991.2 manual throttle clipping issue
09-11-2019, 04:45 AM
#1
Advanced
Thread Starter
991.2 manual throttle clipping issue
Hi... have a 2018 gt3 manual with about 3000 miles... I'm wandering if anyone else here thinks the throttle blip response is sometimes inconsistent on the 991.2 GT3 cars .... I practice heel toe at times n at times usev the sport mode for auto blips....
Anyways...despite what I think is a descent throttle tap.... some times the car just does not go up in rpm much even though I think I pressed the pedal deep n long enough.... I mean... I hear the click (not sure what that noise is from...like some relay or vacuum source opening in the engine bay) but the rpm doesnt do much n i have to reblip but I've lost the speed by then....
Anyone else or suggestions??
Anyways...despite what I think is a descent throttle tap.... some times the car just does not go up in rpm much even though I think I pressed the pedal deep n long enough.... I mean... I hear the click (not sure what that noise is from...like some relay or vacuum source opening in the engine bay) but the rpm doesnt do much n i have to reblip but I've lost the speed by then....
Anyone else or suggestions??
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carbondan (09-11-2019)
09-11-2019, 12:29 PM
#2
Racer
This has been covered in some detail in this post https://rennlist.com/forums/991-gt3-...t-shift-3.html
Basically it comes down to people's individual shifting style not being compatible with how Porsche wants you to shift. You will likely need to change how you shift.
This poll aims to capture the most conventional methods that work with our cars https://rennlist.com/forums/991-gt3-...downshift.html
Basically it comes down to people's individual shifting style not being compatible with how Porsche wants you to shift. You will likely need to change how you shift.
This poll aims to capture the most conventional methods that work with our cars https://rennlist.com/forums/991-gt3-...downshift.html
09-11-2019, 01:31 PM
#3
Burning Brakes
I never have a problem when I do my own throttle blip on my manual GT3. I think I must be instinctively hitting the throttle while I'm shifting thru neutral between gears.
09-11-2019, 01:39 PM
#4
Yes you and many other (myself included) have this issue.
https://rennlist.com/forums/991-gt3-...t3-manual.html
It's caused by overly aggressive no-lift shift coding where the ECU thinks you're trying to no lift upshift (hold gas down while upshifting). So it rev limits a few hundred rpm higher than where you are, it doesn't allow it to blip/rev freely.
You have to wait until you're already into the lower gear's gate before the ECU will allow you to blip normally.
It's extremely annoying to me. I'm learning to live with it and work around it but so far it is by far the low point of the car for me. Kinda spoils the joy of having a manual when it forces you to work around a feature that I would never use in the first place.
https://rennlist.com/forums/991-gt3-...t3-manual.html
It's caused by overly aggressive no-lift shift coding where the ECU thinks you're trying to no lift upshift (hold gas down while upshifting). So it rev limits a few hundred rpm higher than where you are, it doesn't allow it to blip/rev freely.
You have to wait until you're already into the lower gear's gate before the ECU will allow you to blip normally.
It's extremely annoying to me. I'm learning to live with it and work around it but so far it is by far the low point of the car for me. Kinda spoils the joy of having a manual when it forces you to work around a feature that I would never use in the first place.
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NevB (09-11-2019)
09-11-2019, 03:07 PM
#6
This process will be slower, but what you have to do is wait until your gear lever is already starting to enter the lower gear's gate before you then blip the throttle.
If you start blipping while the lever is still in the original gear's gate, or even as it's crossing neutral, it will automatically assume you're trying to no-lift upshift and will only let you rev up 2-400 RPM.
If you start blipping while the lever is still in the original gear's gate, or even as it's crossing neutral, it will automatically assume you're trying to no-lift upshift and will only let you rev up 2-400 RPM.
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09-11-2019, 03:49 PM
#8
Advanced
Thread Starter
ah, ok...let me try that.... I still dont' know my cars idiosyncracies but.... thanks for your help...;
and until this thread, I had no concept of NLS.... is that on down shifting or up shifting.... I always just let the rpm come down a bit on up shifting and blip up for down shifting...idk... old school... ?
and until this thread, I had no concept of NLS.... is that on down shifting or up shifting.... I always just let the rpm come down a bit on up shifting and blip up for down shifting...idk... old school... ?
