is where my lack of track driving makes it difficult to understand these concepts but it appears that if the driver instinctively knew the cars handling limits without the car signaling that to the driver, the MKII style handling would be faster and more desirable for a skilled driver. And if this is the case why wouldn’t the MKII be faster on the more narrow HHR track. It would seem to me that like the results of the slalom, the MKII should be better on tighter more narrow tracks than the MKI.

Sorry I am really confused by this and was hoping you could you possibly explain why Porsche would deliberately narrow the dynamic handling and why that is desirable? Also I thought that the 996 increased cornering speeds relative to the 993.
…quite confusing for a german speaking guy, but I think I know what you´re meaning and´ll try to explain, plz let me know if I didn´t catch the point…
so, first, it wasn´t really wanted by Porsche to narrow the dynamic handling, it simply happened, but as you see, no one really recognised that, i´ve read many test back then, there where pros and cons the common bla bla bla but from what i´ve read, only SA mentioned that behaviour, we knew about it, but it´s really only at the limit and for an average skilled driver with quite some track experience, he wouldn´t notice all this that much, the whole handling mainly depends on the tyres, the MkI was equipped with Pirellis the MkII with wider Michelins, so through the years, maybe not today, but in the past Porsche models were faster with Pirellis, don´t know exactly why, it´s a matter of fact, just look at CGT times, 20!!!!!!! seconds faster with Pirellis round NS than with Pilot Sports…
another thing are the wider tyres on the MKII, the wider the tyres the faster you´ll loose it when at the limit, one can catch it back quite easy then because of the wide tyres = more grip, but you´ll loose time with all that…
we´ve tried it with other tyres, e.g. Conti Sport Contact and Pirellis but it´s been more or less the same, slightly better with the Pirellis, even worse with the Contis…
slalom speeds and evasive course speed can´t be directly compared with HHR lap time IMO…
so it´s not that surprising that the MkII is not significantly faster than the MkI, sad but true it´s not that perfectly balanced, but I can only say: only 10% of the C2 customers´ll experience that, it´s not the typical track car, mainly the lawyer, yuppie,… ride
for the track with a professional driver there´s only one Porsche: GT3(RS)…

let me know if that “helps” you further….
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