[IOMike]

From what I've seen, this is a step further than the 8 speed FCA is using.

The GM 8l90 is as fast as the zf 8 speed, it's only the paddles that have delay (and I've read the ZF paddles have delay too, just slightly less).

[FenwickHockey65]

As long as the ZF 8 speed isn't anything like the disaster the ZF 9 speed in the 200 is.

[IOMike]

Originally Posted by FenwickHockey65

As long as the ZF 8 speed isn't anything like the disaster the ZF 9 speed in the 200 is.

No doubt. Had a 9 speed Cherokee rental on a vacation and that was the worst transmission I'd ever experienced in a car. You had to give it the beans to pass (4 cylinder, understandable) and it took like 3 or 4 seconds to downshift. Surged a lot, like a manual would.

[SuperSound]

Originally Posted by IOMike

From what I've seen, this is a step further than the 8 speed FCA is using.

The GM 8l90 is as fast as the zf 8 speed, it's only the paddles that have delay (and I've read the ZF paddles have delay too, just slightly less).

My 328i (with ZF 8) definitely has some compared to the videos I have seen of guys with 8L90s. Especially on downshifts but it's also very dependent on throttle input on how fast it reacts. The 6th gen I test drove (with had been on the lot for awhile) was definitely slower. But how much of that is do to adaptive abuse I don't know. Hopefully if my car arrives in July, I'll be able to test both back to back multiple times.

[HCT]

Originally Posted by SuperSound

My 328i (with ZF 8) definitely has some compared to the videos I have seen of guys with 8L90s. Especially on downshifts but it's also very dependent on throttle input on how fast it reacts. The 6th gen I test drove (with had been on the lot for awhile) was definitely slower. But how much of that is do to adaptive abuse I don't know. Hopefully if my car arrives in July, I'll be able to test both back to back multiple times.

At the risk of muddying the waters, people should know that when they refer to "the" ZF 8-speed they're actually not quite accurate. There are several models of the ZF unit rated to handle differing amounts of torque. For example, while Chrysler licenses and builds lower model ZF 8-speeds under the TorqueFlite name, they buy the German made 8HP90 units for the Hellcats.

Plus each application of the ZF can be programmed differently. So the ZF in a Bentley is going to have its own unique shift behavior which isn't the same as when it's in a BMW, etc.

Check this article to see how wide the product range is.

[SuperSound]

Originally Posted by HCT

At the risk of muddying the waters, people should know that when they refer to "the" ZF 8-speed they're actually not quite accurate. There are several models of the ZF unit rated to handle differing amounts of torque. For example, while Chrysler licenses and builds lower model ZF 8-speeds under the TorqueFlite name, they buy the German made 8HP90 units for the Hellcats.

Plus each application of the ZF can be programmed differently. So the ZF in a Bentley is going to have its own unique shift behavior which isn't the same as when it's in a BMW, etc.

Check this article to see how wide the product range is.

Agreed I was just conveying mine is a ZF sourced unit (and is the optional sport trans for the 3 series). The same holds true for the 8L90 and 8L45. Same design, different torque capacities. Believe FCA isn't the only one building ZF units under license.

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[crabman]

Originally Posted by SuperSound

Just as long as you remember FCA didn't develop it. They bought the license to manufacture it from ZF.

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They licenced to build the ligher duty 8HP for the 6 cylinder GCs in Indiana, the trans in the in the hemi/diesel/SRT cars are (were) imported and built in the ZF plant in Saarbrücken Germany unless thats changed since 14?

About your callout, you know I cant prove out what there are no meaningful and comparable numbers for but since you have stated the manufacturers numbers are your God until someone proves otherwise we'll go with that. That being the case I'm sure you're aware that the ZF unit has a 50 millisecond faster claimed shift speed than the A8 for all upshifts and downshifts save GMs laughable double speed 1 to 2 upshift were it would get the crown on that shift. I personally think the numbers from all these OEMs are utterly meaningless since they adhere to no standard and cant be used comparatively but your rules so we'll go with the ad copy.

Maybe you take exception to the more sophisticated portion of my comments about that hypothetical Grand Cherokee and 14 Vette? In that case just a few of the things that make the ZF unit more sophisticated... Its able to change all eight forward ratios and reverse with 4 simple planetary gear sets which are not nested while utilizing only 5 shifting elements, 3 clutches and two brakes. All conventional friction, no dog clutches required. All sequential shifts up or down involve releasing just one shift element and engaging just one other. A so called “clutch to clutch” shift because no other intermediary step is required. The transmission is also able to change multiple gears clutch to clutch as well without engaging the intermediate gears on the way. It's also true between first and reverse, clutch to clutch. Not that anybody cares in that case but it is a remarkably elegant design. It spins its gears at a lower velocity than its A8 competition making it more efficient. It has a more sophisticated damper system which reduces NVH to a greater extent. I can go on here if you want but I think you get the idea.