09-11-2019, 05:44 PM
#9
ah, ok...let me try that.... I still dont' know my cars idiosyncracies but.... thanks for your help...;
and until this thread, I had no concept of NLS.... is that on down shifting or up shifting.... I always just let the rpm come down a bit on up shifting and blip up for down shifting...idk... old school... ?
and until this thread, I had no concept of NLS.... is that on down shifting or up shifting.... I always just let the rpm come down a bit on up shifting and blip up for down shifting...idk... old school... ?
On a normal car without this coding, obviously the revs would spike and bang off the rev limiter. With no lift shift on the GT3, the revs stay steady so that as you get your foot off the clutch you're already floored on the throttle and it's marginally faster.
It works just fine on my car, but I would never make a practice of using it as it builds terrible habits and I don't need to upshift quite that fast.
I would much rather prefer they hadn't fiddled with that coding and let the throttle react normally without any electronic interventions. At the very minimum allow us to switch that feature off (perhaps make it a part of 'sport' mode?).
I believe some ECU revision made this behavior far more aggressive as several users reported being surprised by this 'feature' suddenly after service after a considerable amount of time owning the car.
09-11-2019, 07:06 PM
#10
Burning Brakes
This process will be slower, but what you have to do is wait until your gear lever is already starting to enter the lower gear's gate before you then blip the throttle.
If you start blipping while the lever is still in the original gear's gate, or even as it's crossing neutral, it will automatically assume you're trying to no-lift upshift and will only let you rev up 2-400 RPM.
If you start blipping while the lever is still in the original gear's gate, or even as it's crossing neutral, it will automatically assume you're trying to no-lift upshift and will only let you rev up 2-400 RPM.
04-26-2022, 01:07 AM
#11
6th Gear
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Yes you and many other (myself included) have this issue.
https://rennlist.com/forums/991-gt3-...t3-manual.html
It's caused by overly aggressive no-lift shift coding where the ECU thinks you're trying to no lift upshift (hold gas down while upshifting). So it rev limits a few hundred rpm higher than where you are, it doesn't allow it to blip/rev freely.
You have to wait until you're already into the lower gear's gate before the ECU will allow you to blip normally.
It's extremely annoying to me. I'm learning to live with it and work around it but so far it is by far the low point of the car for me. Kinda spoils the joy of having a manual when it forces you to work around a feature that I would never use in the first place.
https://rennlist.com/forums/991-gt3-...t3-manual.html
It's caused by overly aggressive no-lift shift coding where the ECU thinks you're trying to no lift upshift (hold gas down while upshifting). So it rev limits a few hundred rpm higher than where you are, it doesn't allow it to blip/rev freely.
You have to wait until you're already into the lower gear's gate before the ECU will allow you to blip normally.
It's extremely annoying to me. I'm learning to live with it and work around it but so far it is by far the low point of the car for me. Kinda spoils the joy of having a manual when it forces you to work around a feature that I would never use in the first place.
It was originally done to match gears which didn't have full "synchronizers", but of course, our gears have those. However, rev matching is needed for another very important reason: to not cause weight transfer during downshifts. If you don't do it, the differences between the engine speed and the wheel speed, which are "adjusted to match each other" by the clutch - these forces can cause the car to become unbalanced. Guess what? If you are maxing out cornering forces and cause weight transfer from the back to the front, the rear tires lose traction. And the car can spin out.
Think of a straight section of road that you can use third gear in... and that ends in a hard left turn. You know that you need second gear for best acceleration out of the hard left turn... Therefore, you will need to move from third to select second gear at the optimal time... You, in your "manual" GT3 are approaching the turn gaining speed in third gear. At the latest moment possible, you hit the brakes to reduce speed to the max you will be able to carry through the hard left turn. You are hard on the brakes and revs are coming down as well. While continuing to brake hard, you... and here is where I would like to emphasize my point... in order to "rev match" the engine speed to driveline speed, and to keep a large speed differential between the two from causing the car to become unbalanced (i.e. weight transfer from the back of the car to the front of the car while max cornering forces are being achieved)... and while the car tracing an arc through the turn... you have to double clutch shift from third to second. Only... the GT3 WON'T LET YOU. Instead, you do all of the above except at the point in time when you've put the shifter in neutral and quickly let out the clutch, you blip the throttle while hard on the brake pedal, and the engine bog, bog, bog, bog -- and the shift is ruined.
