[coolhand]

How does A8 compare to the widely used ZF 8 transmission found in many BMWs and Audis?

I understand A8 is no PDK, but is it comparable to ZF8 in manual paddle shifting mode?

[cellsafemode]

There's a lot of variants of the ZF8 ... you'll have to be a bit more specific.

The 8L90 matches if not exceeds the performance of pdk transmissions in most cars. There have been a number of tests major publications have made comparing the 8L90 to various pdk transmissions and it's not missing out at all.

Depending on which variant of the Zf8 you're referring to, you might be able to find a direct comparison since the A8 8L90 has been in use in the vette since last year I believe.

I think motortrend and car and driver have done tests on the A8 in the various modes.

[mt3130]

Originally Posted by cellsafemode

There's a lot of variants of the ZF8 ... you'll have to be a bit more specific.

The 8L90 matches if not exceeds the performance of pdk transmissions in most cars. There have been a number of tests major publications have made comparing the 8L90 to various pdk transmissions and it's not missing out at all.

Depending on which variant of the Zf8 you're referring to, you might be able to find a direct comparison since the A8 8L90 has been in use in the vette since last year I believe.

I think motortrend and car and driver have done tests on the A8 in the various modes.

The PDK is specific to Porsche, and GM's 8 speed doesn't hold a candle to it. They (GM) advertised that it was faster than the Porsche unit, but real world testing shows that GM still has a ways to go in terms of transmission downshift times as well as paddle responsiveness for both upshifts and downshifts.

The 10 speed is more promising in that the torque converter doesn't have to unlock to change gears. If the paddle shifters work properly, then the 10 speed is probably the unit to compare to the PDK.

[LSxWittles]

Originally Posted by mt3130

The PDK is specific to Porsche, and GM's 8 speed doesn't hold a candle to it. They (GM) advertised that it was faster than the Porsche unit, but real world testing shows that GM still has a ways to go in terms of transmission downshift times as well as paddle responsiveness for both upshifts and downshifts.

The 10 speed is more promising in that the torque converter doesn't have to unlock to change gears. If the paddle shifters work properly, then the 10 speed is probably the unit to compare to the PDK.

This. Although I haven't driven the A8, everything I have seen shows clearly noticeable lag and responsiveness through the paddles unfortunately. Only driven one vehicle with a ZF 8 speed (buddies scat pack) and it seemed to respond from the paddles pretty well. I should go test drive an A8 6th gen lol.

[cellsafemode]

This post seems to break it down better than can be hoped for in here or referencing marketing materials from 2 years ago.

http://www.camaro6.com/forums/showthread.php?p=9095693

[SuperSound]

Yep just to be clear, the paddle delay is a programming issue...not hardware. And the paddles are were lag is present. In AUTO mode, mine compares exactly to the ZF 8 that was in my 328i. The paddles were definitely faster on the ZF 8.

[Sp00ner]

Originally Posted by LSxWittles

This. Although I haven't driven the A8, everything I have seen shows clearly noticeable lag and responsiveness through the paddles unfortunately. Only driven one vehicle with a ZF 8 speed (buddies scat pack) and it seemed to respond from the paddles pretty well. I should go test drive an A8 6th gen lol.

Seems to be a difference in shift speed between modes as well. TR vs all others, in particular. Could be in my head though.

The 1-2 upshift is the only one I'd say has 'lag', although thus far I see no reason to launch in anything but D, and 2-3/2-3 shift seem to fire off immediately. I don't have any direct euro brand experience to compare it with though.

Coming from a manual 5th Gen (and manuals in general for the last 15+ years), I was pretty shocked and how well it drove itself in both Manual Mode and Performance Shifting Mode (I think that's the name). Honestly, when it goes into the Perf Shifting mode, I love it, just sits the powerband and shifts up/down as needed but I keep reaching for the shifter out of habit.

Disclaimer: Have not been to the track yet, car is barely past break in, we'll see how I feel about the 'auto' after a day on the course.

[coolhand]

Originally Posted by SuperSound

Yep just to be clear, the paddle delay is a programming issue...not hardware. And the paddles are were lag is present. In AUTO mode, mine compares exactly to the ZF 8 that was in my 328i. The paddles were definitely faster on the ZF 8.

Are you saying that shifting in manual mode with the *gear lever* does not have lag?

Or do you mean that in all the manual M modes, including paddle and gear lever shifts have lags, and only in auto D mode, it's just as fast and smooth as ZF?

If it's laggy on all kinds of manual shifting, whether paddle or gear lever, than it's not just a programming issue; it's the actual performance and limitation of A8.

[cleoent]

Paddle shifter respoveniss and shift speed are two different things. The 8a in the ss shifts ridiculously fast. Faster than the smg 3 in my old m5. As fast as dual clutches.

It however responds to the paddles a bit slower.

[SuperSound]

Originally Posted by coolhand

Are you saying that shifting in manual mode with the *gear lever* does not have lag?

Or do you mean that in all the manual M modes, including paddle and gear lever shifts have lags, and only in auto D mode, it's just as fast and smooth as ZF?

If it's laggy on all kinds of manual shifting, whether paddle or gear lever, than it's not just a programming issue; it's the actual performance and limitation of A8.

Paddles and the console shifter are both electronic and have lag. The problem is they are not directly executing a shift. They are requesting the computer to shift. This is where the programming comes in. GM left the computer with too much to control. This is one of the main changes with the A10. They added what they call a DSC (direct shift controller) which gives the driver full control and bypass the nannies.

The guy above is right. There's shift speed and paddle response...two different things. If it was a limitation of the trans itself, it would not perform like it does in auto. The ZF and the 8L90 share a similar design, but with very different takes on programing and control. Lag is present on ZF units as well, just not as bad as the 8L90.

Sent from my SAMSUNG-SM-G920A using Tapatalk

[LSxWittles]

Is there a way to tune the response time for the paddles? Apologies if it's a dumb question but I don't have much experience with these new auto's and paddle shifters (have owned nothing but manual performance vehicles). Just curious.

[SuperSound]

Originally Posted by LSxWittles

Is there a way to tune the response time for the paddles? Apologies if it's a dumb question but I don't have much experience with these new auto's and paddle shifters (have owned nothing but manual performance vehicles). Just curious.

I think I heard no one has really done any tuning with the 8L90s yet. So the answer is probably no for now at least.

[cellsafemode]

Originally Posted by SuperSound

I think I heard no one has really done any tuning with the 8L90s yet. So the answer is probably no for now at least.

Trifecta modifies the tcm with a new tune. Not sure if it affected the paddle shifters at all. I've yet to feel the urge to even try paddle shifting so I couldn't tell you if it got faster or not.

[KMPrenger]

Originally Posted by mt3130

The PDK is specific to Porsche, and GM's 8 speed doesn't hold a candle to it. They (GM) advertised that it was faster than the Porsche unit, but real world testing shows that GM still has a ways to go in terms of transmission downshift times as well as paddle responsiveness for both upshifts and downshifts.

The 10 speed is more promising in that the torque converter doesn't have to unlock to change gears. If the paddle shifters work properly, then the 10 speed is probably the unit to compare to the PDK.

Incorrect. I'm amazed how often I read this and people get it wrong. GM only said the 8 speed was faster in upshifts under WOT. (and I don't think this was even talking about paddle shifts either...just the transmission shifting)