I'm an engineer Super, I understand numbers. If previous history is an indicator GMs ad copy about their automatics isn't going to be exactly representative of the actual product. The A8 was a quick and dirty band-aid to put on the lack of an 8 speed at a time when GM didn't have a lot of resources to go around. The ZF trans had more time and money spent on its development initially and as you probably remember 14 saw it significantly revised. The playing field wasn't exactly level but it is a competitive market and it often isn't. This new trans is a different beast in that regard. It's had much more development time and money invested and I hope to see a better showing. You might be surprised to learn that I am optimistic about it. Sounds good shifting and it appears the trans is reacting to the paddles well. Time will tell.

As to disappearing I didn't continue before for the same reason I didn't now. I said my piece. I like to think most people here have functional brains and got it the first time. Some might agree, others wont, either way I'm not here to win the internet. I'm a car guy so I come to talk about cars, learn a few things, sometimes pass on what I learned previously. Your just going to have to settle for calling me a dumbass and walk away.

[SuperSound]

Originally Posted by crabman

They licenced to build the ligher duty 8HP for the 6 cylinder GCs in Indiana, the trans in the in the hemi/diesel/SRT cars are (were) imported and built in the ZF plant in Saarbrücken Germany unless thats changed since 14?

The 8HP70 (used in all the Hemi cars except the Hellcat) is built under license by FCA in Indiana. Couldn't find where the Hellcat's is made or if sourced straight from ZF. Maybe ZF initially built some as they were turning up production but it was hard enough to find that info.

http://www.dieselhub.com/trans/torqueflite-8.html

Originally Posted by crabman

About your callout, you know I cant prove out what there are no meaningful and comparable numbers for but since you have stated the manufacturers numbers are your God until someone proves otherwise we'll go with that. That being the case I'm sure you're aware that the ZF unit has a 50 millisecond faster claimed shift speed than the A8 for all upshifts and downshifts save GMs laughable double speed 1 to 2 upshift were it would get the crown on that shift. I personally think the numbers from all these OEMs are utterly meaningless since they adhere to no standard and cant be used comparatively but your rules so we'll go with the ad copy.

Funny Dodge says the 8H90 (the best one) can only do it in 160ms. But again you made my point, neither of us can prove anything which is why I called it out. You can talk about paddle lag and downshift performance because I have witnessed it too. But you clearly were being facetious. Though I can put up with your posts about the subject better than the other guy who has been banned multiple times for trolling. It's perfectly fine to agree to disagree and state your opinion, but he always resorts to personal attacks, completely false statements, or pure biased opinions.

Originally Posted by crabman

Maybe you take exception to the more sophisticated portion of my comments about that hypothetical Grand Cherokee and 14 Vette? In that case just a few of the things that make the ZF unit more sophisticated... Its able to change all eight forward ratios and reverse with 4 simple planetary gear sets which are not nested while utilizing only 5 shifting elements, 3 clutches and two brakes. All conventional friction, no dog clutches required. All sequential shifts up or down involve releasing just one shift element and engaging just one other. A so called “clutch to clutch” shift because no other intermediary step is required. The transmission is also able to change multiple gears clutch to clutch as well without engaging the intermediate gears on the way. It's also true between first and reverse, clutch to clutch. Not that anybody cares in that case but it is a remarkably elegant design. It spins its gears at a lower velocity than its A8 competition making it more efficient. It has a more sophisticated damper system which reduces NVH to a greater extent. I can go on here if you want but I think you get the idea.

I can copy and paste engineering data too:

"On the surface, there are many similarities between the ZF 8HP transmission family and the GM 8L90. Namely both use 4 gear sets, 5 shifting elements (3 clutches and two brakes), off axis pumps, and have roughly the same gear ratio spread at about 7:1 overall spread. The saturation dive is not about dealing with things that are on the surface. To be entirely honest as the details started to emerge on the GM 8L family of transmissions I suspected that it would end up being a ZF licensed design, the ZF 8HP after all is a very good design in my opinion. But the abstract of the paper that we managed to snag before SAE took it down revealed one very important detail – all 3 of the clutches were located in front of the planetary gear sets very much unlike the ZF design.