Alright... so, there is sport mode. So, push that button and guess what, the car does that rev match for you. Congrats. Well done. Sort of like having someone else screw your girlfriend or wife, if you ask me. I get no... satisfaction.
I've got some more experimenting to do before it is a completely lost cause, but I... am... completely bummed by this. This car isn't a manual. It's an automatic with a stick.
Last edited by gmathews; 04-27-2022 at 01:01 PM.
04-26-2022, 11:58 AM
#13
I purchased my 2018 6 speed GT3 in February and now have about 550 miles behind the wheel. I have been experiencing this same issue on and off, and am very sad to now discover a lot of banter in the forums about the throttle not responding to double clutching. It doesn't sound like I am going to find a solution that I will be happy with. It's simple. Double clutching means clutch in, shifter from a gear to neutral, clutch out, REV HERE, clutch in, shifter from neutral to a lower numbered gear, clutch out.
It was originally done to match gears which didn't have full "synchronizers", but of course, our gears have those. However, rev matching is needed for another very important reason: to not cause weight transfer during downshifts. If you don't do it, the differences between the engine speed and the wheel speed, which are "adjusted to match each other" by the clutch - these forces can cause the car to become unbalanced. Guess what? If you are maxing out cornering forces and cause weight transfer from the back to the front, the rear tires lose traction. And the car can spin out.
Think of a straight section of road that you can use third gear in... and that ends in a hard left turn. You know that you need second gear for best acceleration out of the hard left turn... Therefore, you will need to move from third to select second gear at the optimal time... You, in your "manual" GT3 are approaching the turn gaining speed in third gear. At the latest moment possible, you hit the brakes to reduce speed to the max you will be able to carry through the hard left turn. You are hard on the brakes and revs are coming down as well. While continuing to brake hard, you... and here is where I would like to emphasize my point... in order to "rev match" the engine speed to driveline speed, and to keep a large speed differential between the two from causing the car to become unbalanced (i.e. weight transfer from the back of the car to the front of the car while max cornering forces are being achieved)... and while the car tracing an arc through the turn... you have to double clutch shift from third to second. Only... the GT3 WON'T LET YOU. Instead, you do all of the above except at the point in time when you've put the shifter in neutral and quickly let out the clutch, you blip the throttle while hard on the brake pedal, and the engine bog, bog, bog, bog -- and the shift is ruined.
Alright... so, there is sport mode. So, push that button and guess what, the car does that rev match for you. Congrats. Well done. Sort of like having someone else screw your girlfriend or wife, if you ask me. I get no... satisfaction.
I've got some more experimenting to do before it is a completely lost cause, but I... am... completely bummed by this. This car isn't a manual. It's an automatic with a stick.
It was originally done to match gears which didn't have full "synchronizers", but of course, our gears have those. However, rev matching is needed for another very important reason: to not cause weight transfer during downshifts. If you don't do it, the differences between the engine speed and the wheel speed, which are "adjusted to match each other" by the clutch - these forces can cause the car to become unbalanced. Guess what? If you are maxing out cornering forces and cause weight transfer from the back to the front, the rear tires lose traction. And the car can spin out.
