[KyleL]

So if a tuner can load a zl1 equivalent algorithm in the 8 speed, could we be seeing significantly increased shift responses? I see where they go into detail on the hardware, which I'm sure the 8 speed doesn't have quite the same parts, but I wonder how much improved the shift responsiveness would be with just the zl1-based tuned loaded in??

[Mikes SS]

Originally Posted by Zeke.Malvo

GM has plenty of four cammed engines, it's not like they would have problems creating a DOHC V8.

On the flip side, how come they got rid of their OHV V6's? Why don't they just lop off two cylinders and create a V6 based on the LT1?

And the longer both companies go without developing a proper CVT, the worse off they'll be in the long run IMO.

they do have an LT1 based V6, its called the GenV LV3 4.3L 285Hp and 305TQ

[doc7000]

The chevy spark offers a cvt btw...

[DGthe3]

Originally Posted by Zeke.Malvo

GM has plenty of four cammed engines, it's not like they would have problems creating a DOHC V8.

On the flip side, how come they got rid of their OHV V6's? Why don't they just lop off two cylinders and create a V6 based on the LT1?

And the longer both companies go without developing a proper CVT, the worse off they'll be in the long run IMO.

CVTs are horribly inefficient compared to a typical manual or automatic transmission. The only reason they have any fuel economy advantage at all is because an engine can always be at its optimal RPM. But with more gears and faster shifting that advantage can be eliminated.

On the flip side, CVTs are now being programmed to 'shift' like a regular transmission because most people hate the constant engine drone you get while accelerating with a CVT. People want their engine to go 'BWAA - BWWAAAA - BWWWAAAAAAAAA' when the hit the gas. This reduces some of their net efficiency, in the name of consumer acceptance.

Plus, I don't think CVTs scale up all that well with power. Its one thing to transmit 75 - 150 hp through a rubber belt. But 650? Bit of a different story. And I doubt anybody really cares if the belt slips when you hit the gas in some little economy car. But launching a Camaro off the line at the drag strip? Thats a problem. Sure, these problems could be overcome with some R&D. But a thicker, heavier belt will rob even more power than a thin light one. Having an ultra high friction contact surface (to transmit all the power) does the same thing, and probably causes pre-mature wear on the belt. These issues are much harder to solve.

I wouldn't be surprised if its easier and more effective to have a multi-stage transmission, similar in concept to semi's and bicycles, than it would be to develop an effective high-powered CTV. A high, medium, and low range selector with a set of closely spaced gears as additional gears. A 3 speed selector + 10 speed 'regular' transmission = 30 forward speeds (and 3 reverse!). The regular gears could be space fairly tightly (like a 3:1 spread over the 10 gears) while the range selector might have a 4:1 spread over 3 gears (each is twice the one before it). That would make for a 12:1 overall spread, with a bit of overlap between gears so that it doesn't need to double-shift as often.

This way, the engine could stay within a pretty narrow operating range (like in a CVT), but send the power through a step-gear transmission (like a normal car). That combines the most efficient aspects of both, although there might be extra losses due to the addition of the range-selector.

I'll stop now because I think I'm rambling ...

[bbrown450]

I have a CVT in the Altima...drives me crazy at speed a lot of RPM's mean a lot of noise. With regard to the new 10 speed trannies.....I would not want to own the first gen of these sorry GM has a bad track record on new trannies and this is a complicated item...All the best

[Z_Rocks]

When it comes to "engagement & fun" with performance cars, I still go with manual. After 40 years of driving, I still prefer manual in high performance car.

[DannyB]

Any of you worried about how fast this tranny shifts in manual mode just go to youtube and watch the hotlaps that were done in the auto during the reveal of the ZL1.

[libertyforall]

Would love to see MORE technical articles like this!

[Obsessed 17]

Originally Posted by libertyforall

Would love to see MORE technical articles like this!

Yeah me too. And one that has technical info on downshift speed compared to dual clutches and upshift speed at lighter throttle compared to dual clutch. I will say that from the videos the trans seems very promising.

[doc7000]

Originally Posted by Mikes SS

they do have an LT1 based V6, its called the GenV LV3 4.3L 285Hp and 305TQ

A more accurate way to state it is that they have a V-6 engine based on the Gen V small block V-8 engine. The engine is rated at 285/305 on regular unleaded 87 octane and 297/330 on E85 fuel.

[mlee]

Fast Forward to 5:40

[Zeke.Malvo]

I bet they're the same.

[SuperSound]

Originally Posted by Zeke.Malvo

I think some people are severely overestimating this new transmission. The biggest difference is an addition of a new gear between 4th and 5th, where the old 5th becomes 6th, and an addition of an OD gear before 8th. 10th gear is essentially the same as 8th on the 8 spd. Even with the new snake oil in the transmission, I don't see an improvement of more than 1mpg highway. City might see 1-2mpg. That may get it out of GG tax, not sure.

As for performance, it toots it's own upshifting horn, which I thought the 8 spd did fine, but not much is mentioned or cited with raw numbers of it's downshifting or input response time like they do for the upshifts.

1-2mpg might not seem like much, but that's a big step for a trans that will be widely used in GM/Ford in the next few years. That makes a major step in meeting CAFE targets, especially given the fines for not meeting just skyrocketed. FCA is in real trouble, meanwhile GM/Ford's collaboration is really going to pay for both.

I think we all have earned the right to be skeptical of the manual shift performance. But the talk about the DSC changes (no computer oversight) sounds like it will work fast everytime no matter what. We will see once it gets into the media's hands.

[Hypertrophy]

Originally Posted by DGthe3

...On the flip side, CVTs are now being programmed to 'shift' like a regular transmission because most people hate the constant engine drone you get while accelerating with a CVT. People want their engine to go 'BWAA - BWWAAAA - BWWWAAAAAAAAA' when the hit the gas

I'm picturing Elon Musk in a recording studio growling "BWAA! - BWWAAAA! - BWWWAAAAAAAAA..." so it can be played over the speakers in the new Teslas.