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991 cup downshift behavior

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Old 05-29-2015, 08:13 PM
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RSRRacer
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Originally Posted by analogmike
I can't imagine a manual sequential shifter "storing" your downshift request and implementing it even a fraction of a second later, as you won't be using the clutch at that time. I understand with a PDK as there is no clutch needed. What am I missing?
No clutch on downshift. All by ECU.
Old 05-30-2015, 01:32 AM
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Originally Posted by Porschecup
Yes u can preload ..say 5th to 3rd corner hit it two times straight away and let it engage when it's ready ..! I don't do this as u have to wait and id prefer to be in control each gear change so I wait and hit 2 times slower
You must have a 2014 car that hasn't been re-flashed.
Old 05-30-2015, 01:36 AM
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Originally Posted by BBMGT3
Springs are not soft. Tire sidewall is huge. That's why you think it's soft.

Rear springs are same as 997 cup..
Whole car is soft and is less communicative. But it's getting better.
Old 05-30-2015, 02:25 AM
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Originally Posted by RSRRacer
Yes but mechanical and aero grip is higher. Bigger rear tires. More Wing. Just feels like it needs suffer setup. I'll figure it out :-)
I know what you mean, I have a 997 and the 991 feels like a Cadillac. However the 991 is just as tricky at the limit, if not more so because it can catch you unaware. Once you figure out how the car goes you will love it
Old 05-30-2015, 02:37 AM
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also, for those shifting down with higher rpm's... as far as I understand and from the carrera cup weekends I did in the car, if you're running the bias -1.4 which i believe is 45/55 then you don't want a lot of rpm on downshifts... shift down later

far cry from the drama and mechanical symphony that was a 997 in a big braking zone, but i guess progress is progress
Old 05-30-2015, 08:34 AM
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Is -1.4 the "preferred" bias? I know there is no magic number. What do most competitive guys run??

Seems like my dash says either .7 or -.7 I will need to look this am.
Old 05-30-2015, 09:34 AM
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Originally Posted by RSRRacer
Is -1.4 the "preferred" bias? I know there is no magic number. What do most competitive guys run??

Seems like my dash says either .7 or -.7 I will need to look this am.
Dry normal circuit maybe yes. I was a 2.2 guy on the 997 which was about 50/50. Ultimately use whatever you like. Your engineer should be able to help you depending on your braking trace and the circuit.
Old 05-30-2015, 10:15 AM
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Originally Posted by BBMGT3
Dry normal circuit maybe yes. I was a 2.2 guy on the 997 which was about 50/50. Ultimately use whatever you like. Your engineer should be able to help you depending on your braking trace and the circuit.
Agreed in general. I always use 50/50 baseline in the 997 and adjust from there based on track conditions. 991 bias split I based from I forgot. But the 991 brakes are so much better !
Old 05-30-2015, 11:20 AM
  #24  
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Originally Posted by Polesitter
Agreed in general. I always use 50/50 baseline in the 997 and adjust from there based on track conditions. 991 bias split I based from I forgot. But the 991 brakes are so much better !
Yep, car actually stops!



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