Think of a straight section of road that you can use third gear in... and that ends in a hard left turn. You know that you need second gear for best acceleration out of the hard left turn... Therefore, you will need to move from third to select second gear at the optimal time... You, in your "manual" GT3 are approaching the turn gaining speed in third gear. At the latest moment possible, you hit the brakes to reduce speed to the max you will be able to carry through the hard left turn. You are hard on the brakes and revs are coming down as well. While continuing to brake hard, you... and here is where I would like to emphasize my point... in order to "rev match" the engine speed to driveline speed, and to keep a large speed differential between the two from causing the car to become unbalanced (i.e. weight transfer from the back of the car to the front of the car while max cornering forces are being achieved)... and while the car tracing an arc through the turn... you have to double clutch shift from third to second. Only... the GT3 WON'T LET YOU. Instead, you do all of the above except at the point in time when you've put the shifter in neutral and quickly let out the clutch, you blip the throttle while hard on the brake pedal, and the engine bog, bog, bog, bog -- and the shift is ruined.
Alright... so, there is sport mode. So, push that button and guess what, the car does that rev match for you. Congrats. Well done. Sort of like having someone else screw your girlfriend or wife, if you ask me. I get no... satisfaction.
I've got some more experimenting to do before it is a completely lost cause, but I... am... completely bummed by this. This car isn't a manual. It's an automatic with a stick.
This has been my issue since 2019 and I used the car heavily on track for 2-3 years, unfortunately I gave up. I have to turn on sport mode and let the damn computer do it for me.
It's SUCH an easy fix to!! They just have to release a patch for the ECU/TCU to enable flatfoot shifting only when throttle is depressed 100%.
The car is doing this because of the flat foot shifting program. When you're in 3rd and clutch in and give it throttle, it THINKS you're planning on holding the throttle down and going to 4th gear, when it's extremely easy to program that that is NOT what you're trying to do.
If RPM >8K AND TPS >90% --- enable flat foot shift program
Else,
Let them drive the car like a normal ****ing manual.
And you know it's horribly executed program because it still enables the flat shift programming when you're in 6th gear...... on a 6 speed car.... think about that for a moment.
Last edited by carbondan; 04-26-2022 at 11:59 AM.
04-26-2022, 01:06 PM
#14
6th Gear
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BOOM. explained 100% perfectly.
This has been my issue since 2019 and I used the car heavily on track for 2-3 years, unfortunately I gave up. I have to turn on sport mode and let the damn computer do it for me.
It's SUCH an easy fix to!! They just have to release a patch for the ECU/TCU to enable flatfoot shifting only when throttle is depressed 100%.
The car is doing this because of the flat foot shifting program. When you're in 3rd and clutch in and give it throttle, it THINKS you're planning on holding the throttle down and going to 4th gear, when it's extremely easy to program that that is NOT what you're trying to do.
If RPM >8K AND TPS >90% --- enable flat foot shift program
This has been my issue since 2019 and I used the car heavily on track for 2-3 years, unfortunately I gave up. I have to turn on sport mode and let the damn computer do it for me.
It's SUCH an easy fix to!! They just have to release a patch for the ECU/TCU to enable flatfoot shifting only when throttle is depressed 100%.
The car is doing this because of the flat foot shifting program. When you're in 3rd and clutch in and give it throttle, it THINKS you're planning on holding the throttle down and going to 4th gear, when it's extremely easy to program that that is NOT what you're trying to do.
If RPM >8K AND TPS >90% --- enable flat foot shift program
This car was a huge purchase for me. The most I've ever spent on a car for myself was $39k back in 2009. I was surprised by my excitement for this car and somehow was able to convince myself that it was worth the $200k+ price for me to get one - and to pay the slight premium for the "manual". I didn't even look at any pdk cars or the GT3RS!!! Zero interest.
This is not the kind of thing I think I would have been able to determine on test drives. And none of the myriad of videos by test drivers of the car which I watched on Youtube pointed this out??? To find this out now sucks. I am just whining and complaining at this point, but this sucks bad. Wealth is relative... and this was a lot of money for me. Not sure that the rest of the merits of the car can warrant me holding on to it.
Last edited by gmathews; 04-26-2022 at 01:11 PM.
04-26-2022, 04:31 PM
#15
Burning Brakes
As stated previously, I never have this issue when manually rev matching on down shifts. You guy must be doing something strange to have the computer cut your throttle blip. I will have to pay closer attention to exactly when I'm blipping the throttle and report back. My street is being repaved the week, so won't be taking my GT3 out before the weekend.