No lift shift in MT 991.2 GT3
#91
Race Director
Originally Posted by usctrojanGT3
So no lift up shift and no lift down shift? Wow, my head is blown....will try it this weekend.
#92
By what mechanism does the car slow the engine to rev match on the upshift? Or does it just keep it from falling too far as the revs decrease naturally? Surely there is no brake on the flywheel or some such.
#94
Now... to be fair... I'm not seeing value in any of this. The huge value in rev-matching to me is the perfect heel-toe downshifts. I'm mediocre at best at it and when I let the car do it there's zero question in my mind that I couldn't possibly have matched what it did. There's no heel-toe up-shifting though. I'm perfectly capable of managing the throttle on my own during an up-shift. This no-lift business sounds just lazy to me and isn't a thing I need help with. That said... maybe I'll change my mind when I try it. You never know. Maybe it's really neat.
Everything that's going on here is being done by electronically controlling the throttle and doing things with it that you're not doing with your foot.
#95
Race Director
Originally Posted by Wild Weasel
I still think my scenario of it effectively acting like an automatic kick-down is plausible. With a PDK if you're puttering along and want to accelerate, you mash the pedal and it'll downshift and go. That's a no-lift downshift. Everything I'm reading here suggests this should work with the manual and this no-lift shifting business going on....
#96
But here's my scenario. Let me know what you think happens.
You're cruising along in 6th gear at some low RPM. You decide you want to speed up. Here's the sequence you perform:
1. Mash pedal to the floor.
2. Clutch in.
3. Shift to 3rd.
4. Clutch out.
What does the car do?
In my imagination, based on what I'm reading here about this no-lift shifting, the car will not just rev up to the rev limiter like any normal car would as soon as you put the clutch in. I imagine it holding the RPM when you push the clutch in and, when the gear lever goes into 3rd the computer rev-matches for 3rd appropriately and when you let the clutch out you're accelerating as hard as you can.
Is this complete fiction or is this what actually happens?
#97
Race Director
I personally would never try that stunt, which is why it is great to be able to do that same thing without risk in the PDK.
#98
Here's the situation. If you floor a PDK-S in auto and you are going any speed, it will drop down to the optimal lowest gear pretty much instantaneously. It knows the lowest gear it can do at any given speed/rev range, and it can make that decision instantly. In the manual, you can mash the peddle and make the wrong decision about what gear to downshift into, then you will need a new motor. So you better know exactly what you are doing before you try that. For example, you are putting in 3rd gear totally ******* the motor going 25 mph, and you floor it while simultaneously throwing it into 1st. If you get the speed right you won't over-rev. Otherwise, get out your checkbook.
I personally would never try that stunt, which is why it is great to be able to do that same thing without risk in the PDK.
I personally would never try that stunt, which is why it is great to be able to do that same thing without risk in the PDK.
Are you saying you'd never downshift in a manual?
If so, then you have definitely made the right choice in sticking with PDK. I'm assuming I've somehow misunderstood you though.
#99
Race Director
What's you're describing here is just downshifting. If you do it wrong, bad things can happen. Are you saying you'd never downshift in a manual? If so, then you have definitely made the right choice in sticking with PDK. I'm assuming I've somehow misunderstood you though.
#100
it will save someone more time, the worse they are at quick gearchanges, with minimum time off throttle.
#101
Rennlist Member
This isn’t that hard. Upshift - no lift. Downshift - lift as normal and let the blip match the revs. I’ve done both of these - pretty cool.
Would not do a no lift downshift. If someone does (not recommending it!) - please report back
Would not do a no lift downshift. If someone does (not recommending it!) - please report back
#102
Race Director
#103
Rennlist Member
This no lift downshift is really not useful anyway. I guess you can do it when cruising on the highway and want to downshift and accelerate quickly. Definitely useless and can't be used at the track.
Here is a short video I did today demonstrating the no-lift downshifts.
#104
Burning Brakes
I used to do no lift downshifts in my mom's VW when I was a kid (a very long time ago). I would simply make sure I was at the right speed and shift from 4th to 3rd, and the revs would go up to match the lower gear. Sometimes it worked perfectly and I got a very smooth (on power) downshift. Fun stuff.
#105
You can check my video here. I was doing power-shifting and heel toeing for a full session. Computer doesn’t interfere in throttle inputs as you can see on Throttle bar.