Based on the available information, this article makes educated guesses at likely gear parameters for the GM 8L90. The likely gear parameters are

Gear set 1: Sun gear S1 = 39, Ring gear R1 = 77
Gear set 2: Sun gear S2 = 42, Ring gear R2 = 78
Gear set 3: Sun gear S3 = 39, Ring gear R3 = 77
Gear set 4: Sun gear S4 = 29, Ring gear R4 = 103
The gear ratio spacing is very good, the transmission feel of the GM 8L90 should be very competitive to the acclaimed ZF 8HP family of transmissions.

There are some obvious similarities between the gear arrangement of the GM 8L90 and the ZF 8HP but there are significant differences as well. These similarities and differences have been explained in this article. The one advantage of locating the clutches close to the hydraulic pump and the valve body is better shifting times since less fluid has to be moved in and out of the clutch pistons to apply and release the clutches. Also, this design is likely very competitive in terms of mass for a given torque capacity, and is better than the ZF 8HP design in terms of rotational inertia.

There are other advances made in this transmission design as well, especially with regards to the hydraulic pump design. This particular transmission features a “cylinder deactivation” of sorts for the pump, when line pressure demands are low (highway cruising) half of the pump can be shut down to achieve higher efficiency while still retaining the pump displacement required to deliver enough flow rate for fast shifts.

Conclusions

This is a very good design, hats off to the engineers at GM. The filing date on the patent is May 1, 2009 therefore props to the management at GM for letting this program move forward through the darkest days of their bankruptcy. This will be considered a seminal design in the history of automatic transmissions."

http://www.thetruthaboutcars.com/201...-transmission/




There's a hell of a lot more but that's not why I posted it. All of this is meaningless because it's the performance of it that matters. I've driven the 8HP70 in an RT and SP, I've owned the BMW for 3 years, and I've driven several dealer lot Camaros. The SP was a used one with 5000k miles. It felt perfect and did not do anything unexpected. The RT was a lot tester and had several issues. One it failed to shift into 7th at a 60mph cruise. I had to manually shift it. Two the paddles were slow to respond on downshifts but not terrible and in general lacked a "firm" feel. My BMW's only real continuing issue is the clunk of 1-2 and 2-1 shifts. This exact behavior is talked about frequently on the LX forums. It's annoying but not worth a compliant from me since it's obvious the way the trans was designed. Paddle shifts at WOT are firm and quick. Downshifts definitely have lag in them but then again I'm not doing autoX or track days in it. Upshifts at part throttle can be hit or miss with lag. Doesn't this sound familar? Guys on the LX and BMW forums report the same. And we've seen plenty of people here and on the C7 forum say the same thing too. Can't be a coincidence right? Could it be the computer trying to anticpate what the hell you are doing and not getting it right all the time? Sounds like it to me, then I saw this in the press relase about the A10. "Driver Shift Control allows the driver to shift the transmission via the steering wheel-mounted paddle shifters. Electronic safeguards prevent over-revving if the wrong gear position is selected, but relies on the driver to make upshifts or downshifts." That last part about downshifts is what's interesting. The 8L90, 8H70, and the verison my BMW uses all will downshift automatically to prevent lugging. These safeguards are probably exactly what leads to lag in the paddles. With their removal, we seem to have the explanation for why the A10 will perform that much better.

Originally Posted by crabman

I'm an engineer Super, I understand numbers. If previous history is an indicator GMs ad copy about their automatics isn't going to be exactly representative of the actual product. The A8 was a quick and dirty band-aid to put on the lack of an 8 speed at a time when GM didn't have a lot of resources to go around. The ZF trans had more time and money spent on its development initially and as you probably remember 14 saw it significantly revised. The playing field wasn't exactly level but it is a competitive market and it often isn't. This new trans is a different beast in that regard. It's had much more development time and money invested and I hope to see a better showing. You might be surprised to learn that I am optimistic about it. Sounds good shifting and it appears the trans is reacting to the paddles well. Time will tell.

As to disappearing I didn't continue before for the same reason I didn't now. I said my piece. I like to think most people here have functional brains and got it the first time. Some might agree, others wont, either way I'm not here to win the internet. I'm a car guy so I come to talk about cars, learn a few things, sometimes pass on what I learned previously. Your just going to have to settle for calling me a dumbass and walk away.

Obviously Ford doesn't share that opinion of it, otherwise they wouldn't have gone to lengths to get a partneship to co-develope a new 10 speed based off the ground work of the 8L90. And you can't say that Ford had a real ground work already since they didn't even design the 6 speed in the Mustang. It's another built under license from ZF. Why wouldn't they just have bought a license from ZF like FCA? Afterall that is much cheaper than jointly developing two new transmissions. So Ford had to see value in what GM had otherwise they would have went somewhere else.

