Mike in CA

I'm sure I'm missing something but I'm not sure that's right.

It appears that the 100ms example with gear engagements widely spaced is for a non-preselected gear, and the 60ms with gear engagements close together is for a pre-selected gear. The T2 reference on the top example seems to bear that out as the T2 time refers to "selecting".

fun2k

I think it makes good linear power till 8500. Even though power falls of rapidly after that its still making near the max power of the previous gt3 model at 9000rpm. The rs models will definitly make peak power after 8500 just like in the last iteration 997s gt3 7600, rs 7900, 4.0 rs 8250. Same with boxster to cayman and gt2 to gt2rs.

Although the prev 997 gt3s had a very slight hp drop after reaching their max power band compared to this new one. And thinking back at APs remarks regarding those last special magical whatnot 500 rpms, why would i want to push the car after 8500 ?just to hear a special bang from the exhaust?

Still i reserve my judgement until i drive the car.I hope they cured the low speed understeer with this new car, that was the only complaint i had with the old one.Oh and i deeply miss the mezger and getrag combo.

StirlingMoss

Did you make those graphs yourself in Excel?

Here is the official 997.1 GT3. Mezger. Manual. Dip.

zanwar

How could the VW box complete a shift in 8ms? That's less than a hundredth of a second. One revolution of the crankshaft at 6000rpm takes 10ms. Perhaps 8ms is the reaction time of the system but the total shifting time is much greater.

Macca

The 8500 rpm peak is about right. Ideally you need a safe 500 rpm runway beyond peak torque to hit the limiter, especially with an engine spinning this fast. As a previous poster pointed out its still making around 420+ bhp at cut out.

My 1996.1 GT3 made peak at 7600 rpm and kept spinning until 8400 rpm. That seemed like a screamer of an engine coming from a 993 RS where the limiter was at 6900 rpm.

With the PDK optimized to use every last rpm given the quick shifts and going by small sound bites from the videos Id say this engine will be a screamer.

Macca

The 8500 rpm peak is about right. Ideally you need a safe 500 rpm runway beyond peak torque to hit the limiter, especially with an engine spinning this fast. As a previous poster pointed out its still making around 420+ bhp at cut out.

My 1996.1 GT3 made peak at 7600 rpm and kept spinning until 8400 rpm. That seemed like a screamer of an engine coming from a 993 RS where the limiter was at 6900 rpm.

With the PDK optimized to use every last rpm given the quick shifts and going by small sound bites from the videos Id say this engine will be a screamer.

vf430

I read this full article sometime before, the top example is of 599GTB gearbox , bottom example is for Scud exclusively. It shows the improvement in shift times of Superfast F1 to superfast 2.


From the article:
"Further examination of Ferrari's shift event indicates that, while 60 milliseconds elapse between the time when the acceleration begins to fall (as the shift paddle is flicked) and the time full engine power resumes accelerating again, the time spent at an acceleration rate at or below zero is more like 40 milliseconds."

Read more: http://www.motortrend.com/roadtests/...#ixzz2NWZLBC6w

orthojoe

No I didn't. I merely copied what was posted by another rennlister on this very forum. I see that there is a dip in the 997.1 chart you posted, but I would say that the dip is not as dramatic as what is seen in the 991GT3.

Mike in CA

Thanks for the further clarification. The issue that I still don't see being addressed in the article is concerning pre-selection. Admittedly, with what follows, I'm relying on information posted by another RL'er and have not seen documentation first-hand.

With PDK, and I assume the F1 gearbox, the transmission predicts which gear will be used next and preselects it. When it's time for the shift to occur the pre-selected gear is engaged. Now. lets assume that you are driving at a steady speed in 4th gear and abruptly decide to downshift to 3rd and accelerate. Presumably the transmission hasn't predicted this action and no gear has been pre-selected. It seems reasonable to assume that this shift event will take longer than if a gear was primed and ready to go.

According to what was posted, it is this unpredicted event that takes less than 100ms in the new PDK gearbox, which compares very favorably to the 60-100ms time for predicted shifts in other gearboxes.

HiWind

i've been trying all day but i can't find a way to tell the difference
between 60 and 100 milliseconds. I just can't.

StirlingMoss

Mike in CA

That's good......

996FLT6

A blink is between 300-400 ms. 60-100ms- I think its pretty quick IMO : ). Mike

outline

Mike in CA,
The F1 trans in the scuderia is a single clutch electro hydraulic box. Think of it like a manual gearbox with hydraulics depressing and releasing the clutch and also shifting the gear selector each time you hit a paddle.
It is not dual clutch and as a result cannot preselect anything.
The PDK and the transmission in the 458 are dual clutch and can thus preselect.
The 430 scud transmission has a time of 60ms from paddle press to complete acceleration restoration. The actual shifting component of that process is around 40ms.

Mike in CA

I knew Ferrari had moved from a single clutch to the dual clutch box, but despite the fact that the F1 reference was there in black and white, I thought we were discussing the relative speed of the Porsche and Ferrari dual clutch boxes. I just whiffed it. Thanks.