I never called or thought you were a dumbass. You've made good points and I agreed with you on them. Quite a number of your posts (not just this subject) are informative. Like I said earlier, I'm fine with your opinions and observations. But some you made out as fact and they are simply not the case. That is why I responded directly to them, not the others. Either way, I wouldn't argue with someone who I felt was simply trolling or posting completely false info. I'm not here either to win arguments. I just want the facts to clear.

[HCT]

Originally Posted by SuperSound

then I saw this in the press relase about the A10. "Driver Shift Control allows the driver to shift the transmission via the steering wheel-mounted paddle shifters. Electronic safeguards prevent over-revving if the wrong gear position is selected, but relies on the driver to make upshifts or downshifts." That last part about downshifts is what's interesting. The 8L90, 8H70, and the verison my BMW uses all will downshift automatically to prevent lugging. These safeguards are probably exactly what leads to lag in the paddles. With their removal, we seem to have the explanation for why the A10 will perform that much better.

I know we're all speculating here but I disagree with your reasoning. Modern controllers monitor things like throttle position and engine RPM hundreds of times per second. The decision of whether or not to downshift if engine RPM gets dangerously low doesn't take up significant computational overhead. It's just a programming decision whether to allow it or not.

Of course it's highly likely that the A10 uses a faster processor (or processors) than the 8L90. That will allow it to run more code and still stay within its time response limits but in the end it comes down to the quality of the programming. I know in my Hellcat they updated the transmission's firmware a couple of times after the first cars hit production -- they were still tweaking it based on real world feedback even after all their preproduction testing.

Obviously Ford doesn't share that opinion of it, otherwise they wouldn't have gone to lengths to get a partneship to co-develope a new 10 speed based off the ground work of the 8L90.

The chronology doesn't really support that reasoning. The 8L90 first rolled out in 2014. But GM and Ford announced working on the 10-speed in 2012, which means they likely started talking/negotiating in 2010 or 2011.

Also, remember Ford and GM worked together on transmissions before: back in 2002 they codesigned a 6-speed.

Ford and GM both have thousands of talented engineers. Both companies saw a need for a modern transmission and worked together on it -- it would've happened even if the 8L90 was a poor design. The 10-speed project is more about working with a proven partner to share knowledge and reduce costs, rather than being based on building on a particular prior design.

Of course, take all this with a grain of salt -- this is just guesswork based on my general business & tech background but it's not like I have any real data!

[SuperSound]

Originally Posted by HCT

I know we're all speculating here but I disagree with your reasoning. Modern controllers monitor things like throttle position and engine RPM hundreds of times per second. The decision of whether or not to downshift if engine RPM gets dangerously low doesn't take up significant computational overhead. It's just a programming decision whether to allow it or not.

Of course it's highly likely that the A10 uses a faster processor (or processors) than the 8L90. That will allow it to run more code and still stay within its time response limits but in the end it comes down to the quality of the programming. I know in my Hellcat they updated the transmission's firmware a couple of times after the first cars hit production -- they were still tweaking it based on real world feedback even after all their preproduction testing.

No that's exactly what I was trying to say. They decided to ax the computer oversight is what it sounds. So we agree there.

Originally Posted by HCT

The chronology doesn't really support that reasoning. The 8L90 first rolled out in 2014. But GM and Ford announced working on the 10-speed in 2012, which means they likely started talking/negotiating in 2010 or 2011.

Also, remember Ford and GM worked together on transmissions before: back in 2002 they codesigned a 6-speed.

Ford and GM both have thousands of talented engineers. Both companies saw a need for a modern transmission and worked together on it -- it would've happened even if the 8L90 was a poor design. The 10-speed project is more about working with a proven partner to share knowledge and reduce costs, rather than being based on building on a particular prior design.

Of course, take all this with a grain of salt -- this is just guesswork based on my general business & tech background but it's not like I have any real data!

The story only broke in 2013, now whether preliminary talks started earlier no one will probably say. But at that stage there was likely no talk about specifics. But regardless the 8L90 is out the next year, so you can be sure it was well into development by the time the agreement was reached and would have been a bargaining chip. I'm sure ZF's decision not to pursue a 9 or 10 speed RWD trans is also being a factor here. ZF isn't worried about trying to make trucks pass CAFE, but GM and Ford are.

[ADM PERFORMANCE]

This pic from along time ago

[DrkPhx]

^^^ Wow. Good catch.

[Zeke.Malvo]

Originally Posted by ADM PERFORMANCE

This pic from along time ago

The ribbing looks different

[SuperSound]

Originally Posted by Zeke.Malvo

The ribbing looks different

On the trans casing? Yep I see that too and 3 holes vs 2 near the valve body(?).